Adaptive Fuzzy Finite-time Dynamic Surface Control for High-order Nonlinear System with Output Constraints

This paper studies the problem of finite-time fuzzy adaptive dynamic surface control (DSC) design for a class of single-input and single-output (SISO) high-order nonlinear systems with output constraint. Fuzzy logic systems (FLSs) are utilized to identify the unknown smooth functions. By adopting Barrier Lyapunov function (BLF), the problem of output constrain is handled. Combining adding a power integrator and adaptive backstepping recursion design technique, a novel fuzzy adaptive finite-time DSC algorithm is proposed. Based on finite-time Lyapunov stable theory, the developed control algorithm means that all the signals of the closed-loop system are semi-global practical finite-time stable (SGPFS) and the tracking error converges to a small neighborhood of origin in finite time. In addition, the output does not violate the given constrain bound. Finally, both numerical and practical simulation examples are given to illustrate the effectiveness of the proposed control algorithm.

     

Observer-based Finite-time Control of Stochastic Non-strict-feedback Nonlinear Systems

This paper investigates the observer-based adaptive finite-time neural control issue of stochastic non-strict-feedback nonlinear systems. By establishing a state observer and utilizing the approximation property of the neural network, an adaptive neural network output-feedback controller is constructed. The controller solves the issue that the states of stochastic nonlinear system cannot be measured, and assures that all signals in the closed-loop system are bounded. Different from the existing adaptive control researches of stochastic nonlinear systems with unmeasured states, the proposed control scheme can guarantee the finite-time stability of the stochastic nonlinear systems. Furthermore, the effectiveness of the proposed control approach is verified by the simulation results.

     

Adaptive finite-time congestion controller design of TCP/AQM systems based on neural network and funnel control

This work investigates an adaptive finite-time congestion control problem of transmission control protocol/active queue management. By means of the funnel control, neural networks and sliding mode control, a new AQM algorithm is proposed to ensure that the tracking error \(e_{1}\left( t\right) \) converges to the prescribed boundary in finite time and the transient and steady-state performances of \(e_{1}\left( t\right) \) can be satisfied. The stability analysis is given to prove that all the signals of the closed-loop system are finite-time bounded. Finally, a comparison example is considered to demonstrate the feasibility and superiority of the presented scheme.

     

保持拓扑连通的多智能体网络有限时间聚集控制

针对个体动态为二阶积分器的多智能体网络,研究有限时间聚集控制问题,采用势能函数法和变结构控制思想设计分布式非光滑有界控制协议.在网络初始能量有限的前提下,得出该非线性耦合网络拓扑始终保持连通的结论.基于不变集原理和Lyapunov函数的二阶集值李导数信息,进行有限时间稳定性分析,得出在选取合适牵制权值的情况下,网络可实现保持拓扑连通的有限时间聚集的控制策略.最后通过仿真实例验证了理论方案的有效性.     

输入饱和受限下的刚体飞行器姿态系统的有限时间镇定

研究存在输入饱和受限下的飞行器姿态控制问题, 提出一种有限时间姿态镇定方案. 针对基于修改的Rodriguez 参数模型的飞行器姿态控制系统, 基于齐次性理论和饱和控制器设计方法, 并充分利用系统的模型结构特征, 设计一类饱和的有限时间姿态控制器, 使得姿态可以在有限时间内被镇定到平衡点. 仿真结果验证了所设计姿态控制器的有效性.

     

一类扩展结构大系统的分散有限时间鲁棒关联镇定

研究一类扩展结构大系统分散有限时间鲁棒关联镇定问题. 扩展结构大系统是在原结构系统上增加新子系统而构成的, 在原系统分散控制律确定不变的情况下, 设计新加入子系统的鲁棒分散控制律, 使扩展后的系统仍能保持有限时间关联稳定. 利用LMI 方法推导此类系统基于状态反馈和输出反馈的分散有限时间关联镇定的充分条件, 并给出扩展子系统的相应控制器的设计方法. 最后通过仿真实验表明了所提出方法的可行性和有效性.

