基于plc的车辆出入库管理系统.doc

基于PLC的车辆出入库管理系统


摘 要
随着生产力和科学技术的不断发展，人们的日常生活和生产活动大量的使用自动化控制，不仅节约了人力资源，而且很大程度的提高了生产效率，又进一步的促进了生产力快速发展，并不断的丰富着人们的生活。
早期的自动控制系统是依靠继电-接触器来实现的，其特点是：结构简单、价格低廉、抗干扰能力强，可以实现集中控制和远距离控制，但是其采用固定接线，通用性和灵活性差；又采用触点的开关动作，工作频率低，触点易损坏，可靠性差。
1969年，出现了可编程逻辑控制器PLC（Programmable Logic Controller），其特点是：具备逻辑控制、定时、计数等功能，编程语言采用直观的梯形图语言，软件更改方便，通用性和灵活性好。
目前，可编程控制器PLC主要是朝着小型化、廉价化、标准化、高速化、智能化、大容量化、网络化的方向发展，与计算机技术相结合，形成工业控制机系统、分布式控制系统DCS(Distributed Control System)、现场总线控制系统FCS(Field bus Control System)，这将使PLC的功能更强，可靠性更高，使用更方便，适用范围更广。
本设计是基于PLC的车辆出入库管理系统，采用两位LED来显示车库内车辆的实际数量。使用两个光传感器来监控车辆的进出并完成计数工作，车辆进入时经过两个传感器使显示数字加一，车辆外出时经过两个传感器使显示数字减一，但当车辆只经过一个传感器时不计数。
为了防止意外计数错误，本系统采用反复程序校验，来提高系统的可靠性。
首先，注意控制两个传感器之间的距离，用程序验证进出车库的是否是车辆，当人通过传感器时不计数；其次，采用逻辑互锁方式，启动加计数则要锁定减计数，产生加计数脉冲时则要锁定减计数脉冲，如此以保证可靠性；最后，及时的进行复位处理，以免车辆在传感器附近作往返运动时错误计数。

关键词： PLC   传感器  车辆   可靠性
Abstract
With productivity and the continuous development of science and technology, people's daily lives and production activities of a large number of the use of automated control, not only saving human resources, but a large degree of improved production efficiency, further promote the rapid development of productive forces, and constant enrich people's lives.
Early automatic control system relies on the relay - Contactor to achieve, and its features are: simple structure, low cost, anti-interference capability, can achieve centralized control and remote control, but the introduction of fixed wiring, versatile and flexible of the poor and by the switch contacts, the low frequency contacts easily damaged, poor reliability.
1969, a programmable logic controller PLC (Programmable Logic Controller), its features are: a logic control, timing, counting, and other functions, intuitive programming language used ladder diagram language, software changes convenience, versatility and flexibility good.
At present, the major PLC programmable controller is a small, low-cost, standardized, high-speed, intelligent, high-capacity, in the direction of the network, and computer technology, formation of industrial control systems, distributed Control Systems DCS (Distributed Control System), fieldbus control system FCS (Field bus Control System), the PLC will enable more powerful, more reliable, more convenient to use, a wider scope.
The design is based on the storage of vehicles PLC management systems, LED used two vehicles in the garage to show that the actual number. The use of two light sensor to monitor vehicle access and complete count, the two vehicles entered the house through the sensor and a digital display, two vehicles going through the sensor by a digital display, but only after a sensor vehicles will not count.
In order to prevent accidents counting error, the system used repeatedly checking procedures to enhance the reliability of the system.
First of all, pay attention to control the distance between the two sensors, access to the garage with the certification procedures for the vehicles, through the sensor when people do not count; Secondly, the introduction of the logical interlocked, and counting would start by counting lock, a Canadian Counting will have to lock pulse by pulse count, so in order to ensure reliability; Finally, a reduction of the processing time to avoid vehicles in the vicinity of sensors for counting from the wrong campaign.

Key words: PLC    Sensor   Vehicles   Reliability

目 录
摘 要 I
Abstract II
目 录 III
第一章  引 言 4
1.1  PLC的基本结构 4
1.2   PLC的工作原理 5
第二章  车辆出入库管理系统的构成 6
2.1  整体框架 6
2.2  传感器的布置 6
2.3  显示电路 7
第三章  PLC的I/O端口接线 8
第四章  I/O 口地址分配 9
第五章  程序设计 10
5.1  控制要求 10
5.2  计数逻辑 10
5.3  程序流程图 11
5.4  梯形图 12
第六章  结 论 14
致谢 15
参考文献 16
毕业论文小结 23
附录..............................................................................................................24