【作者】 袁智；

【导师】 王常虹；

【作者基本信息】 哈尔滨工业大学 ， 控制理论与控制工程， 2010， 博士

【摘要】 随着通信技术的飞速发展,系统的网络化需求不断提高,传统的点对点的控制策略已经不能满足对控制系统的性能要求,点对点的结构在很多场合逐渐被通信网络所取代,系统中的传感器、控制器、执行器等部件通过通信网络来进行连接的网络化控制系统由此产生。与传统的点对点结构相比,网络化控制系统有很多优势,比如降低布线成本,易于诊断与维护,增加系统的可靠性等,因此在航空、航天、军事、医学、工业及交通等领域得到了广泛的关注。然而反馈回路中网络的引入使得网络化控制系统的分析与设计变得更加复杂,数据通信延时、丢包、多包、抖动、乱序等问题使得系统的性能下降甚至不稳定。因此,对网络化控制系统的研究具有重要的理论意义及实际应用价值。本文主要从单包传输与多包传输两方面研究网络化控制系统的建模、控制与故障检测问题,并基于移动机器人设计了网络化控制系统试验平台。主要研究工作如下:第1章介绍了网络化控制系统的概念及其产生的过程,描述了网络化控制系统的三种基本结构,接着分析网络化控制系统的若干基本问题,并综述了网络化控制系统的研究现状,最后概述了本论文的主要研究内容。第2章考虑离散网络化控制系统中具有单包传输的情况,研究含有任意时变时延以及数据包丢失的离散网络化控制系统的建模、稳定性分析及鲁棒控制问题。针对双边网络同时含有数据包丢失及任意时变网络时延的离散网络化控制系统,建立具有普遍意义的离散系统模型。在此模型的基础上,首先讨论了当不含外界干扰时,系统的稳定性分析及镇定控制器设计问题,设网络时延为可以大于一个采样周期的任意时变时延,推导出系统的镇定条件并给出了控制器的具体求解算法。然后在系统含有外界干扰时,研究系统的鲁棒H∞H∞控制和鲁棒l 2? l∞控制问题,分别推导出使系统渐近稳定并满足H∞性能指标以及性能指标的充分条件,并给出了求解最大时延以及l 2?l∞H∞、l 2? l∞扰动衰减度的算法。为了优化结果,求解扰动衰减度的算法中采用二分法来进行迭代。由于条件中非线性项的存在使得矩阵不等式难于求解,文中采用锥补线性化的方法来求解控制器。第3章考虑离散网络化控制系统中具有多包传输的情况,研究含有任意时变时延以及数据包丢失的离散网络化控制系统的建模、稳定性分析及鲁棒控制问题。针对含有多包传输、数据包丢失以及时变网络短时延的离散网络化控制系H∞统,建立具有普遍意义的离散系统模型。首先从无时延及含有时变短时延两方面把同时含有多包传输、数据包丢失的离散网络化控制系统建模成为具有固定事件率约束的异步动态系统(ADS),推导出使系统渐近稳定的充分条件并给出了镇定控制器的具体求解算法。再从系统含有外界干扰以及不含外界干扰两方面把同时含有丢包、多包及时变短时延的离散网络化控制系统建模成为具有任意切换信号的离散线性切换系统,并结合切换Lyapunov函数研究系统的镇定和鲁棒控制问题。H∞第4章从单包传输及多包传输两种情况来研究离散网络化控制系统的鲁棒故障检测问题。首先针对含有时变网络短时延及范数有界的未知输入影响的单包传输网络化控制系统,设计鲁棒故障检测滤波器,最终将故障检测滤波器的设计问题转化成一类具有线性矩阵不等式约束和目标函数的凸优化问题,然后考虑同时含有数据包丢失及多包传输的离散网络化控制系统,利用多包传输及数据包丢失的特点将误差系统等效为离散线性切换系统,利用切换系统理论推导出使误差系统在任意切换信号下渐近稳定并具有H∞性能指标γ的充分条件。第5章采用上海广茂达伙伴机器人有限公司生产的智能风暴研究版AS-R型机器人作为被控对象,以机器人避障为例构建了网络化控制系统试验平台,为网络化控制系统的算法验证提供试验环境。整体系统分为视觉子系统及控制子系统两部分进行构建,详细给出了控制子系统及视觉子系统的设计过程及网络接口的设计方法。更多还原

