Book: Neural Network Control of Nonlinear Discrete-Time Systems

Started by Dara Shayda. Last reply by Dara Shayda Apr 16. 1 Reply 0 Likes

by J. Saranpagani Taylor and Francis GroupAn encyclopedia like list of all known NN applications to control systems all the way from 1940s to now with MATLAB and some C code. All the math explicated with explicit calculations so the coding can be more educated rather than just copying. I will type up all the equations and algorithms, for people who do not have the book.The control systems are from actual machinery used in different industries and all the relevant research papers listed. My hope is to code the known methods in C/C++ and Mathematica (for visualization and tutorials). The tutorials will be in CDF format and animation can be run on a free player. I will port the code into Beaglebone and is possible into Arduino boards. I am coding on IMAC + XCODE as the native platform. I would also publish the error analysis and stats for each method as time goes by. My thoughts are to use the GNU PUBLIC LICENSE 3.0 but please let me know what other licensing is appropirate If any…Continue

Ideas for simulation input to NN

Started by Dara Shayda. Last reply by Dara Shayda Mar 30. 2 Replies 0 Likes

I got this generous input from one of the XFOIL's usergroup. These ideas give a better simulation for the copter than the one's I have hacked already since the suggested tools are more mature and worked on by the experts in the field. Amazing thing I recognized this week was that the complicated rotor crafts can be off-line trained by NN for complex flying i.e. the customer purchases a copter and downloads the NN offline trained weight matrices for immediate flight e.g. the novice fliers will not destroy thousands of dollars of equipment because they do not have the RC fingers to manually manipulate the copter.From:GEORGE <georgepehli@yahoo.com>Subject: [xfoil] Re: Neural Network ControlDate:March 30, 2012 1:38:24 AM EDTTo:xfoil@yahoogroups.comReply-To:xfoil@yahoogroups.comHello Dara, I think it would be possible to use some of the existing open source and very powerful tools from the wind energy sector for your project. You essentially have 4 rotors that (in a simplified case)…Continue

CAMRAD

Started by Dara Shayda Mar 29. 0 Replies 0 Likes

For those interested to develop control systems for rotor crafts:http://johnson-aeronautics.com/documents/CAMRADIIoutline.pdf   I was told  that the simulation aspect and calculations for the phase-space can be obtained from this software, rather writing my own which is reduntant. This took might be quite useful for the community here, since slight alterations to the Arducopter is difficult to debug and maintain. dContinue

Offline Training: Take-off in Winds

Started by Dara Shayda. Last reply by Dara Shayda Mar 28. 1 Reply 0 Likes

HelloFinally got to the actual control algorithm for the Neural Network based guidance system:http://lossofgenerality.devzing.com/blog/2012/03/28/nn-control-takeoff-in-wind/  The test cases were variety of take-offs, straight or bowed or even crashes. However no explicit wind was blow in the offline test cases. Then the quad-copter performed a take-off in a gust, it turned on its NN control when needed and reduced the drift substantially!I added an actual animation at the end of the html file, so please see how the copter wobbles specially at the higher heights. There might be an issue there or simply the errors are too much and cause serious shaking. The conclusion is then clear: The NN control is viable and probably a superior option for small and larger quad-copters, in adverse weather and situations where the CG is compromised or heavy weights are loaded. DaraContinue

Twin Rotor Helicopter

Started by Chris Card. Last reply by R_Lefebvre Mar 26. 1 Reply 0 Likes

Is it possible to configure APM for use with a twin rotor helicopter?A friend of mine was wondering if it could be used with a Chinook type helicopter.He thought that maybe it would take two APM boards, in communication with each other, to perform control.I wonder if modifying the traditional helicopter firmware to re-mix or blend the outputs to two provide the required control signals for the two rotors.I have never looked at how the real Chinook system works, so I can only make guesses.Has this even been tried?Continue

Beta Tests Flights in the field...

Started by Jean-Louis Naudin. Last reply by Dara Shayda Mar 17. 15 Replies 0 Likes

ArduCopter v2.4.1:beta test flight of LOITER (GPS Position Hold)Here a video of a LOITER test flight of the firmware ArduCopter v2.4.1 (beta) with the latest fix on STAB_D and Throttle.This version tested include the auto-land mod XP2Regards,Jean-LouisContinue

Tags: ARDUCOPTER, BETA

NN accuracy for quad copter

Started by Dara Shayda. Last reply by Dara Shayda Mar 15. 4 Replies 0 Likes

HellloSingle layer of 64 neurons with 8 input and outputs and learning rate set to 0.1. Training cases created for vertical take off. The Universal Approximate was constructed for smooth function:CONTROL: Vn+1 --> Vn V is {motor1, motor2, motor3, motor4, Roll, Pitch, Yaw, zcoor}Desired from simulator: {motor1, motor2, motor3, motor4, Roll, Pitch, Yaw, zcoor}{0.701, 0.7, 0.7, 0.7, 0.500005, 0.491911, 0.500174, 0.051289}NN calculated thru adaptive learning from a set of 105,000 test cases, offline, zcoor was normalized by a factor maxZ = 30:Obtained from NN learning:{motor1, motor2, motor3, motor4, Roll, Pitch, Yaw, zcoor}{0.751359, 0.69765, 0.743422, 0.710697, 0.572931, 0.580407, 0.620613, 0.107281}  First four numbers are the motors's RPM, normalized between 0 and 1.Complexity:128 multiplications and additions required + 10 multiplications and 4 additions for taylor series expansion of Sigmoid function around 0. 128 word or long word for the learning matrices. The motors' accuracy…Continue

Tutorial: Universal Approximator and NN

Started by Dara Shayda. Last reply by Dara Shayda Mar 6. 1 Reply 0 Likes

Hellohttp://lossofgenerality.devzing.com/blog/2012/03/06/tutorial-universal-approximator-neural-networks/  Single layer neuron network is trained for simple set of mappings:http://www.wolfram.com/cdf-player/  <---- download this free plugging to see the calculationshttp://lossofgenerality.devzing.com/blog/2012/03/06/tutorial-universal-approximator-neural-networks/ The emphasis was to make the NN training more accessible for programmers without requiring a PhD.The code was actually implemented in Mathematica 8.0 but the pseudo C code is quite accurate. The algorithm was matched to number of papers and 8000 training loop was experimented with. DaraContinue

Book: Machine Learning

Started by Dara Shayda Mar 4. 0 Replies 0 Likes

http://robotics.stanford.edu/~nilsson/MLBOOK.pdf  For our 2 layer network I am using calculations similar to this book.There are other forms of machine learning that probably would benefit arducopter.DaraContinue

Slow User Trainer

Started by Dara Shayda Mar 3. 0 Replies 0 Likes

HelloAs a beginner Arducopter user, I think an NN application to take off and land Arducopter semi-manullly is great. In other words a super slow take off indoors or outdoors can allow the new user to learn the controls at an RC and learn the caveats of flying arducopter. Right now we crash the machine many times before getting a hang of take off and landing. This idea at the same time will allow us to learn how to develop an NN control system for arducopter  as in baby steps. If we can do that then the user usage of RC can be incorporated into the NN learning, so the UAV is controlled both by the NN and what is learned from the user moves.DContinue