Two-degree-of-freedom controller incorporating RBF adaptation for precision motion control applications

Abstract

This paper presents a robust servo control method for linear motor systems, based on a composite of two-degree-of-freedom (DOF) control theory and nonlinear adaptive control using a Radial Basis Function (RBF). This controller consists of a simple feedforward compensator, a PD+D2 feedback control, and the RBF adaptive compensator. The proposed method can determine the control parameters for both the feedforward and PD+D2 feedback control based on only an estimated dominant second-order model. The RBF compensator is a form of self-tuning control which compensate for remaining uncertainties in the system, residual of the linear model. Rigid proofs are provided guaranteeing the robustness of the proposed controller. Simulation results confirm the much superior performance of the proposed control over a conventional feed-forward plus feedback control.