Gastropods - a Silly idea ??
Britannicus
Posts: 98
I've been musing ...
Just about every method of locomotion in the animal world has been mimicked in robotics. I've seen Fish, hexapods, ornithopters, octopods, synthetic trunks and tentacles, bipeds, even monopods, tripods milipedes frogs and snakes
Yet for reasons that I guess in the main are obvious, (but when did obvious inutility ever stop us !) One entire taxonomic group has been missed out of the "robots mimicking nature stakes", and not a minor one either!
Now as a paleaonotology buff I feel the need to highlight what is probably one of the oldest and certainly most successful forms of locomotion - The Gastropod ! (slugs, snails and their relatives - over 80,000 named species, second only to the insects ), this fine group of creaures surely should be represented cybernetically. Yet I've never heard of a robot gastropod ! - why has no-one tried the GASTROBOT !! - I feel a strong urge to right this wrong.
Does such a beast exist and I've missed it ? - A quick google seems to draw very few uninspiring examples and none from the Hobby world.... I feel a mission coming on!
I'd have to define gastropod movement as having the following parameters - maybe in this thread we could explore further criteria that would have to apply for a robotic slug or snail to be sufficiently "sluggy" :
1/ Broad single contact space with the ground in a single flexible planar contact (a "foot" as in a slug or snail)
2/ Natural gastropods move by linear muscular contractions similar to peristalsys- often facilitated by exuding mucus (definite extra points for mucus!). So rule out tracks or belts of some kind.
Given their limited visual ability and slow pace of operation, I think some kind of "line follower" should be in order. maybe sensing the conductivity of a pre-laid slime trail.
for more info http://en.wikipedia.org/wiki/Gastropod
Just about every method of locomotion in the animal world has been mimicked in robotics. I've seen Fish, hexapods, ornithopters, octopods, synthetic trunks and tentacles, bipeds, even monopods, tripods milipedes frogs and snakes
Yet for reasons that I guess in the main are obvious, (but when did obvious inutility ever stop us !) One entire taxonomic group has been missed out of the "robots mimicking nature stakes", and not a minor one either!
Now as a paleaonotology buff I feel the need to highlight what is probably one of the oldest and certainly most successful forms of locomotion - The Gastropod ! (slugs, snails and their relatives - over 80,000 named species, second only to the insects ), this fine group of creaures surely should be represented cybernetically. Yet I've never heard of a robot gastropod ! - why has no-one tried the GASTROBOT !! - I feel a strong urge to right this wrong.
Does such a beast exist and I've missed it ? - A quick google seems to draw very few uninspiring examples and none from the Hobby world.... I feel a mission coming on!
I'd have to define gastropod movement as having the following parameters - maybe in this thread we could explore further criteria that would have to apply for a robotic slug or snail to be sufficiently "sluggy" :
1/ Broad single contact space with the ground in a single flexible planar contact (a "foot" as in a slug or snail)
2/ Natural gastropods move by linear muscular contractions similar to peristalsys- often facilitated by exuding mucus (definite extra points for mucus!). So rule out tracks or belts of some kind.
Given their limited visual ability and slow pace of operation, I think some kind of "line follower" should be in order. maybe sensing the conductivity of a pre-laid slime trail.
for more info http://en.wikipedia.org/wiki/Gastropod
Comments
No slime though.
Make one of those go uphill and you'll have something!
Not exactly what you were looking for, but pretty close and very interesting
Also, I did a quick search on Google (snail robot, no pluses or quote marks) yielded nearly 2 million hits, now many of them are false, and several were for wheeled (or other) bots that mimiced snails or slugs, but there were a few interesting ones:
http://www.engadget.com/2005/12/14/mits-robo-snail/
http://www.vestaldesign.com/blog/2005/12/mit-snail-robot/
http://www.technovelgy.com/ct/Science-Fiction-News.asp?NewsNum=750
Will they bubble and writhe in agony if salt is shaken on them, too?
http://forums.parallax.com/showthread.php?124495-Fill-the-Big-Brain&p=1003798&viewfull=1#post1003798
My first thought for a peristaltic drive - I thought of rototating units under a flexible membrane - rather as one sees in a peristaltic pump something like this :
This creates a genuine peristaltic wave as in a gastropod - one could have 2 in parallel, so in effect "skid steer" the resulting 'bot - this is a slightly different steering model to a genuine slug, which reduces the wavelength of the peristalsys on one side, and shortens the muscles on one side of the entire body to enable a turn. This could be achieved, I guess with a longitudinally placed solanoid on each side, but i fear the rollers might be a problem unless they were articulated very well.
