Implementation Of Communication Protocol For Gaseous Fuel Engine Control System

Electronic control system is a important means of improving engine power, improvingengine economy and reducing exhaust pollution. During the development process of theengine electronic control system, communication module is one of its major auxiliarymodules. Along with more and more electronic control unit (ECU) added to the car network,connecting problems, timing control and information exchange problems between each ECUhas become increasingly sophisticated. Controller Area Network (CAN) bus provide a goodsolution to the communication problem between the vehicle interior each ECU, because of itshigh reliability, openness, high communication speed, scalability, etc. In order to establish acomplete communication system, the CAN bus protocol not only needs to defines the physicallayer and the data link layer of the OSI model, but also needs to select the appropriateapplication layer protocol which based on the CAN bus. SAE J1939CAN bus protocol is anapplication layer protocol which was American Society of Automotive Engineers designed fortrucks and commercial vehicles. Currently, SAE J1939protocol is the most widely usedhigh-level protocols used by trucks and commercial vehicles.Firstly, this paper gives a briefly introduction to the automotive network technologycharacteristics and classification. Then we select the Controller Area Network--CAN bus andSAE J1939communication protocol as a gas engine control system communication networkinfrastructure. Next, briefly introduced the development of the CAN bus and the SAE J1939protocol in recent years at home and abroad, and conducted in-depth analysis and research onthe CAN bus specification and the SAE J1939protocol layers.On this basis, the main task of the paper is developing a communication module based onthe SAE J1939protocol for gas engine electronic control system and master the developmenttechnology which based on the SAE J1939. Microcontroller used by development object ofthe article is a32-bit DSP chip of Texas Instruments--TM320F28035.The development dutymainly includes the following two parts: one is achieving the hardware abstraction layer, thispart includes the design of CAN communication module and the design of underlying CAN-driven programming which used for the realization of the basic CAN communication function; the other one is implementing the SAE J1939protocol stack, this part isprogramming to implement the data link layer, transport layer, application layer and networkmanagement layer of the SAE J1939communication protocol to achieve it basic functions.Introducing all the design ideas, the implementation method of the SAE J1939in detail,we use virtual network node which consists of a Guangcheng technology company USBCANwide converter and PC to test the actual node consists of the development of the gas engineelectronic control system. The test basically has a satisfactory result.Finally, this paper demonstrates an instance of SAE J1939communication network by agas engine ECU development board node, PC virtual node and intelligent NOxsensor node.The examples demonstrate that the proposed design of the SAE J1939protocolcommunication module has various functions, data transmission in real time during theexperiment, stable and reliable.