How to interpret the Accelerator raw data in HDL-32E?
Hi, We have a Velodyne Lidar (HDL-32E)(equipped with IMU) that I am trying to start with it. we have gathered UDP positioning packet(port 8308) which includes gyroscope, accelerometer and temperature measurements. I have a few questions:
1- Should all gyro measurements be negative? (mine are)
2- We get 6 accelerometer measurements (ACC1x, ACC1y, ACC2x, ACC2y, ACC3x, ACC3y). I expected to have 3 acceleration measures. How can I get these 6 to 3 x-y-z accelerations?
3- We get 3 temperature measures? why 3? do they differ?
I really appreciate your help.
I have no access to that device and no experience with it. Maybe others can help.
Appendix B in the 32E manual does have some diagrams and hints: http://velodynelidar.com/lidar/products/manual/63-9113%20HDL-32E%20manual_Rev%20E_NOV2012.pdf .
I have the same question 2, how can I get the 3 x-y-z accelerations from these 6 measurements? You already figured it out?
In order to get the orientation and accelerations out of these 6 measurements, you should use some IMU algorithm. For example this: http://dx.doi.org/10.1155/2015/503814 and it has source code available here: https://github.com/hhyyti/dcm-imu
Note: there is now an experimental
velodyne_gps_imu
package in github. It's currently in thegps_imu
branch, not yet merged intomaster
. Anyone who tries it, please comment on pull request #53