Performance Improvement of Servo Drives with Mechanical Elasticity via Extended Acceleration Feedback

In this paper, the application of acceleration feedback technique for improving the performance of an industrial servo drive whose velocity loop bandwidth is limited by torsional oscillations, caused by mechanical resonance, is considered. Acceleration feedback works by effectively increasing the moment of inertia of the motor, thereby reducing the drive's sensitivity to mechanical resonance. The performance improvement achievable with this technique is limited due to the presence of dead time in the system. An extended version of this technique, using loop shaping techniques is proposed. It is shown experimentally that the extended version is superior to the original version in terms of achievable performance.