Single axis gimbal setup using encoder
  • Hi,

    I would like to setup a single axis gimbal using an iPower GBM8017-120T motor and an AS5048A encoder over PWM.
    I'm basically trying to make a turntable with the axis of the motor in a vertical orientation.
    Is it possible to set up a position control PID loop using just motor and encoder and no IMU and then to command the angle over the serial API?
    If so can any of the motor channels (RPY) be used to do this?

    Thanks in advance,
  • Hello,

    No, feedback from an encoder is not supported. You always need IMU to make the SimpleBGC32 system working.

    What you are talking is "servo drive" mode over speed or position, that is implemented in most of industry BLDC controllers, but not in our system that is dedicated for a gimbals only.
  • Hi Alexmos,

    Thanks for the quick reply!
    In the CAN driver manual there are a few mentions of a 'servo mode' using the encoders as feedback.
    It sounds like this is what I'm looking for. Would this do what I need or has it been implemented in the firmware yet?
    If not could you recommend a good alternative BLDC servo controller?

    Thanks in advance,
  • Hi AOPEN3434,

    Thanks for the suggestion. I'm not sure if it's right for my application though unfortunately.

    Here's a better description of my setup:
    I want to make an experimental rig which can orient a test item (approx. 2kg) in 3D space, so it is basically a 3-axis gimbal. I also want to have continuous rotation in all three axes so I have sliprings setup on all motors. I have already started to build the frame and have purchased the motors: iPower GBM8017-120T gimbal motors. I was hoping to use the simpleBGC with the separate CAN controller boards on each axis and with encoders on each motor. I just want to command the angle of each motor without any stabilisation or IMU feedback as the frame will always be fixed in place. I could probably still achieve this using the IMU and with the stabilisation contoller running. It would be cleaner however if the IMU could be removed from the loop completely and just the encoders on the motors used. This is the 'servo mode' that is mentioned in the CAN controller reference manual. My question is whether that has been implemented in the firmware of the CAN controllers and whether I can access any API to command them through either the CAN interface or the main SBGC controller board?

    Thanks in advance,