【作者】 刁伟；

【导师】 李志军；

【作者基本信息】 天津大学 ， 动力机械及工程， 2009， 硕士

【摘要】 为了降低油耗以及满足日益严格的汽车排放法规要求,越来越多的汽油机采用电子控制技术。伴随着电子和计算机技术的发展,发动机控制策略也在不断更新,进步。由于电控系统中部分传感器的响应以及随后的信号处理和计算等过程都需要一定的时间,造成了时间的延迟,并且一些传感器价格昂贵不适宜电控单元所采用,因此本文引入了一种气体状态参数预估理论,初步研究了用某些参数的估算值代替传感器的测量值来对发动机进行控制的方法,并成功应用于实际发动机电控系统。本文首先介绍了气体流量、压力和温度预估的一般模型。预估模型分为三个模块:流量预估、压力预估和温度预估,三者相互依赖、相互影响是一个有机整体。对不同的预估对象和不同的预估条件,预估的方法也有差异。然后针对发动机电控系统中的一些重要控制参数提出了相应的预估计算式并对估算过程中需要修正的一些影响参数进行了详细分析。选取一台排量为1.8L的直列四缸汽油机在发动机台架上进行了大量的实验研究。完成了对该发动机进气流量、排气背压、进气温度、排气口温度以及排气总管的温度预估。而后根据在所有工况点下采集的数据将预估值与实测值做了分析比较,结果显示预估值和实测值比较一致,表明用一些参数的预估值代替传感器的测量值来对发动机进行控制的方法,应用在发动机电控系统中能够取得比较满意的效果。更多还原

【Abstract】 In order to reduce the fuel consumption to meet the standard of vehicle exhaust legislation which becomes more rigorous, more and more engines applied electronic control technology. With the development of electronic and computer technology, the control strategy of automobile engines has being updated continually. Due to some of the sensors response of the electronic control system and the subsequent signal processing and computing processes all require a certain amount of time, it caused some delay, and some sensors are expensive which are not suitable for electronic control unit, therefore, this article introduces an estimation theory, which preliminarily studies on the application of estimation of parameters in place of the sensor measurement to the engine electronic control system.This thesis first introduces the general model of the estimation of the gas flow、pressure and temperature in the engine. The estimated model is divided into three modules: flow estimation, pressure estimation and temperature estimation. The three is an organic whole which is interdependent and interacting. The method of estimation is different according to different objects and different conditions of the estimation, and it brings forward a corresponding calculation method aimed at some of the important control parameters of the engine electronic control system and makes a detailed analysis of some certain influencing parameters which need to be corrected in the process of estimation.we did a great amount of experiment research on the engine bench with a 1.8 L inline four-cylinder gasoline engine. The estimation of the intake air flow、the exhaust back pressure、the intake air temperature、the exhaust port gas temperature and the exhaust manifold temperature were accomplished. The estimated value at all points of condition were compared with the measured values,the results show that they are very consistent, indicating that the result can be satisfied to used the estimated values of some parameters instead of the measured values got from the sensors in engine electronic control system.更多还原