Advances in Disturbance/Uncertainty Estimation and Attenuation [Guest editors' introduction]

Uncertainty and Disturbance Estimator-Based Controller Equipped With a Time-Delayed Filter to Improve the Voltage Quality of Inverters

“…The overall control action u(t) is then described by (7) with (11) and (24). Rearranging, it may be expressed in a two-degrees of freedom form as…”

“…Disturbance observer (DOB) based controllers [24] - [26] are probably the most widely used two-degrees-of-freedom structure, allowing the aforementioned decoupling to be attained. There, the DOB nominalizes the system [27] by estimating and compensating the total uncertainty and disturbance while a tracking controller is only concerned with forcing the nominal system to follow the reference precisely.…”

Fast and Accurate Trajectory Tracking Control of an Autonomous Surface Vehicle With Unmodeled Dynamics and Disturbances

“…In this context, we eventually have (33) together with (34) and (43) into (14) yieldṡ η e,j = w e,j w e,j = −K 1 sig β1 (η e,j ) − K 2 sig β2 (w e,j ) +d j (44)…”

Robust controller design for input‐delayed systems using predictive feedback and an uncertainty estimator

“…Regarding robustness improvement, which is the problem this paper is concerned with, a sliding mode control with delay compensation is proposed in [27] to deal with matched uncertainties; in [28], adaptive schemes are introduced to estimate uncertain plant parameters and input delay, and a control strategy is proposed in [29] to deal with Euler-Lagrange-like nonlinear systems with time-varying input delay.In this paper, the disturbance observer based control is adopted to improve the robustness of the state predictor. The basic idea behind this technique is to use a model of the system along with its input/output information to identify uncertainties and disturbances [30]. There are slightly different techniques that pursue the same goal, which have been recently summarized and explained in [31] (see also the references therein).…”

“…In this paper, the disturbance observer based control is adopted to improve the robustness of the state predictor. The basic idea behind this technique is to use a model of the system along with its input/output information to identify uncertainties and disturbances [30]. There are slightly different techniques that pursue the same goal, which have been recently summarized and explained in [31] (see also the references therein).…”