Design and implementation of resilient controllers for uncertain quadruple tank systems: A nonlinear approach

A quadruple tank system using a new anti-disturbance technique called Modified Active Disturbance Rejection Control (MADRC) is introduced in this paper, along with a detailed examination of its design and hardware (H/W) implementation. To maintain the water levels in the quadruple system at predefined targets while minimizing the impact of external disturbances, the proposed scheme employs two advanced nonlinear controllers, enhanced tracking differentiator schemes, and newly developed nonlinear extended state observers (NNLESO). The proposed modified ADRC method outperforms the alternatives, according to the experimental data. With an improved ability to reject disturbances, the STC-ADRC approach reduced the output response oscillation to 3.33% of the equilibrium value. The NLPD-ADRC method, on the other hand, effectively managed system dynamics under disturbance conditions, as evidenced by a 4.666% oscillation. Additionally, disturbances had a significant impact on the S-fal-ADRC scheme, highlighting how distinct the proposed control mechanisms were in terms of performance. This work represents a significant advancement in the control of interconnected non-linear quadruple tank systems and proves that the MADRC method is effective in enhancing system stability and disturbance attenuation.