Measurement feedback control for a class of feedforward nonlinear systems

Abstract

SUMMARYWe propose a measurement feedback controller for a class of feedforward nonlinear systems under sensor noise. The sensor noise has unknown magnitude, frequency, and phase. Our proposed controller is coupled with a low‐pass filter in such a way that the sensor noise is attenuated. We show that the controlled system results in bounded states whose ultimate bounds are inversely proportional to the minimum frequency of the sensor noise. Our result is further generalized to work in a case where the sensor noise is only required to have a Fourier transform with finite energy. Moreover, if the sensor noise enters only at partial states, depending on the location of the sensor noise, the ultimate bounds of the particular states can be made arbitrarily small via the gain factor of the controller. Copyright © 2012 John Wiley & Sons, Ltd.

Output feedback control for a class of nonlinear systems with actuator degradation and sensor noise

“…To reduce or even eliminate the effect of sensor noise on the system performance, many design schemes were developed. In [1], the authors proposed a measurement feedback controller for a class of feedforward nonlinear systems. The controller was coupled with a low-pass filter to attenuate the effect of sensor noise and rendered the system state ultimately bounded.…”

“…The controller was coupled with a low-pass filter to attenuate the effect of sensor noise and rendered the system state ultimately bounded. Compared with [1], the condition of sensor noise in [2] was not limited to deterministic periodic signals and allowed to be a random signal having nonzero-mean. By introducing a notion of virtual state and using high-gain observer technique, the authors proposed a scaled output feedback controller for a class of feedforward system to render that all the system states and output remained to be bounded in the presence of sensor noise.…”

“…There exist some drawbacks in the design schemes of [1][2][3][4][5][6][7][8], that is, the effect of sensor noise on the system performance is only reduced not eliminated and sensor noise cannot be reconstructed. Besides, actuator fault is not considered.…”

Measurement Feedback Control of a Class of Nonlinear Systems via Matrix Inequality Approach

“…To dilute the effect of sensor noise, there have been various control results on measurement feedback control problems [1][2][3][4]7]. The presented controller in [1,2] via high gain observer can reduce the sensor noise.…”

“…The presented controller in [1,2] via high gain observer can reduce the sensor noise. In [4], using a low-pass filter for feedforward nonlinear systems, the sensor noise is reduced for the unknown magnitude, frequency, and phase. However, the considered systems and control methods in [4] are limited to a class of feedforward systems and there are other limitation such that the condition in [4] is conservative because the condition is developed based on norm-bound.…”