随着汽车电子技术的不断发展,现代汽车中所使用的电子控制系统和通讯系统越来越多,巨大的数据交换量,如仍然采用传统数据交换的方法,即用导线进行点对点的连接的传输方式将是难以想象的。CAN(Controller Area Network)作为汽车环境中的微控制器通讯总线,解决了这一问题,它在车载各电子控制装置 ECU之间交换信息,形成了汽车电子控制网络。而目前,几乎所有大巴中的空调空调系统,仍用导线经行点对点的连接,导线连接复杂,通讯不可靠,而且与车身CAN-bus系统无法实现互连,不能实现信息共享,与汽车电子的现有技术水平不相匹配。
鉴于此,本设计采用CAN-bus通信技术,选用集成有CAN控制器的单片机PIC18F2580作为主控制器,实现大巴空调控制系统CAN-bus通讯。该系统节约了导线的使用量,降低了线路发热损耗,提高控制系统的检测精度与控制的稳定性,并可以与车身CAN-bus系统实现直接对接。
关键词:汽车电子,CAN-bus,空调控制,PIC18F2580
Abstract
With the continuous development of Automotive Electronics Technology, electronic control system and communication system used in modern automotive is more and more. If we still use the traditional methods of data exchange, that is, transmission with wires connected to a point-to-point, the result will be unimaginable. The issue was resolved by CAN (Controller Area Network), as the micro-controller communication bus in automotive environment. Automotive electronic control devices (ECU) exchange information by CAN-bus which formed a network of automotive electronic control. While at present, almost all buses air-conditioning control system still use wire line to a point-to-point connection. If so, wire connection is complex, communication is unreliable, also it is unable to achieve interconnection to the CAN-bus system of automobile body, information sharing can not be achieved and it is not matched with the the existing level of Automotive Electronics Technology.
So the bus air-conditioning control system in this design used CAN-bus communication technology, selected single chip microcomputer PIC18F2580 integrating CAN-controller and realized CAN-bus communication. The system saved the use of wire, reduce heat loss of lines, improved detection accuracy and control stability of control system, also able to achieve interconnection to the CAN-bus system of automobile body.