（毕业设计论文）《PLC交通信号灯的设计》.docVIP

摘要 如今，交通信号灯安装在各个十字路口，已经成为指导交通车辆最常见和最有效的手段。随着社会的进步，人们的消费能力不断的提高，很多人购买私家，导致现在的交通拥堵不堪。因此采用有效的方法控制交通灯是势在必行的。PLC能够把东西方向或南北方向的车辆按数量多少进行统计，然后计算出给定东西方向与南北方向的红绿灯时长。这样就可以实现按车流量大小给定绿灯时长，达到最大限度的有车放行，减少十字路口的车辆滞流，缓解交通拥挤、实现最优控制，从而提高了交通指挥系统的效率。 PLC的应用正在不断地走向深入，也带动了传统控制行业更新发展。PLC具有结构简单、编程方便、可靠性高等优点，已广泛用于工业过程和位置的自动控制中。它对使用环境适应性强，同时其内部定时器资源十分丰富，可对目前普遍使用的“渐进式”信号灯进行精确控制，特别对多岔路口的交通控制可方便地实现。因此现在越来越多地将PLC应用于交通信号灯系统中。 同时，PLC本身内部还具有通讯联网功能，能够将同一条道路上的信号灯组成一局域网进行统一调度和管理，可以缩短车辆等候时间，实现科学化人性化的管理。在实时检测和自动控制的PLC应用系统中，PLC往往是作为一个核心部件来使用。 关键词：交通灯，PLC，车流量，最优控制 Abstract Today, the traffic lights installed at various crossroads, has become the most common and most effective means of guiding transport vehicles. Along with social progress, peoples spending power is continuously improving, many people buy private, resulting in gridlocked traffic. Therefore an effective method to control the traffic lights is imperative. PLC to the east-west or north-south direction of the vehicle according to the number the number of statistics, and then calculate the long given the traffic lights of the east-west direction and north-south direction. This can be achieved given the green light traffic flow size and duration, to achieve maximum vehicle clearance, reducing the crossroads of the vehicle stagnation, relieve traffic congestion, to achieve optimal control, thereby increasing the efficiency of the traffic control system.PLC application is continuously deepening, has also led to the development of traditional control industry updates. PLC has a simple structure, easy programming, high reliability, has been widely used for automatic control of industrial processes and location. Its use environment adaptability, while its internal timer resources are very rich, precise control of the current widespread use of progressive signal, in particular traffic control in the multi-fork can be easily implemented. So now more and more the PLC used in traffic lights system.At the same time, the PLC itself internal communication