A revised Terminal Sliding Mode controller design for servo implementation

Terminal sliding mode (TSM) control is known for its high gain property nearby the vicinity of the equilibrium while retaining reasonably low gain elsewhere. This is desirable in digital implementation where the limited sampling frequency may incur chattering if the controller gain is overly high. In this work we integrate a linear switching surface with a terminal switching surface. The mixed switching surface can be designed according to the precision requirement. The analysis, simulations and experimental investigation show that the mixed SMC design outperforms the linear SMC as well as the pure TSMC.