If I was looking for the extra points of mucus, this could be introduced in front via a few holes in the membrane - peristalsys, would do the rest, feeding it back under the 'bot and reducing friction. As with the real thing a relatively viscous material would be best.
Looking at Humanoido's Suggestion - I'm not sure I get the idea of how this is driven - what I think you envisage is a sort of cam type mechanism which stretches and then relaxes the membrane a bit like in the 2 diags below :
What I'm struggling to think about is how to ensure a "directional push" to provide movement, and stop it just going up and down on the spot - I've included in the picture 1 the option of a "hairy foot" with angled bristles (stolen from the bristle bot) - but this is more like the motion of an earthworm through it's burrow - (I can't resist a reference to a "worm drive"
What do you think ??
I don't think they will work as a gastropod foot. They are a lot like those sticky octopus mentioned earlier. They (the GekkoDots) might make a good feet from a wall climbing bot. The bot would need to use a pealing motion when raising its feet.
Good luck on your noble quest.
Duane
http://www.bigsiteofamazingfacts.com/how-does-a-snail-move
The snail has an unusual body sticking out from the underside of its coiled shell. This body is actually a strong muscle called a foot. A snail’s foot is made up of many tiny muscles which help it to crawl about in an up-and-down, or wavelike, motion. The waves start at the front of the snail’s foot and move backwards. As the waves pass through the muscles from one end of the foot to the other, the snail glides forward.
These use a pair of screws instead of treads to provide skid steering. Although the screw rotating, the line of contact provides peristaltic wave motion.
From the videos I saw, the thing floats on snow and coesn't get stuck. In addition to forward, backward, and skid steer turning, it also can go sideways.
I thought about building something like this, but I didn't want bare screws, they would scratch up the floor. Maybe if the "foot" had the screws in a silicon bag, suspended in oil?
http://spectrum.ieee.org/automaton/robotics/industrial-robots/little-amphibious-tumbling-robot-tackles-tough-terrain
(pretty dang cool, PJ)
Sort of an amphibious Turbot with bladder control issues...
http://www.youtube.com/watch?v=xyX9Jsoqv_0
This is a good example of alternate mobility. But don't try this in the home! It appears it will leave marks on the floor, possible even chunks taken out, gouges, or dents on a wood floor. It would shake up the internal electronics and make it more prone to failures, cracked printed circuit boards, and shifted assemblies. If it contains batteries, it will take more energy and use it less efficiently to inertially flip the mass weight of the robot over end to end. It positional accuracy is severely limited by its means of locomotion. Incidental contact with some objects will cause damage, i,.e. plants, glass objects, lighter weight positional elements, etc. This is also called amphibious yet it cannot use its prime method of locomotion in water - it cannot flip over.
Here's a robot that reinvents the wheel using caterpillar movements. Its soft latest is more user friendly.
http://bigthink.com/ideas/38491
The GoQBot seeks to overcome past limitations of robot design. While robot engineers typically have to decide between making a robot flexible or fast, the Tufts team uses a castable silicone rubber called Dragonskin that allows for robot flexibility. And by studying the movement of the caterpillar, which generates speed very efficiently by rolling itself into a ball, the team hopes to create a better kind of robot locomotion. The small size of a caterpillar robot, coupled with its flexibility, makes it ideal for a range of uses, including accessing very difficult to reach places during search and rescue missions.
What a light-weight. You've been stacking propeller protoboards way too long.
A plastic case flopping around. Is that your idea of high impact?
Do they let you out of the house by yourself? Don't go anywhere without your bicycle helmet fastened.
Looks like it does OK to me.
You are now free to panic, but please securely fasten your bicycle helmet (on your head.)
Cost is $11.95.
http://www.electronickits.com/robot/CK21673.htm
http://www.electronickits.com/robot/CK21650.htm
I had one a few years back - very satisfying because of it's compressed air motor produced a sort of wheezing chugging noise. would have been good to genuinely robot-ise it, but sadly it demised years ago
I googled it and found this http://www.jeffbots.com/stoomdorm.html - someone else who remembers them fondly.
On the debate about the laminate floor damage with robots, I have to go with Humanoido -
The consequenses of "colateral robot damage meets non-geek wife" well justifies the caution ! - failure to observe the niceties can find your rubbish bin well stocked with electonic components.
