UM7 accel drift
I am experiencing some odd behavior with my CH Robotics UM7 IMU that I recently purhcased. When the unit is just sitting on the table, it reads 9.2 instead of 9.8 m/s/s for acceleration. I can find instructions on how to zero the rate gyros but nowhere does it mention calibrating the accelerometers. Has anyone run into something similar before with these IMUs or any other unit? I have included an example message
header:
seq: 3506
stamp:
secs: 1450136355
nsecs: 252817294
frame_id: imu_link
orientation:
x: -0.0238677723
y: 0.0203094265
z: -0.9840840295
w: -0.1747282065
orientation_covariance: [0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0]
angular_velocity:
x: -0.000581685356641
y: -0.000610669209776
z: 7.07960511619e-05
angular_velocity_covariance: [0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0]
linear_acceleration:
x: -0.0682945557769
y: 0.22608049971
z: 9.21032193719
linear_acceleration_covariance: [0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0]
Hey, did you ever end up figuring out how to fix this problem? I'm getting a similar error with my new UM7, where my z-acceleration is hovering at around 10 m/s^2 when resting. My UM7 is running firmware version U72A.
Yes I did. The UM7 (and all accelerometers) are very sensitive to mechanical strain, temperature and a variety of other factors. As such, you need to calibrate the accelerometer fairly frequently. I would suggest the CH Robotics utility to do this