【作者】 黎善斌；

【导师】 孙优贤；

【作者基本信息】 浙江大学 ， 控制科学与控制工程， 2005， 博士

【摘要】 利用通讯网络实现地域上分布的现场传感器、控制器及执行器之间的信息相互交换,以达到被控对象的实时反馈控制,这样的一类被称为网络控制系统的新型控制系统近年来得到了广泛地关注。与传统的点对点控制系统相比,网络控制系统具有可实现复杂大系统和远程控制、可实现资源共享、具有高的诊断能力、交互性好、减少系统的布线、增加系统柔性和可靠性、安装维护方便等诸多的优点。因此,在众多领域得到了广泛地应用。然而,网络中的延时、丢包、通讯约束等问题也使网络控制系统的分析和设计变得异常复杂。 本文结合鲁棒控制理论,对网络控制系统进行了合理地建模,通过引入多种性能指标,对系统的鲁棒性和稳定性进行了协调研究,从而建立了性能指标与网络因素之间的内在联系;着眼于减少结果的保守性,提出了网络控制系统新的稳定性条件和控制器设计方法。 将分布式的网络延时合并为单一延时,简化了网络控制系统的复杂结构和系统设计过程。从抑制负载干扰的角度出发,提出了一种继电自整定双PID的控制结构。在此结构下,针对不同特点的控制对象,提出了PID控制器的鲁棒数字化设计方法。 通过将时变的网络延时分解成恒定的平均延时和不确定延时两部分,网络延时大于一个采样周期情况下的网络控制系统进而可建模成具有结构不确定性的离散时间模型。基于这个模型,我们给出了网络控制系统渐近稳定的线性矩阵不等式条件,通过迭代线性矩阵不等式方法设计了一种新型的控制策略。 在不确定时滞系统的背景下,分别对不确定离散对象和连续对象,研究了含有界时变延时的网络控制系统,提出了网络控制系统的保性能控制。通过引入一新的Lyapunov-Krasovskii泛函和广义系统模型方法,提出了网络控制系统保性能控制器存在新的时滞依赖型充分条件。通过求解线性矩阵不等式方程组,给出了控制器的参数化设计方法。 将具有随机网络延时和丢包的网络控制系统建模成Markov跳变系统,通过引入一新的随机Lyapunov-Krasovskii泛函和松弛矩阵变量技术,给出了延时依赖的随机稳定和扰动衰减的线性矩阵不等式条件。从而提出了网络控制系统新的鲁棒H_∞和扰动衰减性能分析方法。随后,还研究了不确定连续Markov跳变系统的鲁棒H_∞随机控制和扰动更多还原

【Abstract】 A great deal of attention has recently been focused on a class of networked control systems （NCS） wherein the control loops are closed through communication networks. This family of systems is an integration of plants, sensors, controllers, actuators and communication networks of certain local field. It aims to ensure data transmission and coordinating manipulation among spatially distributed components. Compared with conventional point-to-point control systems, the advantages of NCS are less wiring, lower install cost as well as greater agility in diagnosis and maintenance. Because of these distinctive benefits, typical application of these systems ranges over various fields, such as automotive, mobile robotics, advanced aircraft, and so on.However, the introduction of communication networks in the control loops makes the analysis and design of NCS complex. The requirements for stable feedback control with network are not yet satisfied due to random network-induced delays, jitter, packet losses as well as limited bandwidth.In this dissertation, networked control systems in the frame of robust control theory are reasonably modeled. By introducing kinds of performance index and co-considering the robust and stability, the inner relationship between performance index and network quality is also established. With an aim to decrease the conservatism of results, new stability results and control law design methods are presented by some new techniques.Summing the distributed network-induced delays as a single delay simplifies the complex structure and design procedure of networked control systems. From the viewpoint of load-disturbance rejection, a structure with dual relay auto-tuning robust PID is proposed. On different plants, a novel digital robust PID design scheme is presented according to the structure.Time-varying delays are regarded as the sum of the mean delays and uncertain delays. Furthermore, NCS with long time delays is modeled as a discrete-time model with structural uncertainty for its time-varying network-induced delays. Based on the model, a new control law via an iterative LMI approach is presented which can stabilize the closed-loop system.Time-varying but bounded delay issue of networked control systems （NCS） within the framework of discrete-time as well as continuous-time linear state-delayed system with norm-boundeduncertainty is addressed. A delay-dependent sufficient condition for the existence of guaranteed cost controller for NCS is presented by a new Lyapunov-Krasovskii functional and descriptor systems method.Random time-delays and packet losses issues of networked control systems （NCS） within the framework of jump linear systems with mode-dependent time-delays are addressed. A new delay-dependent condition on the stochastic stability is proposed by a new stochastic Lyapunov-Krasovskii functional and slack variables method. The condition is formulated as a set of coupled linear matrix inequalities （LMIs）. Then a new stable H_∞ design method is developed. Furthermore, the robust H_∞ issue of uncertain Markovian jump linear systems （MJLSs） with mode-dependent time-delays is also addressed. An H₂/H_∞ issue of networked control systems is presented without the involvement of matrix bounding technique. Therefore, the less conservative results are expected.At last, a novel testbed of Internet-based mobile robot is designed so that the remote user can control the mobile robot through Internet. The testbed also serves as a very useful tool for theoretical researchers on networked control and real-time scheduling.更多还原