Stretch 3 Gripper Camera Transform Issue

Hi Hello Robot,

We are finding that on our Stretch 3, the camera depth frame:

overlaps with the gripper camera depth frame:

Not sure why that is. We are currently trying to get the correct transform for the gripper camera and it seems that there may not be a transform for it.


Hi @jehan, thanks for reporting this. We’re going to see if we can reproduce this and get back to you with a fix.

Hi @jehan, fyi, we have recently made a few updates to Stretch URDF and Stretch ROS2 to support the new gripper camera which should resolve the issue you are facing. I am unsure of which version you are using. Therefore as the first step I would recommend you to update your Stretch URDF package and pull the latest changes in Stretch ROS2 package in ~/ament_ws/src/stretch_ros2.

pip3 install -U hello-robot-stretch-urdf --ros2_rebuild

Hi @Mohamed_Fazil, unfortunately we weren’t able to fix this issue by updating. I also created a new user to test by installing a new ament_ws from scratch, and this issue wasn’t resolved either.

The gripper camera frames still are aligned with the head camera frame rather than around the gripper.

HI @jehan,
It looks like the frame gripper_camera_link might not be present in the utilized stretch.urdf. Could you verify your Tf tree and check if that link is present? The final Tf tree must look like the one I have attached where you will find the link chain link_gripper_s3gripper_camera_bottom_Screwgripper_camera_link.
frames_2024-06-24_12.31.19.pdf (25.1 KB)

You can examine the file ~/ament_ws/src/stretch_ros2/stretch_description/urdf/stretch.urdf and also make sure that the same URDF file is located at the Install directory ~/ament_ws/install/stretch_description/share/stretch_description/urdf/stretch.urdf.
If the gripper camera link is not present in the way I described above, there was likely an issue updating your URDF.
Could you repeat the steps bellow and again check if stretch.urdf file in the two places are updated

pip3 install -U hello-robot-stretch-urdf --ros2_rebuild

It turns out that the issue seems to stem from the use of ros2 launch stretch_web_teleop rather than ros2 launch stretch_core

Not sure why, but it seems like the stretch_web_teleop package might a bug in the urdf specification.

@jehan Glad you found an intermediate fix. I have filed an issue in the Stretch Web Teleop repository which will be handled soon. Thank you for reporting this issue.