Simple PI and PID tuning for open-loop unstable systems

PID-Like Controller Tuning for Second-Order Unstable Dead-Time Processes

“…Table 5 presents a stability robustness comparison with other existing PID tuning methods. In particular, the tuning methods presented in Sections 4 and 5 are compared with the R&L method with λ=2.2 (Rotstein & Lewin, 1991), the P&M method (De Paor and O'Malley, 1989), the H&X method with specifications A m =1.3 and φ m =10 o (Ho & Xu, 1998), the P&P method based on the ITAE criterion (Poulin & Pomerleau, 1997) and the J&C method based on the IMC tuning rule with λ=2.5 (Jacob & Chidambaram, 1996), in the special case where d=0.5 and τ S =1. Table 5 show that the DPC method provides more robust controllers than most other methods (except the J&C method with λ=2.5, that gives a significantly slower response in both set point tracking and regulatory control).…”

A unified double-loop multi-scale control strategy for NMP integrating-unstable systems

“…[4,6] proposed an IMCbased PID tuning rules for open-loop unstable process models without time delay, whilst [7] introduced a similar tuning method for delayed unstable process. [8] developed a graphical tuning method for integrating and unstable processes with time delay based on the analysis of the open-loop frequency response of the process on the Nichols chart.…”

Pid Control of Unstable Time Delay Systems

“…However robustness studies of the controlled system for the perturbations in time delay, time constant and gain are not reported. Rotstein and Lewin (1991) have proposed a method for designing PI/PIO controllers based on IMC methods. The method first neglects the ·Corresponding author.…”