Distributed Adaptive Fault-tolerant Control for Heterogeneous Nonlinear Multi-agent Systems with Actuator Faults

International Journal of Control, Automation and Systems - This paper investigates the fuzzy cooperative reliable output regulation (CROR) problem for heterogeneous nonlinear multi-agent systems...     

Fault-tolerant Control for Uncertain Vehicle Active Steering Systems with Time-delay and Actuator Fault

International Journal of Control, Automation and Systems - In this paper, the fuzzy control problem for uncertain time-delay active steering systems with actuator fault is investigated. Due to the...     

Sliding Mode Control for Uncertain Switched Systems with Partial Actuator Faults

This paper considers the sliding mode control for a class of uncertain switched systems with partial actuator faults. By employing a weighted sum of the input matrices, a common integral sliding surface is designed. Moreover, the exponential stability of the sliding mode dynamics is analyzed by adopting the multiple Lyapunov function method and the average dwell time strategy. It is shown that the state trajectory can be driven onto the proposed sliding surface despite the presence of parameter uncertainties, external disturbances, and actuator faults. A numerical example is given to demonstrate the effectiveness of the proposed method.     

群体觅食行为启发的多机器人分布式编队控制方法研究

群集智能由简单个体之间的相互作用涌现出来,这种涌现出来的智能可以解决许多复杂的问题.首先,从细茵群体觅食特性出发,引出了该行为与多机器人编队任务的相关性.然后,通过对群体觅食行为模型的扩展,建立了基于势场的多机器人分布式编队控制模型;最后,在不同规模下的多机器人编队仿真实验表明,本文的方法能够控制多机器人完成编队任务,并且使得机器人在遇到障碍物时能灵活躲避障碍物,离开障碍物后又快速恢复队形.     

针对一类执行器故障连续系统的保性能控制设计

本文利用线性矩阵不等式 (LMI)方法 ,讨论了一类存在执行器故障不确定连续系统的保性能控制问题 ,给出了故障时系统保性能状态反馈控制器存在的充分条件并应用基于LMI的凸优化方法实现了针对系统故障的最优保性能状态反馈控制器设计。仿真实例验证了该方法的有效性。     

分布式流处理系统的容错性能基准测试

随着对数据处理的实时性要求越来越高,分布式流处理系统应运而生。但是在分布式的集群规模下,各种软硬件原因导致的故障很难避免的。现有的相关基准测试主要关注于分布式流处理系统的处理性能,很少对该类系统处理故障的容错性能进行评测,以至于关键应用在系统选型的时候特别艰难。针对分布式流处理系统的容错性能,本文设计并实现了一套灵活的基准测试框架。最后,本文在开源数据流处理系统ApacheStorm和ApacheFlink进行了容错性能的基准测试,验证定义的测试基准的正确性和有效性,实验结果也表明Flink的容错性能相对较好。     

基于行为的多机器人队形控制仿真研究

采用基于行为的控制方法,设计了多机器人队形控制的五个子行为:奔向目标、躲避障碍物、围绕障碍物、保持队形和随机扰动。在子行为设计中引入了阶梯控制区法,提高了队形控制的容错性。使用Teambots仿真平台对典型的直线队形控制进行了仿真。针对单向虚拟参照点法队形控制不稳定的情况,采用双向虚拟参考点法对控制方法进行改进,根据运行时间对改进的队形控制方法进行了评估,实验结果表明,改进的方法大幅提高了队形控制的稳定性与系统运行效率。     

Characteristic Model-based Adaptive Fault Tolerant Control for Four-motor Synchronization Systems Considering Actuator Failure

This article proposes a characteristic model-based adaptive fault tolerant control scheme to deal with actuator failure in four-motor synchronization systems, which usually causes sudden inertia ratio change and backlash increase. Firstly, the characteristic modeling method is applied into servo system to obtain a simplified system model without losing high-order features. Also, this model could reflect real-time system status through three characteristic parameters. Secondly, a particle swarm optimization algorithm-based estimator is designed to identify characteristic parameters online. By this way, the characteristic model could react to inertia ratio changes quickly and eliminate its negative effect in signal tracking. Thirdly, an improved adaptive electric anti-backlash method is used to restrain backlash. Compared to regular anti-backlash technique, this adaptive one uses a neural network-based fault detector to monitor motors and adjust bias current according to different actuator status, even when one motor breaks down. With these three steps combined, a fast terminal sliding mode controller is finally designed as fault tolerant controller and the stability of this closed-loop system is guaranteed by Lyapunov stability theorem. At last, the simulation and experiment results prove the effectiveness of the proposed control scheme in system control and fault tolerance.

