ROS Resources: Documentation | Support | Discussion Forum | Index | Service Status | ros @ Robotics Stack Exchange
Ask Your Question

How to interpret the Accelerator raw data in HDL-32E?

asked 2013-10-25 09:16:45 -0500

MinaAttari gravatar image

updated 2014-01-28 17:18:21 -0500

ngrennan gravatar image

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.

edit retag flag offensive close merge delete


I have no access to that device and no experience with it. Maybe others can help.

joq gravatar image joq  ( 2013-10-25 12:51:29 -0500 )edit

Appendix B in the 32E manual does have some diagrams and hints: .

joq gravatar image joq  ( 2013-10-25 12:52:54 -0500 )edit

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?

Michiel gravatar image Michiel  ( 2014-07-28 06:48:14 -0500 )edit

In order to get the orientation and accelerations out of these 6 measurements, you should use some IMU algorithm. For example this: and it has source code available here:

Heikki gravatar image Heikki  ( 2015-12-04 03:17:58 -0500 )edit

Note: there is now an experimental velodyne_gps_imu package in github. It's currently in the gps_imu branch, not yet merged into master. Anyone who tries it, please comment on pull request #53

joq gravatar image joq  ( 2015-12-04 14:48:14 -0500 )edit

1 Answer

Sort by ยป oldest newest most voted

answered 2014-07-28 13:02:02 -0500

ahendrix gravatar image

Figure B2 on Page 18 of the manual that @joq linked shows the orientation of the accelerometers and gyros.

The manual also notes "Note: Each gyro incorporates a 2-axis accelerometer which results in redundancy in some axial directions"

From all of that, it sounds like they're using three separate gyroscopes internally, each of which probably has its own temperature sensor for calibration.

edit flag offensive delete link more

Question Tools

1 follower


Asked: 2013-10-25 09:16:45 -0500

Seen: 1,335 times

Last updated: Jul 28 '14