First Micro Space Rocket MSR-01 Launch Photo Sequence
This is a series of MSR-01 photos showing the steps of a Micro Space air-rocket launch. The MSR-01 has launched around 50 times and is still in good condition. For this sequence of photos, the rocket was positioned and then launched about 25 times and the best photos were selected for the incremental take-off sequence. The rocket is a reusable air-rocket with a paper body and environmentally safe fuel - air. The internal body of the rocket is pressurized with air for flight during lift-off. Lift off is from a launcher (with air pressurization chamber) made with a glass lens duster. The nozzle guides the rocket during the initial launch and acts as a fuel injector to pressurize the rocket's internal fuel chamber.
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The arrow cursor points to the launcher rod. This stem should have parallel sides. There are many devices (especially larger ones) with sloped sides and these do not work well with the rocket in maintaining a propellent chamber seal along the rod's length and the rocket's body as the rocket takes off. Experiments with the degree of "pressurization seal" show this factor is significant in the flight of the rocket.
The MSR-01 is the precursor to a larger scale robotic rocket. MSR-01 can launch from atop the Big Brain's Airport. For these photos, the rocket was launched from the MSP Lab base in Taiwan. In the photos backgrounds are larger bottles that can launch larger air rockets. The rocket program is testing various rockets, construction materials, propellants, designs, and launching methods.
At the top of the list is a fuel that's completely safe to the environment and to the handling personnel. In the past, manufacturing plants that made fuel used in solid rocket boosters have blown up causing injury and loss of life, and considerable damage to the Earth's environment. The MSR Program's air fuel is relatively safe from spontaneous combustion and is perhaps the only fuel that completely recycles back into the environment unchanged and is healthy to breathe all throughout operations.
A slipstream drive device is invented for flying aero craft by delivering energy from the ground. It uses transmitted packets of high pressure energy delivered and focussed to the craft as a slipstream within the micro space atmosphere
Hate to break it to you but using a fan to elevate objects is not a new invention.
There was once a toy on the market that allowed "remote control" of balloon flight by directing the fan that was providing their lift.
Elevating ping pong balls and steering them around in an air stream provided by a vacuum cleaner hose (connected to the vacs output) is an old aerodynamics demonstration.
Spinning like a planet - with the USB fan, the heavier balloon craft was modulated into a spinning vortex using the fabric air beam modulator seen at bottom right. The spinning propellers are visible on both devices.
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This massive chromed fan could launch the heavier balloon easier but lofting control was difficult. This is because the fan has a front grating pattern designed to disperse the slipstream. A way to remove the grate may be found. This fan has a swivel mount that can fully aim 90-degrees up to the zenith for lofting craft directly overhead. The CFM on the high setting appeared to be the perfect amount of air flow. To launch larger and heavier craft, more fans and higher speeds are needed. However, this initial goal is to fly a vehicle not exceeding but reaching the maximum dimensional height of Micro Space. This should be achievable relatively soon in the Micro Space Program.
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There was once a toy on the market that allowed "remote control" of balloon flight by directing the fan that was providing their lift... "Johnny Astro" from the 1960's. Ideal for micro-space, you will love it, http://www.johnnyastro.com/johnnymain.htm Elevating ping pong balls and steering them around in an air stream provided by a vacuum cleaner hose (connected to the vacs output) is an old aerodynamics demonstration.
Heater, thanks for the this great toy info, you're right. I love it! Elevation of objects with a fan is not new. It's only new to the Big Brain. The web site shows the concept with a balloon was made into a toy in 1967 and some research shows a long time before that, Bernoulli fully developed the principle. I had not tried it on a balloon, but now you got me started wanting toys. I visited five toy stores but did not find any similar toy devices.
I spent the last 4 hours working with three fans, two are USB, and one is a giant chrome fan. I used the smaller fan to modulate the slipstream, help create a vortex, then camera captured the results of two different sized balloons, one of 7-inch diameter and one at 3-inches. The 7-inch is quite heavy and the 3-inch almost weightless.
I experimented with plain balloons and attaching miniature gondolas to both crafts for stability and orientation balance. With the large chrome fan, the three power settings were used to send the balloon upward. The best power setting was the strongest. The photos show the launch results of two experiments.
Now I want a vacuum cleaner to reverse the forced air and get some ping pong balls going... These are Ping Pong Space Capsules to launch into Micro Space. Next thing you know, we'll need a jet turbine nozzle and a large array of joined massive air compressors, huge arrays of ballast tanks, steel tubing, and a giant Ping Pong air ball with a hatch to ride slip stream of space.. any volunteers?
Newton's 2nd Law Applies
"Bernoulli's principle can also be derived directly from Newton's 2nd law. If a small volume of fluid is flowing horizontally from a region of high pressure to a region of low pressure, then there is more pressure behind than in front. This gives a net force on the volume, accelerating it along the streamline."
"In fluid dynamics, Bernoulli's principle states that for an inviscid flow, an increase in the speed of the fluid occurs simultaneously with a decrease in pressure or a decrease in the fluid's potential energy."
Implications http://www.britannica.com/EBchecked/topic/62615/Bernoullis-theorem
"Bernoulli’s theorem implies, therefore, that if the fluid flows horizontally so that no change in gravitational potential energy occurs, then a decrease in fluid pressure is associated with an increase in fluid velocity. If the fluid is flowing through a horizontal pipe of varying cross-sectional area, for example, the fluid speeds up in constricted areas so that the pressure the fluid exerts is least where the cross section is smallest. This phenomenon is sometimes called the Venturi effect, after the Italian scientist G.B. Venturi (1746–1822), who first noted the effects of constricted channels on fluid flow."
Aircraft Design
Bernoulli’s theorem is the basis for many engineering applications, such as aircraft-wing design. The air flowing over the upper curved surface of an aircraft wing moves faster than the air beneath the wing, so that the pressure underneath is greater than that on the top of the wing, causing lift.
Fluid Flow
Bernoulli's principle states that in a steady, streamlined, incompressible flow of a fluid, the pressure of the fluid is inversely proportional to its velocity. If a fluid is flowing through a horizontal pipe of varying cross-sectional area, as in Figure 1 for example, the fluid speeds up in constricted areas so that the pressure the fluid exerts is least where the cross section is smallest. This phenomenon is also called the Venturi effect. The Venturi effect has several applications including that associated with generating lift atop an aerofoil, making all forms of flight on aeroplanes, gyroplanes, and helicopters possible.
Magnus Effect
Magnus effect, generation of a sidewise force on a spinning cylindrical or spherical solid immersed in a fluid (liquid or gas) when there is relative motion between the spinning body and the fluid. Named after the German physicist and chemist H.G. Magnus, who first (1853) experimentally investigated the effect, it is responsible for the “curve” of a served tennis ball or a driven golf ball and affects the trajectory of a spinning artillery shell.
Spinning Objects in Air - Balls and Balloons
A spinning object moving through a fluid departs from its straight path because of pressure differences that develop in the fluid as a result of velocity changes induced by the spinning body. The Magnus effect is a particular manifestation of Bernoulli’s theorem: fluid pressure decreases at points where the speed of the fluid increases. In the case of a ball spinning through the air, the turning ball drags some of the air around with it. Viewed from the position of the ball, the air is rushing by on all sides. The drag of the side of the ball turning into the air (into the direction the ball is traveling) retards the airflow, whereas on the other side the drag speeds up the airflow. Greater pressure on the side where the airflow is slowed down forces the ball in the direction of the low-pressure region on the opposite side, where a relative increase in airflow occurs. See Bernoulli’s theorem; fluid mechanics.
Now I want a vacuum cleaner to reverse and to get some ping pong balls... Next thing you know, I'll need a jet nozzle and massive air compressor, steel tubing, and a chair to ride a giant slip stream..
Yup, that is exactly how it happens, Except in my case, it would sound more like.."Here, hold my beer and watch this!"...
You have some really cool experiments going on Humanoido, (I haven't flown a balloon in years.) keep up the good fun.
It gives a whole new meaning to the word "kitchen." If we alot one room per person, and each room is a Micro Space Universe of approximately 10 x 10 x 10 feet average in three dimensions, excluding all the office space and factories in the world, one can estimate there are over 7 billion Micro Space Universes. That's a combined Universe space of 7 trillion cubic feet!
If we used a UPS package measuring string laid out for girth of each Micro Space Universe, we'd have 30 running feet for each and 30 x 7 billion = 210 billion feet or 39,772,727.3 miles. That would take us to the Moon 147 times (it's about 270,000 miles to the Moon) and equal a trip to Mars during opposition (about 35 million miles).
The Parallax BoeBot tires have a diameter of 2.62-inchs. The 210 billion feet in all the Micro Universes is equal to 2.52e12 inches. This means Boe-Bot would turn its wheels 961,832,061,068.7 times or 961 billion times.
If BoeBot moves at a velocity of 6-inches per second, it would take 4.2e+11 seconds, or 7,000,000,000 minutes or 116,666,666.7 hours or 4,861,111 days (constant 24 hour travel non stop). That's 13,309 years for a BoeBot to travel all the Micro Space Universes.. (are we there yet?)
http://en.wikipedia.org/wiki/World_population
The world population is the total number of living humans on the planet Earth, currently estimated to be 6.96 billion by the United States Census Bureau as of July 1, 2011.
If you spread* that population over the 74,469,550 sq km of land that isn't mountains or ice covered and has topsoil, that would give each person about 10,000 square meters of "space". Which when you look at the population density in major cities, it makes you appreciate the areas where there are still vast regions of unpeopled land.....or mid-space.
*of course, by "spread", I mean evenly distribute individuals, not as a homogeneous paste, that would be the world fate in some bad sci-fi story.
If I did the math correctly, an unfortunate 100 Kg individual ...
One of the virtues of working in Micro Space environments and a Micro Space Universe is the great degrees of working safety.
Heights are relatively minimal, many engine tests are performed with air and small USB fans - some with cloth propellers, rockets and crafts move relatively slow and have low pressurized air for fuel and many of the space crafts are made from materials like sponge, nerf, cotton, balloon, soft rubber, paper, gossamer plastic, limp thread, tissue paper, string and foil.
There are no flammable or harmful-to-breathe fuels. With a reasonable amount of applied safety in this environment (and applying the common sense rules of home safety), one can avoid an eye poke or a paper cut or a balloon popping in the face, and completely avoid becoming an unfortunate 100 Kg individual.
Many of the Micro Space crafts, devices, machines, structures, tests, and sensors can run on either a Parallax Propeller chip(s) (aka the Big Brain), or, one or more BASIC Stamp modules (BS1, BS2, BS2px...)
Even the Big Brain has at least two BASIC Stamp boards (one host HomeWork Board and one BS2 BOE Board of Education embedded into the Brain Stem) amidst the mass of Propeller arrays to maintain compatibility with Stamping.
The question is, do we continue development only with Propeller chip(s) or should we do the experiments in Micro Space with Stamps?
Choose One
( ) Propeller
( ) Stamp
( ) All the Above
( ) Other Option
Therefore, to satisfy all options, the Micro Space projects will have the greatest development with the Propeller chip, along with less frequent co-development using the Stamp. Sometimes projects will be presented specifically for the Stamp.
The BIg Brain has decided to begin work on a Space Tether. The ST will contain a multipurpose platform. Depending on the stability of this "Tethered Platform," a variety of programs will become available.
This may also be the precursor to a Space Telescope on a tethered platform in space, the success of which will be determined by the amount of stability. A whole gamut of ideas open up.
One idea takes up the tether with a micro craft on the end that has aerodynamic hovering, suspending and lofting ability. This stabilizes the payload and ensures a safe return trip.
The mechanical tether can lead to other technology, like a hovering space craft moving up and down. Heavier mechanical tethers are not as susceptible to wind shear like light weight helicopters. Lighter tethers can anchor at both ends once deployed.
A special tether, like a single strand of spider web, can suspend itself in air.
