A novel tuning approach with SSR algorithm for non-minimum phase system

Cascade control is extensively used in process industries. The enhanced performance of cascade control depends on the effective tuning. However, after encountering the non-minimum phase zeros in the system, the tuning of cascade control becomes complex. This work proposes a modified Bode’s ideal transfer function for tuning fractional filter. This modification is completed after consideration of non-minimum phase zeros in Bode’s ideal transfer function approach. This modified tuning approach elucidated the common pitfalls in the existing techniques. Here, the internal model control (IMC) context is utilized to construct the outer loop controller of the series cascade scheme after embedding the fractional filter and inverse response compensator. Moreover, a rudimentary structure of the IMC scheme is revealed for the inner loop controller design. The suggested way enhances the non-minimum phase system performance without compromising setpoint tracking and disturbance rejection. Additionally, the Riemann sheet principle is utilized for the stability analysis. Sensitivity analysis is carried out to adjudge the robustness. The search space reduction algorithm is employed to optimize the closed-loop response utilizing an objective function that minimizes the integral of square error. Two case studies are utilized for effectuating the benefits of the suggested control approach associated with state-of-the-art.