Globally convergent observers are designed for a class of systems with monotonic nonlinearities. The approach is to represent the observer error system as the feedback interconnection of a linear system and a time-varying multivariable sector nonlinearity. Using LMI software, observer gain matrices are computed to satisfy the circle criterion and, hence, to drive the observer error to zero. In ...

This paper addresses parameter and state estimation problem in the presence of the perturbation of observer gain bounded input disturbances for the Lipschitz systems that are linear in unknown parameters and nonlinear in states. A new nonlinear adaptive resilient observer is designed, and its stability conditions based on Lyapunov technique are derived. The gain for this observer is derived sys...

This paper is concerned with the observer design for one-dimensional linear parabolic partial differential equations whose output is a weighted spatial average of the state over the entire spatial domain. We focus on the backstepping approach, which provides a systematic procedure to design an observer gain for systems with boundary measurement. If the output is not a boundary value of the stat...

In this paper, a variable gain design approach for the high-gain disturbance observer, called Proportional-Integral-Observer (PI-Observer), is proposed to solve the problem of choosing suitable observer gains. The high-gain PI-Observer is successfully applied to estimate unknown inputs of systems together with the system states. It is known that reasonable estimations of unknown inputs can only...

In this paper, the design of an interval observer with an adaptive dynamical gain is presented. The observer is formulated in the framework of robust state estimation of uncertain dynamical systems, where an interval that encloses the unknown state variables is provided. For a specific type of interval observer design, an optimal gain could provide the narrowest interval. Since this gain depend...

In this paper, a high gain observer is designed for a parameter varying polytopic model to estimate the enclosed mass in the combustion chamber of a spark ignited engine. The high gain strategy allows the design of an observer that handles the uncertain part of the system. The observer uses the cylinder pressure measurement during the compression stroke to estimate the enclosed mass. An engine ...

In this study, nonlinear second order systems with unmeasured system states and bounded external disturbances are considered. The observer gain of the sliding mode observer is adjusted by using a support vector machine based plant model. Computer simulations are presented to show the effect of the proposed adjustment mechanism on the performance of the output feedback sliding mode controller. I...

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...

State space based nonlinear model predictive control (NMPC) needs the state for the prediction of the system behavior. Unfortunately, for most applications, not all states are directly measurable. To recover the unmeasured states, typically a stable state observer is used. However, this implies that the stability of the closed-loop should be examined carefully, since no general nonlinear separa...

This paper deals with the design of a high gain observer and sliding mode controller for a remotely controlled quadrotor vertical take off and landing aircraft. Under the restriction that only the inertial coordinates and yaw angle are available for measurement, a high gain observer is designed which allows estimating on-line the roll and pitching angles as well as all the linear and angular ve...