Inversion-free feed-forward and feedback control of MSM based actuator with large non-smooth input hysteresis

TL;DR

This paper develops an inversion-free control method for MSM actuators with large non-smooth hysteresis, combining a novel feedforward compensator and robust feedback to enhance position control despite noise and system uncertainties.

Contribution

It introduces an inversion-free hysteresis compensator adapted for the Krasnoselskii-Pokrovskii model and demonstrates improved control performance through combined feedforward and feedback strategies.

Findings

Enhanced position control accuracy with combined feedforward and feedback.

Effective hysteresis compensation without inversion in complex MSM systems.

Robust control performance under noisy sensing conditions.

Abstract

Dynamic systems with a large and non-smooth hysteresis in the feedforward channel challenge the design of feedback control since the instantaneous input gain is varying during the operation, in the worst case between zero and infinity. Magnetic shape memory (MSM) actuators with multi-stable transitions represent such untypical system plant with only the output displacement being measured. This paper provides a case study of designing the feedforward and feedback control system for an MSM-based actuator setup with a fairly high level of the output sensing noise. First, the recently introduced inversion-free feedforward hysteresis compensator is adapted for the Krasnoselskii-Pokrovskii operator model. Then, a robust feedback proportional-integral (PI) loop shaping is performed, while taking into account the lagging behavior of the low-pass filtering and system uncertainties. Experimental results show that the parallel action of feedforward and feedback parts improves the overall performance of position control.