Applied Mechanics and Materials Submitted: 2014-06-05 ISSN: 1662-7482, Vols. 602-605, pp 1512-1517 Accepted: 2014-06-11 doi:10.4028/www.scientific.net/amm.602-605.1512 Online: 2014-08-11 2014 Trans Tech Publications, Switzerland Development and Optimization System of Vehicle Electronic Fuel Injection Kecheng TAN 1, a,guanneng XU 2,b 1 Liuzhou Railway Vocational Technical College, Liuzhou, 545007, China 2 Guangxi Truck Research Institute, Liuzhou, 545007, China a Email: tankecheng@163.com, b Email: xgn698@163.com Keywords: electronic fuel injection system for vehicle, development and optimization Abstract. Based on the establishment of a system of electronic control gasoline engine, we try to develop and optimize a set of electronic control fuel injection system which aims at the LJ462Q gasoline engine. At the same time, we can provide the beneficial reference for the other similar product s design and development. Introduction Vehicle electronic control fuel injection system of gasoline engine is a new product. It has conformed its way to the development of China's automobile industry and the need to improve the gasoline engine independent brand competing and launching to a high technical level. How to make full use of the abundant engine R & D and bench test experience, integrate emission control technology, the gasoline engine exhaust pollutants to meet the requirements of GB14761-2001 standard (released in 2001 and carried in July 1, 2004 the implementation of GB18352.2-2001 light vehicle emission limits and measurement methods (II), promoting to the compliance with GB18352.2-2001 standard). Energy saving environmental protection theme will meet the needs of our rapid growth in the development of the automobile industry, which has a broad market space. The development of electronic fuel injection system for vehicle, with its improving the technical level, enhancing the competitiveness, can promote the development of related parts and components enterprises, and bring more economic benefits for the automotive industry. The Process of Optimizing System and Developing Main Technology The sensor system data acquisition system data processing system control system execution system prototype prototype test and adjustment type test complete data collection and pass the identification industrial production acceptance set of data project acceptance. Technical Principle Electronic fuel injection control system is what with an electronic control device (also known as a computer or ECU) as the control center, using a variety of sensors installed indifferent parts of the engine, measured a variety operating parameters of engine, in accordance with the control program set in the computer, through controlling the fuel injector, precise control of fuel injection quantity, make the mixed gas of the engine can be the best concentration under various working conditions. In addition, through the control program in the computer, the electronic control fuel injection system can also realize the starting, warm and strong, acceleration enrichment, full load and concentrated, deceleration dilute, forced off the oil, automatic idle speed control and other function in order to meet the needs of special conditions of the engine to the mixture, so that the engine will obtain the good fuel economy and emissions, improve the performance of the vehicle as well. The Development Process of System Optimization and Development Design and fabrication of system software design and ECU circuit board Making the overall scheme of electronic fuel injection system and optimization of the system, control the design of unit, circuit board production and the design of the software of control system. Software design including: gasoline engine management system, sub control system, fuel injection control system, ignition timing control system, idle speed control system, emission control system, fault diagnosis system. All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of Trans Tech Publications, www.ttp.net. (ID: 130.203.136.75, Pennsylvania State University, University Park, USA-06/03/16,17:10:31)
Applied Mechanics and Materials Vols. 602-605 1513 Purchase test equipment and related parts for the experiments of engine calibration Purchase the EIM604/06 type engine test bench system and engine supplies of the calibration test, make calibration debugging and optimizing preparation for gasoline engine electronic fuel injection system and optimization system. Debugging of gasoline engine management system Change the carburetor system into electronic control fuel injection of oil supply system of gasoline engine--multi point electronic controlled fuel injection system, the original ignition system by mechanical controlled adapted for electronic controlled, as well as the petrol engine intake system and exhaust system modification (including the installations of temperature sensor and pressure sensor of intake system and oxygen sensor, the inlet solar term valve and idle speed control valve of exhaust system), each sensor use the wire to connect to the instrument of control unit and monitoring, joint debugging and preliminary calibration of each sensor, and then transferred to the data optimization work. Optimal operation of gasoline control system According to the simulation running of gasoline engine test bench in different conditions, next, get the calibration of various control parameters and the result of bench gasoline engine running to test the fuel injection control system, ignition timing control system, idle speed control system and exhaust emission control system whether the parameters is the optimum -- namely, under the conditions that gasoline engine running with power and better economy, the environmental protection performance is also very good to meet the control requirements. In addition, sub control system such as the fuel pump control, it use the gasoline engine startup and start to