Performance Evaluation of Second Order Sliding Mode Control Strategies for a Coupled Tank System

The main merit of the SMC (sliding mode controller) is low sensitive to plant parameter inequality and disturbances, which banish the necessity of perfect modeling. This paper deals with the second order sliding mode controller design for a coupled tank liquid level system using step and sinusoidal reference signals. The designed non-linear sliding mode controller are capable of tracking the desired water level under these reference signals with a high degree of accuracy. Performance of the control signal and trajectory tracking performance of sliding surface and its derivative under these input conditions are evaluated. A simulation is carried out using MATLAB to control this system for these different signals.