基于PLC的車輛出入庫管理系統(tǒng)


摘 要
隨著生產(chǎn)力和科學技術的不斷發(fā)展，人們的日常生活和生產(chǎn)活動大量的使用自動化控制，不僅節(jié)約了人力資源，而且很大程度的提高了生產(chǎn)效率，又進一步的促進了生產(chǎn)力快速發(fā)展，并不斷的豐富著人們的生活。
早期的自動控制系統(tǒng)是依靠繼電-接觸器來實現(xiàn)的，其特點是：結(jié)構(gòu)簡單、價格低廉、抗干擾能力強，可以實現(xiàn)集中控制和遠距離控制，但是其采用固定接線，通用性和靈活性差；又采用觸點的開關動作，工作頻率低，觸點易損壞，可靠性差。
1969年，出現(xiàn)了可編程邏輯控制器PLC（Programmable Logic Controller），其特點是：具備邏輯控制、定時、計數(shù)等功能，編程語言采用直觀的梯形圖語言，軟件更改方便，通用性和靈活性好。
目前，可編程控制器PLC主要是朝著小型化、廉價化、標準化、高速化、智能化、大容量化、網(wǎng)絡化的方向發(fā)展，與計算機技術相結(jié)合，形成工業(yè)控制機系統(tǒng)、分布式控制系統(tǒng)DCS(Distributed Control System)、現(xiàn)場總線控制系統(tǒng)FCS(Field bus Control System)，這將使PLC的功能更強，可靠性更高，使用更方便，適用范圍更廣。
本設計是基于PLC的車輛出入庫管理系統(tǒng)，采用兩位LED來顯示車庫內(nèi)車輛的實際數(shù)量。使用兩個光傳感器來監(jiān)控車輛的進出并完成計數(shù)工作，車輛進入時經(jīng)過兩個傳感器使顯示數(shù)字加一，車輛外出時經(jīng)過兩個傳感器使顯示數(shù)字減一，但當車輛只經(jīng)過一個傳感器時不計數(shù)。
為了防止意外計數(shù)錯誤，本系統(tǒng)采用反復程序校驗，來提高系統(tǒng)的可靠性。
首先，注意控制兩個傳感器之間的距離，用程序驗證進出車庫的是否是車輛，當人通過傳感器時不計數(shù)；其次，采用邏輯互鎖方式，啟動加計數(shù)則要鎖定減計數(shù)，產(chǎn)生加計數(shù)脈沖時則要鎖定減計數(shù)脈沖，如此以保證可靠性；最后，及時的進行復位處理，以免車輛在傳感器附近作往返運動時錯誤計數(shù)。

關鍵詞： PLC   傳感器  車輛   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 錄
摘 要 I
Abstract II
目 錄 III
第一章  引 言 4
1.1  PLC的基本結(jié)構(gòu) 4
1.2   PLC的工作原理 5
第二章  車輛出入庫管理系統(tǒng)的構(gòu)成 6
2.1  整體框架 6
2.2  傳感器的布置 6
2.3  顯示電路 7
第三章  PLC的I/O端口接線 8
第四章  I/O 口地址分配 9
第五章  程序設計 10
5.1  控制要求 10
5.2  計數(shù)邏輯 10
5.3  程序流程圖 11
5.4  梯形圖 12
第六章  結(jié) 論 14
致謝 15
參考文獻 16
畢業(yè)論文小結(jié) 23
附錄..............................................................................................................24