高压共轨柴油机电控技术分析与研究

高压共轨燃油喷射技术和发动机电控技术是现代柴油机的两大技术核心,高压共轨燃油喷射技术与电控技术的紧密结合,成为内燃机行业公认的20世纪三大突破之一。柴油机高压共轨燃油喷射系统是迄今最先进的柴油机燃油喷射系统:燃油喷射压力高且独立于发动机转速、可实现对喷油量、喷油定时和喷油速率的全工况柔性控制。高压共轨喷油系统是全电子控制系统,其燃油喷射压力、喷射油量、喷射正时和喷油速率均通过电子控制单元(ECU)来实现。     

电喷发动机使用维护要点

1.用油 电控燃油喷射发动机对汽油的清洁度要求很高,应使用牌号和质量完全符合要求的无铅汽油。燃油滤清器应定期更换,以防喷油器堵塞和氧传感器的工作性能丧失,特别应指出的是：在电控燃油喷射发动机中普遍采用闭环控制方式,在排气歧管中均装有一个反映混合气燃烧状况的氧传感器,一旦用含铅汽油．便会导致氧传感器中毒失效,造成发动机工作性能下降。     

电控单体泵燃油喷射系统的研究

电控单体泵燃油喷射系统是一种电磁阀溢流控制式供油系统，系统地分析了电控单体泵燃油喷射系统的结构和工作原理。     

现代汽油发动机燃油喷射技术综述

燃油喷射系统是汽油发动机的重要组成部分,燃油喷射技术不仅影响可燃混合气的形成,还间接影响气缸中的燃油燃烧和废气形成。总结了汽油发动机燃油喷射系统现有的进气道喷射技术、缸内直喷技术的特点;展望了混合喷射和定容式燃烧多段喷射新技术;提出了在高度提倡环保的大环境下,电控汽油喷射技术的进一步发展是必然的结论。     

标致505轿车单点燃油喷射电控系统的开发

本文介绍了作者在广州标致汽车公司制造的XN1A发动机及505轿车上所开展的单点燃油喷射电控系统的研究开发工作，绘出了XN1A发动机采用电控燃油喷射系统后的外特性曲线及万有特性曲线，并与原SOLEX化油器式的特性曲线进行了比较．本文还示出了505SX车匹配上该单点电控燃油喷射系统后的整车等速油耗试验曲线，并与原化油器式的进行比较．试验结果表明，在XN1A发动机及505轿车上所开发的这种电控燃油喷射系统能使发动机及整车的燃油耗相比原化油器降低约10％，而动力性能基本保持不变．     

电控汽油喷射系统设计及分析

汽油机电控技术发展是为了应对当前世界日益严格的排放法规和能源危机,这一技术应用对于汽车发动机性能有很好的改善作用,所以其发展比较迅速。本文基于汽油机电子控制技术研究现状和发展趋势,对于电控汽油机的燃油喷射以及点火系统进行分析,研究一种点火与燃油喷射相结合的电控汽油喷射系统。     

浅谈利用汽车氧传感器波形信号分析发动机故障

由于汽车喷射技术的迅速发展,发动机化油器已经遭受淘汰,现在的汽车燃油供给系统都采用电控燃油喷射技术,并且利用氧传感器对燃油喷射进行闭环反馈控制。本文利用氧传感器的波形信号来分析发动机的故障,以提高发动机故障诊断效率。     

标致505轿车单点燃油喷射电控系统的开发

本文介绍了作者在广州标致汽车公司制造的ＸＮ１Ａ发动机及５０５轿车上所开发的单点燃油喷射电控系统的研究开发工作，给出了ＸＮ１Ａ发动机采用电控燃油喷射系统后的外特性曲线及万有特性曲线，并与原ＳＯＬＥＸ化油器式的特性曲线进行了比较。本文还示出了５０５ＳＸ车匹配上该单点电控燃油喷射系统后的整车等速油耗试验曲线，并与原化油器式的进行比较。试验结果表明，在ＸＮ１Ａ发动机及５０５轿车上所开发的这种电控燃油喷射系     

车用电控柴油机喷射系统的控制

柴油机电控技术的发展过程与汽油机电控系统相似。自20世纪80年代开始进入市场的现代汽车柴油机电控系统也是随着控制项目的不断增多，控制任务从简单到复杂，直至全方位控制。早期的电控燃油喷射系统采用“位置控制”。到20世纪90年代初，“时间控制”式电控燃油喷射系统开发成功。到20世纪90年代中期，一种新型的电控共轨式燃油喷射系统问世，抛弃了传统的脉冲高压供油原理，     

