Output feedback regulation of a class of high‐order feedforward nonlinear systems with unknown time‐varying delay in the input under measurement sensitivity

Abstract

An output feedback regulation problem is considered for a class of high-order feedforward nonlinear systems with delay in the input under measurement sensitivity. The key features are that the considered systems have uncertain high-order feedforward nonlinearity and unknown time-varying delay in the input. Then, the controller is supposed to be engaged where the output feedback information is distorted by measurement sensitivity. Our proposed controller has two gains-fixed and adaptive gains. The fixed gain is first designed to compensate for measurement sensitivity, and the adaptive gain is next utilized to dominate both unknown input delay and uncertain high-order feedforward nonlinearity. Simulation examples are given to highlight the advantage of our control scheme.

Distributed consensus control of nonlinear multi‐agent systems with sensor uncertainty

“…The control design for nonlinear systems with upper triangular structure is a significant problem. [27][28][29] The nonlinear function f n−1 in Reference 9 is related to the control u i and is not equal to zero. Since the sensor uncertainty is considered here, it is difficult to handle the function f n−1 with control u i .…”

“…where 𝜃 satisfies (17), the distributed consensus protocol (29) achieves the leader-follower consensus of system (1).…”

“…) , where 𝜒 i , i = 2, 3, are two positive design parameters. Moreover, due to the fact that the controllers (29) have the low-gain feature, by choosing a smaller design parameter 𝜅 1 , the strength of the controllers ( 29) is larger, which leads to a faster convergence speed of the consensus errors.…”

Robust Stabilization for Uncertain Nonlinear Systems Subject to Feedforward Growth Constraint

“…The existence of perturbation ω may cause the system equilibrium to deviate from the origin, which can produce some difficult to stabilize the controlled systems. When ω = 0, the system will degenerate into a general form of feedforward nonlinear system, and there are a lot of results about this kind of systems, e.g., [6], [9], [12]- [15].…”

“…[12] and [13] investigated adaptive regulation by output feedback for feedforward nonlinear systems with constant delay and distributed delay, respectively. In the existing of uncertain output function or measurement sensitivity, adaptive output feedback regulation was achieved by introducing novel dynamic gains in [14], [15]. Also, [16] and [17] focused on output feedback control problem of stochastic feedforward systems under unknown measurement sensitivity.…”