On adaptive robust backstepping control schemes suitable for PM synchronous motors

This paper presents new adaptive robust control strategies suitable for permanent magnet (PM) synchronous motors. By using the backstepping approach, both the adaptive and robust controllers are appropriately designed to ensure global stability. Taking into account the variation ranges of system parameters, the adaptive robust methods are further developed to achieve better tracking performance. It is shown that the synthesized adaptive robust control schemes developed here can retain advantages of both adaptive and robust control schemes and overcome their shortcomings. To avoid discontinuous control laws which may cause problems in both theoretical and practical aspects, a continuous adaptive robust control method associated with a mu - modification scheme is also proposed to guarantee both the uniform boundedness of the system and suitably designated tracking precision. The paper includes simulation studies demonstrating the performance of the proposed control schemes.