SimpleBGC control over MAVlink is very slow
  • I have setup a pixhawk running latest ArduPilot to send gimbal control commands over MAVlink. When I send commands the gimbal moves accurately but it is very slow compared to when I use the Simple BGC scripts to point the gimbal. I tried modifying the operation speeds of Yaw and Pitch in the RC Settings tab but there was no effect. It also looks like the mavlink commands only allow you to pass pitch, yaw, and roll angles and no speed. Is there any way for me to make this faster? ArduPilot also supports talking over the Alexmos protocol and that allows me to set speeds in addition to the desired angles, but I am not sure if my Simple BGC gimbal supports the Alexmos protocol.

    Any help on this would be appreciated.
  • Hello! Are you using ardupilot or PX4? It sounds like px4, cuz i had the same issue with it being slow. If not and u are using ardupilot, then what settings are you using? And are u using MP or QGC?
  • We are using Ardupilot and set the following settings:
    MNT_TYPE to 4 / “Mount Type (None, Servo or MavLink)”
    SERIAL2_PROTOCOL to 1 / “MavLink” (Notee “SERIAL2” should be “SERIAL1” if using Telem1 port, SERIAL4 if using Serial4/5, etc)
    SR2_EXTRA1 to 20
    SR2_POSITION to 10
    SR2_RC_CHAN to 20 and all other SR2_* variables to 0.

    Looking at the Ardupilot source code, it is talking Mavlink between Pixhawk and SimpleBGC. The mavlink protocol being used doesn't have the commands that let you set angular rate. In the ardupilot source, if I set the MNT_TYPE to 3 then it will use the Alexmos serial protocol, but I am not sure if my simple BGC supports that protocol.
  • Hello!
    The parameter that is responsible for the speed of movement, is "RC settings" - "Speed". If Ardupilot sends command COMMAND_LONG / DO_MOUNT_CONTROL in angle mode, speed from RC settings should be used and should have an effect, so I wonder why it does not.
  • One thing I have noticed is that it is actually slowing down when it gets to the set point that we send over mavlink. Is there some sort of smoothing function that we should turn off? Is the stabilization PID controller being used in this situation so we need to retune things?