Simulation of Direct Model Reference Adaptive Control on a Coupled-Tank System using Nonlinear Plant Model

This paper presents the application of direct model reference adaptive control (DMRAC) on a nonlinear model of coupled-tank liquid level control system through simulation. The coupled-tank liquid level control system is regarded as the relevant plant to emulate the process control in petrol and chemical industries. The processing plants in these industries largely involve in controlling the liquid level and the flow rate from one reservoir to another in the presence of nonlinearity and disturbance. This requires the use of adaptive techniques such as DMRAC in the process control system. Coupled-tank which resembles the model of the chemical or mixing process plant is used to evaluate the performance of DMRAC under various conditions. A simulation is carried out using MATLAB® and Simulink® to control the modeled nonlinear coupled-tank using the adaptive control algorithm. It is also utilised to show that the controller can produce the appropriate control signals to the coupled-tank system to control the liquid level in the presence of plant nonlinearity, disturbance and measurement noise.