ABSTRACT
The quadruple tank plant (QTP) is one of the examples of multivariable plant whose level control is major concern in process industries. The plant has multiple inputs and multiple outputs (MIMO) with complicated interactions among the control variables, inputs, and outputs. Hence, the processes are very difficult to control at desired reference due to the presence of these interactions. In this chapter, sliding mode controller (SMC) is designed for a quadruple tank process in the presence of matched uncertainty and disturbances acting on it. Particularly, two different approaches are explored for designing the SMC-based level controllers with (i) exponential reaching law and (ii) nonswitching reaching law. The sufficient condition for closed-loop stability is derived for both the approaches using Lyapunov function. The efficacy and effectiveness of the derived control algorithms using two different approaches are compared by simulation in the presence of matched uncertainties. It is inferred from the simulation results that the control algorithm derived using nonswitching reaching law is more robust than exponential reaching law as it improves the performance of the system and increases the efficiency of the pumps.
