混合动力系统VVT响应性故障在线诊断策略开发  

Development of Online Diagnosis Strategy for Variable Valve Timing Response Fault in Hybrid Power System

作　　者：王沛 王字满 张冬生 刘少飞 WANG Pei;WANG Ziman;ZHANG Dongsheng;LIU Shaofei(Beiqi Foton Motor Co.,Ltd.,Beijing 102206,China;School of Mechanical Engineering,Beijing Institute of Technology,Beijing 100081,China)

机构地区：[1]北汽福田汽车股份有限公司,北京102206 [2]北京理工大学机械与车辆学院,北京100081

出　　处：《车用发动机》2022年第4期69-76,共8页Vehicle Engine

基　　金：国家自然科学基金项目(51806012)。

摘　　要：为提高混合动力发动机可变气门正时(Variable Valve Timing,VVT)系统响应性故障诊断适用性,提出了一种基于VVT动作偏差累计值的在线诊断策略,该策略以统计窗口内所有计算周期的角度变化绝对值之和为诊断基础,通过VVT实际与目标位置偏差累计值比例系数表征不同的故障状态,从而实现诊断过程不再受限于VVT的动作范围和变化程度。实车验证试验结果表明,全球轻型车测试循环(World-harmonized Light-duty vehicle Test Cycle,WLTC)工况下,无故障、卡滞与慢响应三种状态均可实现准确诊断,实际城市道路试验下车载诊断系统(On-Board Diagnostics system,OBD)的故障报出与修复功能可正常执行;根据响应极限状态下试验结果,设置卡滞故障阈值为8%、慢响应故障阈值为50%;统计学分析结果表明,故障阈值的设置满足3σ标准,不会出现误判故障的风险。In order to improve the applicability of response fault diagnosis for variable valve timing(VVT)system of hybrid engine,an online diagnosis strategy was proposed based on the accumulative value of VVT action deviation.Based on the sum of absolute values for angle change in all calculation cycles of the statistical window,different fault states were characterized by the proportional coefficient of the deviation accumulated value between the actual and the target position of VVT so that the diagnosis process was no longer limited by the range and variation of VVT operation.The real vehicle verification results showed that the accurate diagnosis could be achieved in the three states of no-fault,stuck and slow response under the world-harmonized light-duty vehicle test cycle(WLTC).The fault reporting and repair functions of the on-board diagnostics system(OBD)could be executed normally on the actual urban road.According to the test results under the response-limit state,the stuck fault threshold was set to 8%and the slow response fault threshold was set to 50%.The statistical analysis results showed that the setting of fault threshold met the 3σstandard,and hence there is no risk of misjudgment.

关 键 词：可变气门正时 响应性故障 在线诊断 车载诊断 混合动力 

分 类 号：U472.9[机械工程—车辆工程]