     

离散线性切换系统的一致有限时间稳定分析和反馈控制及其在网络控制系统中的应用

研究了一类离散线性切换系统的一致有限时间稳定性分析和反馈镇定．基于线性矩阵不等式技术,给出了在任意切换信号作用下,离散线性切换系统有限时间稳定和有限时间有界的充分条件,并给出了离散线性切换控制系统一致有限时间状态反馈控制器的设计方法．将上述分析结果应用于一类丢包有界的网络控制系统,得到了保证其有限时间稳定的反馈控制器．最后,通过两个数值仿真例子验证了所提方法的有效性．     

多航天器系统分布式有限时间姿态协同跟踪控制

基于一致性算法, 在有向通讯拓扑下, 研究存在状态约束的多航天器系统分布式有限时间姿态协同跟踪控制问题. 在仅有部分跟随航天器可以获取领航航天器状态, 并且跟随航天器之间存在不完全信息交互的情形下, 设计了分布式快速终端滑模面, 提出了不依赖于模型的分布式有限时间姿态协同跟踪控制律. 根据有限时间Lyapunov 稳定性定理, 证明了系统的状态在有限时间内收敛于领航航天器状态的小邻域内. 最后通过仿真算例验证了所提出算法的有效性.

     

Decentralised adaptive neural connectively finite-time control for a class of p-normal form large-scale nonlinear systems

ABSTRACT

This paper focuses on the decentralised adaptive finite-time connective stabilisation problem for a class of p-normal form large-scale nonlinear systems at the first. By combining the adding a power integrator technique, the neural network technique and the finite-time Lyapunov stability theory, the decentralised adaptive neural finite-time controllers are designed, which can guarantee the large-scale system is finite-time connectively stable. In order to avoid the effect of neural network estimation error on satisfying the finite-time criteria, the combination vectors are composed by the weights and the estimation errors of the neural networks. The maximal upper bounds of the combination vector norms are taken as the adaptive parameters. Because of employing neural networks, the restriction of the unknown nonlinear terms in some literature about finite-time control is relaxed. Two simulation examples are provided to prove the effectiveness and advantage of the proposed control method.     

航天器姿态跟踪有限时间饱和控制

针对卫星姿态跟踪系统, 在无扰动和有扰动的情况下, 利用双曲正切函数和辅助系统设计两个有限时间饱和控制器. 双曲正切函数可以严格地保证卫星姿态跟踪系统的控制输入是有界的. 通过李雅普诺夫理论可以证明, 系统在两个控制器的作用下既是渐近稳定的又是有限时间稳定的, 系统可以快速收敛到平衡点. 数值仿真进一步表明了所提出的有限时间控制器的有效性.

     

基于模型依赖平均驻留时间的线性切换系统有限时间??∞ 控制

针对一类具有有界干扰的线性切换系统研究其有限时间鲁棒控制问题。基于模型依赖平均驻留时间,提出了系统有限时间有界且具有H∞性能指标的充分条件,与传统方法中系统具有单一平均驻留时间不同,各切换子系统具有各自的平均驻留时间,因而降低了设计的保守性。进一步,将切换系统的有限时间状态反馈控制器设计转化为具有线性矩阵不等式约束的优化问题。数值算例和仿真对比表明,所提出的方法增加了切换律设计的自由度。     

Robust finite-time <Emphasis Type="Italic">H</Emphasis><Subscript>∞</Subscript> control of stochastic jump systems

This paper provides the stochastic finite-time stabilization and H _∞ control problem of Markov jump systems with norm-bounded uncertainties and state delays that possess randomly jumping parameters. The transition of the jumping parameters is governed by a finite-state Markov process. The finite-time H _∞ controller via state feedback is provided to guarantee the stochastic finite-time bounded-ness and stochastic finite-time stabilization of the resulting closed-loop system for all admissible uncertainties and unknown time-delays. The control criterion is formulated in the form of linear matrix inequalities and the designed finite-time stabilization controller is described as an optimization one. Simulation results illustrate the effectiveness of the developed approaches.     

Adaptive finite-time control of a class of non-triangular nonlinear systems with input saturation

This paper studies the problem of adaptive neural network finite-time control for a class of non-triangular nonlinear systems with input saturation. Under the assumption that the nonlinearities have strict increasing smooth bounding functions, the backstepping technique can be used to design the state feedback controller and adaptive laws. Neural networks are adopted to approximate some unknown nonlinear functions. With the help of the finite-time Lyapunov stability theorem, it can be proved that the state of the closed-loop system can converge to an arbitrarily small neighborhood of the origin in a finite time. Finally, a numerical simulation example is given to show the effectiveness of the proposed design method.

     

时变时滞连续切换奇异系统的一致有限时间稳定分析

讨论一类含有时变时滞的连续时间切换奇异系统的一致有限时间稳定、有限时间有界和状态反馈镇定问题. 在给定任意的切换规则下, 运用多Lyapunov 函数和平均驻留时间方法设计使得闭环系统一致有限时间稳定和有限时间有界的状态反馈控制器, 同时给出基于线性矩阵不等式表示的控制器存在的充分条件. 最后通过数值算例表明了所提出方法的合理性和有效性.

