【作者】 李欢；

【导师】 林建龙； 刘玉德；

【作者基本信息】 北京工商大学 ， 机械设计及理论， 2009， 硕士

【摘要】 本文以城市干道上的两个相邻交叉路口为控制对象,设计了一套交通信号控制系统,并分别从硬件和软件方面,对以可编程逻辑控制器(Programmble Logical Controller,简称PLC)为主控制器的交通信号控制系统的整体设计进行了介绍。本系统的硬件电路主要包括:主控部分、车流量检测部分、通信接口电路、异常诊断与定位电路和保安控制电路等。在设计硬件时,为了减少控制系统的成本和体积,采用了由PC作为上位机,PLC作为下位机,以及单片机作为传感器信号采集与处理装置的方法来组成现场总线结构,并给出了实现PC与PLC间通信,以及PLC与单片机间通信的方法。本系统的软件设计由数据采集与处理部分程序和主控部分程序组成。主控部分程序可以实现信号控制系统的四种不同的控制方式:手动控制方式、多时段控制方式,闪光控制方式和感应控制方式。在感应控制方式中,基于大系统的分解—协调控制原理,对控制干道上两个相邻路口的系统提出了两级模糊协调控制结构。第一级为控制级,由两个相似的模糊控制器构成,用来调整各个路口的信号周期和绿信比;第二级为协调级,根据测得的交通流数据协调相邻子系统间的车辆数,以使车辆的平均延误时间尽可能小。最后,用Matlab软件对该系统的感应控制方式进行仿真,仿真结果表明控制效果优于传统的定时控制,证明了本文提出的基于模糊控制的交通信号控制系统在提高城市道路通行方面具有一定的现实意义。更多还原

【Abstract】 The thesis designs a new traffic signal control system which takes the two-adjacent intersections on the urban traffic trunk road as a control object. The overall hardware and software design of the traffic signal system which uses the PLC as the host controller is introduced.The system hardware circuits include the main control circuits, the communication interface circuits, the abnormity diagnose and orientation circuits, the control circuits, etc. In order to reduce the costs and volume of the control system, a fieldbus structure which adopts the method of taking a PC as host computer, PLC as a client computer, as well as monochip as a sensor signal acquisition equipment, and the implementation methods of communication between PC and PLC, as well as communication between PLC and monochip are presented.The system software design consists of the program for the data collection and processing part and the program for the main control part. The program for the main control part could implement four different control modes of the signal control system, which include the manually control mode, time-division control mode, light-flicker control mode, and actuated control mode. Based on the principle of decomposition-coordination for large scale systems, a two-level coordinated fuzzy control structure is used in the actuated control mode of the system which controls two-adjacent intersections on the trunk road. The first layer which consists of two kindred fuzzy controllers adjusts the cycle and splits of every intersection. Based on the traffic volume data measured from every intersection, the second layer coordinates the vehicle number between the adjacent intersections to make the average vehicle delay time shorten.In the end of the thesis, the actuated control mode is simulated by using Matlab, and the simulation indicates that the control effect is better than the conventional time-fixed mode, which proves that the traffic signal control system based on fuzzy logic in the thesis is practical and significant to improve the traffic ability of the urban roads.更多还原