关于电控柴油机使用的探讨

（1）电控式柴油机的优点 与传统的机械控制燃油系统相比,电控式燃油喷射和控制系统具有更多优点。能够对柴油机的燃油经济性、排气烟度和污染物进行优化控制,还能防止柴油机因冷却液和机油温度过高以及机油压力过低等故障。主要优点：     

电控燃油喷射系统相位识别新方法

本文提出利用进气压力传感器及摩托车磁电机触发信号为电控燃油喷射系统提供相位基准的新方法。磁电机每个工作循环产生两个触发信号，仅根据该信号不可能精确控制喷油及点火时刻。进气过程中进气压力传感器输出信号先减小，后升高，而这一变化过程正好位于两次触发信号之间，根据这一特征可以区分两次触发信号。在低转速工况，将当前采集的进气压力值同预设的参考值进行比较，通过判断进气过程是否到来，区分两个触发信号；高转速时在进气冲程只是保存进气压力数据，根据上一循环确定的触发信号进行喷油和点火控制，为防止电磁干扰带来的判断失误，在每个循环的“空闲时间”将采样的压力值进行校验，保证最多只有一个循环系统工作异常。利用该方法进行电控系统MAP图标定试验，整个过程中，系统工作正常，表明该方法是可行的。     

Multiple incipient sensor faults diagnosis with application to high-speed railway traction devices

This paper deals with the problem of incipient fault diagnosis for a class of Lipschitz nonlinear systems with sensor biases and explores further results of total measurable fault information residual (ToMFIR). Firstly, state and output transformations are introduced to transform the original system into two subsystems. The first subsystem is subject to system disturbances and free from sensor faults, while the second subsystem contains sensor faults but without any system disturbances. Sensor faults in the second subsystem are then formed as actuator faults by using a pseudo-actuator based approach. Since the effects of system disturbances on the residual are completely decoupled, multiple incipient sensor faults can be detected by constructing ToMFIR, and the fault detectability condition is then derived for discriminating the detectable incipient sensor faults. Further, a sliding-mode observers (SMOs) based fault isolation scheme is designed to guarantee accurate isolation of multiple sensor faults. Finally, simulation results conducted on a CRH2 high-speed railway traction device are given to demonstrate the effectiveness of the proposed approach.     

Sensor configuration and test for fault diagnoses of subway braking system based on signed digraph method

Fault diagnosis of various systems on rolling stock has drawn the attention of many researchers. However, obtaining an optimized sensor set of these systems, which is a prerequisite for fault diagnosis, remains a major challenge. Available literature suggests that the configuration of sensors in these systems is presently dependent on the knowledge and engineering experiences of designers, which may lead to insufficient or redundant development of various sensors. In this paper, the optimization of sensor sets is addressed by using the signed digraph （SDG） method. The method is modified for use in braking systems by the introduction of an effect-function method to replace the traditional quantitative methods. Two criteria are adopted to evaluate the capability of the sensor sets, namely, observability and resolution. The sensors configuration method of braking system is proposed. It consists of generating bipartite graphs from SDG models and then solving the set cover problem using a greedy algorithm. To demonstrate the improvement, the sensor configuration of the HP2008 braking system is investigated and fault diagnosis on a test bench is performed. The test results show that SDG algorithm can improve single-fault resolution from 6 faults to 10 faults, and with additional four brake cylinder pressure （BCP） sensors it can cover up to 67 double faults which were not considered by traditional fault diagnosis system. SDG methods are suitable for reducing redundant sensors and that the sensor sets thereby obtained are capable of detecting typical faults, such as the failure of a release valve. This study investigates the formal extension of the SDG method to the sensor configuration of braking system, as well as the adaptation supported by the effect-function method.     

