In this paper we address the problem of augmenting a linear observer with an adaptive element. The design of the adaptive element employs two nonlinearly parameterized neural networks, the input and output layer weights of which are adapted on line. The goal is to improve the performance of the linear observer when applied to a nonlinear system. The networks’ teaching signal is generated using ...

This paper proposes an interval observer for continuous or fed-batch chemical reactors with uncertainties related to both the heat exchange coefficient and the kinetics. The interval observer provides an upper and a lower bound of the state given bounds for the uncertain parameters. The underand over-estimators are state observers for the non-linear reactor model with two positive tuning parame...

In this paper, we extend the observer/control strategies previously published in [25] to an n-link, serially connected, direct drive, rigid link, revolute robot operating in the presence of nonlinear friction effects modeled by the LuGre model. In addition, we also present a new adaptive control technique for compensating for the nonlinear parameterizable Stribeck effects. Specifically, an adap...

— Control of nonlinear systems with unknown disturbances is considered in this paper using disturbance observer based control (DOBC) approach. The disturbances concerned are supposed to be time-varying but with bounded variation. For a nonlinear system with well-defined relative degree from the disturbances to the output, a nonlinear disturbance observer is presented to estimate the unknown dis...

This paper focuses on observer based fault reconstruction for a class of nonlinear uncertain systems with Lipschitz nonlinearities. An adaptive-gain Super-Twisting (STW) observer is developed for observing the system states, where the adaptive law compensates the uncertainty in parameters. The inherent equivalent output error injection feature of STW algorithm is then used to reconstruct the fa...

In this paper, we present a sampled-data nonlinear extended state observer (NLESO) design method for a class of nonlinear systems with uncertainties and discrete time output measurement. To accommodate the inter-sample dynamics, an inter-sample output predictor is employed in the structure of the NLESO to estimate the system output in the sampling intervals, where the prediction is used in the ...

This paper presents a conception of an exponential observer for a class of linear distributed-parameter systems (DPSs), in which the dynamics are partially unknown. The given distributed-parameter observer ensures asymptotic state estimator with exponentially decay error, based on the theory of -semigroups in a Hilbert space. The theoretical observer developed is applied to a chemical tubular r...

In various applications of land vehicle navigation and automatic guidance systems, Global Navigation Satellite System/Inertial Measurement Unit (GNSS/IMU) positioning performance crucially depends on the attitude determination accuracy affected by gyro and accelerometer bias instabilities. Traditional bias estimation approaches based on the Kalman filter suffer from implementation complexity an...

The sensorless DTC of Brushless AC (BLAC) machine using Luenberger observer is proposed in this paper. In Direct Torque Control (DTC), accurate rotor position information is not essential. The speed is estimated by Luenberger observer, which used to improve the performance of dynamic tracking and accuracy of the whole system. The speed regulation is realized by a conventional PI regulator. Simu...

This paper compares the ability of human observers to detect target image curves with that of an ideal observer. The target curves are sampled from a generative model which specifies (probabilistically) the geometry and local intensity properties of the curve. The ideal observer performs Bayesian inference on the generative model using MAP estimation. Varying the probability model for the curve...