Design of continuous sliding mode controller for BLDD motor with prescribed tracking performance

A continuous, accurate and robust sliding-mode tracking controller with a disturbance observer is presented for a brushless direct drive servo motor (BLDDSM). Although the conventional sliding-mode control (SMC) can give the desired tracking performance, there is an inevitable chattering problem which is harmful to a direct drive system. The continuous SMC can be obtained by the efficient compensation of the disturbance observer. The proposed sliding mode control with bounded stability is theoretically investigated in detail. The design of the sliding mode tracking controller for the prescribed accurate and robust tracking performance without the chattering problem is possible using the results of a detailed stability analysis. The prescribed tracking performance and the robustness of the proposed algorithm are demonstrated through the computer simulations for a BLDDSM under load variations and parameter uncertainties