Detection of faults in gearboxes using acoustic emission signal

Vibration analysis is widely used in machinery diagnosis, and wavelet transform and envelope analysis have also been implemented in many applications to monitor machinery condition. Envelope analysis is well known as a useful tool for the detection of rolling element bearing faults, and wavelet transform is used in research to detect faults in gearboxes. These are applied for the development of the condition monitoring system for early detection of the faults generated in several key components of machinery. Early detection of the faults is a very important factor for condition monitoring and a basic component to extend CBM (Condition-Based Maintenance) to PM (Prediction Maintenance). The AE (acoustic emission) sensor has a specific characteristic on the high sensitivity of the signal, high frequency and low energy. Recently, AE technique has been applied in some studies for the early detection of machine fault. In this paper, a signal processing method for AE signal by envelope analysis with discrete wavelet transforms is proposed. Through the 15 days test using AE sensor, misalignment and bearing faults were observed and early fault stage was detected. Also, in order to find the advantage of the proposed signal processing method, the result was compared to that of the traditional envelope analysis and the accelerometer signal.     

RETRACTED ARTICLE: Development and application of intensified envelope analysis for the condition monitoring system using acoustic emission signal

The application of the high-frequency acoustic-emission (AE) technique in the condition monitoring of rotating machinery has been increasing of late. It has a major drawback, though, the attenuation of the signal, and as such, the AE sensor has to be close to its source. Two signal-processing methods, envelope analysis and wavelet transform, were found to be useful for detecting faults in the rolling element bearing and gearboxes. These methods have a disadvantage, though: their application is focused only on a component of the assembled machine. For example, envelope analysis is a powerful method for detecting faults in the bearing system, but it is not proper for use in the gear system. Thus, these methods could not be used to detect combined faults in the common assembled machines. Therefore, we propose a signal-processing method consisting of envelope analysis and DWT (discrete wavelet transform). In addition, a novel mother function optimized for the AE signal for DWT was extracted through a fatigue crack growth test, and is also proposed herein. Then the proposed method, called intensified envelope analysis (IEA), was used to detect the faults in the rolling element bearing and rotating shaft. According to the results, IEA can be a better signal processing method for the condition monitoring system using AE technique.     

An observer based approach for achieving fault diagnosis and fault tolerant control of systems modeled as hybrid Petri nets

In this paper, we propose an approach for achieving detection and identification of faults, and provide fault tolerant control for systems that are modeled using timed hybrid Petri nets. For this purpose, an observer based technique is adopted which is useful in detection of faults, such as sensor faults, actuator faults, signal conditioning faults, etc. The concepts of estimation, reachability and diagnosability have been considered for analyzing faulty behaviors, and based on the detected faults, different schemes are proposed for achieving fault tolerant control using optimization techniques. These concepts are applied to a typical three tank system and numerical results are obtained.     

凌志LS-400轿车发动机电控燃油喷射系统的故障模拟与实验分析

本文针对凌志LS-400轿车发动机电控汽油喷射系统的主要执行器和传感器,怠速控制阀、水温传感器、爆震传感器、氧传感器进行了故障模拟,并用示波器对各种故障产生后ECU的控制信号进行检测,将检测结果与理论分析进行对比。     

CAWS600系列自动气象站故障分析及排除方法

根据CWAS600系列自动气象站的系统结构和工作原理,将其故障分为：通信、电源供电系统、传感器、采集器四类故障。文章列举了几个典型故障的分析和处理方法。重点介绍了＂测量法＂,通过测量关键点的电信号,将故障进行分级判断和定位。熟悉这些典型故障的处理方法,可以大大提高自动气象站故障排除的时效性。     

燃气轮机气路与传感器耦合故障诊断模型研究

燃气轮机传感器如在运行期间发生故障,产生的测量偏差会严重影响气路诊断结果的准确性。针对以上问题,提出一种燃气轮机气路与传感器耦合故障诊断模型,该模型采用工况变化引起的测量变化量替代常规的测量量,以减少传感器偏置故障的干扰。在此基础上,应用无迹卡尔曼滤波器跟踪测量变化量与不同工况引起的非线性模型预测变化量之间的残差估计气路健康参数,并以此更新传感器诊断系统中各个滤波器,根据滤波器的残差序列加权平方和进行传感器故障隔离。最后,对某典型三轴式燃气轮机进行仿真实例研究,结果表明该模型可减少气路故障与传感器故障的耦合效应,实现气路与传感器故障的准确诊断。     

基于虚拟仪器技术的柴油机喷油器故障诊断研究

针对柴油机高压油管内燃油压力波动特性，设计和选择了故障诊断系统的硬件和软件。通过对某一柴油机喷油器典型故障的实验模拟，用串接式压力传感器测取高压油管的燃油压力波，并利用人工神经网络模型进行了故障诊断。