Augmentation of Short-Span Seeking Performance Using Dynamic Saturation

We present a method for improving the short-span seeking performance of a recently proposed compensator-based control system for a dual-stage servo actuator. The method consists of replacing a constant saturation nonlinearity in the secondary loop of the dual-stage control system by a dynamic saturation nonlinearity. This results in a significantly faster response of the secondary actuator and hence faster seeking times. The improvement in seeking times is greatest for short-range seeks that are within the range of the secondary actuator. We also present experimental results comparing the performance of a dual-stage servo actuator with constant and with dynamic saturation in the secondary loop.