基于模型的液力变矩器故障诊断系统的设计与校验

Design and Verification of Model-based Fault Diagnosis System for Hydraulic Torque Converter

液力变矩器是将发动机动力传递给变速器的重要部件,为全面监控其工作状态并保障其可靠运行,运用基于结构分析法(SA)的故障诊断理论,设计液力变矩器的故障诊断与识别(FDI)系统,实现对所有关键故障的检测和定位。基于对液力变矩器系统的关键故障的分析,建立了系统的故障模型;再通过SA中的Dulmage-Mendelsohn分解和故障可隔离性矩阵,进行故障的可检测性和可隔离性分析。结果表明,所有5个关键故障均可检测,且可隔离;通过求解系统的最小型超定方程集(MSO sets),并基于解析冗余关系式理论,完成了FDI系统的设计。在MATLAB中建立FDI系统的仿真模型并进行仿真。结果表明:该FDI系统能检测和隔离出预先设置的所有故障,与SA的理论分析结果一致。

Hydraulic torque converter(HTC)is an important component that transfers power from engine to gear transmission.In order to overall monitor the working state of HTC and ensure its reliable operation,by applying the theory of fault diagnosis based on structural analysis(SA),fault diagnosis and identification(FDI)system for HTC is designed to detect and locate all the key faults of HTC.Firstly,based on the analysis of the key faults of HTC,the fault model for HTC is established.Next,by means of Dulmage-Mendelsohn decomposition and fault isolability matrix analysis in SA,the fault detectability and fault isolability of HTC are analyzed,indicating that all the 5 key faults of HTC are detectable and isolatable.Then,through the solving of minimal structurally overdetermined sets and based on the theory of analytic redundant relation,the design of FDI system is fulfilled.Finally,the simulation model for FDI system is set up with MATLAB and a simulation is conducted.The results show that the FDI system can detect and isolate all the preset faults,which is consistent with the results of theoretical analysis using SA.