Design of SMC with decoupler for multi-variable coupled tank process

This paper presents sliding mode controller design based on decoupling approach for multivariable process. The performance of proposed controller is experimentally verified on multivariable coupled tank system. The controller and decoupler are designed from process model obtained from fundamentals and experimental step response data. SMC is designed using linear sliding surface and stability of the system can be approximately analyzed via Lyapunov function method. A process decoupled through decouplers consisting higher order elements represented in the form of first-order-plus-dead-time (FOPDT) model using model reduction method. The closed-loop system performance and robustness is verified using Matlab/Simulink and NI DAQ card interface with multi-variable coupled tank process. Thus the proposed method is effective despite the effect of exogenous disturbance.