Sliding mode control with switching command devices

In this chapter this second type of variable structure control system is described, beginning with scalar control systems. The basic structure, the sliding conditions and the state equations in the sliding mode will be considered. The pole assignment method will be used to design the switching strategy. Afterwards the sliding mode domain and the switching frequency will be studied. These theoretical considerations will be illustrated with a practical example, the position control of a DC drive. Next, for multivariable systems, the sliding mode conditions, the design of the multivariable switching strategy with a pole assignment method and robustness, i.e. invariance properties with regard to parameter variations, will be described.