Bitcraze Forums

Hello,

I am attempting to simulate the LPS system. I am currently attempting to add noise to the state estimate of the simulated robot, but am unsure of where to add it in to reliably simulate error. As I see it, I have two options:

1) Add the noise when the position of the robot is computed
2) Add the noise in the distance difference measurement

I am using an extended Kalman filter like that in the Crazyflie.

I was also wondering how the measurement noise standard deviation (https://github.com/bitcraze/crazyflie-f ... 2Tag.c#L43) was chosen?

Thank you!
Thomas

Hi!

The STD was measured as part of this paper:

Fusing ultra-wideband range measurements with accelerometers and rate gyroscopes for quadrocopter state estimation
Meuller et all (2015) ICRA (see here for pdf).

I believe they use a mocap system to measure it and they came to a 0.17 ns STD but that is now 0.15 ns for some reason (still pretty close)

If you would simulate the LPS system, I think you should go for option 2). The noise is supposed to be in the measurement anyway, so that will be closer to reality.