Tethers have other unique abilities. On one design in the works currently, the tether space craft has mobility along the +/- Y-Axis via a drive connection to the tether. A light craft can go up and down carrying its own battery pack. This could be a pound in weight depending on the type of tether and its mooring ability.
Tethers will have a study to determine how the upper end can be anchored cheaply and easily at the highest possible space. A balloon can rise to high altitude and release a grappling hook on the high end of the tether, which will drop and connect to some object suitable for anchoring.
Perhaps a tether can attach to the roof on the back side of a tall skyscraper, antenna structure, tall tower, or mega project.
In the case of a mega project whose attachment is prohibited, a new kind of tether could be invented. This tether is taken aloft by a balloon to a high elevation and released, whereupon the high end anchors itself to the air and surrounding space for a short period of time, enough to achieve aerial imaging and scientific study. Then the tether can slowly float back to Earth, the resistance of which will act like a parachute thus protecting the cargo.
One tether idea uses pressure gel. A chord is distributed and pressure is applied to harden it.
Another tether has the weight of string balanced against the uplifting air cells on a hot day.
A micro tether can have several mini hot air vesicles attached to provide gossamer lift. A small electrical nichrome can supplement as a short term hot air producing source.
A propeller lifted tether can rise up to a height based on the time length of the battery, the weight of the tether and the lifting force of the mechanism.
Tethers are safe, made from thin string that breaks and/or vaporizes if struck by another aircraft, jet, windmill, or if blown by excessive wind forces.
Tethers can be parachuted at the top end when released to ensure a safe payload return and to stall the return for longer scientific analysis.
The motorized tether has a top engine, battery and propeller to take the tether up to a specific altitude and free fall back to the Earth.
StratoSail - a sail hung on a tether from the balloon. http://hobbyspace.com/NearSpace/index.html
The StratoSail(R) balloon guidance system (BGS) is designed to alter the flight path of balloons. The StratoSail(R) BGS takes advantage of the natural difference in wind speed at different altitudes in the atmosphere. A wing is suspended several kilometers below the balloon gondola using a long thin tether. The wing is hanging on end, so its "lift" acts sideways rather than upward as in an airplane. This sideways lift force is used to drag the balloon across the wind. This allows the balloon to be maneuvered towards regions of interest and away from unfavorable conditions. The BGS can drive the balloon to sites of interest to scientists. Some governments do not give permission to fly over their countries. With a StratoSail(R) BGS aboard, the balloon can be directed around these uncooperative regions. Hazardous weather patterns can be avoided. Balloon flights may last many weeks and go around the world several times. At the end of a flight, the balloon can be redirected to land back near its launch site. This makes balloon operations much simpler.
HASTOL - a concept at Tethers Unlimited in which the end of a rotating tether will rendevous with a rocketplane at 100km and pick up a payload to take to orbit.
Tethered Formations http://www.tethers.com/
Clusters of small spacecraft flying in formation may provide revolutionary capabilities for a wide range of applications, including interferometric astronomy for investigation of the structure of the cosmos, synthetic aperture radar for environmental studies, and military surveilance missions. Due to the nature of orbital mechanics, however, a group of satellites in orbit will tend to drift away from each other. Consequently, to hold the spacecraft in formation requires some form of propulsion. For some applications, rockets or electric thrusters for formation flying is an acceptable solution, but for many applications the propellant requirements would be prohibitive.
Optical Tether http://www.tethers.com/UOTD.html
An optical tether can provide a two-way, high-bandwidth communications link to mobile robots, ROV's, UUV's, deployable sensors, and other systems. Unlike RF-based communications systems, an optical tether is secure, covert, and immune to the jamming, multipath, and line-of-sight problems.
The HLR Heavy Launch Rocket is designed to carry Parallax Propeller chip
payloads into Micro Space for the first time.
The Big Brain and its Micro Space Program is extending its domain with a new Micro Space Heavy Launch Rocket. This will eventually replace the existing MSR-01 rocket. The Micro Space Heavy Launch Rocket is intended for heavier payloads to include scientific instruments and it opens the door to new studies with Parallax Propeller chips and related sensors.
The launch system's initial design is generally complete. On Monday, October 3rd, 2011, the parts to build the new launch complex were found and purchased. The budget for the HLR Heavy Launch Rocket, otherwise coded as MSR-02 Micro Space Rocket, was pushed up. As luck would have it, the amount spent on the launcher at this time is $5 plus $.50 for a 90-degree G-310 pipe. The nearly complete parts package is under PAT.ZL.200520118326.0 China and PAT.NO.M281417 Taiwan and was purchased through the Aquarium Store.
The 90 Deg Fuel Diversion Pipe is model G-310 available from Up. Aquarium Supply sourced online at www.up-aqua.com. It has an outside diameter of 16mm with an ID of 12.84mm.
This collection of parts is needed to construct the heavy lift launcher
The Launch Base LB component is being fabricated from common materials and will not add cost to the project. The LB will hold the Standard Vertical Launching Rod and Fuel Compression Delivery Chamber with a mounting at the base.
Rocket Launcher Component List
2 - 90 Deg Fuel Diversion Pipe
1 - Flexible Fuel Delivery Hose (long)
1 - Standard Vertical Launching Rod and Fuel Compression Delivery Chamber
1 - Very Large Vertical Launching Rod and Compression Fuel Delivery Chamber
1 - Incremental Fuel Cutoff Valve with 360-deg Rotation
1 - Fuel Injection Delivery Pipe with 1" to 1/2" Adaptation
1 - Fuel Compression Engine
1 - Fuel Compression Engine Back-flow Prevention Valve w/1/2" Fitting
Big Brain Performs Engine Tests
for the Micro Space Program Heavy Lift Launcher & Engine
Fuel flow valve test, partially opened
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The fuel pressure mounted as the flow valve was slowly opened allowing rocket fuel to flood the compartment. Successful pressurization was achieved in a fraction of a second. The fuel flow valve was tested at several main settings. Pressurization was possible and achieved with the fuel flow diverter pipe, the fuel delivery hose, and the fuel pressurization chamber.
Fuel can be successfully regulated and calibrated at a flow rate from maximum to zero. This enables an adjustment to the potential height of the rocket's trip at launch time. A higher pressurization rate allows the rocket to have more fuel and achieve a higher Micro Space altitude.
Adjustment of fuel also enables the launching of a variance in increased payload weight, given the same rocket height. At increased fuel pressure, the payload could include heavier devices: camera, live passenger (Insectronaut), sensor, Propeller chip, and other scientific micro apparatus.
New Engine Design
Performance Tests of the new Engine Design
A new engine design places the rocket completely inside the launch tube gantry. This is opposing the previous technology where the rocket surrounds the the launch tube. The design is based on an existing rocket tube body that form fits into the launch tube and is open on the bottom to hold pressurized fuel. The design works only with internal payloads and is offered as a supplement to the Heavy Lift Vehicle.
Tests show good launching capabilities with minimal fueling pressurization. Escape and liftoff is very smooth with minimal friction. An internal air layer is maintained as lubricant between the rocket and the launch tube.
Big Brain Discovers Micro Space Zero-G
How to Make Weightlessness in Micro Space
Welcome to the Micro Space Program. The Big Brain has discovered, through launches of the MSR-01 rocket, there is a zone of weightlessness that can be created in a Micro Space environment.
Create Weightlessness
If you're following along, you can create your own packet of Zero-G weightlessness in your own room. You'll need a BASIC Stamp or Propeller chip to confirm or document the effects. If a Propeller is used, other functions such as timing (with the SoftClock previously posted) and data logging with no extra parts are possible.
Limitations of Micro Space Zero-G
To make and use or study Zero-G there are some stipulations. One, it only lasts a fraction of a second, and two, you can't experience it directly with your own body, however small live insectronauts (insects as passengers) can experience weightlessness.
Experimenting with Weightless Payloads
It will be interesting to place a small camera on the rocket looking through a window to the inside capsule to monitor the weightless condition of the payload, to see if it's caught floating for a fraction of a second on one of the DV frames. So it's likely our camera will point into the rocket ship and not necessarily out for aerial photography.
The Technique
The method employs a launch vehicle to closely approximate the flight path of a inverted parabola. At the crux of the geometric figure there is domain after rise and before fall. The effects of these three Micro Space domains are studied using a tiny Parallax accelerometer to help determine several parameters.
1) The location of Zero-G
2) When weightless begins
3) When weightless ends
4) The duration of Zero-G
5) Zero-G effects
Camera as Payload
The camera can also be used as a payload to determine if it experiences weightlessness. Don't affix the camera but just focus it on some internal object or wall drawing inside the space craft. A small circle inside the craft drawn on the wall with a pencil will suffice. Check the camera DV frames to see changes any changes in position of this drawing.
Questions for Exploration
This leads to the question, can we extend the time of weightlessness? Experimenting with different rockets, various launch accelerations, varying altitudes, and variations of a flight path may give interesting results. What fascinating apps can you think of for working and playing in this new Micro Space weightless environment?
The T1 duration (Memsic output) is captured by PULSIN in the variable xRaw. Since each BASIC Stamp module has its own speed and will return a different raw value for the pulse, the factor called Scale (set by the compiler based on the BASIC Stamp module installed) is used to convert the raw output to microseconds. This will allow the program to operate properly with any BASIC Stamp 2-series module. At this point the standard equation provided by Memsic can be applied, adjusting the values to account for the pulse-width in microseconds. Fortunately, one divided by divided by 0.125 (12.5%) is eight, hence the final multiplication. The result is a signed value representing g-force in milli-g's (1/1000th g).
Parallax Sources http://www.parallax.com/Store/Sensors/AccelerationTilt/tabid/172/CategoryID/47/List/0/SortField/0/Level/a/ProductID/93/Default.aspx
Downloads & Resources:
Memsic 2125 Datasheet (.pdf)
Stamps in Class Memsic Tutorial (.pdf)
Memsic 2125 Demo Kit Documentation (.pdf)
MXD2125G&M (.pdf)
Memsic 2125 Demo Kit BASIC Stamp Source Code (.zip)
Memsic 2125 Schematic (.pdf)
Stamps in Class Tilt Display Control (.pdf)
Javelin Stamp Example Code (.zip)
N&V column "It's all about Angles" #92 (.pdf)
N&V code "It's all about Angles" #92 (.zip)
Memsic web site (Off Site)
Sensor Objects for Propeller Programmers
The Memsic 2125 is a low cost, dual-axis thermal accelerometer capable of measuring tilt, acceleration, rotation, and vibration with a range of ±3 g. For integration into existing applications, the Memsic 2125 is electrically compatible with other popular accelerometers. Memsic (http://www.memsic.com) provides the 2125 in a surface-mount format. Parallax mounts the circuit on a through-hole providing all I/O connections so it can easily be inserted on a breadboard or through-hole prototype area.
I was just taking apart a Wii Nunchuck when I saw your recent updates.
Nunchucks have a triple axis accelerometer.
I'm taking one of mine apart in order to mount the circuit board securely to my project (a digital level).
I personally think a triple axis accelerometer would be a better match for weightless experiments. A dual axis is fine for measuring angles (or for a digital level) but your missing one component of acceleration.
One thing I'd like to point out about weightlessness (or free-fall in these cases). An object doesn't have to be traveling downward to experience zero-G. I frequently see this error on model rocket websites. People tend to think zero-G occurs at apogee but it occurs once thrust is removed from the object. The initial period of simulated weightlessness in the "Vomit Comet" is while the aircraft is still flying upward. When we jump in the air, we experience weightlessness once our feet leave the ground.
I'm attaching a couple of pictures (I took them right before reading your recent posts) of the Nunchuck's PCB. You can see, by removing the outer shell of the Nunchuck one is left with a much smaller board which would be easier to install in an airplane or rocket.
I'm not sure how quickly a Propeller can read a Nunchuck. I think I might try to add a logging feature to my digital level and then toss it in the air to record the acceleration.
