A globally stable high performance adaptive robust control algorithm with input saturation for precision motion control of linear motor drive system

This paper focuses on the synthesis of nonlinear adaptive robust controller with saturated actuator authority for a linear motor drive system, which is subject to parametric uncertainties, unmodeled nonlinearities and input disturbances as well. Global stability is achieved by breaking down the overall uncertainties to state-linearly-dependent uncertainties (such as viscous friction) and bounded nonlinearities (such as coulomb friction, cogging force and etc.) and treating them with different strategies. Furthermore, a guaranteed transient performance and final tracking accuracy can be obtained by incorporating the well-developed adaptive robust controller and effective parameter identifier. Asymptotic output tracking is also achievable in the presence of parametric uncertainties only. Meanwhile, the choice of design parameters is easier to make with the controller designed based on the original states which have physical meanings than the existing control structure with saturation designed in a transformed coordinate