【Abstract】 With the rapid development of communication technology and the networking of control systems, the traditional point-to-point control strategy can not meet the performance requirements of control systems. Point-to-point structure in many occasions has been gradually replaced by communication networks and Networked Control System(NCS) in which sensors, controllers, actuators and other components connected through the communication network thus generated. Compared with the traditional point-to-point structure, NCS has many advantages such as lower wiring costs, easy diagnosis and maintenance, increased system reliability, so NCS has received wide attention in the aviation, aerospace, military, medical, industrial and transportation fields. However, the introduction of network in feedback loops makes the analysis and design of NCS more complex. Network-induced delay, packet loss, multiple-packet transmission, networked jitter, packets disorder and other issues make the system performance degraded or even unstable. Therefore, the research of NCS has important theoretical significance and practical value.In this paper, both the single-packet transmission and multi-packet transmission are considered, and the research concentrates on the modeling, control and fault detection of the NCS. Networked control system test platform is designed and implemented based on robots. The main contents are as follows:In Chapter 1, the concept of NCS and production process are introduced, and three basic structures of the system are described, then a number of fundamental issues of the system are discussed and the research status at home and abroad in this field is introduced. Finally, we outline the main contents of this paper.In Chapter 2, with the discrete NCS in single-packet transmission considered, the problems of modeling, stability analysis, robust H∞control and robust l 2? l∞control of the system with arbitrary time-varying delay and packet loss are discussed. For the NCS with network-induced delay and packet loss, the universal model of the discrete system is established. First, we discuss the stability and control of the discrete NCS without disturbance based on this model. Networked-induced delay is time-varying and it can be set to any of more than one sampling cycle. Then we introduce the external disturbance into the system and discuss the problem of robust control and robust control. Sufficient conditions to asymptotic stabilize the system and meet the requirements of the given robust H∞l 2?l∞H∞performance index and robust l 2?l∞performance index are derived. Algorithms to solve the maximum delay as well as , disturbance attenuation are presented. To optimize results, dichotomy is used in the iterate algorithm to solve the disturbance attenuation. As conditions in the presence of nonlinear term make it difficult to solve the matrix inequalities, cone complementarity linearization method is used to solve the controller. H∞l 2?l∞In Chapter 3, with the discrete NCS in multiple-packet transmission considered, modeling, stability analysis and robust H∞control of the system with arbitrary short time-varying delay and packet loss are discussed. For the discrete NCS in multiple-packet transmission, packet loss and arbitrary short time-varying delay, the universal model of the discrete system is established. First, the discrete NCS in multiple-packet transmission and packet loss is modeled as an asynchronous dynamical system(ADS) in both case of with and without arbitrary short time-varying delay. Sufficient conditions to asymptotic stabilize the system are derived and the algrithm to solve the controller is presented. Then the discrete NCS with packet loss, multiple-packet transmission, and arbitrary short time-varying delay is modeled as a discrete linear switched system with arbitrary switching signal in both case of with and without external disturbance. Stability analysis and robust control of the system are discussed combined with switching Lyapunov functions. H∞In Chapter 4, the problem of robust fault detection of the discrete NCS is discussed in both case of single-packet and multiple-packet transmission. First, a fault detection filter is designed for the NCS with short time-varying delay and norm bounded unknown input in the case of single-packet transmission. The problem of filter design is finally transformed into a class of the convex optimization problem with linear matrix inequalities constraints and objective function. Then the discrete NCS with both packet loss and multiple-packet transmission is considered and the error system is equivalent to discrete linear switched system by the characteristic of the multiple-packet transmission and packet loss. Sufficient conditions to asymptotically stablize the error system with H∞performance indexγand arbitrary switching signals are derived by the theory of switched systems.In Chapter 5, networked control control test platform is built with the AS-R type robot producted by Shanghai Grandar Robotics Co., LTD chosen as the plant to implement robot obstacle avoidance as an example. The platform provides test environment to verify the algorithm of NCS. The overall system is divided into two parts: the vision subsystem and the control subsystem, and the process of system design and network interface design of the two subsystems are given in details.更多还原