Humanoido, I was just taking apart a Wii Nunchuck when I saw your recent updates. Nunchucks have a triple axis accelerometer. I'm taking one of mine apart in order to mount the circuit board securely to my project (a digital level). I personally think a triple axis accelerometer would be a better match for weightless experiments. A dual axis is fine for measuring angles (or for a digital level) but your missing one component of acceleration.
One thing I'd like to point out about weightlessness (or free-fall in these cases). An object doesn't have to be traveling downward to experience zero-G. I frequently see this error on model rocket websites. People tend to think zero-G occurs at apogee but it occurs once thrust is removed from the object. The initial period of simulated weightlessness in the "Vomit Comet" is while the aircraft is still flying upward. When we jump in the air, we experience weightlessness once our feet leave the ground.
I'm attaching a couple of pictures (I took them right before reading your recent posts) of the Nunchuck's PCB. You can see, by removing the outer shell of the Nunchuck one is left with a much smaller board which would be easier to install in an airplane or rocket. I'm not sure how quickly a Propeller can read a Nunchuck. I think I might try to add a logging feature to my digital level and then toss it in the air to record the acceleration. Duane
Duane, thanks for these informative comments. In particular, the rocket may alter orientation and the additional accelerometer axis would be useful to have all three acceleration components. I will revise the Zero-G study to include the Hitachi Tri-Axis Accelerometer, sold by Parallax, for better data during this experiment.
I had studied the flight path of NASA's aircraft and the parabolic path it makes. It was quite surprising to see that weightlessness was not occurring on the down side of the parabolic shape but rather at its inverted peak. Studying it more makes good sense. I'm looking for a better way to determine the flight path of a rocket indoors.
It would be beneficial to correlate DV data with the accelerometer data logging to determine the curve and the nodal points of Zero-G. A tiny keychain camera was recently purchased for flights on the helicopter and rocket. It now looks like another application will include an external stationary camera view with a scale to determine rocket path. I've seen this camera technique used on Mythbusters a number of times.
Measuring the Effects of Zero-G in Micro Space
with the Parallax Hitachi H48C Tri-Axis Accelerometer Module
And the Reason Why the Hitachi H48C is the Ultimate Accelerometer! Parallax offers the Hitachi
H48C Tri-Axis Accelerometer
Module Item code 28026
price $24.99. Find out why
this sensor is the ultimate
selection for the Big Brain's
Micro Space Program and
the study of Micro Gravity.
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The Parallax Hitachi H48C Tri-Axis Accelerometer Module will capture the third component of gravity and collect useful data during the tumbling part of the rocket either on the upward path, mid point, or going downward. It assists three dimensional reconstruction of flight paths and gravity components from lift-off to recovery and can be the prime sensor in detecting, studying and exploring the new world of Micro Space Zero-G.
The Reason Why the Hitachi H48C is the Ultimate Accelerometer
The Automatic Zero-G Detector! It was a very good recommendation when Duane Degn suggested using a Tri-Axis Accelerometer. Without that suggestion, we may have never discovered the best feature of the H48C - the automatic Zero-G Detector! When the Parallax Hitachi H48C Tri-Axis Accelerometer was examined, it was found to carry an indispensable feature to automatically detect Zero-G by simply reading a pin state, which can be accomplished with Spin and PBASIC. So you'll definitely want to hook up to PIN 4 and take advantage of this feature.
http://www.parallax.com/Store/Sensors/AccelerationTilt/tabid/172/CategoryID/47/List/0/SortField/0/Level/a/ProductID/97/Default.aspx
The Hitachi H48C Tri-Axis Accelerometer is an integrated module that can sense gravitational (g) force of ±3g on three axes (X, Y, and Z). The module contains an onboard regulator to provide 3.3-volt power to the H48C, analog signal conditioning, and an MCP3204 (four channel, 12-bit) analog-to-digital converter to read the H48C voltage outputs. All components are mounted on a 0.7 by 0.8 inch module. Acquiring measurements from the module is simplified through a synchronous serial interface. With the BASIC Stamp® series, for example, this is easily handled with the SHIFTOUT and SHIFTIN commands.
Hookup information for the Zero-G rocket detection flight circuit
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How It Works http://www.parallax.com/Portals/0/Downloads/docs/prod/acc/HitachiH48C3AxisAccelerometer.pdf
Through MEMS (Micro Electro-Mechanical System) technology and built-in compensation, the H48C
accelerometer provides simultaneous outputs through analog conditioning circuitry to an MCP3204 ADC. To "read" g-force of a given axis we actually read the voltage output from that axis and calculate g-force using this formula:
G = ((axis – vRef) / 4095) x (3.3 / 0.3663)
In the formula, axis and vRef are expressed in counts from the ADC, 4095 is the maximum output count from a 12-bit ADC channel, 3.3 is the H48C supply voltage, and 0.3663 is the H48C output voltage for 1g (when operating at 3.3v). In practice this can be simplified to:
G = (axis – vRef) x 0.0022
Using the BASIC Stamp 2 module as a host controller, we should multiply the 0.0022 by 100 (to 0.22) to express the result in units of 0.01g. Using the ** operator, we are able to multiply by 0.22 and convert the raw readings to g-force with this bit of code:
The Amazing Built in Free Fall Detector
Of special interest is PIN 4 which is the Zero-G "Free-fall" output. To return a true condition, the pin goes active-high. Use of the accelerometer is as simple as reading pin 4 for the detection of Zero-G. The method works when free-fall output indicates simultaneous 0g an all axes.
The Hitachi H48C 3-Axis Accelerometer is an integrated module that can sense gravitational (g) force of
±3g on three axes (X, Y, and Z). The module contains an onboard regulator to provide 3.3-volt power to
the H48C, analog signal conditioning, and an MCP3204 (four channel, 12-bit) analog-to-digital converter
to read the H48C voltage outputs. All components are mounted on a breadboard-friendly, 0.7 by 0.8 inch
module. Acquiring measurements from the module is simplified through a synchronous serial interface.
With the BASIC Stamp® 2 series, for example, this is easily handled with the SHIFTOUT and SHIFTIN
commands.
For the Propeller
H48C Tri-Axis Accelerometer http://obex.parallax.com/objects/178/
Interface to the H48C Tri-Axis Accelerometer. The included demo displays orientation information on a VGA monitor. By Beau Schwabe. Revision History: Version 1.0 - (Sept. 2006) - Initial release with a TV mode 3D- graphics cube. Version 1.1 - (March 2008) - 3D-graphics cube removed - Basic VGA display used instead of TV - Added 600nS padding delay around Clock rise and fall times
H48C synchronized driver http://obex.parallax.com/objects/430/
This PST terminal application proves the H48C_Sync_Driver.spin object. This driver object can synchronize the data readouts of H48C Tri-axis accelerometer modules. In this demo four H48C sensors are synchronized. The uniform timing and precise intervals of the synchronous readouts are verified. The H48C_Sync_Driver can be used in 6DOF IMU projects where four H48C tri-axis accelerometers are arranged in space to provide a cheap but precise close equivalent of high dollar 6DOF IMU sensors. See attached PDF file for the mathematical details. By I.Kövesdi.
How to obtain angular velocity and angular acceleration values directly from 3D accelerometer array data using simple matrix operations in Propeller/SPIN http://obex.parallax.com/objects/download/aux/47/
Duane, we need a very simple Propeller data logging program that can log two numbers. One number is a 0 or a 1 detected from a Propeller pin high or low. The other number is the seconds of time, from 0 to 10 seconds.
EDIT: now that I think about it, the entire rocket flight may last only a second or two, so maybe the time units should be a number we can set, maybe a log every 100 milliseconds or where it can be adjusted to the best time increment by trial and error.
Where do you want the data being logged stored? The fastest and easiest method is to store it in hub RAM of the Propeller chip. Storing data to RAM means it could be easily lost though.
Storing to EEPROM is just about as easy as storing to RAM. If you have a 64K EEPROM chip attached to the Propeller you could store the data to upper EEPROM.
Do you have a SD card adapter to use with the Propeller. A SD card removes any size concerns so we could store as much data as you'd like. Kye's SD Card driver is easy to use. By logging to a SD card you could just move the card to a computer to data analysis. You wouldn't need to figure out a way of getting the data logged from the Propeller to the computer.
If you have a way of using a SD card with a Propeller, I think it would be the best choice for data logging experiments.
You mentioned
How to obtain angular velocity and angular acceleration values directly from 3D accelerometer array data
The attached paper shows, in order to measure angular acceleration (and velocity) you need two accelerometers in each plane being measured. In order to measure all three axes of rotation you need four accelerometers.
It would probably be less expensive, smaller and lighter, to use a triple axis gyro. (I'm not sure if Parallax sells a triple axis gyro.) I have one of these. I haven't taken time to use it yet.
Let me know if a SD card would be a good logging method for you or not and I'll start working on some code. I think a software clock would be a good fit for this application. It shouldn't be hard to make the logger easily configurable to use different logging intervals.
The Micronaut Space Program
Big Brain Rocket Program and the Selection of Tiny Astronauts
Micronauts are small astronauts that go into the Propeller Brain's Micro Space domain, riding inside Micro Space Rockets. When insects go into space they are sometimes referred to as Insectronauts.
The Micro Space Program (MSP) is run and operated by the expansive Big Brain project, which consists of massive quantities of Parallax processors (many are Propeller chips) and Parallax sensors. In its expansion phase, the Brain seeks knowledge and understanding of the world that surrounds it. This includes knowledge and assimilation of sensors and devices, methods and designs.
The program is gearing up with Parallax sensors and devices - the PIR already in use, and the RADAR, plus the SoftClock using Spin programming. In the heavy lift launch vehicle phase, sensors will actually fly on board the rocket, notably the Tri-Axis Accelerometer, a Propeller chip, with full support from the Brain below.
Insectronaut Micro Space Program
The Insectronaut Micro Space Program includes aerospace and education - and launching live insects into space. It was created as a Brain project within the Micro Space Program as an adjunct to studying the effects of Micro Space travel on live passengers and the reults of a changing environment.
Insectronaut Studies
The Insectronaut Program will include the study of G-forces sustained at lift-off, the effects of weightlessness and Zero-G, various capsule and rocket designs, and changes in character, personality, behavior etc.
The MSP
This has led to the construction of a Brain-connected Airport, a robotic helicopter flying program, a rocket development program, a micro space telescope which is being robotized, aerial imaging program & camera, and many micro space crafts.
The Quest of Curiosity
This quest of curiosity (using Parallax components as low cost available resources) has led to the Micro Space Program, a scientific educational program that's conducted in a room of approximately 10 x 10 x 10 feet, known as the Micro Space Universe - essentially the living space of the Big Brain's domain.
Rocket Passengers
Insects are the primary creatures in nature that may weigh almost nothing, approaching the weight of a postage stamp or two. This is within the payload weight capacity of the MSR-01 rocket.
Statistics
Are these little insects ideal candidates for the Micro Space Program? Big Brain put their statistics to the test.. We're looking for a few good insects modeled after these requirements.
Small physical size
Very low weight
Good disposition
Capable of sustaining rocket g-forces
Heathy
In good hardy conditioning
Does not require exceptional environment
Minimal preparation
In reviewing the Insectronaut candidates for the Micro Space Program, we have the following potential applicant backgrounds classified by their average body statistics.
Ant - 6mm long, 3mg weight, 250,000 brain cells, strong - can lift 20x body weight, lives up to 60 days, intelligent, exploratory personality, can bite, can use tools, no special environment required, not trainable, moderately easy management, ground mobility for most varieties http://www.lingolex.com/ants.htm
Fruit Fly - 3.2mm long, 250,000 neurons, live 30 days, not trainable, semi-special environment required, semi-challenging management, air mobility
Gnat - 1-2mm long, 200,000 neurons, 2mg weight, live 120 days, special environment required, not trainable, fussy management, air mobility
Conclusions
Weight & Size
All three candidates meet established weight and size requirements.
