Operator-based external disturbance rejection of perturbed nonlinear systems by using robust right coprime factorization

Abstract

In this paper, a class of nonlinear systems with external disturbance and internal perturbation are considered by using operator-based robust right coprime factorization for guaranteeing robust stability, rejecting adverse effects resulting from the existing disturbance and perturbation quantitatively and, meanwhile, realizing output tracking performance. In detail, firstly, robust stability is guaranteed based on a Lipschitz norm inequation using robust right coprime factorization. Secondly, based on the proposed design scheme, a convenient framework is obtained for discussing rejection issues for external disturbance and internal perturbation. Thirdly, from an error signal point of view, the adverse effects resulting from the external disturbance and internal perturbation of the nonlinear system are removed by the designed nonlinear operator. Moreover, output tracking performance is realized using the proposed design scheme simultaneously. Finally, a simulation example is given to confirm the effectiveness of the proposed design scheme of this paper.

Robustness Analysis for Sundry Disturbed Open Loop Dynamics Using Robust Right Coprime Factorization

“…Additionally, if the condition can be satisfied by using the bounded information of ∆P r , ∆F, then the detailed information of ∆P r , ∆F is not essential. In comparison with the robust stability condition proposed in [31], where the disturbed open loop dynamics are all related with the plant, the robust right coprime factorization approach in a new form proposed in this paper also expands the range of control for plant with sundry disturbed open loop dynamics, since the backward disturbed open loop dynamics can be plant-independent.…”

“…[30] overcomes the influence of disturbed open loop dynamics in the form of external disturbances, by combining the passivity-based control and RRCF, for the double inverted pendulum system. In [31], robust stability and tracking performance of a class of nonlinear systems with disturbed open loop dynamics in the form of external disturbance and internal perturbation are addressed by RRCF. Ref.…”

Robust Linear Output Regulation Using Extended State Observer

“…We note that various methods have been reported in the literature for the general problem of disturbance rejection/attenuation of control systems; for example, LMIs-based L 2 disturbance attenuation for nonlinear systems with input delays [18], operator-based disturbance attenuation/rejection [19], disturbance observer-based disturbance attenuation for stochastic systems [20], disturbance rejection based on the equivalent-input-disturbance approach [21], ESO-based disturbance rejection controller for fully actuated EulerLagrange systems [22], and sliding mode observer/controller hybrid control structure [15]. With respect to these methods, the main advantages of our method lie in combining the strong points of the output regulation and the disturbance rejection techniques.…”