KumarRobotics/imu_vn_100

can not obtain high freuqnecy

Closed this issue · 6 comments

At first when i use the driver, if i set hz rate to be 400. it will be close
but after using like 1 month. if i set 400 now, the rate is only 100 to 300 only.
why this could happen?

I've added a possible reason for this in the FAQ: https://github.com/KumarRobotics/imu_vn_100#faq
Can you try it and see if it works for you?

Yes thats the issue. b4 if target is 400, it was like 150- 250. now if 400, its 380 to 390. is there any possible way to increase it to 400? or make it less oscillate

We've never gotten it to work at full 400Hz either, we get around 380-390Hz maximum. For our purpose, we run it at 200Hz and it works perfectly.

But i 'm really interested to know why my pc initially can get exact 400 hz. Thanks for the help. now i understand why my visual inertial navigation might drift. So it is all because of the kernel delay for FDTI cable

Don't know how you got it to work at 400Hz before, so can't help you there.
For the VIO algorithm I think that 200Hz (or maybe even 100Hz) IMU data would be sufficient, you don't really need to run the IMU at 400Hz.

Ok it is ture. 400 hz is only for those fast moving UAVs. for small MAV 200 hz is fine. Thanks