Intelligence
Ants are superior in intelligence with average life span.
Training
It appears that all candidates reviewed are not trainable. As the micro space launch only requires the insectronaut to be on board, the training aspect is of little importance and can be disregarded.
Special Environments
The fruit fly and gnat require special environments while the ant does not.
Strength
Ants are the strongest.
Life Span
Ants have an average life span. Gnats live the longest. Fruit flies have the shortest life span.
Environment
Ants are the most versatile with adaptation to environment. Fruit flies and gnats have special requirements.
Management
Ants are the most easily managed however some species will bite. Gnats are the most challenging and annoying in flight, followed by fruit flies.
Mobility
Most ant varieties stay on the ground. Gnats and fruit flies have flight mobility.
Conclusion
The ant is chosen to go into space. The fruit fly and gnat are on the backup program.
A no parts data logger that relies on Propeller pin states and a SoftClock to record and hold data for hot read-back
Duane: I like doing many things with LEDs or no parts. In this case, I would try something a little different because LEDs draw too much power for the rocket's on-board tiny prop cell battery. The data logging should reside in the pin states with no extra parts. Tell me if you think the following will work.
The Micro Space Data Logger
This methods requires only one propeller chip and battery, with a connector and resistor to load the initial program. The program data logs the zeros and ones from the Parallax Hitachi H48C Tri-Axis Accelerometer's pin 4 (the Zero-G pin detector) into 20 prop pins that act as the output and storage device, storing 20 values of either high or low.
From one pin to the next, a timing increment is represented, depending on whether 1, 2 or 3 seconds is needed for the duration of the rocket flight. (see chart below) The number of prop pins used determine the resolution. One second is the highest resolution at 50ms between readings (or logs). Two seconds in 100ms and three seconds is 150ms.
After the rocket flight, the prop is kept on, and a small probe or meter reads the prop pins and determines which is a 0 or 1. That will determine when Zero-G began, when it was active, and when it terminated. These pins are arranged in timing order like this for a one second time period:
For 1-Second Data Logging (add 50)
The first entry is the elapsed time when the data reading was recorded. The second entry is the Propeller's pin number. The third entry is the data read - the 0 or 1 pin state of the Parallax Hitachi H48C Tri-Axis Accelerometer's pin 4 (the Zero-G pin detector).
0050 ms - Pin 00 - Data Log 0 or 1
0100 ms - Pin 01 - Data Log 0 or 1
0150 ms - Pin 02 - Data Log 0 or 1
0200 ms - Pin 03 - Data Log 0 or 1
0250 ms - Pin 04 - Data Log 0 or 1
0300 ms - Pin 05 - Data Log 0 or 1
0350 ms - Pin 06 - Data Log 0 or 1
0400 ms - Pin 07 - Data Log 0 or 1
0450 ms - Pin 08 - Data Log 0 or 1
0500 ms - Pin 09 - Data Log 0 or 1
0550 ms - Pin 10 - Data Log 0 or 1
0600 ms - Pin 11 - Data Log 0 or 1
0650 ms - Pin 12 - Data Log 0 or 1
0700 ms - Pin 13 - Data Log 0 or 1
0750 ms - Pin 14 - Data Log 0 or 1
0800 ms - Pin 15 - Data Log 0 or 1
0850 ms - Pin 16 - Data Log 0 or 1
0900 ms - Pin 17 - Data Log 0 or 1
0950 ms - Pin 18 - Data Log 0 or 1
1000 ms - Pin 19 - Data Log 0 or 1
This uses 20 pins. The Propeller has 0 though 31. This frees up at least ten pins for other telemetry that could be held as a binary number. Other timing may work better. Here's how the incremental seconds look at 2 and 3 seconds.
For Two Seconds Data Logging (add 100)
0100 ms - Pin 00 - Data Log 0 or 1
0200 ms - Pin 01 - Data Log 0 or 1
0300 ms - Pin 02 - Data Log 0 or 1
0400 ms - Pin 03 - Data Log 0 or 1
0500 ms - Pin 04 - Data Log 0 or 1
0600 ms - Pin 05 - Data Log 0 or 1
0700 ms - Pin 06 - Data Log 0 or 1
0800 ms - Pin 07 - Data Log 0 or 1
0900 ms - Pin 08 - Data Log 0 or 1
1000 ms - Pin 09 - Data Log 0 or 1
1100 ms - Pin 10 - Data Log 0 or 1
1200 ms - Pin 11 - Data Log 0 or 1
1300 ms - Pin 12 - Data Log 0 or 1
1400 ms - Pin 13 - Data Log 0 or 1
1500 ms - Pin 14 - Data Log 0 or 1
1600 ms - Pin 15 - Data Log 0 or 1
1700 ms - Pin 16 - Data Log 0 or 1
1800 ms - Pin 17 - Data Log 0 or 1
1900 ms - Pin 18 - Data Log 0 or 1
2000 ms - Pin 19 - Data Log 0 or 1
For 3-Seconds Data Logging (add 150)
0150 ms - Pin 00 - Data Log 0 or 1
0300 ms - Pin 01 - Data Log 0 or 1
0450 ms - Pin 02 - Data Log 0 or 1
0600 ms - Pin 03 - Data Log 0 or 1
0750 ms - Pin 04 - Data Log 0 or 1
0900 ms - Pin 05 - Data Log 0 or 1
1050 ms - Pin 06 - Data Log 0 or 1
1200 ms - Pin 07 - Data Log 0 or 1
1350 ms - Pin 08 - Data Log 0 or 1
1500 ms - Pin 09 - Data Log 0 or 1
1650 ms - Pin 10 - Data Log 0 or 1
1800 ms - Pin 11 - Data Log 0 or 1
1950 ms - Pin 12 - Data Log 0 or 1
2100 ms - Pin 13 - Data Log 0 or 1
2250 ms - Pin 14 - Data Log 0 or 1
2400 ms - Pin 15 - Data Log 0 or 1
2550 ms - Pin 16 - Data Log 0 or 1
2700 ms - Pin 17 - Data Log 0 or 1
2850 ms - Pin 18 - Data Log 0 or 1
3000 ms - Pin 19 - Data Log 0 or 1
The New MSR-01A Rocket
A modified MSR-01 for Launching Micronauts into Micro Space
The MSR-01A is an improved Big Brain rocket with a new micro space capsule. The new rocket has a number of great add-on features.
New Features of the MSR-01A Rocket
Micronaut Space Capsule
Entry/Exit Hatch
G-Force Shock Absorbers
Space Capsule Window
Capsule Viewer
Floor
New Space Capsule
The space capsule is built internally into the upper rocket body. The top of the capsule is the nose cone that has dual purpose. One, is serves as the entry and exit points to the capsule and two, it creates a pointed aerodynamic shape.
G-Force Shock Absorbers
The capsule is cylindrical shaped and g-force cushioned with cotton spring shock absorbers for launch stress reduction.
Capsule Floor
The paper floor is structurally reinforced against the high pressure of the fuel tank beneath it.
Capsule Window
The deluxe capsule has a clear cellophane window for viewing the rocket's occupant prior to launch and immediately upon recovery. A special viewing device allows looking through the MSR-01A's window into the capsule interior. This is made from a 12mm FL telescope ocular borrowed from the Big Brain's FirstScope telescope.
Entry Exit Hatch
The hatch is at the top of the rocket's nose cone for occupant entry and exit It folds to close and unfolds to open, forming a peak at its closure junction. No latch is needed as the hatch is self latching due to its dual side creased fold.
Capsule Crossbeams
The capsule is structurally reinforced with crossbeams created from supporting strips of scotch tape.
Dimensions
The rocket is 2.75-inches tall with a capsule section that does not exceed one quarter inch in height with a diameter of 3/8th inch (the same as the rocket).
Launching System
The MSR-01A's launching system is the same, producing compressed air fuel that fills and propels the rocket to its maximum Micro Space altitude.
Rocket Weight
The MSR-01A is extremely light and even with the capsule added it tumbles back to Earth on a cushion of air by very quickly reaching terminal velocity.
Telemetry
For telemetry, the same guidance tracking and control is in effect with the Big Brain (when launches are from the Airport).
The Large Launcher consists of these basic parts. Fuel pressurization tank is in the foreground. Flexible and rigid air intake and exhaust lines. Bleeder Valve for Pressure Adjustment not shown, located behind the red Ballast Fuel Reservoir, Larger Fuel Containment Piping and Secondary Fuel Distribution Hose etc. In this configuration the system requires cutting the rigid distribution air intake manifold and attaching it to the pressurization hose.
____________________
A new Large Rocket Launcher is now added to the Micro Space Program (see photo). The Large Launcher for rockets is remarkable in numerous ways and allows for the launching and construction of much larger rockets.
The large launcher is like an exciting quantum leap in Micro Space technology.
Longer Launch Tube
Larger Ballast Fuel Reservoir
Larger Fuel Containment Piping
Secondary Fuel Distribution Hose
Low Cost (NT$30)
Capable of Higher Fuel Pressure
Bleeder Valve for Pressure Adjustment
This view shows current routing of Large Launcher piping. Note a flexible hose that can direct pressurization to the rocket and the rigid launch tube.
______________________
Note: This is one in a series of Micro Launchers being developed for the Micro Space Program. A variety of Launchers can fit different types of rockets, their various sizes, with various features determined by weight. For example, a small launcher can handle a small rocket with no payload. A large launcher can handle a small rocket with a heavy payload or a large rocket with no payload. Launchers have different features and can handle varying fuel pressures. One variable to consider is pressure over time. Delivering pressure in less time can launch rockets at higher altitudes or launch rockets with greater mass payloads.
Large Launcher Rocket Coupler
_______________________
The first rocket launcher is a small device which is portable and can position on top of the Big Brain Airport. This is advantageous in utilizing Big Brain sensors and computing power. The Large Rocket Launcher is designed for the floor and potentially could be foot activated for creating higher fuel pressures. Hand activation will better fit the lower altitudes for test rocket flights.
It's unknown how large a rocket will fit the Large Launcher or how heavy a payload it will handle. More tests are required including the development of new rockets to fit the launcher. The Large Launcher is compatible with Big Brain's RADAR, PIR, and SoftClock.
The Bleeder Valve for Pressure Adjustment is the knob control attached to the Pressurization Ballast Chamber. This control sets the height of the rocket after the launch.
____________________
This PSI meter is now added as a resource
________________________
Air pressure reservoir added to the collective
_________________________
A new pressure gauge and tank are now added to the system. This will service a new high pressure launcher and system at pressurization to 100 pounds per square inch.
Comments
This is a series of MSR-01 photos showing the steps of a Micro Space air-rocket launch. The MSR-01 has launched around 50 times and is still in good condition. For this sequence of photos, the rocket was positioned and then launched about 25 times and the best photos were selected for the incremental take-off sequence. The rocket is a reusable air-rocket with a paper body and environmentally safe fuel - air. The internal body of the rocket is pressurized with air for flight during lift-off. Lift off is from a launcher (with air pressurization chamber) made with a glass lens duster. The nozzle guides the rocket during the initial launch and acts as a fuel injector to pressurize the rocket's internal fuel chamber.
________________
The arrow cursor points to the launcher rod. This stem should have parallel sides. There are many devices (especially larger ones) with sloped sides and these do not work well with the rocket in maintaining a propellent chamber seal along the rod's length and the rocket's body as the rocket takes off. Experiments with the degree of "pressurization seal" show this factor is significant in the flight of the rocket.
The MSR-01 is the precursor to a larger scale robotic rocket. MSR-01 can launch from atop the Big Brain's Airport. For these photos, the rocket was launched from the MSP Lab base in Taiwan. In the photos backgrounds are larger bottles that can launch larger air rockets. The rocket program is testing various rockets, construction materials, propellants, designs, and launching methods.
