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PX4 / px4_msgs

ROS/ROS2 messages that match the uORB messages counterparts on the PX4 Firmware
http://px4.io
BSD 3-Clause "New" or "Revised" License
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Visual Odometry #17

Closed 321thijs123 closed 1 year ago

321thijs123 commented 1 year ago

Previously I used timesync and vehicle_visual_odometry to take fly using external position estimates from a motion capture system. These topics have been removed and documentation on it has not been updated.

How can visual odometry be used now?

dagar commented 1 year ago

The topic is /fmu/in/vehicle_visual_odometry and the type is https://github.com/PX4/px4_msgs/blob/main/msg/VehicleOdometry.msg.

https://github.com/PX4/PX4-Autopilot/blob/498937c56cd1b1a676bb93fa22ee7b7bc99c69cc/src/modules/microdds_client/dds_topics.yaml#L76-L77

Things are still a bit in flux with the switch to micro XRCE DDS, but please let me know how it goes. Separately for PX4 itself we've got a number of changes slowly coming in improving EKF2 VIO. https://github.com/PX4/PX4-Autopilot/pull/19128

dagar commented 1 year ago

For the timestamp (and timestamp_sample) just use get_clock()->now() converted to microseconds. The XRCE agent (micro-ros-agent) handles the actual time sync with microdds_client in PX4.

https://github.com/PX4/px4_ros_com/blob/abc59d8381f7bc944af4c73b6c58dcc85ac5ef45/src/examples/offboard/offboard_control.cpp#L180

321thijs123 commented 1 year ago

Thanks! This answers my question