自动变速操纵系统稳态工况下非平稳随机信号的故障诊断技术研究

提出了基于信号冗余关系的自动变速操纵系统（ASCS）稳态行驶工况非平稳随机信号多重故障检测和诊断策略。通过分析ASCS非平稳信号特性以及信号之间的冗余关系，提出故障检测和诊断策略设计原则：不可信原则、多故障兼容原则和概率原则，作为故障检测和诊断策略设计的指导思想。同时根据故障诊断结果的准确性和有效性特点将故障诊断结果划分为一级、二级、三级3种类型。通过分析ASCS稳态工况的先验知识，提出非平稳随机信号故障检测和诊断策略，实现发动机转速、变速箱输入轴转速、车速和车辆挡位信号之间单或多重故障诊断的功能。向实车数据中注入不同类型故障来检测故障诊断策略的完整性和正确性，试验结果证实了该方法的有效性和实用性。

Research on Fault Diagnosis of Non stationary Random Signals under ASCS’s Steady State Condition

A multiple fault detection and diagnosis strategy of non stationary random signals is presented for automatic shift control system (ASCS), which is based on the redundancy relationship between signals under the steady state condition. The design principles of fault diagnosis strategy are put forward based on the characteristics of ASCS non stationary random signals and the redundancy relationship between them. These principles, including credibility principle, fault compatible principle and probability principle, are the design guidelines of fault diagnosis strategy. According to the accuracy and efficiency of fault diagnosis results, the results are divided into three types. Then the fault detection and diagnosis strategy of non stationary random signals is put forward on the basis of prior knowledge under the steady state condition of ASCS, which can realize the single fault or multiple fault diagnosis of engine speed, transmission input speed, vehicle speed and gear signal. Man made fault is injected through the real vehicle test process to detect the integrity and validity of fault diagnosis strategy. The car data and test results show that the method is effective and practical.