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car bus system

2022-09-23 09:20:18A programmer who does not lose hair


1、AClass bus standard

2、BClass bus standard

3、CClass bus standard

4、Diagnosis system bus standard

5、Multimedia system bus standard

6、Safety bus and the standard


Has not been a communication network can fully satisfy all of the cars of the future cost and performance requirements,为此,Carmakers andOEM (Original Equipment Manufacture)Traders still use a variety of protocol(LIN、CAN和 MOST等),Realize networking on future car.

美国汽车工程师协会(SAE)Vehicle network committee according to the standardSAE J2057The car data transmission network is divided intoA、B、C三类.

本篇博文将对A、B、CThree types of bus standard and diagnosis system、Comparing multimedia system such as bus standard and introduce.

1、AClass bus standard

A类的网络通信大部分采用UART (Universal Asynchronous Receiver/Transmitter)标准,UARTTo use simple and economic,但随着技术的发展,在2005Years later has to be eliminated from the automobile communication system.

The table below for some of the mainAClass standards and protocols and their features were compared.

AClass is the standard of first selection isLIN (Local Interconnect Network),LINIs used in automobile distributed electrical control system of a new type of low-cost serial communication system,它是一种基于UART的数据格式、Master-slave structure of single12VThe bus communication system,Mainly used for smart sensors(Smart Sensors)And actuator serial communication,而这正是CAN总线的带宽和功能所不要求的部分.Because has yet to establish a low-end multiplex communication standard of car,因此LINIs trying to become a low-cost serial communication industry standards.

LINUsing a low-cost single wire connection,传输速度最高可达20Kb/s,For most of low-end application object,这个速度是可以接受的.It with one main media access/From the mechanism of,No need for arbitration.You don't need a crystal oscillator from the node and can perform a self synchronous,This greatly reduce the cost of hardware platform.

2、BClass bus standard

BApplication on the car class standard isISO11898(ISO11898-3),传输速率在100Kb/s左右,On the truck and bus application isSAE的标准J1939,传输速率是250Kb/s.从1992年起,Europe's largest car company always USES isISO 11898,By using transmission rate in the range of47.6~500Kb/s.

The table below for the current majorBClass standards and protocols and their features were compared.

BInternational standards are in classCAN总线.CAN总线是德国BOSCH公司从20世纪80年代初为解决现代汽车中众多的控制与测试仪器之间的数据交换而开发的一种串行数据通信协议,它是一种多主总线,通信介质可以是双绞线、同轴电缆或光导纤维,通信速率可达1Mb/s.

CAN总线通信接口中集成了CAN协议的物理层和数据链路层功能,可完成对通信数据的成帧处理,包括位填充、数据块编码、循环冗余检验、优先级判别等项工作.CAN协议的一个最大特点是废除了传统的站地址编码,And replace it with the communication data block coding,A maximum of id2048 (2.0A)个或5亿(2.0B)多个数据块.Using the advantage of this approach can make the network nodes is not restricted in theory.数据段长度最多为8字节,Don't take the bus time is too long,To ensure the real-time communication.CAN协议采用CRC检验并可提供相应的错误处理功能,保证了数据通信的可靠性.



3、CClass bus standard

由于CClass standard is mainly used in automotive safety related,As well as the real-time demand higher place,如动力系统,So its transmission rate is high,通常在125Kb/s~1 Mb/s之间,Must support real-time、The parameters of the periodic transmission.

在CClass in the standard,Europe's carmakers basically is the high-speed communication are usedCAN总线标准ISO 11898(ISO 11898-2).

The table below for the current majorCClass standards and protocols and their features were compared.

当汽车(轿车)电子控制单元(Electronic Control Units,ECU)Communication between the transmission rate is more than125 Kb/s、最高1Mb/s时,ISO 11898(11898-2)To use the controller local area network construction of digital information exchange of the provisions of the relevant features in detail.

4、Diagnosis system bus standard

The purpose of the discharge diagnosis is mainly in order to satisfy theOBD-II(On Board Diagnose)、OBD-III或E-OBD (European-On Board Diagnose)标准.

Many car manufacturers are usingISO 9141和ISO 14230 (Keyword Protocol 2000)As the communication standard in the diagnosis of system,它们满足OBD-II.美国的GM、Ford、DC 公司广泛使用J1850作为满足OBD-II The communication standard in the diagnosis of system,But the European auto makers refused to adopt the standard.到2004年,America's three big car company for passenger car based onCAN的J2480Diagnosis system communication standard,它满足OBD-III 的通信要求.在欧洲,Diagnosis system used in the pastISO 9141,它是一种基于UART的通信标准,满足OBD-II的要求.从2000年开始,European car manufacturers have begun to use based onCAN总线的Diagnosis system communication standardISO 15765,它满足E-OBD的系统要求.

The table below for the current major diagnostic system bus standards and protocols and their features were compared.

ISO 15765Applicable to vehicle diagnosis system inCANOn the bus to implement the occasion of.ISO 15765Web services are in line with based onCANThe requirement of on-board network system,是遵照ISO 14230-3及ISO 15031-5About the content of the diagnostic services to develop,因此ISO 15765对于ISO 14230The application layer service and parameters is fully compatible with,But not limited to only in the international standard of.

5、Multimedia system bus standard

汽车多媒体网络和协议分为三种类型,分别是低速、High speed and wireless,对应SAEThe classification of the corresponding to:IDB-C (Intelligent Data Bus-CAN)、IDB-M(Multimedia)和IDB-Wireless,其传输速率在250Kb/s~100 Mb/s之间.

Low speed for remote communication、Diagnosis and general information,IDB-C按CANThe format of the bus to250Kb/sThe bit rate of transmission of information.Due to the characteristics of its low cost,IDB-CIs expected to become one of the standard of automobile product.

High speed is mainly used for real time audio and video communication,如 MP3、DVD和CDSuch as play,The transmission medium is used by fiber optic,In this category are mainlyIDB-M、D2B、MOST和IEEE 1394.

The table below for some of the major automobile multimedia system bus standards and protocols and their features were compared.

6、Safety bus and the standard

Safe bus is mainly used for airbag system,To connect the accelerometer、Security sensor device,For passive safety guarantee.There are some companies have developed the bus and related protocols,包括Delphi公司的SafetyBus 和 BMW公司的 Byteflight.

The following table for automotive safety system bus standards and protocols and their features were compared.

Byteflight主要以BMWCompany as the center set.数据传输速度为10 Mb/s,Optical fiber can be up to43 m.Byteflight Not only can be used for the airbag system network communication,还可用于X-by-WireSystem of communication and control.BMW公司在其2001年推出的BMW7系列车型中,采用了一套名为ISIS(Intelligent SafetyIntegrated System)The airbag control system,它是由14Consisting of a sensor network,利用ByteflightTo connect and collecting front air bag、The back air bag safety devices such as signal.在紧急情况下,The central computer can more quickly and accurately determine the different position of airbag cast range with the time,Play the best protection effect.


X-by-WireWas first used in the aircraft control system,Called telex control,Now has been widely used in aircraft control.Due to the fault tolerance and high reliability of communication system on car demand growing,X-by-WireStart application in the field of automotive electronic control.

下表对X-by-WireThe system bus standards and protocols and their features are compared.

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