传感器故障检测、分离与恢复的神经网络方法

传感器是测控系统不可缺少的部件,传感器数据的高可靠性是系统正常工作的重要保证,本文基于递归神经网络具有优良的动态系统建模能力和时间数据序列预报区能力,融合时空信息,构造出具有传感器故障检测,分离和故障恢复能力的智能传感器系统,理论 仿真结果表明,所研究系统的优良性能。     

具有传输时延的网络控制系统故障估计与调节

In this paper,a method of fault estimation and fault tolerant control for networked control system (NCS) with transfer delay and process noise is presented.First,the networked control system is modeled as a multiple-input-multiple-output (MIMO) discrete-time system with transfer delays,process noise,and model uncertainties.Under this model and under some conditions, a fault estimation method is proposed to estimate the system faults.On the basis of the information on fault estimation and the sliding mode control theory,a fault tolerant controller is designed to recover the system performance. Finally, simulation results are used to verify the efficiency of the method.     

Fault Detection and Isolation of Distributed Time-Delay Systems

This paper investigates the development of fault detection and isolation (FDI) filters for distributed time-delay systems. The notion of a finite unobservability subspace is introduced for distributed time-delay systems and an algorithm for its construction is presented. A bank of residual generators is designed based on our developed geometric framework so that each residual is affected by one fault and is decoupled from the others while the $H_{infty} $ norm of the transfer function between the disturbance and the residual signals are kept at less than a prespecified value. Simulation results for a combustion system in a rocket motor chamber demonstrate the effectiveness and capabilities of our proposed FDI algorithm.      

控制系统执行机构故障的检测与诊断

评述了近年来执行机构故障检测与诊断的主要研究成果和发展现状,并给出了各种诊断方法的典型应用,对各种诊断方法的优缺点进行了比较,最后指出了该领域有待进一步研究的若干问题和发展趋势.     

网络控制系统故障诊断滤波器

针对一类具有不确定网络诱导时延和范数有界未知输入影响的网络控制系统(Networked Control Systems,简称NCS),研究了故障诊断滤波器的设计问题.通过构造基于观测器的滤波残差系统,将故障诊断滤波器的设计问题归结为H∞滤波问题.通过引入2个附加的松弛矩阵使Lyapunov矩阵和系统矩阵分离,得到了一个新的鲁棒H∞性能判据,并基于该判据设计了系统的鲁棒H∞滤波器.设计的滤波器不但保证闭环系统的二次稳定性,同时使残差系统的H∞范数小于一个给定的衰减水平γ,并且设计了一个迭代算法来得到问题的优化解.最后通过一个仿真算例验证了所提出算法的可行性和有效性.     

Unknown Input Fault Detection and Isolation Observer Design for Neutral Systems

This paper deals with actuator fault diagnosis of neutral delayed systems with multiple time delays using an unknown input observer. The main purpose is to design an observer that guarantees the asymptotic stability of the estimate error dynamics and the actuator fault detection. The existence conditions for such an observer are established. The main problem studied in this paper aims at designing observer‐based fault detection and isolation. The designed observer enhances the robust diagnosis performance, including rapidity and accuracy, and generates residuals that enjoy perfect decoupling properties among faults. Based on Lyapunov stability theory, the design of the observer is formulated in terms of linear matrix inequalities, and the diagnosis scheme is based on a bank of unknown input observers for residual generation that guarantees fault detection and isolation in the presence of external disturbances. A numerical example is presented to illustrate the efficiency of the proposed approach.     

基于渐近调节的容错控制

针对线性动态故障系统,提出了一种基于线性二次型问题的容错控制方法,该方法可以通过牛顿一拉普森迭代算法来渐近调节状态反馈控制律,以降低故障系统由于故障诊断和系统重构的延时所产生的运行风险,从而提高系统性能。给出了适用该方法的充分条件,并进一步讨论了该方法在系统能耗方面的优越性,对一个具体航空系统进行了仿真,结果证实了该渐近方法的有效性。     

具有输出时延的网络控制系统故障检测

考虑一类具有长时延的网络控制系统,假定其传感器到控制器之间存在输出时延,对其进行故障检测研究.建立具有时延补偿功能的故障观测器,得到状态估计误差方程.基于离散切换系统理论,将观测器系统的稳定条件归结为一个线性矩阵不等式.当系统正常时,只要给定的矩阵不等式条件成立,该观测器系统就是渐近稳定的.当系统发生故障时,观测器残差能够迅速发生跳变,从而检测出故障的发生.仿真示例验证了方法的有效性.     

不确定短时延网络控制系统的故障检测

针对远程被控对象为线性模型,且网络诱导时延小于一个采样周期的一类网络控制系统(NCS),假设可能发生执行器故障,对系统进行故障检测。将随机时延对系统的影响转化为未知有界条件下的不确定项,建立了系统的离散数学模型。按照时延补偿策略设计了系统的故障观测器,并基于Lyapunov稳定性定理和线性矩阵不等式理论,推导出了整个观测器系统全局渐近稳定的充分条件。仿真例子验证了方法的有效性。     

一类非线性网络控制系统的故障检测

针对远程被控对象为非线性模型,且具有输出诱导时延的一类网络控制系统（NCS）,假设可能发生执行器故障,对系统进行故障检测：利用T—S模糊模型将对象线性化,建立了模糊观测器,并给出了观测器系统渐近稳定的条件。进一步地,又考虑到满足该观测器稳定条件的矩阵难以寻找到,因此利用模糊模型中的主导子系统思想,重新设计了观测器,并基于Lyapunov稳定性定理,推导出了整个观测器系统全局渐近稳定的充分条件。最后,通过一个仿真例子验证了方法的有效性。     

具有长时延和丢包的网络控制系统的故障检测

研究了具有长时延和数据包丢失的网络控制系统,针对网络控制系统故障检测问题,假设数据包丢失率一定时,根据执行器接收数据包的情况,设计了系统的故障观测器,用建模为异步动态系统进行了稳定性分析,当条件满足时,整个系统是指数稳定的.通过建立的检测模型,研究了系统的故障检测,并进行仿真.当系统发生故障时,观测器残差能够迅速发生跳...     

