基于CAN通讯的汽车组合仪表的数据定义和测试平台
摘要
随着汽车电子的飞速发展和消费者对各种车载设备需求量的增长,汽车仪表上需要显示的信息越来越多,由七八十年代的十余种信号,到现在的超过四十种信号。由于总线技术可大大简化信号传输用的线束,故总线化已经成为汽车仪表的发展趋势之一。
本文首先对汽车仪表的研究现状及发展趋势进行了调研,分析了仪表的几种不同显示方式,对相应元件的特性和工作原理作了归纳整理,对CAN通讯的基本原理做了简要介绍。然后,根据项目要求,设计开发了整车的网络拓扑结构,该网络包括发动机控制器、变速箱控制器、气囊控制器、ABS控制器、组合仪表等典型节点;在该网络中,以仪表节点为重点研究对象,对与仪表相关的CAN通讯数据进行了分类和定义,确定了数据帧的优先级、发送间隔、基准值、放大系数等参数;OSEK(即汽车电子开发系统及其接口)是由欧洲汽车厂商最早提出的一种实时操作系统规范,其中的OSEK COM部分为车载通信提供了统一的接口和协议,本文以OSEK传输规范为基础,进一步制定了当一次传输的信息量超过8字节时所使用的通讯协议,以此为基础可以进行防盗、诊断等应用层通讯协议的制定;为了方便地对开发中和完成后的CAN总线网络进行测试和评价,本文以通用CAN设计开发测试软件CANoe为基础,结合CANstress和CANscope,通过控制面板、模拟显示面板的设计及CAPL编程,开发了组合仪表的CAN通讯测试平台。基于该平台,对仪表实物样品的采样率、抗干扰能力、CAN通讯可靠性等进行了测试,为仪表的CAN通讯软硬件设计和改进提供了技术依据。目前该测试平台已具备对物理层参数、抗干扰能力及CAN通讯数据的测试功能并已应用于实际研发中,使用结果表明本论文的设计方案是可行和正确的。
Automotive electronic has been developed very quickly in the recent years, the customers need also always more comfort equipment on the car. More and more information must be displayed on the cluster of the automobile. On 1970’s only about 10 signals are displayed on the cluster, but now on some car more than 40 signals are displayed on the cluster. Bus technology can simplify the wire harness of automobile very much, so to use BUS is a trend of development of automotive cluster.
This study has first researched the current situation and develop trend of the automotive cluster, analyzed several different display method, introduced the communication mechanism of CAN—the most widely used BUS System on automobile. This study has then developed the topology of the whole car network, including the nodes of engine ECU, gearbox ECU, Airbag ECU, ABS ECU, Cluster and so on. The cluster is handled here as a focused point. The communication data with cluster are sorted and defined, priority, interval, reference and constant of the messages are determined. OSEK communication (OSEK COM) is a uniform communication environment for automotive control unit application software. The OSEK COM specification increases the portability of application software modules by defining common software communication interfaces and behaviour for internal communication and external communication. Based on OSEK COM, this study has defined transport protocol, which is needed when more than 8 byte information must be transported one time, on this basis can application such as diagnostic and secret code be developed. To test a cluster in the constructions phase, this study has constructed a test bench with common tool from company Vector: CANoe, CANstress and CAN scope. Control and display panel, CAPL programming are finished in the construction of the test bench. With this test bench, we can test the property of the being developed cluster such as sampling rate, ability of antidisturbance, action on CAN message. This is very helpful for the construction of the cluster. This test bench has been in put into use. It’s proved very useful. So the construction in this study is feasible and right.
