Application and development of CAN bus technology in the automotive field Chengdu Panfeng Technology

Application and development of bus technology in the automotive field Chengdu Panfeng Technology
() Controller Area Network is one of the most widely used open field buses in the world. As a technologically advanced and highly reliable , network communication control methods with complete functions and reasonable costs have also been widely used in automobiles. The automotive electronic body network system is composed of multiple high-speed bus network communications to achieve rapid interaction of vehicle power and operating system information, low-speed bus network communication to achieve vehicle body operation control information interaction, and low-cost buses to perform necessary expansion of the network. Through the connection of the bus, multiple control networks are interconnected and interconnected, making the car safer, more reliable, and the expansion of intelligent functions more convenient and lighter.
In the coming years, traditional automotive mechanical systems (such as braking and driving systems) will become electrical systems connected to high performance through high-speed fault-tolerant communication buses. Features such as electronically controlled braking, electronically controlled driving and electronic valve control on a car equipped with integrated driver assistance systems will provide the driver with the ultimate driving experience. Providing secure communication between these systems requires a high-speed, fault-tolerant and time-triggered communication protocol.
r is a new network communication system particularly suitable for next-generation automotive applications. An association has been established to urge the industry to adopt the same standards for these electronic control systems. , r, Motorola and Philips Semiconductors jointly developed and established this r standard. This standard not only improves consistency, reliability, competitiveness and efficiency, but also simplifies development and use and reduces costs.
r will enable the development of automobiles into 100% electronic control systems that do not require the support of backup mechanical systems. Electronic control applications require high-speed bus systems that are both deterministic and fault-tolerant and support distributed control systems. In addition, the technology can meet key automotive application requirements such as reliability, availability, flexibility and high data rates to make up for the shortcomings of the current main networking standards in the car.
The communication system is far more complex than a communication protocol. It includes a specially designed high-speed data transceiver and defines the hardware and software interfaces between the components within the r-node. r protocol defines the format and functionality of communication processing within networked automotive systems.
Different from existing automotive protocols, , , and r can meet critical reliability requirements and play an important role in communication between various electronic systems in a car.
The need for speed
In today's cars the body and comfort control modules are connected to the controller area network (CAN) bus and control the peripheral devices with the help of the local interconnection network (CAN). Telematics and multimedia connectivity requiring high-speed interconnect video transmission and synchronized data streaming formats can be implemented by protocols. In many cases high-speed automotive control systems such as powertrain and transmission control are now connected together using dedicated and networked systems.
Achieving high speed data transfer rates becomes important as the amount of data communication between electronic control units increases. r was originally designed to target approximately data rates but the protocol allows higher rates to be achieved.
r is a scalable communication system that supports synchronous or asynchronous data transmission. Synchronous data transfer enables time-triggered communication to meet system reliability requirements. Asynchronous data transfer based on protocol fundamentals allows each node to utilize the full bandwidth in event-driven communication.
r's synchronous data transmission is deterministic while ensuring minimal message transmission delay and message jitter. Compared with the optimization method, this performance is superior. The arbitration method can delay the sending of low-priority messages and allow high-priority messages to be sent first. Therefore, the delay of any message except the highest priority message cannot be determined in advance. r Ensure that the transmission time is preset for each message in the synchronous transmission part without affecting other messages.
r Supports redundant and fault-tolerant distributed clock synchronization based on global standard time to ensure that all network nodes can work in an orderly manner within a compact, preset precise time window. In the synchronous communication section, each electronic control unit is assigned a fixed time slot number. This ensures that each message gets the required bandwidth and time slot. This allocation ensures that all messages can be transmitted without competing for bandwidth or going through arbitration.
An independent bus monitoring circuit is used to detect physical layer errors to ensure that no data transmission conflicts occur in the event of a communication controller failure. In electronic control applications, it is very important that all application information in a distributed system is connected through a communication protocol so that the application function can be executed within a known time range.
r The communication system supports both optical fiber and electrical physical layers, which allows users to adopt whichever cabling scheme best suits their needs. Fiber optic data transmission has the advantage of being immune to electromagnetic interference, which can have a very damaging effect on communications over electrical lines.
Regrettably, there is still no communication network that can meet all the cost and performance requirements of future cars. Therefore, car manufacturers will continue to use multiple networking protocols (including AV, AV, and AV). The cars of the future will be networked.