A discrete output feedback 2-SMC using Linear Matrix Inequalities and adaptive switching gain approaches: Real application on a chemical reactor

The chattering phenomenon is one of the most pervasive problems in sliding mode control (SMC), especially for discrete time applications. In this paper, we propose a new discrete output feedback second order sliding mode control (DOF2SMC). The design of this controller is based on the Linear Matrix Inequalities (LMI) approach. Then, an adaptive switching gain (ASG) is incorporated into the discontinuous part of the controller to obtain good closed loop performance in terms of tracking and reducing chattering in the case of systems subject to internal and external disturbances. Simulation results of a steer-by-wire (SBW) system show the effectiveness of the proposed DOF2SMC with ASG. To validate, once again, the performance of the proposed control system, an experimental validation on a transesterification reactor is presented. The obtained results show good closed loop performance.