ROS Answers: Open Source Q&A Forum - RSS feedhttps://answers.ros.org/questions/Open source question and answer forum written in Python and DjangoenROS Answers is licensed under Creative Commons Attribution 3.0Fri, 04 Dec 2015 14:48:14 -0600How to interpret the Accelerator raw data in HDL-32E?https://answers.ros.org/question/94421/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.
Fri, 25 Oct 2013 09:16:45 -0500https://answers.ros.org/question/94421/how-to-interpret-the-accelerator-raw-data-in-hdl-32e/Comment by joq for <p>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:</p>
<p>1- Should all gyro measurements be negative? (mine are)</p>
<p>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?</p>
<p>3- We get 3 temperature measures? why 3? do they differ?</p>
<p>I really appreciate your help.</p>
https://answers.ros.org/question/94421/how-to-interpret-the-accelerator-raw-data-in-hdl-32e/?comment=94461#post-id-94461Appendix 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 .Fri, 25 Oct 2013 12:52:54 -0500https://answers.ros.org/question/94421/how-to-interpret-the-accelerator-raw-data-in-hdl-32e/?comment=94461#post-id-94461Comment by Michiel for <p>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:</p>
<p>1- Should all gyro measurements be negative? (mine are)</p>
<p>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?</p>
<p>3- We get 3 temperature measures? why 3? do they differ?</p>
<p>I really appreciate your help.</p>
https://answers.ros.org/question/94421/how-to-interpret-the-accelerator-raw-data-in-hdl-32e/?comment=187993#post-id-187993I have the same question 2, how can I get the 3 x-y-z accelerations from these 6 measurements? You already figured it out?Mon, 28 Jul 2014 06:48:14 -0500https://answers.ros.org/question/94421/how-to-interpret-the-accelerator-raw-data-in-hdl-32e/?comment=187993#post-id-187993Comment by joq for <p>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:</p>
<p>1- Should all gyro measurements be negative? (mine are)</p>
<p>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?</p>
<p>3- We get 3 temperature measures? why 3? do they differ?</p>
<p>I really appreciate your help.</p>
https://answers.ros.org/question/94421/how-to-interpret-the-accelerator-raw-data-in-hdl-32e/?comment=94456#post-id-94456I have no access to that device and no experience with it. Maybe others can help.Fri, 25 Oct 2013 12:51:29 -0500https://answers.ros.org/question/94421/how-to-interpret-the-accelerator-raw-data-in-hdl-32e/?comment=94456#post-id-94456Comment by Heikki for <p>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:</p>
<p>1- Should all gyro measurements be negative? (mine are)</p>
<p>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?</p>
<p>3- We get 3 temperature measures? why 3? do they differ?</p>
<p>I really appreciate your help.</p>
https://answers.ros.org/question/94421/how-to-interpret-the-accelerator-raw-data-in-hdl-32e/?comment=221960#post-id-221960In 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](http://dx.doi.org/10.1155/2015/503814) and it has source code available here: https://github.com/hhyyti/dcm-imuFri, 04 Dec 2015 03:17:58 -0600https://answers.ros.org/question/94421/how-to-interpret-the-accelerator-raw-data-in-hdl-32e/?comment=221960#post-id-221960Comment by joq for <p>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:</p>
<p>1- Should all gyro measurements be negative? (mine are)</p>
<p>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?</p>
<p>3- We get 3 temperature measures? why 3? do they differ?</p>
<p>I really appreciate your help.</p>
https://answers.ros.org/question/94421/how-to-interpret-the-accelerator-raw-data-in-hdl-32e/?comment=221989#post-id-221989Note: 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](https://github.com/ros-drivers/velodyne/pull/53)Fri, 04 Dec 2015 14:48:14 -0600https://answers.ros.org/question/94421/how-to-interpret-the-accelerator-raw-data-in-hdl-32e/?comment=221989#post-id-221989Answer by ahendrix for <p>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:</p>
<p>1- Should all gyro measurements be negative? (mine are)</p>
<p>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?</p>
<p>3- We get 3 temperature measures? why 3? do they differ?</p>
<p>I really appreciate your help.</p>
https://answers.ros.org/question/94421/how-to-interpret-the-accelerator-raw-data-in-hdl-32e/?answer=188040#post-id-188040Figure 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.Mon, 28 Jul 2014 13:02:02 -0500https://answers.ros.org/question/94421/how-to-interpret-the-accelerator-raw-data-in-hdl-32e/?answer=188040#post-id-188040