Hello everybody,
I'm looking into designing my own IMU unit. Can someone clarify what the issue is with gyro's and noise. I hear that heli's have issues with gyro's but I'm not really sure what to look for. Is it noise frequency, amplitude, etc? I'm looking for a really technical answer btw.
Thanks, Travis
Replies
Travis,
What kind of noise are you referring to? Noise in the angles determined by using the gyro? or noise from the output of the gyro itself?
I can't give you a really technical answer except to say that in some experimentation with a gyro on a 1/10 scale RC truck robot, I found that the output was extremely noisy when driving the car with remote control and not noisy when the RC truck was sitting in the passenger seat of my vehicle recording data. The noise floor obscured any meaningful data.
More detail here: http://www.bot-thoughts.com/2011/02/avc-bot-gyro-noise-and-accuracy...
I can also add that changing to a different gyro sensor, one designed to reject vibration, exhibited a much lower noise floor when driving on the same RC truck. MEMS gyro designs vary among manufacturers and some designs are better than others at rejecting external vibrations.
I've read elsewhere that RC trucks and helis share the common requirement of vibration resistant gyros. I would expect helicopter vibration to have some periodicity/pattern to it, while RC truck vibration is due to the road surface and perhaps to wheel and drivetrain imbalance.
Hope this helps.