无线网络控制系统仿真研究

发布时间：2018-03-01 18:13

本文关键词： 无线网络控制系统 TrueTime仿真模糊免疫PID Simth预估补偿　出处：《安徽理工大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着通讯技术的发展,传统的点对点控制方式已经不能满足现代工业控制需求。控制系统逐渐往网络化发展,而无线网络控制系统又有灵活性高等优势,成为控制理论的研究热点。对于无线网络控制系统的研究,由于涉及网络协议,控制器,网络时延及丢包等多方面的因素,仅仅从理论角度研究是很困难的,而如果采取实验的方法,又涉及成本较高的问题。因此,对于无线网络控制系统的研究,利用仿真工具对其进行建模仿真研究是一种可行且实用的方法。而到目前为止,对无线网络控制系统性能的仿真研究比较少,而且不够全面。本文基于TrueTime建立了无线网络控制系统仿真模型,全面系统的从两个角度对其进行了仿真研究： (1)从通讯理论出发了解网络本身,以达到减小网络时延及丢包对系统影响的目的。基于TrueTime仿真工具箱建立无线网络控制系统仿真系统,通过改变网络本身的属性,研究时延、干扰、采样周期、数据传输速率、调度策略和节点间距离对无线网络控制系统性能的影响。仿真结果表明：网络时延越大,网络控制性能越差；随着干扰增大,系统的控制性能越来越差；采样周期过大或过小,都会使系统控制性能变差,因此在实际应用中要选取合适的采样周期；理论上,数据传输速率越大,系统的控制性能越好；不同调度策略对无线网络的控制性能影响不同,实际应用中应选择合适的调度策略；随着节点间距离增大,系统控制性能越来越差。 (2)从控制理论出发,以确定的网络结构为研究对象,设计更优的控制器来达到减小网络时延及丢包对系统影响的目的。针对时延问题,提出用模糊免疫结合一种改进Smith补偿的方法对无线网络控制系统进行控制,设计了模糊免疫PID控制器和改进型的Smith预估补偿结构,并对系统进行了仿真研究。仿真结果表明：被控对象端改进型Smith预估结合模糊免疫PID控制策略对无线网络控制系统是有效的,而且可以对整个系统进行优化,降低时延的随机性对无线网络控制系统的影响,表现出很好的控制效果。
[Abstract]:With the development of communication technology, the traditional point-to-point control mode can no longer meet the needs of modern industrial control. The control system is gradually developing to the network, and the wireless network control system has the advantages of high flexibility, etc. The research of wireless network control system is very difficult because of many factors such as network protocol, controller, network delay and packet loss. If the method of experiment is adopted, the problem of high cost is involved. Therefore, it is a feasible and practical method to use simulation tools to model and simulate wireless networked control system. So far, the simulation research on the performance of wireless network control system is few and not comprehensive enough. This paper establishes the simulation model of wireless network control system based on TrueTime, and makes a simulation study of wireless network control system from two aspects. In order to reduce the network delay and the impact of packet loss on the system, the simulation system of wireless network control system is established based on TrueTime simulation toolbox, and the delay is studied by changing the attributes of the network itself. The effects of interference, sampling period, data transmission rate, scheduling strategy and distance between nodes on the performance of wireless networked control system are discussed. The simulation results show that the greater the network delay, the worse the network control performance. If the sampling period is too large or too small, the control performance of the system will become worse, so it is necessary to select the appropriate sampling period in practical application; in theory, the greater the data transmission rate, the better the control performance of the system. Different scheduling strategies have different effects on the control performance of wireless networks. In practical applications, appropriate scheduling strategies should be chosen, and with the increase of the distance between nodes, the control performance of the system becomes worse and worse. 2) based on the control theory and taking the determined network structure as the research object, a better controller is designed to reduce the network delay and the impact of packet loss on the system. In this paper, a fuzzy immune control method combined with an improved Smith compensation method is proposed to control the wireless network control system. A fuzzy immune PID controller and an improved Smith predictor compensation structure are designed. The simulation results show that the improved Smith predictor combined with the fuzzy immune PID control strategy is effective for the wireless network control system, and the whole system can be optimized. The effect of reducing the randomness of delay on the wireless network control system is very good.
【学位授予单位】：安徽理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TP273;TN92

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