At the top of the list is a fuel that's completely safe to the environment and to the handling personnel. In the past, manufacturing plants that made fuel used in solid rocket boosters have blown up causing injury and loss of life, and considerable damage to the Earth's environment. The MSR Program's air fuel is relatively safe from spontaneous combustion and is perhaps the only fuel that completely recycles back into the environment unchanged and is healthy to breathe all throughout operations.
http://forums.parallax.com/showthread.php?124495-Fill-the-Big-Brain&p=1034631&viewfull=1#post1034631
http://forums.parallax.com/showthread.php?124495-Fill-the-Big-Brain&p=1036900&viewfull=1#post1036900
http://forums.parallax.com/showthread.php?124495-Fill-the-Big-Brain&p=1036903&viewfull=1#post1036903
http://forums.parallax.com/showthread.php?124495-Fill-the-Big-Brain&p=1037156&viewfull=1#post1037156
Hate to break it to you but using a fan to elevate objects is not a new invention.
There was once a toy on the market that allowed "remote control" of balloon flight by directing the fan that was providing their lift.
Ahh...yes. Here it is, "Johnny Astro" from the 1960's. Ideal for micro-space, you will love it, http://www.johnnyastro.com/johnnymain.htm
Elevating ping pong balls and steering them around in an air stream provided by a vacuum cleaner hose (connected to the vacs output) is an old aerodynamics demonstration.
Spinning like a planet - with the USB fan, the heavier balloon craft was modulated into a spinning vortex using the fabric air beam modulator seen at bottom right. The spinning propellers are visible on both devices.
_________________
This massive chromed fan could launch the heavier balloon easier but lofting control was difficult. This is because the fan has a front grating pattern designed to disperse the slipstream. A way to remove the grate may be found. This fan has a swivel mount that can fully aim 90-degrees up to the zenith for lofting craft directly overhead. The CFM on the high setting appeared to be the perfect amount of air flow. To launch larger and heavier craft, more fans and higher speeds are needed. However, this initial goal is to fly a vehicle not exceeding but reaching the maximum dimensional height of Micro Space. This should be achievable relatively soon in the Micro Space Program.
_____________________
There was once a toy on the market that allowed "remote control" of balloon flight by directing the fan that was providing their lift... "Johnny Astro" from the 1960's. Ideal for micro-space, you will love it, http://www.johnnyastro.com/johnnymain.htm Elevating ping pong balls and steering them around in an air stream provided by a vacuum cleaner hose (connected to the vacs output) is an old aerodynamics demonstration.
Heater, thanks for the this great toy info, you're right. I love it! Elevation of objects with a fan is not new. It's only new to the Big Brain. The web site shows the concept with a balloon was made into a toy in 1967 and some research shows a long time before that, Bernoulli fully developed the principle. I had not tried it on a balloon, but now you got me started wanting toys. I visited five toy stores but did not find any similar toy devices.
I spent the last 4 hours working with three fans, two are USB, and one is a giant chrome fan. I used the smaller fan to modulate the slipstream, help create a vortex, then camera captured the results of two different sized balloons, one of 7-inch diameter and one at 3-inches. The 7-inch is quite heavy and the 3-inch almost weightless.
I experimented with plain balloons and attaching miniature gondolas to both crafts for stability and orientation balance. With the large chrome fan, the three power settings were used to send the balloon upward. The best power setting was the strongest. The photos show the launch results of two experiments.
Now I want a vacuum cleaner to reverse the forced air and get some ping pong balls going... These are Ping Pong Space Capsules to launch into Micro Space. Next thing you know, we'll need a jet turbine nozzle and a large array of joined massive air compressors, huge arrays of ballast tanks, steel tubing, and a giant Ping Pong air ball with a hatch to ride slip stream of space.. any volunteers?
Support for the Micro Space Slipstream by Bernoulli's Principle
http://en.wikipedia.org/wiki/Bernoulli's_principle
Newton's 2nd Law Applies
"Bernoulli's principle can also be derived directly from Newton's 2nd law. If a small volume of fluid is flowing horizontally from a region of high pressure to a region of low pressure, then there is more pressure behind than in front. This gives a net force on the volume, accelerating it along the streamline."
"In fluid dynamics, Bernoulli's principle states that for an inviscid flow, an increase in the speed of the fluid occurs simultaneously with a decrease in pressure or a decrease in the fluid's potential energy."
Implications
http://www.britannica.com/EBchecked/topic/62615/Bernoullis-theorem
"Bernoulli’s theorem implies, therefore, that if the fluid flows horizontally so that no change in gravitational potential energy occurs, then a decrease in fluid pressure is associated with an increase in fluid velocity. If the fluid is flowing through a horizontal pipe of varying cross-sectional area, for example, the fluid speeds up in constricted areas so that the pressure the fluid exerts is least where the cross section is smallest. This phenomenon is sometimes called the Venturi effect, after the Italian scientist G.B. Venturi (1746–1822), who first noted the effects of constricted channels on fluid flow."
Aircraft Design
Bernoulli’s theorem is the basis for many engineering applications, such as aircraft-wing design. The air flowing over the upper curved surface of an aircraft wing moves faster than the air beneath the wing, so that the pressure underneath is greater than that on the top of the wing, causing lift.
Fluid Flow
Bernoulli's principle states that in a steady, streamlined, incompressible flow of a fluid, the pressure of the fluid is inversely proportional to its velocity. If a fluid is flowing through a horizontal pipe of varying cross-sectional area, as in Figure 1 for example, the fluid speeds up in constricted areas so that the pressure the fluid exerts is least where the cross section is smallest. This phenomenon is also called the Venturi effect. The Venturi effect has several applications including that associated with generating lift atop an aerofoil, making all forms of flight on aeroplanes, gyroplanes, and helicopters possible.
Magnus Effect
Magnus effect, generation of a sidewise force on a spinning cylindrical or spherical solid immersed in a fluid (liquid or gas) when there is relative motion between the spinning body and the fluid. Named after the German physicist and chemist H.G. Magnus, who first (1853) experimentally investigated the effect, it is responsible for the “curve” of a served tennis ball or a driven golf ball and affects the trajectory of a spinning artillery shell.
Spinning Objects in Air - Balls and Balloons
A spinning object moving through a fluid departs from its straight path because of pressure differences that develop in the fluid as a result of velocity changes induced by the spinning body. The Magnus effect is a particular manifestation of Bernoulli’s theorem: fluid pressure decreases at points where the speed of the fluid increases. In the case of a ball spinning through the air, the turning ball drags some of the air around with it. Viewed from the position of the ball, the air is rushing by on all sides. The drag of the side of the ball turning into the air (into the direction the ball is traveling) retards the airflow, whereas on the other side the drag speeds up the airflow. Greater pressure on the side where the airflow is slowed down forces the ball in the direction of the low-pressure region on the opposite side, where a relative increase in airflow occurs. See Bernoulli’s theorem; fluid mechanics.
You have some really cool experiments going on Humanoido, (I haven't flown a balloon in years.) keep up the good fun.
-Tommy
Mindrobots: Be sure and document the space walk duration on those Dorito EVAs.
It gives a whole new meaning to the word "kitchen." If we alot one room per person, and each room is a Micro Space Universe of approximately 10 x 10 x 10 feet average in three dimensions, excluding all the office space and factories in the world, one can estimate there are over 7 billion Micro Space Universes. That's a combined Universe space of 7 trillion cubic feet!
If we used a UPS package measuring string laid out for girth of each Micro Space Universe, we'd have 30 running feet for each and 30 x 7 billion = 210 billion feet or 39,772,727.3 miles. That would take us to the Moon 147 times (it's about 270,000 miles to the Moon) and equal a trip to Mars during opposition (about 35 million miles).
The Parallax BoeBot tires have a diameter of 2.62-inchs. The 210 billion feet in all the Micro Universes is equal to 2.52e12 inches. This means Boe-Bot would turn its wheels 961,832,061,068.7 times or 961 billion times.
http://www.parallax.com/Portals/0/Downloads/docs/prod/robo/Boe-Bot%20Wheel%20dimensions.pdf
If BoeBot moves at a velocity of 6-inches per second, it would take 4.2e+11 seconds, or 7,000,000,000 minutes or 116,666,666.7 hours or 4,861,111 days (constant 24 hour travel non stop). That's 13,309 years for a BoeBot to travel all the Micro Space Universes.. (are we there yet?)
http://www.parallax.com/Portals/0/Downloads/docs/prod/robo/Boe-Bot%20Wheel%20dimensions.pdf
http://en.wikipedia.org/wiki/World_population
The world population is the total number of living humans on the planet Earth, currently estimated to be 6.96 billion by the United States Census Bureau as of July 1, 2011.
*of course, by "spread", I mean evenly distribute individuals, not as a homogeneous paste, that would be the world fate in some bad sci-fi story.
One of the virtues of working in Micro Space environments and a Micro Space Universe is the great degrees of working safety.
Heights are relatively minimal, many engine tests are performed with air and small USB fans - some with cloth propellers, rockets and crafts move relatively slow and have low pressurized air for fuel and many of the space crafts are made from materials like sponge, nerf, cotton, balloon, soft rubber, paper, gossamer plastic, limp thread, tissue paper, string and foil.
There are no flammable or harmful-to-breathe fuels. With a reasonable amount of applied safety in this environment (and applying the common sense rules of home safety), one can avoid an eye poke or a paper cut or a balloon popping in the face, and completely avoid becoming an unfortunate 100 Kg individual.
Many of the Micro Space crafts, devices, machines, structures, tests, and sensors can run on either a Parallax Propeller chip(s) (aka the Big Brain), or, one or more BASIC Stamp modules (BS1, BS2, BS2px...)
Even the Big Brain has at least two BASIC Stamp boards (one host HomeWork Board and one BS2 BOE Board of Education embedded into the Brain Stem) amidst the mass of Propeller arrays to maintain compatibility with Stamping.
The question is, do we continue development only with Propeller chip(s) or should we do the experiments in Micro Space with Stamps?
Choose One
( ) Propeller
( ) Stamp
( ) All the Above
( ) Other Option
( ) Stamp
( ) All the Above
( ) Other Option
-Tommy
It looks like the voting results are in for making a choice on using the Parallax Propeller chip or the BASIC Stamp module.
Results are shown with this left to right bar chart.
Bothxxxx................... 20%
Stampxx.................... 20%
Propellerx................. ................. ................. 60%
20% want both
20% choose Stamp
60% want Propeller
Therefore, to satisfy all options, the Micro Space projects will have the greatest development with the Propeller chip, along with less frequent co-development using the Stamp. Sometimes projects will be presented specifically for the Stamp.
The Tethered Space Platform
The BIg Brain has decided to begin work on a Space Tether. The ST will contain a multipurpose platform. Depending on the stability of this "Tethered Platform," a variety of programs will become available.
This may also be the precursor to a Space Telescope on a tethered platform in space, the success of which will be determined by the amount of stability. A whole gamut of ideas open up.
One idea takes up the tether with a micro craft on the end that has aerodynamic hovering, suspending and lofting ability. This stabilizes the payload and ensures a safe return trip.
The mechanical tether can lead to other technology, like a hovering space craft moving up and down. Heavier mechanical tethers are not as susceptible to wind shear like light weight helicopters. Lighter tethers can anchor at both ends once deployed.
A special tether, like a single strand of spider web, can suspend itself in air.
Tethers have other unique abilities. On one design in the works currently, the tether space craft has mobility along the +/- Y-Axis via a drive connection to the tether. A light craft can go up and down carrying its own battery pack. This could be a pound in weight depending on the type of tether and its mooring ability.
Tethers will have a study to determine how the upper end can be anchored cheaply and easily at the highest possible space. A balloon can rise to high altitude and release a grappling hook on the high end of the tether, which will drop and connect to some object suitable for anchoring.
