To handle the state estimation of a nonlinear system perturbed by a scalar disturbance distributed by a known nonlinear vector, we incorporate a sliding mode term into a nonlinear observer to realise a robust nonlinear observer. By linking the observability of the unknown input to the output measurement, the so-called matching condition is avoided. The measurable output estimation error is the ...

This paper provides some new developments in the design of unknown input observers for nonlinear systems. An algorithm which states if the state and the unknown input of the system can be recovered in finite time is introduced. This algorithm leads to the transformation of the system into an extended block triangular observable form suitable for the design of finite time observers. The proposed...

In this paper, the terminal sliding mode tracking control is proposed for the uncertain single-input and single-output (SISO) nonlinear system with unknown external disturbance. For the unmeasured disturbance of nonlinear systems, terminal sliding mode disturbance observer is presented. The developed disturbance observer can guarantee the disturbance approximation error to converge to zero in t...

Hydraulic automatic gauge control system of magnesium sheet mill is a complex integrated control system, which including mechanical, hydraulic and electrical comprehensive information. The failure rate of AGC system always is high, and its fault reasons are always complex. Based on analyzing the fault of main components of the automatic gauge control system, unknown input observer is used to re...

This paper proposes a new interval observer design based on a high/low gain concept, developed for the estimation of the input of a bioreactor. In a first step, a high gain bounded error observer is proposed, which is able to estimate the unknown input of the considered system. This observer is useful when an accurate model and noise–free measurements are available. We show that the error of th...

This paper addresses the control problem of heterogeneous vehicle platoons subject to disturbances and modeling errors. The objective is guarantee spatial-geometry constraints vehicles in a platoon. We deal with case where predecessor-leader following (PLF) communication topology used dynamics disturbances. To estimate lumped disturbance, technique unknown input proportional multiple-integral (...