Contouring accuracy improvement of a piezo-actuated micro motion stage based on fuzzy cerebellar model articulation controller

The motion accuracy and performance of piezoelectric actuators (PEA) are hampered by their inherent hysteresis nonlinearity and time-varying parameters. In order to overcome these drawbacks, an integrated motion control scheme is developed in this paper. In the proposed controller scheme, for each axis of the micro motion stage, a fuzzy CMAC feedforward controller combined with a conventional proportional-integral (PI) feedback controller and a critic-based learning mechanism (FCMAC-CLM) is used to improve the tracking performance and deal with the adverse effects due to hysteresis nonlinearity and external disturbance. In addition, one of the most important issues in the contour following tasks performed by a dual-axis micro motion stage is the contour error reduction. In order to improve the contouring accuracy, a fuzzy CMAC that is capable of real-time learning and self-adjusting is exploited to develop a fuzzy CMAC cross-coupled controller (FCMAC-CCC). Several experiments have been conducted to evaluate the tracking performance and contour accuracy of the proposed approach.