ABSTRACT A discrete-time adaptive feedback disturbance rejection algorithm is developed for applications where the disturbance spectrum is unknown. Feedforward control methods are frequently used to reject disturbances with a known spectrum, but a feedback controller is required when the disturbance is unknown. Multi-input multi-output (MIMO) disturbance rejection algorithms are developed for c...

This paper deals with adaptive estimation of unknown disturbances in a class of nonminimum phase nonlinear systems, and the stabilization and disturbance rejection based on the estimated disturbances. The unknown disturbances are combination of sinusoidal disturbances with unknown frequencies, unknown phases and amplitudes. The only information of the unknown disturbances is the number of disti...

This paper presents a new approach to rejection of complex-valued sinusoidal disturbances acting at the output of a discrete-time stable linear plant with unknown and possibly time-varying dynamics. It is assumed that both the instantaneous frequency of the sinusoidal disturbance and its amplitude may be slowly varying with time and that the output signal is contaminated with wideband measureme...

Abstract: This paper deals with asymptotic rejection of unmatched general periodic disturbances in nonminimum phase nonlinear output feedback systems. The steady state responses are defined for unstable systems subject to general periodic disturbances, and the generalized gain and phase are defined for stable systems subject to general periodic disturbances. Based on the new definitions, new re...

This paper proposes a continuous-time model predictive control design for disturbance rejection and set-point following of periodic signals. By assuming input disturbance in the form of sinusoid, the periodic frequency is embedded into the design model. Hence, from internal model principle, the steady-state error of the model predictive control system is ensured to be zero for both disturbance ...

Criteria based on disturbance rejection and system robustness are proposed to assess the performance of PID controllers. The robustness is measured by a two-block structured singular value, and the disturbance rejection is measured by the minimum singular value of the integral gain matrix. Examples show that the criteria can be applied to a variety of processes, whether they are stable, integra...

An adaptive disturbance rejection algorithm is developed for the standard control problem. The multiple input–multiple output (MIMO) system and controller are represented as ARMARKOV/Toeplitz models, and the parameter matrix of the compensator is updated on-line by means of a gradient algorithm. The algorithm requires minimal knowledge of the plant, specifically, the numerator of the ARMARKOV m...

This paper is concerned with disturbance rejection analysis of structured uncertain Lur’e systems through invariant set analysis using Lyapunov function method. The conditions on robust ellipsoidal attractor for uncertain Lur’e systems are presented in terms of LMIs, which simultaneously ensure absolute stability and disturbance rejection of Lur’e systems. An estimate of the maximum set include...

Criteria based on disturbance rejection and system robustness are proposed to assess the performance of PID controllers. A simple robustness measure is defined and the integral gains of the PID controllers are shown to be a good measure for disturbance rejection. An analysis of some well-known PID tuning formulas reveals that the robustness measure should lie between 3 and 5 to have a good comp...

The high resolution and low measurement uncertainty goals for next generation atmospheric sounders will require FTSbased spectrometers which exhibit improved velocity stability and disturbance rejection over previous systems. This paper documents the characterization of and improvements made to existing SDL FTS systems as part of an internal study to meet the demands of future missions. Improve...