CAN总线技术在温室环境监控系统设计中的运用

机械设计制造及其自动化文档，文档编号:JX1445  文档字数:26964.页数:55  附CAD图

 摘    要
　  现场总线技术是80年代末、90年代初国际上发展形成的，用于过程自动化、制造自动化、楼宇自动化等领域的现场智能设备互连通讯网络。它作为工厂数字通信网络的基础，沟通了生产过程现场及控制设备之间及其与更高控制管理层次之间的联系。它不仅是一个基层网络，而且还是一种开放式、新型全分布控制系统。这项以智能传感、控制、计算机、数字通讯等技术为主要内容的综合技术，已经受到世界范围的关注，成为自动化技术发展的热点，并将导致自动化系统结构与设备的深刻变革。CAN总线是现场总线的一种，其数据通信具有可靠性高，实时性强和灵活性好的特点，目前被认为是最有发展前途的现场总线之一。
 温室系统气候受影响的因数各种各样。复杂而且众多，难以完全计算在内。针对目前的温室系统的现状和特点，决定采用当前比较先进的现场总线技术进行控制。设计了温室系统的总体框架，各种植区各由一个智能节点来控制，节点之间采用现场总线相连，实现分散控制，再接入一计算机作为人机接口，实行监督。根据现代温室控制的要求，设计一套合适的应用现场总线技术的温室控制系统。
 本文在查阅大量国内外参考文献的基础上，概述了温室在国内外的发展历史以及发展现状。介绍了国内外温室测控装置的发展动态和发展方向，并且根据温室内影响作物生长的环境因子，即温度、湿度、光照等环境的条件、控制特点和控制方法，提出了适合本系统的环境因子控制方案。
 本文以Philips半导体公司的SJA1000作为独立控制器，通过控制SJA1000实现数据的接受和发送等通信任务。采用TMS320VC5402作为节点的微处理器，总线收发器采用82C250.本文着重介绍了温室环境控制系统的硬件。
 本文的设计思想是在满足系统要求的前提下，尽量选用价格低廉，功耗低的元器件，达到降低系统成本的目的。最后，本文根据项目的实际运行情况，对于应用CAN总线技术的现代温室控制系统进行了评估，对本人的工作进行了总结，展望了现代总线技术的美好应用前景。
关键词：温室环境 SJA1000 微处理器 控制系统

Abstract
  Fieldbus technology is the late 80s, early 90s formed the international development for process automation, manufacturing automation, building automation and other fields of on-site communications network interconnecting smart devices. Factory digital communications network as the foundation of the production process of communication and control equipment on site and with more control and management between the level of links. It is not only a grassroots network, but also an open, new full distributed control system. The intelligent sensing, control, computer, digital communications technology as the main content of the integrated technology has been worldwide concern, the development of automation technology to become hot, and will lead to automation systems and equipment of the profound structural changes. CAN bus is a fieldbus, the data communication with high reliability and flexibility of real-time strong and good, is now considered the most promising one of the fieldbus.    Greenhouse climate affected by various factors. Complex and numerous, difficult to be fully calculated. View of the current situation and characteristics of the greenhouse system, decided to use current technology more advanced field bus control. History and overall system design framework for the various growing areas to control by an intelligent node, nodes connected by field bus to achieve decentralized control, then access to a computer as a human-machine interface, the implementation of supervision. According to modern greenhouse control requirements, design an appropriate application of fieldbus technology, greenhouse control system.    This article reference in the access to a large number of domestic and international basis, an overview of the history of the greenhouse at home and abroad, and current condition. Introduced the domestic and international greenhouse monitoring and control devices and Fazhan direction of developments, and based on the greenhouse environmental factors affecting crop growth, namely, temperature, humidity, light and other environmental of the conditions, Kong Zhi characteristics and control method, suitable for the system proposed by the environmental factors control program.    In this paper, Philips Semiconductor as an independent controller SJA1000, SJA1000 achieved by controlling the data communications tasks such as receiving and sending. 89C51 microprocessor used as a node, the bus transceiver 82C250. This article focuses on the greenhouse environment control system hardware.    This design idea is to meet the system requirements of the premise, as far as possible use low cost, low power consumption components, to achieve lower system costs. Finally, the actual operation of the project, the application of CAN bus technology, modern greenhouse control system was evaluated on a summary of my work and looking forward to a bright modern bus technology applications. Key words: greenhouse environment  control system  microprocessor  SJA1000
 
目  录
中文摘要 i
Abstract ii
目录 iv
第1章 绪论 1
1.1课题背景 1
1.2国内外研究现状 1
1.3课题目的与主要内容 2
1.4本章小结 3
第2章 现场总线系统总体构架及CAN协议简介 4
2.1系统的总体构架 4
2.1.1上位机 4
2.1.2智能检测点 5
2.1.3 CAN通信 5
2.2选择CAN总线的原因 6
2.2.1CAN总线特点 6
2.2.2 CAN在温室控制中的应用 9
2.3本章小结 12
第3章 基于CAN总线系统的硬件电路设计 13
3.1 现场智能节点硬件电路设计 13
3.1.1数据采集模块设计 13
3.1.2单片机模块设计 17
3.1.3输出驱动控制模块设计 20
3.2上位机的设计 22
3.2.1硬件结构和工作原理 22
3.2.2设备驱动程序WDM 23
3.3 CAN总线通信控制器 24
3.4系统的抗干扰设计 27
3.5本章小结 27
第4章 基于CAN总线系统的软件设计 28
4.1CAN总线智能节点软件设计 28
4.2上位机软件设计 37
4.3本章小结 38
第5章 总结与展望 39
5.1回顾总结 39
5.2技术展望 39
参考文献 41
致  谢 43
附录一 滤波稳压电路 44
附录二 SJA1000内部结构图 45
附录三 智能节点硬件系统电路图 46
附录四SJA1000初始化程序： 47

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