Mode Control For Time-delay Systems Research Articles

Sliding Mode Control of Time-Delay Systems with Delayed Nonlinear Uncertainties

This paper considers a class of time delay systems with delayed states and nonlinear uncertainties using sliding mode techniques. In order to improve robustness, matched and mismatched disturbances are considered and assumed to be nonlinear functions of system states and delayed states. A sliding function is designed and a set of sufficient conditions is derived to guarantee the stability of the corresponding sliding motion by using Lyapunov-Razumikhin approach which allows large time varying delay with fast changing rate. A delay dependent sliding mode control is synthesized to drive the system to the sliding surface in finite time and maintain a sliding motion thereafter. Effectiveness of the proposed method is tested via a case study on a continuous stirred tank reactor system.

Adaptive output feedback sliding mode control for time-delay systems with extended disturbance

This study proposes a new adaptive output feedback sliding mode control (SMC) for mismatched uncertain time-delay systems. First, sufficient conditions in terms of linear matrix inequalities are derived such that the equivalent reduced-order system in the sliding mode is asymptotically stable. Second, based on a new lemma and a novel adaptive law, an adaptive sliding mode controller is designed to guarantee the finite-time reachability of the system states using output feedback only. The proposed method is not limited by the following conditions: (1) the exogenous disturbances must be bounded by a known function of the outputs or by a known function of the state and delayed state variables, and (2) the norm of unmeasured states must be bounded by a constant value. As these conditions are required for the application of most existing SMC approaches for time-delay systems, the proposed approach can be applied to a more generalized system, making it a valuable contribution to the field.

Global Robust Sliding Mode Control for Time-Delay Systems with Mismatched Uncertainties

A novel robust sliding mode control method for time-delay systems with mismatched uncertainties is presented, taking into consideration of both the norm-bounded mismatched uncertainties in the inpu...

A Singular System Approach to Output Feedback Sliding Mode Control for Time-delay Systems

摘要: 利用一种奇异系统方法讨论了时滞系统的输出反馈滑模控制问题. 时滞系统的非线性项满足范数有界约束.首先,将滑动模态与线性切换面作为一个奇异时滞系统,基于奇异时滞系统的稳定性理论, 给出滑动模态稳定及切换面存在的线性矩阵不等式(Linear matrix inequality, LMI)充分条件.然后,给出使得系统闭环渐近稳定的静态输出反馈滑模控制器的设计方法,此控制器保证闭环 系统有限时间到达切换面.最后,用数值算例验证本文方法的有效性和正确性. 关键词: 时滞系统 / 滑模控制 / 奇异系统方法 / 静态输出反馈 / 线性矩阵不等式

A Novel Approach to Sliding Mode Control of Time-Delay Systems

This paper is concerned with the sliding mode control for a class of linear systems with time-varying delays. By utilizing a novel Lyapunov-Krasovskii functional and combining it with the delay fractioning approach as well as the free-weighting matrix technology, a sufficient condition is established such that the resulting sliding mode dynamics is asymptotically stable. Then, a sliding mode controller for reaching motion is synthesized to guarantee that the trajectories of the resulting closed-loop system can be driven onto a prescribed sliding surface and maintained there for all subsequent time. A numerical example is provided to illustrate the effectiveness of the proposed design approach.

Integral sliding mode control of time-delay systems with mismatching uncertainties

A linear matrix inequality (LMI)-based sliding surface design method for integral sliding mode control of uncertain time-delay systems with mismatching uncertainties is proposed. The uncertain time-delay system under consideration may have mismatching norm bounded uncertainties in the state matrix as well as the input matrix. A sufficient condition for the existence of a sliding surface is given to guarantee asymptotic stability of the full order sliding mode dynamics. An LMI characterization of the sliding surface is given, together with an integral sliding mode control law guaranteeing the existence of a sliding mode from the initial time. Finally, a simulation is given to show the effectiveness of the proposed method.

Output feedback discrete-time sliding mode control for time delay systems

Several algorithms for discrete-time quasi-sliding mode control of time-delay systems with different delay and disturbance structures are proposed. Four different delay structures are considered. All the algorithms are based on multirate output feedback. Hence, they are more practical than state feedback and are less complex compared with observer-based control strategies.