【作者】 戴彤焱；

【导师】 滕万庆；

【作者基本信息】 哈尔滨工程大学 ， 动力机械及工程， 2003， 硕士

【摘要】 用液化石油气(LPG)和天然气作为汽车代用燃料，是降低我国汽车排放污染和缓解石油能源短缺的一个重要发展方向。由于受现阶段我国加气站网点的制约，绝大部分燃气汽车采用双燃料工作形式。目前，我国的双燃料汽车改装主要技术装置依赖进口，改车成本高。鉴于上述情况，哈尔滨工程大学研制开发了一种具有自主技术的双燃料汽车液化石油气电控供气系统的核心元件——电子控制单元(ECU)。该电子控制单元曾经被用于对一款夏利电喷车进行双燃料改装，经实验证明，其对排放的控制达到了欧洲2号标准，具有较高的控制水平。但是，由于该电子控制单元不具备通信功能，在对不同车型进行双燃料汽车改装时，无法根据需要实现控制参数在线调试，进行整车性能匹配实验很不方便。针对这一问题，本文研究双燃料汽车ECU控制参数在线调试技术，旨在完善该ECU的使用性能，为其进入实用阶段做好技术上的准备，因此具有一定的实际意义。 本文的研究内容及所得到的结果主要有以下几方面： (1)在北京2032SA吉普车上搭建起LPG／汽油双燃料系统试验平台，进行了燃用汽油和LPG、LPG开环系统和闭环系统等排放对比实验研究，实验结果表明自行研制的ECU控制效果良好，具有一定的应用前景。通过实验工作还熟悉了ECU控制原理和相关控制参数的作用，为ECU控制参数在线调试功能的开发积累了有益的经验。 (2)采用RS-232C接口标准和串行异步通信方式，对ECU中的单片机与PC机之间的数据通信系统进行了总体方案设计和论证。 (3)完成了通信系统的硬件电路设计，编制了单片机和PC机的通信程序，实现了单片机与PC机之间的串行通信。所设计的用户界面合理，功能比较完善。模拟实验结果表明，本通信系统工作可靠，使用非常方便，能够满足ECU控制参数在线调试的使用要求。更多还原

【Abstract】 It is an important developmental direction to use liquefied petroleum gas and natural gas as automobiles’ substitutive fuel in our country. It can decrease emission pollution caused by automobiles and relieve the shortage of energy. However, because of the restriction of gas stations, majority of our country’s gas automobiles work on dual fuel form. Presently the main technology devices of refitting dual-fuel automobiles depend on import, and the cost of refitting is very high. In view of the above, Harbin Engineering University has developed a kind of nuclear component of electronic control system-electronic-control-unit (ECU) which owns independent rights. It can control the amount of gas fuel of a dual-fuel automobile. The electronic-control-unit was used to apply to a type of Xia Li automobile once. By the experimental study, it was proved that it had possessed higher standard of control emission, and achieved the Europe standards (II). However, since it hasn’t the function of communication, it couldn’t adjust the control parameters online when we are refitting a dual fuel automobile from different types of automobiles, and it is very not convenient to make matching experiments. In view of this, in order to complete the functions of the electronic-control-unit and make preparation for its practical application, an on-line adjustment technology of control parameters of dual-fuel automobiles’ ECU is worked out in this paper, so the study works have practical significance.The chief study contents and results in this paper are the following:(1) A test-bed of LPG and gasoline dual-fuel system has been set up on 2032SA Beijing jeep, and a series of emission experiments have been done which include the contrast of using petrol and LPG, the contrast of LPG opened loop control system and closed loop control system, et al. The experimental results indicate that the control effects of the ECU are well, and the application prospect is bright. By doing the emission experiments, the control principle of the ECU and the functions of related control parameters are known, and beneficial experience for the developing of on-line adjustment technology of ECU’s control parameters is accumulated.(2) Adopting RS-232C interface standard and asynchronous serialcommunication method, the overall scheme of the data communication system between the microcomputer in the ECU and a PC computer were designed.(3) A series of interface electric circuits of the communication system were completed. The communication programs between the microcomputer and a PC computer are worked out. The designs of user interface are reasonable and its functions are integrity. The simulated experimental results indicate that the communication system designed in this paper is reliable and very convenient to use. At the same time it can meet the demands of on-line adjustments for ECU’s control parameters.更多还原