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PX4 / PX4-Autopilot

PX4 Autopilot Software
https://px4.io
BSD 3-Clause "New" or "Revised" License
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odom.twist.linear is in body frame #7322

Closed marcelinomalmeidan closed 7 years ago

marcelinomalmeidan commented 7 years ago

I am not sure if this is an issue, but I couldn't find a reason for this to be. The message that I get in Mavros for local odometry has linear position expressed in (local) world frame, while linear velocity is expressed in body frame. Is there a reason for this to be? It would be more intuitive to me if linear velocity was expressed in some inertial frame, instead of body frame.

mhkabir commented 7 years ago

As far as I remember, it's a ROS standard. PX4 sends the data in the inertial frame. You should check the mavros transforms.

Please reopen on mavros side if desired.

marcelinomalmeidan commented 7 years ago

@mhkabir, you are right! According with odom documentation, this is how it is supposed to be:

_This represents an estimate of a position and velocity in free space.
The pose in this message should be specified in the coordinate frame given by header.frame_id. The twist in this message should be specified in the coordinate frame given by the child_frameid Header header string child_frame_id geometry_msgs/PoseWithCovariance pose geometry_msgs/TwistWithCovariance twist

Thanks for pointing that out!