共查询到19条相似文献,搜索用时 218 毫秒
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故障现象 一辆97款日产风度轿车,无论在何种情况下都无法启动。 故障检查 用数字式万用表测试发动机基本元件输出信号,发现MAP传感器、TPS传感器、CTS传感器、O2传感器等基本元件输出信号正常。用汽车电脑故障诊断仪调取,读取故障码,发现无故障记忆码。对发动机进行初步保养,再检查均无问题。再用仪器检测发动机控制单元ECU,发现完好无损。然后进行波形分析,用示波器检测主要元件输出信号,发 相似文献
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提出了一种利用排气中HC、CO2、O2浓度和内燃机工况参数神经网络的内燃机失火故障诊断方法,并提出了描述内燃机失火程度的模糊评价指标;进行了内燃机有失火故障和无故障排气成分检测对比实验,利用实验数据和内燃机工况参数,通过广义回归神经网络(GRNN)建立了失火程度评价指标与排气中HC、CO2、O2浓度以及内燃机工况参数之间关系的诊断模型,应用MATLAB软件对该模型进行学习训练,将训练好的神经网络模型应用于内燃机失火故障的诊断,结果表明,此模型能够正确诊断内燃机失火故障。 相似文献
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传感器数据采集和分析是桥梁健康系统对桥梁状态评估的基础。由于传感器采集的数据格式复杂、信息量大,如不能有效的对传感器故障进行自动检测和隔离,将影响评估的准确性,产生错误预警信息。本文提出一种基于几何后非线性 ICA(Geometric Post Nonlinear ICA,gp ICA)的传感器故障检测与隔离算法。该算法通过引入几何后非线性(PNL)混合模型,将非线性数据线性化,再利用快速独立元分析(FastICA)对故障进行检测。通过计算监测数据对监控统计量的贡献度,基于贡献度分析法实现对故障传感器的隔离。利用MATLAB软件进行数值模拟,实现了模拟故障传感器的检测和隔离。该算法相比传统的线性ICA故障检测具有更高的故障检测率,更适用于桥梁健康监测系统的故障检测与隔离。。 相似文献
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通过一辆雪佛兰科鲁兹1.6L轿车的发动机故障实例,进行故障分析,运用汽车故障诊断仪KT-600读取故障码及数据流,然后用数字万用表对加速踏板位置(APP)传感器性能检测,与维修手册中的数据对比,得出故障的诊断结果,分析故障产生的原因,最后确定故障点。简化了加速踏板位置(APP)传感器故障诊断和维修的流程。 相似文献
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针对柴油机电控系统产品开发的故障诊断需求,采用故障自诊断分层结构对故障分类方法,实现了柴油机电控产品传感器、执行器和硬件资源的故障处理.重点介绍了加速踏板传感器和发动机曲轴与凸轮轴传感器的故障自诊断设计原理及应用策略.试验结果表明,该柴油机故障自诊断功能可以有效监控控制系统安全. 相似文献
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B. J. Moon H. G. Jung S. G. Lee D. H. Kim 《International Journal of Automotive Technology》2014,15(3):483-494
This paper describes a parallel model-based fault detection algorithm for an electronic parking brake (EPB) system, which consists of an electronic control unit with built-in current sensor and braking force sensor. For the EPB system to supply sufficient parking force to a vehicle, the parking force sensor is of utmost importance. If a fault occurs in this sensor, sufficient parking force may not be supplied, thereby seriously threatening the safety of the vehicle. Thus, a fault detection method is required for the parking force sensor of the EPB system to improve the safety of vehicles. For this purpose, a highly reliable fault detection method is needed to detect abnormal fault signals, which cannot be detected by the existing on-line sensor monitoring fault detection methods. This paper proposes a novel parallel model-based fault detection algorithm for the EPB system, which compares the physical sensor data with the mathematical model, the fuzzy model, and the neural network model at the same time. In order to reduce false alarms, the magnitude of thresholds and the operation counts are changed adaptively. When the proposed parallel model-based fault detection algorithm detects severe failures of the force sensor, it warns the driver in advance to prevent accidents due to the failures. The proposed algorithm is verified by hardware-in-theloop simulations in various situations. 相似文献
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文章阐述了故障树分析法(FTA)在汽车制动系统可靠性试验中的应用。采用演绎法建立以制动系功能失常为顶事件的故障树,进行定性和定量分析,运用故障树综合分析的计算机应用程序,找出系统失效的关键因素。准确地给出了制动系的累积失效概率及事件概率重要度等可靠性指标。在故障诊断中具有指导意义和使用价值,为汽车制动系可靠性设计工作奠定了基础。 相似文献
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针对传感器故障诊断问题,提出通过分析模型预测电压与传感器观测电压的残差来诊断传感器是否发生故障的方法。使用无迹卡尔曼滤波(Unscented Kalman Filter,UKF)算法估计电池的端电压,并提出使用奇异值分解(Singular Value Decomposition,SVD)代替平方根法分解,以解决协方差矩阵非正定导致的算法无法正常运行的问题。提出使用累积和(Cumulative Sum,CUSUM)法对残差进行分析,通过监测CUSUM的变化来判断传感器是否发生故障。以动应力测试(Dynamic Stress Test,DST)工况作为验证工况,用3类常见的传感器故障对提出的方法进行验证。结果表明,提出的传感器故障检测方法在一些微小故障的检测中,相比于传统的设定残差阈值的方法更灵敏,能更快检测出微小的数据偏移情况。 相似文献
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在电喷摩托车发动机进入闭环控制工况时,ECM将根据氧传感器的电压信号来修正喷油脉宽,使混合气浓度保持在理论空燃比附近。借助发动机数据分析系统对各工况下的氧传感器波形进行分析判断,有助于快速检测出电喷系统中是否存在影响尾气排放的空燃比反馈故障。同时对于完成故障维修的车辆,通过氧传感器波形分析可以验证出维修是否有效,故障是否彻底排除。使车辆在日常使用中的尾气排放也能达到一个良好的状态。 相似文献
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In the future, the conventional hydraulic brake system in automobiles will be removed and replaced by an electrically operated brake system called brake-by-wire. The brake-by-wire units, such as the EMB (Electro-Mechanical Brake), provide better braking performance by directly controlling the brake motor and are environmentally friendly because they do not use hydraulic fluid. For implementation of the EMB systems, reliable and robust fault detection and diagnosis methods become increasingly important. In this study, a sensor fault diagnosis method is proposed with parity space and observer approaches to detect faults in the motor current sensor, speed (or position) sensor and clamping force sensor. The proposed method is verified through a closed-loop simulation using Matlab/Simulink, and the simulation result is compared with the HILS bench test results. 相似文献