Perhaps a tether can attach to the roof on the back side of a tall skyscraper, antenna structure, tall tower, or mega project.
In the case of a mega project whose attachment is prohibited, a new kind of tether could be invented. This tether is taken aloft by a balloon to a high elevation and released, whereupon the high end anchors itself to the air and surrounding space for a short period of time, enough to achieve aerial imaging and scientific study. Then the tether can slowly float back to Earth, the resistance of which will act like a parachute thus protecting the cargo.
One tether idea uses pressure gel. A chord is distributed and pressure is applied to harden it.
Another tether has the weight of string balanced against the uplifting air cells on a hot day.
A micro tether can have several mini hot air vesicles attached to provide gossamer lift. A small electrical nichrome can supplement as a short term hot air producing source.
A propeller lifted tether can rise up to a height based on the time length of the battery, the weight of the tether and the lifting force of the mechanism.
Tethers are safe, made from thin string that breaks and/or vaporizes if struck by another aircraft, jet, windmill, or if blown by excessive wind forces.
Tethers can be parachuted at the top end when released to ensure a safe payload return and to stall the return for longer scientific analysis.
The motorized tether has a top engine, battery and propeller to take the tether up to a specific altitude and free fall back to the Earth.
Tether Simulation in Java
http://spacetethers.com/spacetethers.html
Near Space
http://hobbyspace.com/NearSpace/index.html
Micro Space
Make: Space - Tethered Test
http://blog.makezine.com/archive/2007/03/make-space-tethered-test.html?CMP=OTC-0D6B48984890
StratoSail - a sail hung on a tether from the balloon.
http://hobbyspace.com/NearSpace/index.html
The StratoSail(R) balloon guidance system (BGS) is designed to alter the flight path of balloons. The StratoSail(R) BGS takes advantage of the natural difference in wind speed at different altitudes in the atmosphere. A wing is suspended several kilometers below the balloon gondola using a long thin tether. The wing is hanging on end, so its "lift" acts sideways rather than upward as in an airplane. This sideways lift force is used to drag the balloon across the wind. This allows the balloon to be maneuvered towards regions of interest and away from unfavorable conditions. The BGS can drive the balloon to sites of interest to scientists. Some governments do not give permission to fly over their countries. With a StratoSail(R) BGS aboard, the balloon can be directed around these uncooperative regions. Hazardous weather patterns can be avoided. Balloon flights may last many weeks and go around the world several times. At the end of a flight, the balloon can be redirected to land back near its launch site. This makes balloon operations much simpler.
HASTOL - a concept at Tethers Unlimited in which the end of a rotating tether will rendevous with a rocketplane at 100km and pick up a payload to take to orbit.
Tethered Formations
http://www.tethers.com/
Clusters of small spacecraft flying in formation may provide revolutionary capabilities for a wide range of applications, including interferometric astronomy for investigation of the structure of the cosmos, synthetic aperture radar for environmental studies, and military surveilance missions. Due to the nature of orbital mechanics, however, a group of satellites in orbit will tend to drift away from each other. Consequently, to hold the spacecraft in formation requires some form of propulsion. For some applications, rockets or electric thrusters for formation flying is an acceptable solution, but for many applications the propellant requirements would be prohibitive.
Optical Tether
http://www.tethers.com/UOTD.html
An optical tether can provide a two-way, high-bandwidth communications link to mobile robots, ROV's, UUV's, deployable sensors, and other systems. Unlike RF-based communications systems, an optical tether is secure, covert, and immune to the jamming, multipath, and line-of-sight problems.
Tether Sources
http://hobbyspace.com/Links/SpaceSystems.html#Tethers
http://spacetethers.com/
http://search.yahoo.com/search;_ylt=A0oGdVspGnROtxAAXiWl87UF?p=amateur%20space%20tether&fr=sfp
Big Brain's Tether & the Tethered Space Camera
http://forums.parallax.com/showthread.php?124495-Fill-the-Big-Brain&p=1036417&viewfull=1#post1036417
The HLR Heavy Launch Rocket is designed to carry Parallax Propeller chip
payloads into Micro Space for the first time.
The Big Brain and its Micro Space Program is extending its domain with a new Micro Space Heavy Launch Rocket. This will eventually replace the existing MSR-01 rocket. The Micro Space Heavy Launch Rocket is intended for heavier payloads to include scientific instruments and it opens the door to new studies with Parallax Propeller chips and related sensors.
The launch system's initial design is generally complete. On Monday, October 3rd, 2011, the parts to build the new launch complex were found and purchased. The budget for the HLR Heavy Launch Rocket, otherwise coded as MSR-02 Micro Space Rocket, was pushed up. As luck would have it, the amount spent on the launcher at this time is $5 plus $.50 for a 90-degree G-310 pipe. The nearly complete parts package is under PAT.ZL.200520118326.0 China and PAT.NO.M281417 Taiwan and was purchased through the Aquarium Store.
The 90 Deg Fuel Diversion Pipe is model G-310 available from Up. Aquarium Supply sourced online at www.up-aqua.com. It has an outside diameter of 16mm with an ID of 12.84mm.
This collection of parts is needed to construct the heavy lift launcher
The Launch Base LB component is being fabricated from common materials and will not add cost to the project. The LB will hold the Standard Vertical Launching Rod and Fuel Compression Delivery Chamber with a mounting at the base.
Rocket Launcher Component List
2 - 90 Deg Fuel Diversion Pipe
1 - Flexible Fuel Delivery Hose (long)
1 - Standard Vertical Launching Rod and Fuel Compression Delivery Chamber
1 - Very Large Vertical Launching Rod and Compression Fuel Delivery Chamber
1 - Incremental Fuel Cutoff Valve with 360-deg Rotation
1 - Fuel Injection Delivery Pipe with 1" to 1/2" Adaptation
1 - Fuel Compression Engine
1 - Fuel Compression Engine Back-flow Prevention Valve w/1/2" Fitting
for the Micro Space Program Heavy Lift Launcher & Engine
Fuel flow valve test, partially opened
_____________________
The fuel pressure mounted as the flow valve was slowly opened allowing rocket fuel to flood the compartment. Successful pressurization was achieved in a fraction of a second. The fuel flow valve was tested at several main settings. Pressurization was possible and achieved with the fuel flow diverter pipe, the fuel delivery hose, and the fuel pressurization chamber.
Fuel can be successfully regulated and calibrated at a flow rate from maximum to zero. This enables an adjustment to the potential height of the rocket's trip at launch time. A higher pressurization rate allows the rocket to have more fuel and achieve a higher Micro Space altitude.
Adjustment of fuel also enables the launching of a variance in increased payload weight, given the same rocket height. At increased fuel pressure, the payload could include heavier devices: camera, live passenger (Insectronaut), sensor, Propeller chip, and other scientific micro apparatus.
Performance Tests of the new Engine Design
A new engine design places the rocket completely inside the launch tube gantry. This is opposing the previous technology where the rocket surrounds the the launch tube. The design is based on an existing rocket tube body that form fits into the launch tube and is open on the bottom to hold pressurized fuel. The design works only with internal payloads and is offered as a supplement to the Heavy Lift Vehicle.
Tests show good launching capabilities with minimal fueling pressurization. Escape and liftoff is very smooth with minimal friction. An internal air layer is maintained as lubricant between the rocket and the launch tube.
How to Make Weightlessness in Micro Space
Welcome to the Micro Space Program. The Big Brain has discovered, through launches of the MSR-01 rocket, there is a zone of weightlessness that can be created in a Micro Space environment.
Create Weightlessness
If you're following along, you can create your own packet of Zero-G weightlessness in your own room. You'll need a BASIC Stamp or Propeller chip to confirm or document the effects. If a Propeller is used, other functions such as timing (with the SoftClock previously posted) and data logging with no extra parts are possible.
Limitations of Micro Space Zero-G
To make and use or study Zero-G there are some stipulations. One, it only lasts a fraction of a second, and two, you can't experience it directly with your own body, however small live insectronauts (insects as passengers) can experience weightlessness.
Experimenting with Weightless Payloads
It will be interesting to place a small camera on the rocket looking through a window to the inside capsule to monitor the weightless condition of the payload, to see if it's caught floating for a fraction of a second on one of the DV frames. So it's likely our camera will point into the rocket ship and not necessarily out for aerial photography.
The Technique
The method employs a launch vehicle to closely approximate the flight path of a inverted parabola. At the crux of the geometric figure there is domain after rise and before fall. The effects of these three Micro Space domains are studied using a tiny Parallax accelerometer to help determine several parameters.
1) The location of Zero-G
2) When weightless begins
3) When weightless ends
4) The duration of Zero-G
5) Zero-G effects
Camera as Payload
The camera can also be used as a payload to determine if it experiences weightlessness. Don't affix the camera but just focus it on some internal object or wall drawing inside the space craft. A small circle inside the craft drawn on the wall with a pencil will suffice. Check the camera DV frames to see changes any changes in position of this drawing.
Questions for Exploration
This leads to the question, can we extend the time of weightlessness? Experimenting with different rockets, various launch accelerations, varying altitudes, and variations of a flight path may give interesting results. What fascinating apps can you think of for working and playing in this new Micro Space weightless environment?
with the Parallax Mesmic 2125 Accelerometer
Memsic 2125 Dual-axis Accelerometer
_____________________
From Memsic 2125 Accelerometer Demo Kit (#28017)
Acceleration, Tilt, and Rotation Measurement
http://www.parallax.com/Portals/0/Downloads/docs/prod/acc/memsickit.pdf
The T1 duration (Memsic output) is captured by PULSIN in the variable xRaw. Since each BASIC Stamp module has its own speed and will return a different raw value for the pulse, the factor called Scale (set by the compiler based on the BASIC Stamp module installed) is used to convert the raw output to microseconds. This will allow the program to operate properly with any BASIC Stamp 2-series module. At this point the standard equation provided by Memsic can be applied, adjusting the values to account for the pulse-width in microseconds. Fortunately, one divided by divided by 0.125 (12.5%) is eight, hence the final multiplication. The result is a signed value representing g-force in milli-g's (1/1000th g).
http://forums.parallax.com/showthread.php?90573-Wiring-Diagram-for-Memsic-2125-which-one
Parallax Sources
http://www.parallax.com/Store/Sensors/AccelerationTilt/tabid/172/CategoryID/47/List/0/SortField/0/Level/a/ProductID/93/Default.aspx
Downloads & Resources:
Memsic 2125 Datasheet (.pdf)
Stamps in Class Memsic Tutorial (.pdf)
Memsic 2125 Demo Kit Documentation (.pdf)
MXD2125G&M (.pdf)
Memsic 2125 Demo Kit BASIC Stamp Source Code (.zip)
Memsic 2125 Schematic (.pdf)
Stamps in Class Tilt Display Control (.pdf)
Javelin Stamp Example Code (.zip)
N&V column "It's all about Angles" #92 (.pdf)
N&V code "It's all about Angles" #92 (.zip)
Memsic web site (Off Site)
Sensor Objects for Propeller Programmers
The Memsic 2125 is a low cost, dual-axis thermal accelerometer capable of measuring tilt, acceleration, rotation, and vibration with a range of ±3 g. For integration into existing applications, the Memsic 2125 is electrically compatible with other popular accelerometers. Memsic (http://www.memsic.com) provides the 2125 in a surface-mount format. Parallax mounts the circuit on a through-hole providing all I/O connections so it can easily be inserted on a breadboard or through-hole prototype area.
Mesmic Drivers in Spin for the Propeller chip
http://obex.parallax.com/objects/search/?q=accelerometer&csrfmiddlewaretoken=acca41b0639c1c7aecffa92c76f95ede
I was just taking apart a Wii Nunchuck when I saw your recent updates.
Nunchucks have a triple axis accelerometer.
I'm taking one of mine apart in order to mount the circuit board securely to my project (a digital level).
