Intel D435i IMU data issue

[PeterW]

I'm running Melodic on a Jetson Xavier AGX with an Intel D435i camera Ubuntu 18.04. I am able to run everything as normal, record video, extract point clouds etc. but when I record the session with rosbag there is no IMU data present in the .bag file. I believe from the rqt_graph that it's using visual odometer and not the IMU data for the point clouds. I get the following warning when starting RTabMap.

[ WARN] [1613534649.165041152]: Warning: Some linear velocity entries in parameter imu0_config are listed true, but an sensor_msgs/Imu contains no information about linear velocities

I use this command to record the data with rosbag.

rosbag record -O my_bagfile_1.bag /camera/aligned_depth_to_lor/camera_info  camera/aligned_depth_to_color/image_raw /camera/color/camera_info /camera/color/image_raw /camera/imu /camera/imu_info /tf_static

I've been trying to figure out why it doesn't seem to find the IMU data and I'm a bit stuck. Does anyone have any ideas?

I've run the camera with Intel's SDK and it does find the IMU and it also shows it in real time moving and the values so I know the IMU is working in the camera. Is there maybe someway to verify that RTabMap is actually getting the IMU data from the camera?

[ryleymcc]

I got the same camera so I might be able to help. I think maybe you misunderstand the d435i does not offer 6dof. It's only 3dof for orientation. You need the t265 for 6dof.

[PeterW]

Thank you for your response!
We have the D435i camera which does have the built in imu. The d435 camera does not have the built in imu. Per the intel's datasheet the D435i does have a 6dof imu, so our problem still exists.

[ryleymcc]

Ah, it looks like you are right but i don't see any way to get a good pose without running hardware intensive slam(which is what rtabmap is). Take a look at this post.

Also here is a sc of intels' website


Since intel has not made it easily accessible, I assume there is a reason. Might be so they can sell the rest of the t265 or they are leaving room for a new product that include the t265 localization algo with D series cameras? But for $200 you can buy the t265 and get a very accurate and easy to use 6dof with localization.

[matlabbe]

Based on the startup example here, if you enabled "unite_imu_method" to "linear_interpolation", try with "copy" instead (on my computer with "linear_interpolation", sometimes imu topic is not published):

# ISSUE: Use unite_imu_method:="copy" if imu topics keep stopping
$ roslaunch realsense2_camera rs_camera.launch \
   align_depth:=true \
   unite_imu_method:="copy" \
   enable_gyro:=true \
   enable_accel:=true

# with unite_imu_method:="copy"
$ rostopic hz /camera/imu
subscribed to [/camera/imu]
average rate: 399.385
	min: 0.001s max: 0.004s std dev: 0.00038s window: 380

# with unite_imu_method:="linear_interpolation"
$ rostopic hz /camera/imu
subscribed to [/camera/imu]
average rate: 370.507
	min: 0.000s max: 0.012s std dev: 0.00204s window: 174
no new messages
no new messages
no new messages
average rate: 37.700
	min: 0.000s max: 4.262s std dev: 0.31146s window: 187
average rate: 35.511
	min: 0.000s max: 4.262s std dev: 0.29399s window: 21