机器人控制系统运动学方程

运动学方程可以将起重机的笛卡尔坐标系统转换成球坐标系统。这些等式也可以用于现代运动控制器中。完成计算,实现机器人平滑控制。     

基于T-S模型的网络控制系统故障诊断

针对一类参数不确定并具有时延和丢包情况的非线性网络控制系统,为达到快速准确的进行故障诊断的目的,提出了一种基于T-S模糊模型的故障诊断方法.通过建立此系统的T-S模糊模型,利用平行分布补偿时延的思想设计了满足系统稳定性条件的状态反馈控制器,以及通过引入随机切换系统表示数据有无丢失情况下的基于模糊观测器的鲁棒故障诊断方法,然后基于 Lyapunov函数和线性矩阵不等式方法给出了该闭环网络控制系统渐近稳定的充分条件,最后通过仿真例子验证了该方法能够使闭环控制系统渐进稳定以及能够准确的进行故障诊断,验证了所设计方法的有效性.     

采样数据系统的故障检测

研究了采样数据系统的故障检测问题.关键在于通过引入算子来分别描述连续时间的 未知输入信号和故障信号对离散时间的残差信号的影响,从而把鲁棒性和灵敏度问题定义为一 个优化问题,并给出了相应的解.仿真例子验证了该方法的有效性.     

A Recurrent Neural-Network-Based Sensor and Actuator Fault Detection and Isolation for Nonlinear Systems With Application to the Satellite's Attitude Control Subsystem

This paper presents a robust fault detection and isolation (FDI) scheme for a general class of nonlinear systems using a neural-network-based observer strategy. Both actuator and sensor faults are considered. The nonlinear system considered is subject to both state and sensor uncertainties and disturbances. Two recurrent neural networks are employed to identify general unknown actuator and sensor faults, respectively. The neural network weights are updated according to a modified backpropagation scheme. Unlike many previous methods developed in the literature, our proposed FDI scheme does not rely on availability of full state measurements. The stability of the overall FDI scheme in presence of unknown sensor and actuator faults as well as plant and sensor noise and uncertainties is shown by using the Lyapunov's direct method. The stability analysis developed requires no restrictive assumptions on the system and/or the FDI algorithm. Magnetorquer-type actuators and magnetometer-type sensors that are commonly employed in the attitude control subsystem (ACS) of low-Earth orbit (LEO) satellites for attitude determination and control are considered in our case studies. The effectiveness and capabilities of our proposed fault diagnosis strategy are demonstrated and validated through extensive simulation studies.     

Coordinated Motion and Force Control of Multi-Limbed Robotic Systems

This analytic and experimental study proposes a control algorithm for coordinated position and force control for autonomous multi-limbed mobile robotic systems. The technique is called Coordinated Jacobian Transpose Control (CJTC). Such position/force control algorithms will be required if future robotic systems are to operate effectively in unstructured environments. Generalized Control Variables (GCVs), express in a consistent and coordinated manner the desired behavior of the forces exerted by the multi-limbed robot on the environment and a system's motions. The effectiveness of this algorithm is demonstrated in simulation and laboratory experiments on a climbing system.     

控制系统故障诊断的理论与技术

阐述了控制系统故障诊断技术的研究现状,将现有的各种故障诊断方法分为三类：（1）基于系统动态数学模型的方法;（2）基于信号处理的方法;（3）基于知识的方法。介绍了（1）的特点和当前的研究动态,指出鲁棒残差设计和对非线性系统的诊断是其关键和难点;对（2）中近年来发展的几种诊断方法作了评述。该类方法易于实现,适合故障检测,对故障分析较弱;简述了(3)中典型故障诊断方法的优缺点及应用方式等,其目前的研究趋向于多种方法的有机结合。最后指出了该领域有待进一步研究和主要问题和发展趋势。     

机器人系统有限时间自适应迭代学习控制

研究任意初态下，机器人系统的有限时间自适应迭代学习控制方法。引入初始修正吸引子的概念，构造一个含有初始修正项的误差变量。针对定常机器人系统和时变机器人系统，采用Lyapunov-like方法，分别设计迭代学习控制器处理系统中不确定性。并且，采用未含/含限幅学习机制，保证闭环系统各变量的一致有界性和误差变量在整个作业区间一致收敛性。藉以实现跟踪误差在预先指定区间的完全跟踪。仿真结果验证所设计控制方法的有效性。     

非均匀采样数据系统的故障检测

针对目前涉及较少的非均匀采样数据系统故障检测研究,研究了一类基于观测器的故障检测滤波器设计问题;对于非均匀采样数据系统,首先利用提升技术推导出系统的提升状态空间模型,然后选用基于未知输入观测器的故障检测滤波器来作为残差产生器;同时给出一种故障检测滤波器设计的H_∞最优化设计方法,并给出其最优解及存在条件;最后通过一个示例进行验证,结果证明了该方法的有效性;该方法能够有效地实现对非均匀采样数据系统的故障的检测。