     

An Adaptive Fault-tolerant Control Method for Robot Manipulators

International Journal of Control, Automation and Systems - This paper presents a new method for adaptive continuous nonsingular fast terminal sliding mode control (ACNFTSMC) based on a novel...     

双容液位系统鲁棒自适应容错控制

针对双容液位控制系统的泄漏等故障,通过线性化建模,研究了鲁棒自适应主动容错控制问题.首先在系统无故障正常运行情形,考虑建模误差和外界干扰等不确定性,利用不确定性上界自适应估计,设计了鲁棒自适应控制器.与此同时,对系统进行故障监控,设计了故障诊断滤波器,并利用对不确定性上界的估计终值提出了一种新的故障检测算法,进一步基于神经网络故障逼近,研究了一种修正控制律的自适应鲁棒容错控制器设计方法,该控制器通过补偿故障所带来的影响使闭环系统最终一致有界稳定.最后,通过仿真试验,验证了提出的方法的有效性.     

Distributed Adaptive Dynamic Surface Containment Control for Uncertain Multiple Euler-Lagrange Systems

This paper investigates the distributed containment control for a class of uncertain multiple Euler- Lagrange systems. A directed graph is used to characterize the interactions among the leaders and followers. The proposed approach is based on an adaptive dynamic surface control, where the system uncertainties are approximately modelled by interval type-2 fuzzy neural networks. The adaptive laws of neuro-fuzzy parameters are derived from the Lyapunov stability analysis. The robust stability of the closed-loop system is guaranteed, and then all followers can converge into the convex hull spanned by the dynamic leaders. In this study, a systematic control scheme is proposed and several indexes are used for performance comparisons. Simulation results are also provided to reveal the superiority of the proposed distributed adaptive containment controller.     

An Efficient Adaptive Transmission Control Scheme for Large-Scale Distributed Simulation Systems

Data distribution management (DDM) is one of the most critical component of any large-scale interactive distributed simulation systems. The aim of DDM is to reduce and control the volume of information exchanged among the simulated entities (federates) in a large-scale distributed simulation system. In order to fulfill its goal, a considerable amount of DDM messages needs to be exchanged within the simulation (federation). The question of whether each message should be sent immediately after it is generated or held until it can be grouped with other DDM messages needs to be investigated further. Our experimental results have shown that the total DDM time of a simulation varies considerably depending on which transmission strategy is used. Moreover, in the case of grouping, the DDM time depends on the size of the group. In this paper, we propose a novel DDM approach, which we refer to as Adaptive Grid-based (AGB) DDM. The AGB protocol is distinct from all existing DDM implementations, because it is able to predict the average amount of data generated in each time step of a simulation. Therefore, the AGB DDM approach controls a simulation running in the most appropriate mode to achieve a desired performance. This new DDM approach consists of two adaptive control parts: 1) the Adaptive Resource Allocation Control (ARAC) scheme and 2) the Adaptive Transmission Control (ATC) scheme. The focus of this paper is on the ATC scheme. We describe how to build a switching model to predict the average amount of DDM messages generated and how the ATC scheme uses this estimation result to optimize the overall DDM time. Our experimental results provide a clear evidence that the ATC scheme is able to achieve the best performance in DDM time when compared to all existing DDM protocols using an extensive set of experimental case studies.     

