A practical application of sliding mode control in the motion control of a high precision piezoelectric motor

This paper proposes a practical implementation of sliding mode control (SMC) that utilizes partial modeling compensation. Sliding mode control is well known for its effectiveness as a model free control approach; however, its effectiveness is degraded if there is a constraint on the control gain or limitation on the switching frequency in digital implementation. This is especially the case with systems that involve static friction. This approach aims to enhance the effectiveness of SMC by partial model compensation. Rigorous stability proofs are presented to validate the approach. In addition, experiments are carried out on a piezoelectric motor driven linear stage and the control approach is compared with the discrete-time integral sliding mode (DTISMC) approach proposed by Xu and Abidi as well as conventional PI control. The results show that the proposed control approach has a superior performance in comparison to the other approaches tested.