Control Design - PID and Topic Publishing
I am using 2 phidgets high current motor controllers to operate 4-12VDC motors, using the joy package to interpret my saitek av8ter joystick, with axis scaling for velocity control. With the rxgraph depicting the joy node publishing to a teleop node publishing to a move node, thus commanding the phidget HC controller to move the desired motors with the desired velocity. The callback for the teleop node, that publishes to the move node, listens to the joy topic, interprets the axis change, scales and publishes to the move topic. What I am seeing is a humming of the 12VDC motors during the initial motion of the joystick in the desired direction until a proper velocity to rotate the motor in a sufficient manner.
Has anyone experienced this type of behavior with their VDC motors? Should I not be continuously publishing or subscribing to the topic responsible for velocity changes? Is this even considered a problem?
You should only need to publish when you see a change from the joystick. Probably it's sending some command that is just enough to energise the motors (and thus make them hum) but not enough to overcome the initial inertia
Exactly. Thank you for the confirmation. An additional question is if the continual hum would cause any degradation of the motors in the long term.