Model-Free Adaptive Time-Delay-Based Estimation Control for Input-Saturated Coupled Tank System: Experimental Validation

Coupled tank systems are widely employed in various industries, including wastewater treatment, water desalination, pharmaceuticals, and petrochemicals. Precise liquid level regulation is a critical challenge in these applications, especially under system uncertainty and disturbance. This paper introduces a novel model-free, robust adaptive time delay-based estimation control to address this challenge, with disturbances and input saturation. The proposed controller employs a time delay-based estimation technique to estimate unknown system dynamics using the immediate past input and output data. This estimated information is then integrated into a composite control scheme to compensate for unknown dynamics and disturbances. A new adaptive-based proportional controller is proposed, which avoids overestimating the adaptive gains. The closed-loop analysis through Lyapunov theory guarantees uniformly ultimately boundedness of all the internal states. Experimental results validate the better performance of the proposed controller compared to existing schemes under different operating conditions.