容错分布控制系统设计

研究设计了一种容错离散分布控制系统的网络配置结构,即将控制系统中的每个可编程控制器作为一个控制结点,结点之间通过网络进行连接构成离散分布控制系统;使系统实现容错的方法是,增加一个在Galois域进行运算的冗余控制器结点,从而使系统能够自动侦查系统中的结点（可编程控制器）是否正常工作,并能使不正常工作的结点的功能得到恢复,确保系统的容错性和可靠性;实验证明这种设计是有效可行的;容错分布控制系统具有良好的抗故障能力,有很好的实际应用价值。     

Distributed Adaptive Dynamic Surface Control for Synchronization of Uncertain Nonlinear Multi-agent Systems

In this paper a distributed adaptive dynamic surface controller is proposed for multi-agent systems under fixed directed graph topologies. The agents have uncertain nonlinear dynamics and are influenced by bounded unknown disturbances. The controller should synchronize the states of all agents with the corresponding states of the nonautonomous leader. It is proved that, with the proposed controller, the synchronization error remains bounded; and the bounds can be arbitrarily decreased by increasing the controller gains. The control rules are designed such that each agent only requires the state information of its neighbors, rendering a distributed control. The effectiveness of the proposed method is demonstrated through two simulation examples.     

马尔可夫跳变系统基于观测器的有限时间容错控制

针对具有一般不确定转移速率的单边Lipschitz Markovian跳变系统,设计了有限时间故障估计观测器和容错控制器.首先,提出一种自适应的有限时间故障估计观测器,它对未知输入具有鲁棒性,能够同时估计出系统的状态、执行器故障和传感器故障,并确保了误差系统的H_∞有限时间有界.然后,基于所估计的状态和执行器故障,提出一种有限时间故障容错控制方法确保闭环系统H_∞有限时间有界.通过线性矩阵不等式的形式,给出了所设计的有限时间观测器和控制器存在的充分条件.最后,通过一个仿真实例,验证了所提方法的有效性.     

离散多步时滞系统的容错控制研究

针对离散多步时滞系统,基于Lyapunov稳定性理论,采用具有状态反馈及时滞状态反馈的控制律,推出了当执行器或传感器发生失效故障时闭环系统仍能保持渐近稳定需满足的充分条件;并利用LMI给出了不依赖时滞的线性离散多步时滞系统的容错控制器的通用求解方法;讨论了该方法对具有不同时滞步数离散多步时滞系统容错的普适性。以执行器失效故障为例,仿真结果证明了该方法的有效性。     

线性离散时滞系统的D稳定容错控制

采用状态反馈和带时滞的状态反馈控制律,基于Lyapunov稳定性理论和Riccati方程,针对线性离散一步时滞系统,研究了执行器失效后有一定性能保证的D稳定容错控制问题。在给出对执行器失效具有完整性的D稳定容错控制系统需满足的一个充分条件的基础上,给出了控制器的设计方法和步骤,并推广至传感器失效情况。仿真结果证实了这种方法的有效性,与仅引入状态反馈控制律相比,此方法有更好的动态响应性能。最后指出了时滞状态反馈增益矩阵的选取原则。     

基于EDF的分布式系统实时容错调度算法

将分布式系统的任务分配算法与处理器局部调度算法相结合，提出一种主动备份的、基于EDF的分布式系统实时容错调度算法，其特点是主／副版本执行时间可以重叠。给出了该调度算法的任务集可调度的充分条件、任务集可调度所需最小处理器个数的计算方法。模拟结果比较了主动备份容错调度算法与被动备份容错调度算法，结果表明卞动备份算法效率更优。     

多机器人系统的互联控制问题讨论

从互联的角度对多机器人系统的相关控制问题进行了归纳与总结，强调了互联关系在此类问题中的重要性。首先介绍了从互联角度研究此类问题的意义，然后基于互联关系综述了主要的控制体系结构，控制设计方法，以及相关的稳定性分析方法。列举了此类问题中因互联的复杂性而需结合的其他领域的工具，并介绍了一类热点控制问题-“编队控制”。指出了当前研究的重点、难点以及研究趋势，对多机器人系统的设计分析方法进行了展望，指出其发展前景。     

Fault-tolerant Bipartite Output Regulation of Linear Multi-agent Systems with Loss-of-effectiveness Actuator Faults

International Journal of Control, Automation and Systems - In this paper, the fault-tolerant bipartite output regulation problem of linear multi-agent systems with two antagonistic subgroups and...