【作者】 盛夏；

【导师】 王天宝；

【作者基本信息】 江苏大学 ， 控制工程， 2019， 硕士

【摘要】 网络控制系统以其资源共享、分布式控制和智能化等显著优点,被广泛应用于智能电器、工业机器人、航空航天设备等诸多领域,是当前工业控制领域发展的一个热点。然而,随着控制系统规模的增大,有限的网络资源和愈加复杂的控制任务之间的矛盾日益突出,以及网络结构的日趋复杂化对网络中数据传输的安全性要求也越来越高。基于以上现状,本文以一类网络带宽资源受限的线性网络控制系统为研究对象,分析了系统的稳定性和安全控制问题。首先,研究了改进型事件触发机制下线性网络控制系统的稳定性与控制器设计问题。利用一种更具一般性的改进型事件触发机制控制网络中的数据传输量,在此基础上构造包含尽可能多的系统时延信息的Lyapunov-Krasovskii泛函。基于Lyapunov泛函理论和改进的自由加权矩阵方法,给出了系统渐近稳定的充分条件和控制器设计方案。通过仿真实例与现有文献中事件触发方案比较,验证该事件触发机制拥有更大的平均发送周期,可以有效地减少网络中的数据传输量,节约更多的网络资源。然后,考虑到外部扰动的存在,研究了基于事件触发机制的网络控制系统H_∞控制问题。采用一种事件触发机制对当前传输的数据包进行判断和筛选,该事件触发机制是上述改进型事件触发机制的一种特例。同时,利用时滞系统方法构建了包含网络时延和事件触发机制的时滞模型,选取了一种新型不连续的Lyapunov-Krasovskii泛函,结合线性矩阵不等式技术给出了系统的H_∞稳定性判据和控制器设计方法。数值仿真实例表明该方法的有效性。最后,同时考虑网络时延、外部扰动和网络攻击的影响,研究了基于事件触发机制的H_∞滤波器设计问题。采用一种事件触发机制来减少网络中的数据传输量。同时,引入一个Bernoulli变量来描述网络攻击的随机特性,建立一个能同时刻画事件触发机制、网络时延和网络攻击影响下的H_∞滤波误差系统模型。利用线性矩阵不等式技术给出了系统的均方渐近稳定性判据,该判据刻画了事件触发参数,网络攻击发生概率,时延参数,滤波器参数之间满足的制约条件,以此为基础进行H_∞滤波器设计。通过仿真算例验证了H_∞滤波器设计方法的有效性。更多还原

【Abstract】 Network control system is widely used in many fields such as smart appliances,industrial robots,aerospace equipment,etc.due to its significant advantages such as resource sharing,distributed control and intelligence.It is a hot spot in the development of industrial control.However,as the scale of the control system increases,the contradiction between limited network resources and increasingly complex control tasks becomes increasingly prominent,and the increasingly complex network structure demands for the security of data transmission in the network.Based on the above situation,this paper takes a class of linear network control system with limited network bandwidth resources as the research object,and analyzes the stability and security control of the system.Firstly,the stability and controller design of linear networked control systems under improved event-triggered mechanism are studied.A more general improved event-triggered mechanism is used to control the amount of data transmission in the network,and a Lyapunov-Krasovskii functional with as many system delay information as possible is constructed.Based on the Lyapunov functional theory and the improved free weight matrix method,the sufficient conditions for the asymptotic stability of the system and the controller design scheme are given.By comparing the simulation example with the event triggering scheme in the existing literature,it is verified that the event-triggered mechanism has a larger average transmission period,which can effectively reduce the amount of data transmission in the network and save more network resources.Then,considering the existence of external disturbances,the H_∞control problem of network control system based on event-triggered mechanism is studied.The event-triggered mechanism is used to judge and filter the currently transmitted data packet,and the event-triggered mechanism is a special case of the above improved event-triggered mechanism.At the same time,the time-delay model including network delay and event-triggered mechanism is constructed by using the time-delay system method.A new type of discontinuous Lyapunov-Krasovskii functional is selected,the H_∞stability criterion and controller design method of the system are given by the linear matrix inequality technique.Numerical simulation examples show the effectiveness of the method.Finally,considering the effects of network delay,external disturbance and network attack,the H_∞filter design problem based on event-triggered mechanism is studied.An event-triggered mechanism is used to reduce the amount of data transmission in the network.At the same time,a Bernoulli variable is introduced to describe the random characteristics of network attacks.A H∞filtering error system that can simultaneously describe the event-triggered mechanism,network delay and network attack is established.The mean square asymptotic stability criterion of the system is given by the linear matrix inequality technique.The criterion characterizes the event-triggered parameters,the probability of network attack,the delay parameter,and the constraints between the filter parameters.Based on this,the H_∞filter design is performed.The effectiveness of the H_∞filter design method is verified by simulation examples.更多还原