共查询到20条相似文献,搜索用时 203 毫秒
1.
2.
案例1卡罗拉轿车发动机无法起动故障现象一辆卡罗拉轿车,行驶里程为6.7万km,出现发动机无法起动的故障。故障诊断接车后首先检查蓄电池电压,为12.8 V,正常。检查主继电器,正常;拆下喷油器的连接器,用专用测试二极管检查喷油器的喷油信号,无喷油信号;检查点火系统,火花塞不跳火;检查防盗系统,正常;连接故障检测仪,无法进入该车自诊断系统。对上述检测结果进行分析,推断故障的原因为发动机ECU工作异常。 相似文献
3.
故障6:发动机怠速不正常,有时忽高忽低,不能保持正常怠速。 首先用修车王工具检测,无故障码显示。由ECCS作原理得知,怠速转速是根据冷却液温度传感器信号及控制单元内预先存储的怠速目标转速计算得出的。当空调及动力转向加入、电瓶电压低、水温过高时,ECM要对怠速转速进行修正。仔细检查影响怠速修正的上述因素,未见正常,看来故障还是在ECM控制上。 相似文献
4.
底盘:W220.175。故障现象:遥控器钥匙无法实现中控功能,使用STAR进行诊断无故障码。故障诊断: 1.检查遥控器电池电压,两块电池均为3V,证明电压正常 (但并不证明可以正常发送信号)。 2.在这里我们结合了遥控中央门锁的系统原理,使用 STAR检测发送信号和接收信号是否正常。 相似文献
5.
1.故障现象:一辆风神蓝鸟EQ72200Ⅱ型轿车,热车、冷车都不易起动,运行中加速无力,排气管冒黑烟,且有燃油喷出。2.故障检查:首先检查各缸喷油器工作状况,均正常;然后检查各缸高压火花跳火情况,第三缸不点火;再检测ECU的控制线路正常。再分析,可能是ECU没有收到第三缸上止点位置信号。由于该车的上止点位置信号由设在分电器内的光电式曲轴转角传感器提 相似文献
6.
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
7.
8.
例一奔驰S350轿车中控门锁能正常使用,转向灯也正常闪烁,但在车辆行驶约2km时转向灯闪烁不停。根据遥控器传输无线电信号到O C P(OverheadControlPanel),传输红外线信号至门把手开关红外线接收器。以上两个信号均被传输到电子点火开关(EIS),然后经EIS发送开门或锁门信号到左前SAM、右前SAM和后SAM,再作动闪烁信号。首先检查CANinterior,测量EIS的CAN线电阻,正常(60Ω)。拔掉CAN线时闪烁信号停止,故判定EIS发送错误信号,更换新的EIS,作程序设定,故障排除。例二新款E级轿车(W211底盘)由于新技术应用较多,所以工作中也发现了… 相似文献
9.
10.
11.
Shili Wu Zhenmin Tang Zhaosong Guo 《International Journal of Automotive Technology》2017,18(3):365-375
Mixture faults detection is meaningful for gasoline engines because proper mixture is the basic prerequisite for healthy running of a combustion engine. Among existing methods for faults detection, the data-driven trend analysis technique is widely used due to the simplicity and efficiency in time-domain. The CUSUM (Cumulative Sum Of Errors) algorithm is good at real-time trend extraction, but it’s easy to be costly on the fuel trim signal during the engine in normal working conditions, which will increase battery energy consumption because engine failure is rarely occurs. Hence, the conventional treatment methods of artifacts in the CUSUM algorithm are modified by means of decay function and detection time analysis. The thresholds are tuned according to the characteristics of artifacts instead of residual variability, which leads to better results of trend extraction and less computation. Then, the revised CUSUM algorithm is used for monitoring the mixture abnormal behaviors, and the mixture faults can be detected in real time through analyzing the variation features of fuel trim signal. The lightweight faults detector using the advanced CUSUM algorithm (FD-A-CUSUM) is evaluated on the experimental data collected from a Ford engine. The validation results show that while engine works under normal conditions, the computation of FD-A-CUSUM has decreased by 72.79 % in comparison with the detection method using the original CUSUM algorithm (FD-O-CUSUM), and the false alarm ratio of FD-A-CUSUM is 3.37 %. Futhermore, the detection results of FD-A-CUSUM for two leakage faults have achieved 91.18 % test accuracy. 相似文献
12.
