A New Discrete-time Super Twisting Control of a First Order Plant with Input Saturation

Many real dynamical processes in control engineering practice can be modelled as a first order plant with saturation at its input. This paper proposes a new solution to control such plants, which is a combination of discrete-time first-order sliding mode (SM) control and discrete-time realization of super twisting control algorithm (STA) that is commonly used in second-order SM. A brief mathematical foundation of the proposed controller is given and then demonstrated in induction motor (IM) speed control as an example. A comparative study between conventional PI controller, discretized original STA and the proposed combined STA in tracking of various speed references under action of disturbances. Simulation and experimental results confirm that the proposed simply designed controller provides high quality performance.