Anyone who's had to have the "why are there soldering iron burns on the dinner table?" conversation will understand this and the consequent need for any married geek to have a well set up shed.
One might work a variation on the "twin screws" design though - I remember from a treatise on Archimedes, that the original recommendation to create the archimedian screw ( which is horribly difficult to fashion using craft skills) was to take a cylider (simple using a pole lathe etc) and then wrap a leather strip around it to create the helix, rather like putting the hand grip on a tennis raquet, but with gaps. Several layers of strip would then be nailed through to create an easy (and watertight-ish) thread.
If one did this with some expanded foam as in "karimat" sleeping mats, one might make a "floor friendly" screw. For extra domestic points add a statically charged duster to clean as it goes !
It would probably take a very small portable air compressor run on battery power. Then a series of valves are needed to open and close the source. These valves could be favorably mechanically actuated from one to the next in peristaltic sequence or tripped by an electrical source. A number of tubes could lead from the pneumatic valves to the Peristalsis Motion Unit to generate the required sequential motion.
Instead of a wave of contraction and relaxation of a smooth muscle lining as in the human body, r.e. stomach or esophagus, a propagating expansive wave would be generated along the tubular-like body.
Here's a flash demonstration.
http://www.westga.edu/~lkral/peristalsis/index.html
Liquid nitrogen works too, but make sure you have a pressure relief valve. Here's a steam engine running off liquid nitrogen.
As you can see their relief valve was needed and there's the problem of ice forming on the machine. Also, don't play with a pressure vessels if you're unsure of what you are doing. Canned air in a ventilated area is much safer.
Operating a pneumatic option would present several potential issues that you get with every such project.
1/ To carry enough air on board, you have to have it well compressed (I'm not sure about "canned air" - but assume this to be at normal aerosol pressures (max 5 bar), not much above the couple of bar the stoomdorm must've used. This really represents very little stored energy, If I were to have a go at this, I'd recommend a step up to a small compressed air cylinder (say 1 litre - they're hugely strong - about a kilo and will hold about 250 Bar). This stores an enormous amount of energy I remember in my "diving physics" lectures that a 10 litre cylinder has the equivalent stored energy of a 2 ton truck hitting a brick wall at 50 miles an hour). It's possible to kill people with only 10 bar if you squirt the pressure line on the skin.
2/ This then introduces the complexity of needing a "first stage" reduction valve (buy this - don't even think of making it !)- this drops the pressure to a value between 1.5 and 5 bar above ambient (you choose). Scuba supply shops can supply this as it's a replacement part for a demand valve.
Compressed gas does have the ability to store a lot of power - it's why it's popular in things like fighting robot flippers, but tricky to handle .
The next big issue you have with a "low pressure solution" - is even if you can store a large volume to compensate for low energy, is that for any pneumatic system to work it has to vent to ambient pressure thus losing gas, obviously - venting 2.5 litre of ambient gas from a 200 bar bottle reduces the pressure to ambient ratio by only 1.75% but reduces a 5 Bar source by 50% this means you can' t rely on a consistent supply pressure (another reason for your first stage flow valve).
Lego sells a plastic air tank an as a storage option for their pneumatics. So I think the pressures involved are pretty low.
I wonder if two of these drives could be put in parallel to acheive skid steering....
About the gas source.. I use one of those cheap emergency tire inflators, In takes a while but can reach 250psi. I only need 40 psi max, so a 2 liter reservoir lasts a little while.
Another alternative, for paintball guns, is liquid CO2. It works in cold weather, bu I have not used it yet.
I just flashed on a low profile inchworm to do "colapsed" sewer repair. We have a lot of tree root problems here, and it would be nicer than digging up the lawn....
They can did up your entire yard, exhuming tons of dirt in the process of creating an extensive matrix of underground burrows. They chew buried electrical wires, cable TV wires, phone wires, so they must be reckoned with.
I contacted the city that provided some general information about baiting. Unfortunately, there is no easy way to deliver the bait deep inside the burrows. A robotic inchworm in swarming numbers could be programmed to seek out these vermin and force an evacuation from their premises.
A roto-rooter inch worm that could go in the clogged sewer pipe and chew up the tree roots would definitely be very useful.
So, I'm going to start another project (as if I don't have enough already) to built cylinders out of PVC pipe and other junk around the shop.
The Pneumatic Sewer Slug project is started.
The hydraulic version WILL leave a liquid trail, but it will be tap water for the time being