Modified active disturbance rejection control for time-delay systems

Predictor-Based Disturbance Rejection Control for Sampled Systems With Input Delay

“…To perform the control test as done in [24], a unity step change is added to the set-point at 0 t = (s), and then a load disturbance with a magnitude of 0.1 is added to the plant input at 80 t = (s). For fair comparison in terms of the similar rising speed of the set-point response and the similar disturbance response peak, the observer and controller settings in the proposed method are listed in Table II for different cases, where the pre-filter ( ) F z is designed by using the formula in (22) with 0 h = , and the FSP filter is designed by using the formula in (24) [4] is performed, where the corresponding discrete-time controllers for implementation with the same sampling period are listed in Table III according to the control design formulae given therein.…”

“…To counteract load disturbance and plant uncertainties, the active DRC (ADRC) strategy was developed which could lead to obvious performance improvement when compared to traditional controllers like PID [21], and therefore, has attracted increasing attention in the recent years [22][23][24][25]. The key idea of ADRC lies with treating external disturbance and unmodeled system dynamics as "a generalized disturbance", which is estimated by using a modified state observer, such that the feedback control could be specifically designed to eliminate the disturbance effect.…”

“…However, the developed ADRC methods were mainly focused on delay-free systems. For time-delay systems, it was proposed [24] to design a modified ADRC to tackle the time delay, such that good disturbance rejection could be obtained while maintaining the system stability compared with the standard ADRC. T predictive ADRC was developed [25] to compensate for the input delay for disturbance rejection, which could obtain further improved performance, but is only applicable for stable processes with time delay.…”

Flexure-hinges guided nano-stage for precision manipulations: Design, modeling and control

“…It should be noted that the above parameters are selected based on following considerations: 29 1) The controller bandwidth should be higher than the bandwidth of closed feedback system that we desired;…”

Analytical design of a generalised predictor‐based control scheme for low‐order integrating and unstable systems with long time delay

“…A few modified SP control methods have been recently developed to improve control performance for integrating and unstable processes [19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34] . In the recent papers 35,36 , a generalized predictor (GP) structure was developed to control stable, integrating or unstable processes with long time delay.…”