Design of robust position servo of synchronous motors using sliding mode control

The authors present a design method for a position servo system for synchronous motors with permanent magnet excitation by using sliding mode control. They aim to find a controller so that precise position control with desired fast response is achieved in the presence of variations of system parameters and external disturbances. It is known that synchronous motors exhibit highly coupled nonlinear multivariable control structure, which make it difficult to design a servo system with high dynamic performance. The nonlinearity comes from the nonlinear interaction between the currents of the d and q axes. The authors propose a method of designing a robust position servo system by decoupling the nonlinear interaction between the d and q axes with the use of sliding mode control. The authors implemented the control scheme into a simple model of a single link manipulator with the synchronous motor. The performance of the control scheme is verified experimentally