Output Feedback Controller Design for systems with Amplitude and Rate Control Constraints

Abstract

A method for synthesizing dynamic output feedback controllers for continuous time systems presenting actuators constrained in both amplitude and rate is proposed here. The considered controller structure is composed of a saturating integrator block connected to a linear compensator output, delivering a signal to the actuator input inside all its bounds. Considering that the plant is submitted to L2 bounded disturbances, linear matrix inequality conditions are proposed in order to ensure both external and internal stability of the closed loop system.

Robust disturbance rejection for discrete-time systems having Magnitude and rate bounded inputs

“…In anti-windup techniques, input constraints are not directly considered during the controller design, but mainly used on attenuating the unfavourable effects afterwards by introducing compensation components in the closed loop. For instance, in reference [19], a technique which utilises saturating integral blocks and anti-windup loops is proposed to overcome the magnitude and rate saturation problem. Then, L 2 gain between the disturbance input and the plant output is considered as a performance measure to be minimized by control.…”

An Amplitude‐ and Rate‐Saturated Controller for Linear Plants

“…Some of the previous studies [6][7][8] focus on the stability problems raised by the limitation of the amplitude of the control signal. Imposing constraints on control signal's rate-of-change further complicates the stability problem, as has been studied in [9][10][11][12][13][14][15].…”

“…Most of them employed linear matrix inequality (LMI)‐based conditions to select the suitable linear feedback gains that maintain the stability. The second approach is to construct a nonlinear controller providing control signals that already satisfy the amplitude and rate limitations, which are imposed by the actuators.…”

“… introduced a controller with amplitude and rate‐of‐change limitations involving two anti‐windup loops, which requires additional parameters to be tuned appropriately. This controller has been improved by Bender and Gomes da Silva to take the existence of disturbance into account, where the disturbance tolerance and the system output magnitude are treated in a framework of an optimization problem under LMI constraints.…”