Second order sliding mode control for a class of MIMO uncertain nonlinear systems with application to a quadruple-tank process

Abstract

This paper is concerned with the second order sliding mode (SOSM) control design for a class of multi-inputmulti-output(MIMO) uncertain nonlinear systems.The design objectives of the controller are to stabilise the coupled MIMO systems and asymptotically tracking a specified trajectory. The MIMO system is decomposed into some subsystems and the cross-coupling effects between subsystems are considered as system uncertainty. In order to ensure the robustness properties with respect to system uncertainties and external disturbances, sliding mode technique with a proportional integral (PI) sliding surface is adopted. The proposed controller ensures the closed loop stability, as shown by using the Lyapunov stability theorem. The performance of the control strategy is evaluated by applying to a two degree-of-freedom (DOF) quadruple-tank model with cross-coupled dynamics. Simulation results verify the effectiveness of the proposed control algorithm despite the perturbations. Copyright © 2014 SoftMotor Ltd.