CAN Bus

Also known as vehicle bus CAN bus, its called the “controller area network (CAN-Controller Area Network)”. CAN-bus is a bus (as distinct from the Office bus) is Germany Bosch company in order to solve many modern automobile electronic control module (ECU) between a serial communication protocol for data exchange and development. Design of CAN bus by taking car poor working environment, high reliability. CAN bus in various fieldbus dominate, become synonymous with automotive bus. As vehicle electrical equipment more and more, controlled from the engine to the transmission system control, controlled from the driving, braking and steering systems to security assurances and instrument alarm system, from power management to various efforts to improve comfort, making automotive electrical systems to form a large complex system, and were centralized in the cab control. In addition, with ITS development in recent years, to 3G (GSM and GPS, and GIS) as the representative of the emergence of new electronic communication products, integrated wiring for cars and shared interaction of information put forward higher requirements. From a routing perspective, most of the traditional electrical system using point to point of single means of communication, little contact with each other, which inevitably led to extensive wiring system. According to statistics, in a premium car using traditional routing methods, the wire length can be up to 2000 meters, electrical nodes up to 1500, and, according to the statistics, the figure would be about 1 time every ten years growth times. Both materials cost efficiency, development of traditional routing methods will not be able to adapt to the car. From the perspective of information sharing, modern classic control unit has electronic fuel injection systems, electronic control transmission system, anti-lock braking system (ABS), antiskid control system (ASR), EGR control, navigation systems and air conditioning systems. In order to meet real-time requirements of each subsystem, there is a need for cars applied by public data sharing, such as engine speed, wheel speed, throttle pedal position. But the real-time requirements of each control unit is for data update rate and control cycle varies. This requested its network of data exchange is based on the priority competition mode, and itself has a high traffic rate, CAN-bus is designed to meet these requirements.

Data sharing to reduce the duplication of data processing, the cost savings. For example, electronic fuel injection engine with a CAN bus interface, provided by other units can share their speed, water temperature, oil pressure, oil temperature, instantaneous velocity, and so on, while eliminating the need for additional water temperature, oil pressure, oil temperature sensor, on the other hand these data can be displayed on the instrument, easy driver check engine operating conditions, so as to facilitate engine maintenance.And, for example, Eddy current retarder, air suspension, speed-control and cruise control are used to speed data, results of these appliances have a speed processing circuit, wasting resources. Following the introduction of bus technology, everyone from the bus to get the speed data.Reduced vehicle wiring, further cost savings. Due to the use of bus technology, signaling between the module only requires two signal lines. Wiring of local, get rid of bus in the car outside, all other trans-body lines are no longer needed, saves wiring costs. In addition, data sharing also saves lines, speed signal, for instance, in the absence of buses, Eddy current retarder speed signal to be received, door control, air suspension and electronic fuel injection engine. Once you have a bus as long as the receiving Office, by other electrical bus sharing.

Note: This article taken from the network article are edited for reference only