I personally think a triple axis accelerometer would be a better match for weightless experiments. A dual axis is fine for measuring angles (or for a digital level) but your missing one component of acceleration.
One thing I'd like to point out about weightlessness (or free-fall in these cases). An object doesn't have to be traveling downward to experience zero-G. I frequently see this error on model rocket websites. People tend to think zero-G occurs at apogee but it occurs once thrust is removed from the object. The initial period of simulated weightlessness in the "Vomit Comet" is while the aircraft is still flying upward. When we jump in the air, we experience weightlessness once our feet leave the ground.
I'm attaching a couple of pictures (I took them right before reading your recent posts) of the Nunchuck's PCB. You can see, by removing the outer shell of the Nunchuck one is left with a much smaller board which would be easier to install in an airplane or rocket.
I'm not sure how quickly a Propeller can read a Nunchuck. I think I might try to add a logging feature to my digital level and then toss it in the air to record the acceleration.
Duane
Duane, thanks for these informative comments. In particular, the rocket may alter orientation and the additional accelerometer axis would be useful to have all three acceleration components. I will revise the Zero-G study to include the Hitachi Tri-Axis Accelerometer, sold by Parallax, for better data during this experiment.
I had studied the flight path of NASA's aircraft and the parabolic path it makes. It was quite surprising to see that weightlessness was not occurring on the down side of the parabolic shape but rather at its inverted peak. Studying it more makes good sense. I'm looking for a better way to determine the flight path of a rocket indoors.
It would be beneficial to correlate DV data with the accelerometer data logging to determine the curve and the nodal points of Zero-G. A tiny keychain camera was recently purchased for flights on the helicopter and rocket. It now looks like another application will include an external stationary camera view with a scale to determine rocket path. I've seen this camera technique used on Mythbusters a number of times.
with the Parallax Hitachi H48C Tri-Axis Accelerometer Module
And the Reason Why the Hitachi H48C is the Ultimate Accelerometer!
Parallax offers the Hitachi
H48C Tri-Axis Accelerometer
Module Item code 28026
price $24.99. Find out why
this sensor is the ultimate
selection for the Big Brain's
Micro Space Program and
the study of Micro Gravity.
___________________
The Parallax Hitachi H48C Tri-Axis Accelerometer Module will capture the third component of gravity and collect useful data during the tumbling part of the rocket either on the upward path, mid point, or going downward. It assists three dimensional reconstruction of flight paths and gravity components from lift-off to recovery and can be the prime sensor in detecting, studying and exploring the new world of Micro Space Zero-G.
The Reason Why the Hitachi H48C is the Ultimate Accelerometer
The Automatic Zero-G Detector!
It was a very good recommendation when Duane Degn suggested using a Tri-Axis Accelerometer. Without that suggestion, we may have never discovered the best feature of the H48C - the automatic Zero-G Detector! When the Parallax Hitachi H48C Tri-Axis Accelerometer was examined, it was found to carry an indispensable feature to automatically detect Zero-G by simply reading a pin state, which can be accomplished with Spin and PBASIC. So you'll definitely want to hook up to PIN 4 and take advantage of this feature.
http://www.parallax.com/Store/Sensors/AccelerationTilt/tabid/172/CategoryID/47/List/0/SortField/0/Level/a/ProductID/97/Default.aspx
The Hitachi H48C Tri-Axis Accelerometer is an integrated module that can sense gravitational (g) force of ±3g on three axes (X, Y, and Z). The module contains an onboard regulator to provide 3.3-volt power to the H48C, analog signal conditioning, and an MCP3204 (four channel, 12-bit) analog-to-digital converter to read the H48C voltage outputs. All components are mounted on a 0.7 by 0.8 inch module. Acquiring measurements from the module is simplified through a synchronous serial interface. With the BASIC Stamp® series, for example, this is easily handled with the SHIFTOUT and SHIFTIN commands.
Principle of free-fall detection by a 3-axis accelerometer
http://www.parallax.com/Portals/0/Downloads/docs/prod/acc/H48CPrinciplesofFree-FallDetection.pdf
Hookup information for the Zero-G rocket detection flight circuit
_______________________
How It Works
http://www.parallax.com/Portals/0/Downloads/docs/prod/acc/HitachiH48C3AxisAccelerometer.pdf
Through MEMS (Micro Electro-Mechanical System) technology and built-in compensation, the H48C
accelerometer provides simultaneous outputs through analog conditioning circuitry to an MCP3204 ADC. To "read" g-force of a given axis we actually read the voltage output from that axis and calculate g-force using this formula:
G = ((axis – vRef) / 4095) x (3.3 / 0.3663)
In the formula, axis and vRef are expressed in counts from the ADC, 4095 is the maximum output count from a 12-bit ADC channel, 3.3 is the H48C supply voltage, and 0.3663 is the H48C output voltage for 1g (when operating at 3.3v). In practice this can be simplified to:
G = (axis – vRef) x 0.0022
Using the BASIC Stamp 2 module as a host controller, we should multiply the 0.0022 by 100 (to 0.22) to express the result in units of 0.01g. Using the ** operator, we are able to multiply by 0.22 and convert the raw readings to g-force with this bit of code:
Dio PIN 15 ' data to/from module Clk PIN 14 ' clock output CS PIN 13 ' active-low chip select IF (axCount >= rvCount) THEN gForce = (axCount - rvCount) ** GfCnv ' positive g-force ELSE gForce = -((rvCount - axCount) ** GfCnv) ' negative g-force ENDIFThe Amazing Built in Free Fall Detector
Of special interest is PIN 4 which is the Zero-G "Free-fall" output. To return a true condition, the pin goes active-high. Use of the accelerometer is as simple as reading pin 4 for the detection of Zero-G. The method works when free-fall output indicates simultaneous 0g an all axes.
The Hitachi H48C 3-Axis Accelerometer is an integrated module that can sense gravitational (g) force of
±3g on three axes (X, Y, and Z). The module contains an onboard regulator to provide 3.3-volt power to
the H48C, analog signal conditioning, and an MCP3204 (four channel, 12-bit) analog-to-digital converter
to read the H48C voltage outputs. All components are mounted on a breadboard-friendly, 0.7 by 0.8 inch
module. Acquiring measurements from the module is simplified through a synchronous serial interface.
With the BASIC Stamp® 2 series, for example, this is easily handled with the SHIFTOUT and SHIFTIN
commands.
Downloads & Resources
http://www.parallax.com/Store/Sensors/AccelerationTilt/tabid/172/CategoryID/47/List/0/SortField/0/Level/a/ProductID/97/Default.aspx
Hitachi H48C Tri-Axis Accelerometer Docs v1.2 (.pdf)
H48C Datasheet (.pdf)
Example BASIC Stamp Code (.zip)
H48C Principles of Free-Fall Detection (.pdf)
MCP3204 12-bit A-D Converter Datasheet (.pdf)
Javelin Stamp Example Code (.zip)
Sensor Objects for Propeller Programmers
For the Propeller
H48C Tri-Axis Accelerometer
http://obex.parallax.com/objects/178/
Interface to the H48C Tri-Axis Accelerometer. The included demo displays orientation information on a VGA monitor. By Beau Schwabe. Revision History: Version 1.0 - (Sept. 2006) - Initial release with a TV mode 3D- graphics cube. Version 1.1 - (March 2008) - 3D-graphics cube removed - Basic VGA display used instead of TV - Added 600nS padding delay around Clock rise and fall times
H48C synchronized driver
http://obex.parallax.com/objects/430/
This PST terminal application proves the H48C_Sync_Driver.spin object. This driver object can synchronize the data readouts of H48C Tri-axis accelerometer modules. In this demo four H48C sensors are synchronized. The uniform timing and precise intervals of the synchronous readouts are verified. The H48C_Sync_Driver can be used in 6DOF IMU projects where four H48C tri-axis accelerometers are arranged in space to provide a cheap but precise close equivalent of high dollar 6DOF IMU sensors. See attached PDF file for the mathematical details. By I.Kövesdi.
Micro Space Zero-G & Accelerometer References
Measuring the Effects of Zero-G in Micro Space with the Parallax Mesmic 2125 Accelerometer
http://forums.parallax.com/showthread.php?124495-Fill-the-Big-Brain&p=1040952&viewfull=1#post1040952
Big Brain Discovers Micro Space Zero-G - How to Make Weightlessness in Micro Space
http://forums.parallax.com/showthread.php?124495-Fill-the-Big-Brain&p=1040949&viewfull=1#post1040949
How to obtain angular velocity and angular acceleration values directly from 3D accelerometer array data using simple matrix operations in Propeller/SPIN
http://obex.parallax.com/objects/download/aux/47/
Measuring the Effects of Zero-G in Micro Space with the Parallax Hitachi H48C Tri-Axis Accelerometer Module
http://forums.parallax.com/showthread.php?124495-Fill-the-Big-Brain&p=1041199&viewfull=1#post1041199
Seconds of time can come from the SoftClock program posted earlier and a pushbutton could start the clock.
http://forums.parallax.com/showthread.php?124495-Fill-the-Big-Brain&p=1039474&viewfull=1#post1039474
EDIT: now that I think about it, the entire rocket flight may last only a second or two, so maybe the time units should be a number we can set, maybe a log every 100 milliseconds or where it can be adjusted to the best time increment by trial and error.
Where do you want the data being logged stored? The fastest and easiest method is to store it in hub RAM of the Propeller chip. Storing data to RAM means it could be easily lost though.
Storing to EEPROM is just about as easy as storing to RAM. If you have a 64K EEPROM chip attached to the Propeller you could store the data to upper EEPROM.
Do you have a SD card adapter to use with the Propeller. A SD card removes any size concerns so we could store as much data as you'd like. Kye's SD Card driver is easy to use. By logging to a SD card you could just move the card to a computer to data analysis. You wouldn't need to figure out a way of getting the data logged from the Propeller to the computer.
If you have a way of using a SD card with a Propeller, I think it would be the best choice for data logging experiments.
You mentioned
The attached paper shows, in order to measure angular acceleration (and velocity) you need two accelerometers in each plane being measured. In order to measure all three axes of rotation you need four accelerometers.
It would probably be less expensive, smaller and lighter, to use a triple axis gyro. (I'm not sure if Parallax sells a triple axis gyro.) I have one of these. I haven't taken time to use it yet.
Let me know if a SD card would be a good logging method for you or not and I'll start working on some code. I think a software clock would be a good fit for this application. It shouldn't be hard to make the logger easily configurable to use different logging intervals.
Duane
Big Brain Rocket Program and the Selection of Tiny Astronauts
Micronauts are small astronauts that go into the Propeller Brain's Micro Space domain, riding inside Micro Space Rockets. When insects go into space they are sometimes referred to as Insectronauts.
The Micro Space Program (MSP) is run and operated by the expansive Big Brain project, which consists of massive quantities of Parallax processors (many are Propeller chips) and Parallax sensors. In its expansion phase, the Brain seeks knowledge and understanding of the world that surrounds it. This includes knowledge and assimilation of sensors and devices, methods and designs.
The program is gearing up with Parallax sensors and devices - the PIR already in use, and the RADAR, plus the SoftClock using Spin programming. In the heavy lift launch vehicle phase, sensors will actually fly on board the rocket, notably the Tri-Axis Accelerometer, a Propeller chip, with full support from the Brain below.
Insectronaut Micro Space Program
The Insectronaut Micro Space Program includes aerospace and education - and launching live insects into space. It was created as a Brain project within the Micro Space Program as an adjunct to studying the effects of Micro Space travel on live passengers and the reults of a changing environment.
Insectronaut Studies
The Insectronaut Program will include the study of G-forces sustained at lift-off, the effects of weightlessness and Zero-G, various capsule and rocket designs, and changes in character, personality, behavior etc.
The MSP
This has led to the construction of a Brain-connected Airport, a robotic helicopter flying program, a rocket development program, a micro space telescope which is being robotized, aerial imaging program & camera, and many micro space crafts.
