On 03/08/2013 01:31 PM, PA3GUO wrote:
Things I learned and included in my software: - thresholds are needed to avoid the system oscillating around a target position - corrections need to be made due to overshoot (after a stop command the rotor takes time to actually stop
These are exactly the problems that can be neatly addressed with a variable speed drive rather than the classic bang-bang. If you want a fixed position, you use a control algorithm that slows the motor as it reaches it so it won't overshoot (or at least not as much) and stops at exactly the position you want.
But since you're most likely tracking a moving satellite, you can simply vary the speed of the drive to match the actual speed of the satellite and then you'll never have to stop. You'll have a small error in velocity and position but again, with the right control law those errors can be made very small.
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