本文首先对汽车仪表的研究现状及发展趋势进行了调研,分析了仪表的几种不同显示方式,对相应元件的特性和工作原理作了归纳整理,对CAN通讯的基本原理做了简要介绍。然后,根据项目要求,设计开发了整车的网络拓扑结构,该网络包括发动机控制器、变速箱控制器、气囊控制器、ABS控制器、组合仪表等典型节点;在该网络中,以仪表节点为重点研究对象,对与仪表相关的CAN通讯数据进行了分类和定义,确定了数据帧的优先级、发送间隔、基准值、放大系数等参数;OSEK(即汽车电子开发系统及其接口)是由欧洲汽车厂商最早提出的一种实时操作系统规范,其中的OSEK COM部分为车载通信提供了统一的接口和协议,本文以OSEK传输规范为基础,进一步制定了当一次传输的信息量超过8字节时所使用的通讯协议,以此为基础可以进行防盗、诊断等应用层通讯协议的制定;为了方便地对开发中和完成后的CAN总线网络进行测试和评价,本文以通用CAN设计开发测试软件CANoe为基础,结合CANstress和CANscope,通过控制面板、模拟显示面板的设计及CAPL编程,开发了组合仪表的CAN通讯测试平台。基于该平台,对仪表实物样品的采样率、抗干扰能力、CAN通讯可靠性等进行了测试,为仪表的CAN通讯软硬件设计和改进提供了技术依据。目前该测试平台已具备对物理层参数、抗干扰能力及CAN通讯数据的测试功能并已应用于实际研发中,使用结果表明本论文的设计方案是可行和正确的。
Automotive electronic has been developed very quickly in the recent years, the customers need also always more comfort equipment on the car. More and more information must be displayed on the cluster of the automobile. On 1970’s only about 10 signals are displayed on the cluster, but now on some car more than 40 signals are displayed on the cluster. Bus technology can simplify the wire harness of automobile very much, so to use BUS is a trend of development of automotive cluster.
This study has first researched the current situation and develop trend of the automotive cluster, analyzed several different display method, introduced the communication mechanism of CAN—the most widely used BUS System on automobile. This study has then developed the topology of the whole car network, including the nodes of engine ECU, gearbox ECU, Airbag ECU, ABS ECU, Cluster and so on. The cluster is handled here as a focused point. The communication data with cluster are sorted and defined, priority, interval, reference and constant of the messages are determined. OSEK communication (OSEK COM) is a uniform communication environment for automotive control unit application software. The OSEK COM specification increases the portability of application software modules by defining common software communication interfaces and behaviour for internal communication and external communication. Based on OSEK COM, this study has defined transport protocol, which is needed when more than 8 byte information must be transported one time, on this basis can application such as diagnostic and secret code be developed. To test a cluster in the constructions phase, this study has constructed a test bench with common tool from company Vector: CANoe, CANstress and CAN scope. Control and display panel, CAPL programming are finished in the construction of the test bench. With this test bench, we can test the property of the being developed cluster such as sampling rate, ability of antidisturbance, action on CAN message. This is very helpful for the construction of the cluster. This test bench has been in put into use. It’s proved very useful. So the construction in this study is feasible and right.
引文
[1] ISO-11898. Road Vehicles—Interchange of digital information—Controller area network (CAN) for high speed communication. International Standards Organization. 1993.
[2] VW Cluster Drawing.
[3] TTCAN. TTCAN User’s Manual, Robert Bosch GmbH, 2001. Available from http://www.can.bosch.com/docu/Users_Manual_TTCAN.pdf.
[4] TTP. TTP/C protocol specification. Technical report, TTTech Computertechnik, Wien, Austria. 1999. Available from http://www.tttech.com.
[5] Gerhard Walliser und 38 Mitautoren, Elektronik im Kraftfahrzeugwesen. 1997
[6] M. Zeiss, Anzeigetechnologien zur Informationsdarstellung. 1997
[7] Vector: CANoe Manual V5.0
[8] CAN-bus 现场总线应用方案-汽车电子篇,广州周立功单片机发展有限公司,2004
[9] 魏春源等译,汽车电气与电子,北京理工大学出版社,2004
[10] 邬宽明,CAN 总线原理和应用系统设计,北京航空航天大学出版社,1996
[11] Bosch, CAN specification, Version 2.0, Robert Bosch GmbH, 1991
[12] OSEK Communication Specificatin 3.0.3
[2] VW Cluster Drawing.
[3] TTCAN. TTCAN User’s Manual, Robert Bosch GmbH, 2001. Available from http://www.can.bosch.com/docu/Users_Manual_TTCAN.pdf.
[4] TTP. TTP/C protocol specification. Technical report, TTTech Computertechnik, Wien, Austria. 1999. Available from http://www.tttech.com.
[5] Gerhard Walliser und 38 Mitautoren, Elektronik im Kraftfahrzeugwesen. 1997
[6] M. Zeiss, Anzeigetechnologien zur Informationsdarstellung. 1997
[7] Vector: CANoe Manual V5.0
[8] CAN-bus 现场总线应用方案-汽车电子篇,广州周立功单片机发展有限公司,2004
[9] 魏春源等译,汽车电气与电子,北京理工大学出版社,2004
[10] 邬宽明,CAN 总线原理和应用系统设计,北京航空航天大学出版社,1996
[11] Bosch, CAN specification, Version 2.0, Robert Bosch GmbH, 1991
[12] OSEK Communication Specificatin 3.0.3