Broken ros convention with velocities in body frame

[BRNKR]

Hey,

i think there is a problem with the rotation of the velocity in the setpoint_raw plugin if you specify a velocity in the body frame the movement is different to the setpoint_velocity plugin.

Example:
velocity setpoint in body frame = [2, 0, 0]
x points to the front, y points to the left and z points to the top (ROS convention for base_link).

setpoint_raw flies to the right.
setpoint_velocity flies forward correctly.

i know that for both plugins the body frame "BODY_NED" is defined. but both of them are not NED. a little bit confusing.

[tomasgareau]

We're also confused by this convention... It seems like setpoint raw is using RFU rather than FLU for velocity commands in the body frame.

This also seems to have been alluded to in another issue: #792 (comment) but I don't think any action was taken at that time.