Inquiry about Zed 2i ROS Wrapper: Velocity Parameters for Object Detection

Question

Hello Robot Stack Exchange community,

I am currently working with the Stereolabs Zed 2i camera and its ROS wrapper for object detection. I have been exploring the codebase on GitHub and reviewing the documentation on the official website, but I haven't been able to find information on configuring the velocity parameters for object detection.

Specifically, I am interested in understanding which parameter(s) in the Zed 2i ROS wrapper are responsible for providing the velocity of detected objects. I would like to know if there is a way to configure whether the velocity is reported relative to the camera coordinate system or in the above-ground frame. If there is none I also would like to know if I receive the speed relative to the camera or above ground.

I appreciate any insights or guidance on this matter. Thank you!

Answer 1

the reply to your question is implicitly contained in the detected object message. As you can see in the code, the objects message is in camera coordinates: https://github.com/stereolabs/zed-ros2-wrapper/blob/master/zed_components/src/zed_camera/src/zed_camera_component.cpp#L7141

The ZED SDK allows you to change this behavior by setting the value of the parameter RuntimeParameters::measure3D_reference_frame to sl::REFERENCE_FRAME::WORLD instead of sl::REFERENCE_FRAME::CAMERA, but the ROS 2 Wrapper does not allow to select this option.