Re: [Paparazzi-devel] imu sensor filtering?

[Chris]

Hi
I have read the wiki page about vibration dampening about 100 times and 
Monday i will use 2 more imu mounts, one with ear buds (memory foam) and 
one with latex foam.
I have already started constructing a box similar to the one in the wiki 
and i added a moving
average  filter in the Accelerator raw values like the wiki says.
I will also try to set the mpu6050 to use a 2g range and see what happens.
So far the problem is minimized and i think i can fly (that was the main 
reason that i selected a
twin cylinder engine and not a single.
Btw with IFR do you mean a FIR filter or a Instantaneous Frequency Rate 
filter?
I have been thinking of measuring the Engine's rpm and construct a 
digital notch filter where i move
the notch frequency according to the measured engine rpm.
Chris

On 05/19/2013 07:00 PM, address@hidden wrote:
> Hi Chris,
> the problem is vibration generated by motor and propellers.
> I read in a new dissertation  that a 3 th. order  IFR filter with 50 Hz
> for the raw accelerations values
> before calling the ASH  can help. Currently only a first order is used.
> For the MPU6000 the range is 16g . You can set it down to 2g  an clip
> all valuse over 1.5g .
> There is in the wiki mechanic  damping with a wood box and additional
> mass to fly combustion engines.
> If you fy multirotors you can use only backstepping and no differential
> (D) of the angle.
> This will reduce noise of the motor values set point about 30%.
> Heinrich