不确定离散时间系统的复合非线性反馈积分滑模控制

针对不确定离散时间系统,提出一种基于离散复合非线性反馈的积分滑模(DCNF-ISM)控制策略,并将该算法应用于扰动下的磁盘跟踪问题.该算法由离散复合非线性反馈(DCNF)控制律与积分滑模(ISM)控制律两部分组成,其中DCNF控制律用于保证系统具有较好瞬态性能,基于改进的离散趋近律设计的ISM控制律用于保证系统鲁棒性.基于Lyapunov稳定性理论对本文提出的控制策略的稳定性进行了推导证明,证明了离散时间系统的一致最终有界性.仿真结果表明,本文提出的控制策略能保证系统在扰动下仍然能够精确跟踪给定的参考信号,与传统的DCNF控制相比,该算法能够保证系统具有响应速度快超调量小、鲁棒性强等优点.

Composite nonlinear feedback based integral sliding mode control for uncertain discrete-time system

A discrete composite nonlinear feedback based integral sliding mode (DCNF-ISM) control strategy is proposed for uncertain discrete-time systems, and the algorithm is applied to disk tracking issues under disturbances. The algorithm is composed of discrete composite nonlinear feedback (DCNF) control law and integral sliding mode (ISM) control law. The DCNF control is used to ensure better transient performance of the system, and the ISM control based on an improved discrete reaching law design is used to ensure the robustness of the system. The control strategy proposed in this paper is deduced and proved based on the Lyapunov stability theory, which proves the uniform ultimate boundedness of the discrete-time system. Simulation results show that the proposed control strategy can ensure that the system output tracks the given reference signal in presence of disturbances. Compared with the traditional DCNF control, the proposed algorithm has the advantages of fast response, small overshoot, and strong robustness.