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Hi I am looking for some help with gyros/accelerometers. my project is logging the flights of my flying wings (radio controlled), and stabilize the plane if there is no R/C input. I would like to be able to see the angle of the plane, maybe as well stabilize it... furthermore gather other data of the flight. Controlling the servo is under control, but not the gyro. My problem is how to sort out the angle from the Gyro values... As sensor I have a CRS04 Rate Gyro from www.siliconsensing.com. Alternative sensors: ADXL202, ADXRS150 from Analog Devices. Maybe Somebody wrote a routine for stabilizing a radio control airplane ? The part for the ailerons would be really useful to me. If somebody could help me out with this I would be glad to give him either a CRS-04 Sensor (250$) or 2 ADXRS150 from Analog Devices for helping out.... Thanks a lot Christoph, Email

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Chris, The routine to get the angle from the gyro is pretty simple. Just figure out the time between samples (dt) and multiply that time by the degrees/second value and do a summation. I've found that to work pretty well in testing, although it does drift over time. To fix that you'll have to get a tilt angle from a 2-axis accelerometer on a certain interval. Hopefully someone else can go into detail about that step...?!?!?! I'm using an ADXRS300EB and an ADXL202EB along with the Basicx-24. So far I've gotten them to work separately. I'm currently using the gyro to make my RC car go in a straight line. Eventually I want to make a UAV. Here is a link for College Students to get FREE parts from Analog Devices( So far I've obtained 6 gyros and 6 accelerometers :) http://forms.analog.com/Form_Pages/corporate/parts.asp matt --- In , "christophpgraf" <christophpgraf@y...> wrote: > Hi > > I am looking for some help with gyros/accelerometers. > my project is logging the flights of my flying wings (radio > controlled), and stabilize the plane if there is no R/C input. > > I would like to be able to see the angle of the plane, maybe > as well stabilize it... furthermore gather other data of the > flight. Controlling the servo is under control, but not the gyro. > My problem is how to sort out the angle from the Gyro values... > As sensor I have a CRS04 Rate Gyro from www.siliconsensing.com. > Alternative sensors: ADXL202, ADXRS150 from Analog Devices. > > Maybe Somebody wrote a routine for stabilizing a radio control > airplane ? The part for the ailerons would be really useful to me. > > If somebody could help me out with this I would be glad to give > him either a CRS-04 Sensor (250$) or 2 ADXRS150 from Analog Devices > for helping out.... > > Thanks a lot > > Christoph, > Email chris@t...

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--- christophpgraf <> wrote: > Hi > > I am looking for some help with > gyros/accelerometers. > my project is logging the flights of my flying wings > (radio > controlled), and stabilize the plane if there is no > R/C input. > > I would like to be able to see the angle of the > plane, maybe > as well stabilize it... furthermore gather other > data of the > flight. Controlling the servo is under control, but > not the gyro. > My problem is how to sort out the angle from the > Gyro values... > As sensor I have a CRS04 Rate Gyro from > www.siliconsensing.com. > Alternative sensors: ADXL202, ADXRS150 from Analog > Devices. > > Maybe Somebody wrote a routine for stabilizing a > radio control > airplane ? The part for the ailerons would be really > useful to me. > > If somebody could help me out with this I would be > glad to give > him either a CRS-04 Sensor (250$) or 2 ADXRS150 from > Analog Devices > for helping out.... > > Thanks a lot > > Christoph, > Email > > I've bought the analog devices acceleromter in 2 g version also. I know the device is very sensitive to acceleration and vibrations. It puts out a variable duty cycle versus g changes. If all it gave you was the static tilt output you would be home free,but you also get the dynamic changes too. The device also has a low level dc output in x and y which you would have to amplify and do a low pass filter circuit to extract the slow changing component from it. If you need 360 Degrees of information I understand you can use two of the devices oriented physically 180 degrees from each other. I have mounted these on a six cylinder aircraft engine running on a test stand to look at vibration with some success but they were the 50g flavor. > >I don't know if i helped you any but this is a great project and wish you the best with it. BILL __________________________________

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Hi... I did a two wheeled robot using some gyros and sensors... here is the site : www.fusionglobal.net You can check the code... Gyros give rate of change (NOT ANGLE!). Accelerometers give angle (NOT RATE OF CHANGE!). Accelereometers such as the ADX, is very accurate with angle readings, but when moving forward or having linear acceleration, it will stop reporting angle and start reporting acceleration values, and thus its reading is useless... In order to work out whats your current angle, you have to use a software filter, such as the Kalman Filter or Weiner filte r(i guess?). This filters give an optimal way of fusing both sensors and get actual angle... For stabilizing the wing, there are several ways to do this. I used a PID (proportional Integral Derivative), to compensate for the angle accurately, if you don;t use some sort of damping algorithm you will have your wing resonating back and forth until you get it out of control. My next project is a stabilizing system for a helicopter using three gyros, and three accelerometers. Check my site, i have some source code available that i used that does not implement the full kalman filter, but instead uses the integral value of the gyro as the proportional, and the accelerometer de-drift the gyro with long term average, it worked for me, check the code is for BasicX. Also check the www.rotomotion.com site, they have great resources and Sensors!!!.. I used a gyro like yours (expensive one) and found out that with a simple Tokin cheap gyro is more than enough. You will have to integrate it and de-drift it to get good angle readings... Good luck and if you need help write to me, my link is in my site.. Good luck. Have patience...

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> Chris, > > The routine to get the angle from the gyro is pretty simple. Just > figure out the time between samples (dt) and multiply that time by > the degrees/second value and do a summation. I've found that to > work pretty well in testing, although it does drift over time. To > fix that you'll have to get a tilt angle from a 2-axis accelerometer > on a certain interval. Hopefully someone else can go into detail > about that step...?!?!?! As i mention you need some kind of filtering to fuse both values, cause accelerometers don't report well under linear acceleration.

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