The Quest of Curiosity
This quest of curiosity (using Parallax components as low cost available resources) has led to the Micro Space Program, a scientific educational program that's conducted in a room of approximately 10 x 10 x 10 feet, known as the Micro Space Universe - essentially the living space of the Big Brain's domain.
Rocket Passengers
Insects are the primary creatures in nature that may weigh almost nothing, approaching the weight of a postage stamp or two. This is within the payload weight capacity of the MSR-01 rocket.
Statistics
Are these little insects ideal candidates for the Micro Space Program? Big Brain put their statistics to the test.. We're looking for a few good insects modeled after these requirements.
- Small physical size
- Very low weight
- Good disposition
- Capable of sustaining rocket g-forces
- Heathy
- In good hardy conditioning
- Does not require exceptional environment
- Minimal preparation
In reviewing the Insectronaut candidates for the Micro Space Program, we have the following potential applicant backgrounds classified by their average body statistics.Ant - 6mm long, 3mg weight, 250,000 brain cells, strong - can lift 20x body weight, lives up to 60 days, intelligent, exploratory personality, can bite, can use tools, no special environment required, not trainable, moderately easy management, ground mobility for most varieties
http://www.lingolex.com/ants.htm
Fruit Fly - 3.2mm long, 250,000 neurons, live 30 days, not trainable, semi-special environment required, semi-challenging management, air mobility
Gnat - 1-2mm long, 200,000 neurons, 2mg weight, live 120 days, special environment required, not trainable, fussy management, air mobility
Conclusions
Weight & Size
All three candidates meet established weight and size requirements.
Intelligence
Ants are superior in intelligence with average life span.
Training
It appears that all candidates reviewed are not trainable. As the micro space launch only requires the insectronaut to be on board, the training aspect is of little importance and can be disregarded.
Special Environments
The fruit fly and gnat require special environments while the ant does not.
Strength
Ants are the strongest.
Life Span
Ants have an average life span. Gnats live the longest. Fruit flies have the shortest life span.
Environment
Ants are the most versatile with adaptation to environment. Fruit flies and gnats have special requirements.
Management
Ants are the most easily managed however some species will bite. Gnats are the most challenging and annoying in flight, followed by fruit flies.
Mobility
Most ant varieties stay on the ground. Gnats and fruit flies have flight mobility.
Conclusion
The ant is chosen to go into space. The fruit fly and gnat are on the backup program.
A no parts data logger that relies on Propeller pin states and a SoftClock to record and hold data for hot read-back
Duane: I like doing many things with LEDs or no parts. In this case, I would try something a little different because LEDs draw too much power for the rocket's on-board tiny prop cell battery. The data logging should reside in the pin states with no extra parts. Tell me if you think the following will work.
The Micro Space Data Logger
This methods requires only one propeller chip and battery, with a connector and resistor to load the initial program. The program data logs the zeros and ones from the Parallax Hitachi H48C Tri-Axis Accelerometer's pin 4 (the Zero-G pin detector) into 20 prop pins that act as the output and storage device, storing 20 values of either high or low.
From one pin to the next, a timing increment is represented, depending on whether 1, 2 or 3 seconds is needed for the duration of the rocket flight. (see chart below) The number of prop pins used determine the resolution. One second is the highest resolution at 50ms between readings (or logs). Two seconds in 100ms and three seconds is 150ms.
After the rocket flight, the prop is kept on, and a small probe or meter reads the prop pins and determines which is a 0 or 1. That will determine when Zero-G began, when it was active, and when it terminated. These pins are arranged in timing order like this for a one second time period:
For 1-Second Data Logging (add 50)
The first entry is the elapsed time when the data reading was recorded. The second entry is the Propeller's pin number. The third entry is the data read - the 0 or 1 pin state of the Parallax Hitachi H48C Tri-Axis Accelerometer's pin 4 (the Zero-G pin detector).
0050 ms - Pin 00 - Data Log 0 or 1
0100 ms - Pin 01 - Data Log 0 or 1
0150 ms - Pin 02 - Data Log 0 or 1
0200 ms - Pin 03 - Data Log 0 or 1
0250 ms - Pin 04 - Data Log 0 or 1
0300 ms - Pin 05 - Data Log 0 or 1
0350 ms - Pin 06 - Data Log 0 or 1
0400 ms - Pin 07 - Data Log 0 or 1
0450 ms - Pin 08 - Data Log 0 or 1
0500 ms - Pin 09 - Data Log 0 or 1
0550 ms - Pin 10 - Data Log 0 or 1
0600 ms - Pin 11 - Data Log 0 or 1
0650 ms - Pin 12 - Data Log 0 or 1
0700 ms - Pin 13 - Data Log 0 or 1
0750 ms - Pin 14 - Data Log 0 or 1
0800 ms - Pin 15 - Data Log 0 or 1
0850 ms - Pin 16 - Data Log 0 or 1
0900 ms - Pin 17 - Data Log 0 or 1
0950 ms - Pin 18 - Data Log 0 or 1
1000 ms - Pin 19 - Data Log 0 or 1
This uses 20 pins. The Propeller has 0 though 31. This frees up at least ten pins for other telemetry that could be held as a binary number. Other timing may work better. Here's how the incremental seconds look at 2 and 3 seconds.
For Two Seconds Data Logging (add 100)
0100 ms - Pin 00 - Data Log 0 or 1
0200 ms - Pin 01 - Data Log 0 or 1
0300 ms - Pin 02 - Data Log 0 or 1
0400 ms - Pin 03 - Data Log 0 or 1
0500 ms - Pin 04 - Data Log 0 or 1
0600 ms - Pin 05 - Data Log 0 or 1
0700 ms - Pin 06 - Data Log 0 or 1
0800 ms - Pin 07 - Data Log 0 or 1
0900 ms - Pin 08 - Data Log 0 or 1
1000 ms - Pin 09 - Data Log 0 or 1
1100 ms - Pin 10 - Data Log 0 or 1
1200 ms - Pin 11 - Data Log 0 or 1
1300 ms - Pin 12 - Data Log 0 or 1
1400 ms - Pin 13 - Data Log 0 or 1
1500 ms - Pin 14 - Data Log 0 or 1
1600 ms - Pin 15 - Data Log 0 or 1
1700 ms - Pin 16 - Data Log 0 or 1
1800 ms - Pin 17 - Data Log 0 or 1
1900 ms - Pin 18 - Data Log 0 or 1
2000 ms - Pin 19 - Data Log 0 or 1
For 3-Seconds Data Logging (add 150)
0150 ms - Pin 00 - Data Log 0 or 1
0300 ms - Pin 01 - Data Log 0 or 1
0450 ms - Pin 02 - Data Log 0 or 1
0600 ms - Pin 03 - Data Log 0 or 1
0750 ms - Pin 04 - Data Log 0 or 1
0900 ms - Pin 05 - Data Log 0 or 1
1050 ms - Pin 06 - Data Log 0 or 1
1200 ms - Pin 07 - Data Log 0 or 1
1350 ms - Pin 08 - Data Log 0 or 1
1500 ms - Pin 09 - Data Log 0 or 1
1650 ms - Pin 10 - Data Log 0 or 1
1800 ms - Pin 11 - Data Log 0 or 1
1950 ms - Pin 12 - Data Log 0 or 1
2100 ms - Pin 13 - Data Log 0 or 1
2250 ms - Pin 14 - Data Log 0 or 1
2400 ms - Pin 15 - Data Log 0 or 1
2550 ms - Pin 16 - Data Log 0 or 1
2700 ms - Pin 17 - Data Log 0 or 1
2850 ms - Pin 18 - Data Log 0 or 1
3000 ms - Pin 19 - Data Log 0 or 1
A modified MSR-01 for Launching Micronauts into Micro Space
The MSR-01A is an improved Big Brain rocket with a new micro space capsule. The new rocket has a number of great add-on features.
New Features of the MSR-01A Rocket
- Micronaut Space Capsule
- Entry/Exit Hatch
- G-Force Shock Absorbers
- Space Capsule Window
- Capsule Viewer
- Floor
New Space CapsuleThe space capsule is built internally into the upper rocket body. The top of the capsule is the nose cone that has dual purpose. One, is serves as the entry and exit points to the capsule and two, it creates a pointed aerodynamic shape.
G-Force Shock Absorbers
The capsule is cylindrical shaped and g-force cushioned with cotton spring shock absorbers for launch stress reduction.
Capsule Floor
The paper floor is structurally reinforced against the high pressure of the fuel tank beneath it.
Capsule Window
The deluxe capsule has a clear cellophane window for viewing the rocket's occupant prior to launch and immediately upon recovery. A special viewing device allows looking through the MSR-01A's window into the capsule interior. This is made from a 12mm FL telescope ocular borrowed from the Big Brain's FirstScope telescope.
Entry Exit Hatch
The hatch is at the top of the rocket's nose cone for occupant entry and exit It folds to close and unfolds to open, forming a peak at its closure junction. No latch is needed as the hatch is self latching due to its dual side creased fold.
Capsule Crossbeams
The capsule is structurally reinforced with crossbeams created from supporting strips of scotch tape.
Dimensions
The rocket is 2.75-inches tall with a capsule section that does not exceed one quarter inch in height with a diameter of 3/8th inch (the same as the rocket).
Launching System
The MSR-01A's launching system is the same, producing compressed air fuel that fills and propels the rocket to its maximum Micro Space altitude.
Rocket Weight
The MSR-01A is extremely light and even with the capsule added it tumbles back to Earth on a cushion of air by very quickly reaching terminal velocity.
Telemetry
For telemetry, the same guidance tracking and control is in effect with the Big Brain (when launches are from the Airport).
The Large Launcher consists of these basic parts. Fuel pressurization tank is in the foreground. Flexible and rigid air intake and exhaust lines. Bleeder Valve for Pressure Adjustment not shown, located behind the red Ballast Fuel Reservoir, Larger Fuel Containment Piping and Secondary Fuel Distribution Hose etc. In this configuration the system requires cutting the rigid distribution air intake manifold and attaching it to the pressurization hose.
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A new Large Rocket Launcher is now added to the Micro Space Program (see photo). The Large Launcher for rockets is remarkable in numerous ways and allows for the launching and construction of much larger rockets.
The large launcher is like an exciting quantum leap in Micro Space technology.
This view shows current routing of Large Launcher piping. Note a flexible hose that can direct pressurization to the rocket and the rigid launch tube.
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Note: This is one in a series of Micro Launchers being developed for the Micro Space Program. A variety of Launchers can fit different types of rockets, their various sizes, with various features determined by weight. For example, a small launcher can handle a small rocket with no payload. A large launcher can handle a small rocket with a heavy payload or a large rocket with no payload. Launchers have different features and can handle varying fuel pressures. One variable to consider is pressure over time. Delivering pressure in less time can launch rockets at higher altitudes or launch rockets with greater mass payloads.
Large Launcher Rocket Coupler
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The first rocket launcher is a small device which is portable and can position on top of the Big Brain Airport. This is advantageous in utilizing Big Brain sensors and computing power. The Large Rocket Launcher is designed for the floor and potentially could be foot activated for creating higher fuel pressures. Hand activation will better fit the lower altitudes for test rocket flights.
It's unknown how large a rocket will fit the Large Launcher or how heavy a payload it will handle. More tests are required including the development of new rockets to fit the launcher. The Large Launcher is compatible with Big Brain's RADAR, PIR, and SoftClock.
The Bleeder Valve for Pressure Adjustment is the knob control attached to the Pressurization Ballast Chamber. This control sets the height of the rocket after the launch.
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Flexible fuel pressurization hose clamp
This PSI meter is now added as a resource
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Air pressure reservoir added to the collective
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A new pressure gauge and tank are now added to the system. This will service a new high pressure launcher and system at pressurization to 100 pounds per square inch.