test the fuel pump is working to achieve the control effect need. The fault diagnosis system can error signal by artificially creating various sensors (such as pulling the sensor plug) to simulate the engine fault, to inspect the performance and reliability of fault diagnosis system. Calibration of engine test bench (1) The calibration system of electronically controlled engine In the engine bench test, we need to control the speed, torque, temperature, pressure and other parameters of engine, calculate and correct the test results. In order to save calibration development costs, shorten the development cycle to ensure the repeatability of the calibration work, calibrate testing automatic control system and the parameters of electronic control unit by computer. Calibration system with a high degree of automation, the system not only has a function of reading and writing the ECU data, can also according to need to control the test bench, it can test, measurement, collect data, optimize, calibrate automatically. * according to the needs, set up the operating condition of the engine by the program; * modify control parameters of the engine electronic control unit on-line; * monitor the running condition of engine, gets the engine fuel consumption, emissions, power and other performance indicators * according to the relationship between performance index and control parameters of the engine optimal control parameters, to obtain the optimal control parameters. The system consists of the host, engine dynamometer, ECU development device, emissions instrument, fuel consumption meter and other monitor equipment, the host is the core of the whole system, it controls the operation of the system. In order to realize the automatic control of every part, the host expands various function card, including the GPIB interface board, A/D, D/A, T/C (timer/counter) interface board etc. Using IPC as the host to adapt to the harsh electromagnetic environment of bench test and ensure the reliability of the system. Dynamometer can use 135 kw DC power dynamometer. The host achieve the settings of control model of engine and dynamometer by T/C interface board; Setting the engine speed, solar term door opening and the dynamometer torque, speed and other specific operation parameters by the D/A interface board; collect the parameters of speed, torque, chill-down temperature of water, inlet temperature, inlet pressure, exhaust temperature, the oil temperature, oil pressure and other parameters by A/D interface board, so as to monitor the performance of the engine. The control parameters of ECU development device modify the electronic control unit on-line when it in the normal working hours of the engine, engine can be
1514 Advanced Manufacturing and Information Engineering, Intelligent Instrumentation and Industry Development run according to different control data. Because of using the dual port RAM memory data, the real-time modification of control parameters do not affect the normal operation of the engine. Information exchange by using optical fiber communication between the development device and host, in the bad electromagnetic environment, the bench test can ensure the reliability of the system. Using the direct sampling exhaust analyzer system is necessary, it can measure HC, CO, CO2, NO concentration and air fuel ratio. Fuel consumption instrument is quality fuel consumption meter. Emissions and fuel consumption meter instrument both with GPIB interface card to realize the remote control by the host through GPIB interface card. The CPIB host interface card is the CP488B interface card of 10Tech companies. In order to realize the automatic control, system software includes not only the driver of each component, but also provides a user oriented testing process editor, the user can according to need to test, test results obtained. Flow calibration of electronic control system Calibration work with the general steps, are the same for all kinds of electronic control system. For each selected control system, the implementation of matching different. As a basic simple electric system may need hundreds of calibration data acquisition and adjustment, and the control system of a complex function may need thousands of data. These data are generally can be divided into: the engine steady state calibration parameters, static correction curve, non steady state calibration, idle and start control parameters, special function control parameters, run control parameters and diagnostic data. Generally speaking, the calibration work bench test stage is the core task of the calibration system. A calibration test process is shown in Figure1. Figure 1 Flow calibration of electronic control system
Applied Mechanics and Materials Vols. 602-605 1515 Analysis of Key Techniques and Problems Key Technology It is that mainly electronic control fuel injection system can automatically adjust the ignition angle for fuel supply, in the whole operating process of gasoline engine, the output power of the gasoline engine maximum optimization derived fuel consumption, so as to reduce emissions. 1) the engine control module (ECM) The engine control module (ECM) is a core component of the EFI system, the sensors and actuators to achieve control of the gasoline engine. In the work, the sensor send the gasoline engine work status parameters such as concentration of inlet pressure, inlet temperature, coolant temperature, oxygen in the exhaust gas of the value passed to the ECM, after the processing, issue the instructions to the actuator, adjusted gasoline engine by the actuator. As shown in Figure 2: Analog signal The input circuit A\D Converter Output circuit Actuator Digital signal The input circuit I\O Memory ROM RAM CPU Figure 2 The EMC module The ECM system to control the process of fuel injection,that is the microcomputer controlling device according to the sensor output signal, computing, processing, ana lysing,after making judgment,output the different width of the fuel injection pulses of electricity to the injector, the injection time is corresponding to different condition, thus the injection quantity controlled precisely.when the engine is working,injector will add fuel injection, and then, there are heating of turbine, starting, idling,acceleration, low temperature, high load etc.. When the engine is slow down or speed of more than 5000r / min, injector will stop injecting. Calculation of flow injection pulse width is shown in Figure 3. Figure 3 Calculation of flow injection pulse width
