Research On The Monitoring System Of Electronically Controlled Engine Based On SAE J1939

Electronic control technology is regarded as one of the most important methods to reduce the exhaust emissions .It improves the power and the economy performance. During the development and the application of electronic control system, real time monitoring, data saving and a large amount of matching experiments can not be finished without the monitoring and calibration system. SAE J1939 protocol, which bases on CAN bus, is widely used in international commercial vehicle currently. The study on J1939 technology is still underway in domestic. And its product type is single. The main intention of the paper is to master SAE J1939 protocol, develop a universal protocol stack, build a J1939 network developing platform, and then develop a perfect engine monitoring system.In the paper, a monitoring system of the electronically controlled engine is developed on the basis of research about electronically controlled engine of domestic and foreign monitoring system in-depth. The paper mainly designs the software of the electronically controlled unit and monitoring software on PC. The software of electronically controlled unit is divided into several parts, including background debug software, the bottom body core functions, the integrated chip driving functions, the SAE J1939 protocol stack, CCP driver software and high pressure common rail control software. And the software of monitor consists of the human-computer interface, administration of control, the database and the process of giving an alarm. The paper selects the MC9S12DP256B produced by FreeScale Company as the body core. MC9S12DP256B is integrated high computing ability with plenty of I/O devices resources for automotive control.From the universal point of view, the paper designs the SAE J1939 protocol stack. The stack consists of CAN driver and SAE J1939 application. CAN driver is described firstly. It is the bottom application of the SAE J1939. It is related to the stack reality. And then, the design of the SAE J1939 protocol stack is described, including the data structure, transfer protocol and the design of minimal network function. In this paper, the SAE J1939 protocol is applied on the engine monitoring system, and a universal protocol stack is developed. These works is beneficial to the protocol localization and application.Experiments are finished on the high pressure common rail diesel test bed. The calibration on sensor signal and primary control parameter are preparatorily realized. The experiment results show that monitoring system is feasible and reliable, and anticipated control effect is excellent.