accelerometer and Basic Stamp2 , RC Autopilot ?
Tomvn
Posts: 103
i am new with this , i need some help, can sombody tell me how to make· rc autopilot with accelerometer and Bs2.
Post Edited (Tomvn) : 4/23/2008 3:44:43 PM GMT
Post Edited (Tomvn) : 4/23/2008 3:44:43 PM GMT
Comments
I suggest you do some web searching. Start with the Wikipedia and do a search for "wiki autopilot". Here's one example of a thesis on the design of an autopilot: www2.foi.se/rapp/foir2224.pdf. Search for and look at the manuals for commercial R/C autopilots. Here's one example: www.futaba-rc.com/radioaccys/futm0999.html.
anyway thanks for suggestion.
Since you are new to all this, learning is where you need to start. Things like autopilots are not something you can just get a copy from someone else, try to duplicate, and expect to work. Unless you buy a commercial unit, you will have to significantly modify anything that someone else has used (unless you have the identical aircraft, remote control, and autopilot parts). To do that, you have to understand what you are doing. You'll need to read up on autopilots, check the R/C magazines for systems that others have built, and learn how to program the Stamp in this case. You'll have to figure out how to get an accelerometer to work, how to build and test a horizon sensor, how to interface with an R/C receiver, etc.
Other people here have worked on helicopter autopilots. Use the forum search (search.parallax.com) to look for other messages or just go through the Stamp, Sandbox, and Completed Projects forums for previous messages. Lately, most have used the Propeller since that is faster and has multiple processors with more memory ... handy for something as complex as an autopilot for a fast moving vehicle.
I appreciate that .
http://www.rcgroups.com/forums/showthread.php?t=734456&page=43
This is page 43, it is up to·47 now. If you go to page 1 you see how primitive it started out.
Every code object is custom written by me. For example I am not using the Servo32 method at all, nor am I using any sort of pulsin·object to read the RC receiver channels. I started out this way, but eventually they didn't suit my needs. Several other routines are centered around statistical analysis and filtering of raw real world data to provide something more useful, such as the barometer data, and even post-processing of raw GPS nmea data. My point is yes, you can DEFINATELY make an autopilot with a Prop chip. It is far from trivial. It REALLY helps if you have extensive RC flight experience. The key is to develop a passion for it!
AP
"Design of an integrated strapdown guidance and control system for a tactical missile"
WILLIAMS, D. E.RICHMAN, J.FRIEDLAND, B. (Singer Co., Kearfott Div., Little Falls, NJ)
AIAA-1983-2169
IN: Guidance and Control Conference, Gatlinburg, TN, August 15-17, 1983, Collection of Technical Papers (A83-41659 19-63). New York, American Institute of Aeronautics and Astronautics, 1983, p. 57-66.
You need the gyros to compute the angular motion of the vehicle.· This allows you to know the orientation of the vehicle with respect to the local gravity acceleration.· Then you add the 32.2 fps into the computed acceleratioin from the IMU.·This corrects for the gravity issue.
You have to send signals to the control surfaces based on the errors in the commanded body orientation and measured acceleration.· For level flight, the acceleration should be zero.· If it is greater than that you need decrease the angle of attack and vice versa.
You have to create some type of controller.· A PID controller would be a good choice.· there are many PID controller articles on the Web.
There is a good article on Wikipedia about accelerometers and PID controllers.