Modified Smith predictor‐based optimal fractional PD‐PD controller for double integrating processes with considerable time delay

Abstract

Modified Smith predictor (MSP)‐based fractional propotional derivative (PD)‐PD controller (FO [PD‐PD]) is presented here for controlling double integrating plus time delay (DIPTD) processes. The proposed scheme comprises of two fractional PD controllers together and a first‐order filter to ascertain satisfactory servo as well as regulatory responses. Here, forward path fractional PD controller works towards attaining improved servo response and feedback path fractional PD controller ensures enhanced load regulation. Tuning parameters of both the controllers are obtained through optimization algorithm. The first‐order filter present in the feedback path is responsible for providing improved robustness and is designed with single tuning parameter—closed‐loop time constant ( normalλ). Efficacy of the proposed MSP‐based fractional order PD‐PD controller or MSP‐FO (PD‐PD) is substantiated through simulation study, and its superiority is established in comparison with others' recent works on DIPTD processes.

Direct synthesis approach to design PDμ${\text{PD}}^\mu$ based smith predictor for integrating plants: Studied on a quadrotor UAV

“…These works obtained results with high-order classical controllers with additional filters or fractional orders. For a numerical study, recent works provided by Das et al [12], Sengupta et al [22], Kumar et al [10], Karan and Dey [37], Wang et al [38], and Papadopoulos et al [39] were taken into consideration. The indicators such as the controller energy (TV), settling time (t s in second), and ITSE index were calculated for setpoint and load disturbance.…”

“…Consider the following DIPTD model studied by Sengupta et al [22] and Karan and Dey [37] where the process is modelled as…”

“…The modified indirect fractional‐order (Fo) IMC‐PD decoupled dual‐loop control strategy was discussed by Kumar and Raja for unstable and integrating plant types [20]. Again, a modified Fo‐IMC and tilt controller [21] and a FoPD‐PD scheme [22] were proposed for double integrating systems. Mondal and Dey recommended a cascaded FoPI‐PD control [23] for integrating unstable and non‐minimum phase models to fulfil the desired stability margins at the selected gain crossover frequency.…”

“…FIGURE15 20 % Perturbed system responses for Example-2, (a) proposed, (b) Sengupta et al[22], (c) Karan and Dey[37].…”

An improved anti‐interference predictive PI for first order plus dead time processes

“…Karan and Dey and Sengupta et al combined PD controller with Smith to control second order time delay systems and achieved a better control effect. [8,9] Rao et al proposed an improved Smith scheme for the first order plus dead time (FOPDT) process. [10] This paper proposes an improved predictive PI algorithm (IPPI) for large inertia time lag systems.…”