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Title: quad rotor helicopter Post by: xloving on February 14, 2010, 01:56:44 13:56 some one working with quadrotor helicopter ??
we are planning to build the same using a dspic 30f series. but really speaking i am new to this programming and control.. if someone can help me it would be a real help.. i need the help even for the algorithm development.. we have bought a 6 degrees of freedom inertial measurement system from sparkfun which has 3 axis accelerometer and 3 axis groscope.. but dont know how to use it for the stabilization.. our first phase is to make the helicopter stable in air.. the movement and control for motion will come in second phase only.. if someone can help i would be really thankfull.. thank you xloving Title: Re: quad rotor helicopter Post by: frasenci on February 14, 2010, 02:55:08 14:55 Hi, you do not mention the scale ( size ) of your proyect.
I did something like this with 3 axis acel onboard an RC Helicopter. ( Radio Controlled ) Used 2 parallel 16F877A on board. Of course now we have better CPUs.... Please explain about scale and purpose of your proyect and I will be glad to share my expreriences Greetings Francisco Title: Re: quad rotor helicopter Post by: xloving on February 14, 2010, 03:14:36 15:14 size of the project in the sense??
money or physical size..??? the hardware is already there.. we just have to deal with the control system.. the pcb design,etc Title: Re: quad rotor helicopter Post by: sputnik on February 14, 2010, 05:44:50 17:44 Please note that there are plenty of these projects already online with plenty of information available.
I would not recommend starting from scratch since you noted you are new to programming/control. The PID algorithms for stabilization are no piece of cake. What airframe do you have? The X-Ufo? There are DIY and ready made boards out there that you could use, look at the X3D board or the UAVP board. Or look on RC Groups, there is plenty of info on converting existing brushless controllers for I2C control as well as some main board info. I have had an Xufo that I modified, as well as a Y-Ufo (3 rotor). I have some drawings of an airframe I was designing that I never completed. Title: Re: quad rotor helicopter Post by: th_sak on February 14, 2010, 07:31:44 19:31 A good project for UAVs http://www.mikrokopter.com/ucwiki/en/MikroKopter/
Google is your friend... Title: Re: quad rotor helicopter Post by: sputnik on February 15, 2010, 12:36:15 00:36 A good project for UAVs http://www.mikrokopter.com/ucwiki/en/MikroKopter/ Google is your friend... Forgot to mention the Mikrocopter!!! It is one of the best and what I based my Xufo mods on!!! Title: Re: quad rotor helicopter Post by: xloving on February 22, 2010, 11:51:49 11:51 but i got a simple doubt..
just to keep the helicopter stable in air i should use accelerometers or gyrocopes?? if accelerometer.. then what about the effects from the external forces like the disturbances we give etc.. if gyro then it gives angle turned in seconds.. should i convert it to angle using real time numerical integration or some other ways to deal with the angle tilt measurement?? Title: Re: quad rotor helicopter Post by: sputnik on February 22, 2010, 10:12:33 22:12 but i got a simple doubt.. just to keep the helicopter stable in air i should use accelerometers or gyrocopes?? if accelerometer.. then what about the effects from the external forces like the disturbances we give etc.. if gyro then it gives angle turned in seconds.. should i convert it to angle using real time numerical integration or some other ways to deal with the angle tilt measurement?? To do it properly you would actually use both, a fully complemented IMU (Inertial Measurement Unit). However, 3 gyros, one for each axis will get you pretty darn stable. With either you will need some sort of feedback loop and digital filtering, PID for instance. No reason to doubt any of this, and no reason to try to re-invent what is already been done very well. Just look at the Mikrocopter. It uses 3 gyros for, roll, pitch, yaw, and a pressure sensor for altitude, and it is extremely stable. Just look at the 6 rotor version of the Mikrocopter here http://vimeo.com/6194911 |