I’m reaching out for some help regarding speed commands. I recently tested a mission with my quadcopter (Takeoff → 4 Waypoints → RTL) which included three MAV_CMD_DO_CHANGE_SPEED commands.
While the mission was completed successfully, it seems my speed changes were completely ignored. The drone maintained the default WPNAV_SPEED for horizontal travel, and WPNAV_SPEED_DN / UP for vertical movements throughout the entire flight.
I tried all three speed types (Airspeed, Groundspeed, and Throttle) but none had any effect.
Since I cannot share my full logs, here is a snippet of the mission commands I used:
in copter param 0 and 1 are the same, referring to groundspeed.
Note: The actual horizontal and vertical speed also depends on the distance vertically and horizontally between the two waypoints. So if you have to descent from 11 meters to 6 meters the maximum vertical speed will limit the horizontal speed. The vehicle will always do a trajectory where it reaches the vertical position at the same time as the horizontal.
Thanks for the replies. I will try setting the Speed Type to both 0 and 1 to see if it triggers the horizontal speed change.
However, my concern is also that the climb/descent speed commands were also completely ignored. Despite setting a DO_CHANGE_SPEED for vertical movements at 0.5 m/s, the drone maintained the default WPNAV_SPEED_DN and WPNAV_SPEED_UP values (2 m/s) throughout the mission.
I am aware that the autopilot might throttle down speed when waypoints are close together to manage cornering, but in this case, the distances were more than sufficient to reach the target velocity. It seems the command is being bypassed entirely.
For horizontal speed, we tried with speed type to 1 and it took effect but still not with 0. Seems that 0 is simply ignored ! Bad observations were made during 1st flight for climb and descent speed types, changes were taken into account during 2nd flight …
So conclusion is that XY speed is speed Type =1 , climb = 2 and descent =3.