     

Finite-time synchronisation control of coupled reaction-diffusion systems

ABSTRACT

We consider the finite-time synchronisation for coupled reaction-diffusion systems. At first, we design a pinning control strategy for the coupled systems. For the uncontrolled nodes, we use the adaptive adjustment to the coupling strength. Based on the Poincaré inequality technique and using the finite-time stability lemma, we obtain the sufficient condition to ensure the finite-time synchronisation. Time delay occurs usually in the coupled systems and when there exist time-varying delays in the coupled reaction-diffusion systems, we design a controller to impel the coupled systems to achieve the finite-time synchronisation. Finally, numerical examples are given to illustrate our theoretical results.     

存在飞轮安装偏差与故障的卫星姿态容错控制

基于滑模控制理论提出一种刚体卫星姿态稳定控制方法,实现对反作用飞轮部分失效故障的容错控制,以及对其安装偏差的补偿控制,并从理论上证明了所设计的控制器在有限时间内能够实现对闭环姿态控制系统的几乎全局渐近稳定控制.最后将所设计的控制器应用于某型卫星姿态稳定任务,仿真结果验证了所提出方法的有效性.     

Finite-time Stable Robust Sliding Mode Dynamic Control for Parallel Robots

To address the tracking control problem for n-DOF parallel robots in presence of the lumped disturbance, including modeling errors, friction and external disturbance, a finite-time stable robust sliding mode dynamic control (FRSMDC) for parallel robots is explored. From the implementation condition of the FRSMDC for parallel robots, the limitation on the change rate of the lumped disturbance is relaxed for easy realization. From the results of the FRSMDC for parallel robots, the finite-time stability of the sliding variable is proved and the settling time is derived; the switching gain required is only larger than the upper bound of the disturbance estimation error, instead of the upper bound of the disturbance, due to the feed-forward compensation to the lumped disturbance via a disturbance observer. Consequently, the system robustness is improved and the chattering of FRSMDC is alleviated. The finite-time stability of the closed-loop system is confirmed with Lyapunov theory. Besides, the application of the proposed method is extended to a general multi-input multi-output nonlinear system with the relative degree m by analogy. Finally, the case of the dynamic control of a 6-DOF parallel robot for automobile electro-coating conveying is studied for simulation and experiment, so as to attest the validity of the FRSMDC for parallel robots.

     

New finite-time stability conditions of linear switched singular systems with finite-time unstable subsystems

ABSTRACT

This paper addresses the finite-time stability problem of linear switched singular systems with finite-time unstable subsystems. Dynamic decomposition techniques are used to transform such systems into equivalent one that is a reduced-order switched normal systems. Based on the mode-dependent average dwell time (MDADT) switching signal, new sufficient conditions are presented to guarantee the linear switched singular systems with finite-time unstable subsystems being finite-time stability, finite-time bounded and finite-time stabilization. Finally, a numerical example is employed to verify the efficiency of the preceding method.     

Finite-time Synchronization of a Class of Coupled Memristor-based Recurrent Neural Networks: Static State Control and Dynamic Control Approach

This paper investigates the problem of the finite-time synchronization of a class of coupled memristor-based recurrent neural networks (MRNNs) with time delays. Based on the drive-response concept and differential inclusions theory, several sufficient assumptions are given to ensure the finite-time synchronization of MRNNs. In order to realize the finite-time synchronization between the drive system and the response system, we design three classes of novel control rules such as static state controller, static output controller, dynamic state controller. Using the theory of differential inclusion, a generalized finite-time convergence theorem and Lyapunov method, the conditions herein are easy to be verified. Moreover, the upper bounds of the settling time of synchronization are estimated and the designed dynamic state controllers have good anti-interference capacity. Finally, two numerical examples are presented to illustrate the effectiveness and the validity of theoretical results.

     

Finite-time stability on a class of SICNNs with neutral proportional delays

In this paper, the finite-time stability for a class of shunting inhibitory cellular neural networks with neutral proportional delays is discussed. By employing differential inequality techniques, several sufficient conditions are obtained to ensure the finite-time stability for the considered neural networks. Meanwhile, the generalized exponential synchronization is also established. An example along with its numerical simulation is presented to demonstrate the validity of the proposed results.