Fix inaccurate velocity set-point transformation in FlightTaskOffboard

[junwoo091400]

Describe problem solved by this pull request
Previous code 'assumed' that the craft is parallel to the ground(pitch / roll = 0), when transforming velocity set-point from body-frame to local-frame(NED) for Offboard velocity setpoint control in Body-Frame. Thus, in most cases, if this was used, previously, velocity set-point was over-calculated(because of neglecting pitch / roll).

Describe your solution
By taking into account the craft's 'attitude', Rotation matrix will transform the Velocity set-point, if it is needed, i.e. if(_sub_triplet_setpoint.get().current.velocity_frame == position_setpoint_s::VELOCITY_FRAME_BODY_NED) && (velocity_ctrl_xy || velocity_ctrl_z)

Describe possible alternatives
This is a pretty simple logic issue. So I guess there is no 'alternative'?

Test data / coverage
Not tested :(.

Additional context

• origin of discussion : Handle velocity frames correctly for rover offboard velocity control #13363 comment section.

• I thought about the best way to implement this, as this calculation isn't always needed, so I finally settled on creating a local variable vel_setpoint_local, and perform the calculation only if the setpoint frame is VELOCITY_FRAME_BODY_NED. Also, because the velocity setpoints can be 'invalid', I also took that into account, basically Zero-ing the values(Velocity), if it's not valid.

Any inputs / feedbacks are welcome! I'm a newbie in PX4, so I definitely want to learn from more experienced developers :)

[Jaeyoung-Lim]

@junwoo091400 Pleas test this as it is used in a lot of vehicles

[junwoo091400]

@Jaeyoung-Lim Will do! Just need to buy some propellers..😂😅

[Jaeyoung-Lim]

@junwoo091400 Are you planning to test offboard on real hardware? A quick test can be done through SITL

[junwoo091400]

@Jaeyoung-Lim Oops, Will try that first thing in the morning!!

[junwoo091400]

@Jaeyoung-Lim Currently having some problems setting up SITL on Ubuntu on top of Windows (WSL). jMAVSim didn't work, due to it being 'mounted' on WSL. Trying Gazebo :(

[stale]

This issue has been automatically marked as stale because it has not had recent activity. Thank you for your contributions.

[Jaeyoung-Lim]

@junwoo091400 Any updates?

[stale]

This issue has been automatically marked as stale because it has not had recent activity. Thank you for your contributions.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. Thank you for your contributions.

[junwoo091400]

Closing as FlightTaskOffboard is now not present