1516 Advanced Manufacturing and Information Engineering, Intelligent Instrumentation and Industry Development In the control system, the key is to determine the optimal fuel injection pulse spectrum (MAP). Accurate and the best amount of fuel injection pulse spectrum without reasonable distribution, even with advanced sensors and actuators as well as any control software, are unlikely to improve the performance of supply system and engine. Therefore, matching selection and controlling gasoline engine for electronic injection system, as for ignition control maps, and matching the best adjustment to the mixed gas of the engine components, should also be through bench test for engine. During the experiment, it is mainly to adjust the characteristics by measuring the fuel of different speed and different load, from the perspective of improving the control effect, mode distribution density maps of the bigger the better. Therefore, determine the test conditions points to cover the operating range of automotive engine all as far as the premise, test points in common working area shall be arranged more. In the electronic control unit, storage the mixture components with 15 speed and 15 load points, it is total of 225 operating point data. When measuring the fuel adjustment characteristics for each operating point, it should change 5 ~ 6 air-fuel ratio at least, to determine the condition of the most economical mixture components or power component of gas mixture. When the same speed of different solar term door opening, the fuel adjustment curve is obtained together by envelope, get the most economic changes of mixed gas composition in this speed. The ideal load curve of a certain speed, before the test identify characteristic data made in the map and is stored in the control unit, should according to the given standard of car using, optimize various properties of low fuel consumption, high performance, low exhaust pollution and output requires it is making Characteristics of pulse is supplied by spectrum of the gas mixture air-fuel ratio, in different conditions, it can meet the performance requirements. ECM system in full load condition, the fuel ratio control is at its full speed range of supply air, and under avoid knock conditions, the torque is the biggest and adjust the excess air coefficient mixed gas supply in value at around 0.9. Solar term door position switch can record the signal of engine full load operation, and input the controlling unit. At part load operation, the system in ensuring the premise of mixed gas components in order to achieve the minimum fuel consumption and the low emissions. In the automobile engine idle speed operation, it will focus on the engine performance and low mission performance considerations and supply the mixed gas components. Project Technical Performance Index and Level In the LJ465Q-1A gasoline engine is tested, the results are as follows: Serial number 1 Inspection items Test data Units of technical measurement requirements EFI Carburetor Change rate system Oil pressure MPa 7.5~8.5 8.2 spray cone angle 85~90 87 System Atmospheric parameters pressure spray mm 100 104 penetration distance spray droplet diameter μm Ф20 Ф17 Maximum power kw 38.5 38.6 38.8 +0.5% Maximum torque N m 83 84.2 85.2 +1.2% The lowest fuel consumption g/(kw h) 275 272.2 260.8-4.2% rate 2 Total power 3 Exhaust pollutants CO 2.2 1.9 1.7 g/km HC+NOX 0.5 0.44 0.41
Applied Mechanics and Materials Vols. 602-605 1517 The conclusion After Guangxi automobile and internal combustion engine for quality supervision and inspection station bench test, the design and development of gasoline engine electronic fuel injection system and optimization system exhaust emissions meet the GB18352.2 2011"light vehicle emission limits and measurement methods (II)"standard requirements, the rest performance indicators were superior to or reached the project task requirements of the book. To sum up, the design of gasoline engine electronic fuel injection system and optimization of the system is successful. Acknowledgements This research was supported by Guangxi Scientific Research and Technology Development Project (project number: 0133017-3) References [1] Automobile Engineering Handbook (fundamental), Automobile Engineering Handbook Edit Committee Compile, People Traffic Publishing House, 2001-05 [2] Automobile Engineering Handbook (test paper), Automobile Engineering Handbook Edit Committee Compile, People Traffic Publishing House, 2001-05 [3] Automobile Engineering Handbook (Design), Automobile Engineering Handbook Edit Committee compile, people traffic publishing house, 2001-05 [4] Automobile Engineering Handbook (Manufacturing), Automobile Engineering Handbook Edit Committee Compile, People Traffic Publishing House, 2001-05 [5] Wangyu WANG, Car Design (Fourth Edition) compiled, Jilin University, Mechanical Industry Publishing House, Fourth Edition, 2007-11 [6] Zhisheng YU, Car Theory, Beijing: Mechanical Industry Press, Tsinghua University, 2000-4 [7] Jiarui CHEN, Automobile Structure (volume), Beijing: China Communications Press, 2007-8
Advanced Manufacturing and Information Engineering, Intelligent Instrumentation and Industry Development 10.4028/www.scientific.net/AMM.602-605 Development and Optimization System of Vehicle Electronic Fuel Injection 10.4028/www.scientific.net/AMM.602-605.1512