为了给桥梁结构的健康检测提供参考,将金属磁记忆检测技术引入到钢筋混凝土(RC)梁内部钢筋的应力检测当中,进行了钢筋混凝土T形截面梁四点弯曲加载应力自漏磁信号检测试验。利用基于金属磁记忆的三维扫描检测装置采集了试件在不同荷载下的自漏磁信号,并对不同提离高度和多条扫描路径下的磁信号进行分析,得到了钢筋混凝土T形截面梁在不同应力状态下的空间信号规律,提出了利用“法向漏磁场方均根值”来定量计算RC梁纯弯段处钢筋应力的方法。研究结果表明:在钢筋混凝土T形截面梁纯弯段内,钢筋内部应力与“法向漏磁场方均根值”呈线性关系,且函数的拟合优度R2达到0.988 4,拟合值与实测值之间误差微小;随着提离高度的增加,钢筋混凝土T形截面梁在不同荷载下的自漏磁信号曲线逐渐上移,自漏磁信号的分布规律没有显著变化,“法向漏磁场方均根值”与RC梁内部钢筋的应力在纯弯段内仍满足线性关系,试件在不同提离高度下的R2达到0.965;随着扫描路径的改变,钢筋混凝土T形截面梁在不同荷载下的自漏磁信号曲线呈现出相似的规律,且“法向漏磁场方均根值”与RC梁内部钢筋的应力在多条扫描路径上均满足线性变化的关系,在各条扫描路径下R2的平均值为0.959。所提方法可为RC梁内部钢筋应力的无损检测提供新的思路与参考。 相似文献
13.
根据长城汽车某传统车型改装成纯电动车的实际需求,及对整车控制系统的要求设计整车控制器,详细介绍电源管理、CAN通信、输入信号处理以及继电器驱动等电路的设计方法。基于双MCU的硬件设计方案增强了整车控制系统的硬件故障自诊断能力,大大提高了整车控制器的可靠性。 相似文献
14.
15.
16.
自动检测是桥梁健康监测的核心和关键技术之一,在自动检测确定出损伤大致范围的基础上,可以通过人工检查进一步确认或排除损伤点,这可大大减轻损伤检测的劳动强度,节约开支。根据小波变换多分辨率分析的特性和恒虚损处理自动检测原理,形成以小波恒虚损处理方法为核心的桥梁损伤自动检测理论。该方法通过拾取环境噪声作为参考噪声,与试验信号分别经相同小波滤波器输出后,形成统计量作为恒虚损率处理的输入参数,进而对奇异信号进行自动检测。该技术不需要无损桥梁相关资料,并可满足实时动态监测的要求。最后通过算例进行了验证。 相似文献
17.
18.
19.
为了降低发动机工作时引起的整车振动,提出了使用多通道滤波x-LMS (MFXLMS) 算法作为主动悬置系统的控制算法。以发动机转速信号作为参考信号,主动悬置安装位置下方的两路加速度信号作为误差信号。根据算法完成试验平台搭建。采用白噪声电压信号作为输入激励,通过 LMS算法离线辨识得到主动悬置到加速度传感器的多路次级通道,在dSPACE上完成实车控制试验。试验结果表明,MFXLMS算法的运用显著降低了发动机不同转速工况下引起的测点加速度响应,提高了整车的乘坐舒适性。 相似文献
20.
M. S. Wang N. T. Jeong K. S. Kim S. B. Choi S. M. Yang S. H. You J. H. Lee M. W. Suh 《International Journal of Automotive Technology》2016,17(1):165-173
Drowsy behavior is more likely to occur in sleep-deprived drivers. Individuals’ drowsy behavior detection technology should be developed to prevent drowsiness related crashes. Driving information such as acceleration, steering angle and velocity, and physiological signals of drivers such as electroencephalogram (EEG), and eye tracking are adopted in present drowsy behavior detection technologies. However, it is difficult to measure physiological signal, and eye tracking requires complex experiment equipment. As a result, driving information is adopted for drowsy driving detection. In order to achieve this purpose, driving experiment is performed for obtaining driving information through driving simulator. Moreover, this paper investigates effects of using different input parameter combinations, which is consisted of lateral acceleration, longitudinal acceleration, and steering angles with different time window sizes (i.e. 4 s, 10 s, 20 s, 30 s, 60 s), on drowsy driving detection using random forest algorithm. 20 s-size datasets using parameter combination of accelerations in lateral and longitudinal directions, compared to the other combination cases of driving information such as steering angles combined with lateral and longitudinal acceleration, steering angles only, longitudinal acceleration only, and lateral acceleration only, is considered the most effective information for drivers’ drowsy behavior detection. Moreover, comparing to ANN algorithm, RF algorithm performs better on processing complex input data for drowsy behavior detection. The results, which reveal high accuracy 84.8 % on drowsy driving behavior detection, can be applied on condition of operating real vehicles. 相似文献