Structure-specific analytical PID tuning for load disturbance rejection

Performance Evaluation of a 2DOF_PID Controller Using Metaheuristic Optimization Algorithms

“…Achieving reference input tracking and disturbance rejection simultaneously can be difficult in some cases, especially when the available information is limited or when the system is highly nonlinear. In those cases, the use of advanced control techniques or more complex models may be considered to achieve the desired performance [33,34]. In order to overcome this limitation of traditional 1DOF_PID, a two-degree-of-freedom (2DOF_PID) controller has emerged where setpoint tracking and disturbance rejection can be achieved separately.…”

Performance, robustness and noise amplification trade-offs in Disturbance Observer Control design

“…Without adding any new element to the control structure, a passive strategy consists of selecting the proper controller tuning for disturbance rejection. In that sense, [5] and [6] propose tuning rules that improve disturbance response; [7] exposes a robust design for PI synthesis; [8] presents a pole placement technique that consists of avoiding plateaus in frequency response from disturbance to output, and [9]proposes an optimal PI tuning through genetic algorithms. Furthermore, [10] proves that a PI itself can act like a controller plus and observer in certain kind of systems.…”

Enhanced 2-DOF PID Controller Tuning Based on an Uncertainty and Disturbance Estimator With Experimental Validation

“…Hence, controller synthesis has recently taken into consideration disturbance rejection, rather than set-point tracking. For instance, by means of One-Degree-of-Freedom (1-DOF) PID structure, set-point tracking performance and disturbance rejection requirements cannot generally be simultaneously achieved for control applications [17]. In order to circumvent this drawback, a Two-Degree-of-Freedom (2-DOF) PID was presented in [18], [19] so as the set-point tracking and the disturbance rejection can be handled by tuning a PID controller for each control loop.…”