随车起重机变幅液压系统故障诊断仿真

针对液压系统中元件复杂、故障隐蔽性强而造成的诊断难题,提出了基于模型的故障诊断方法,为验证方法的可行性,进一步提出了故障诊断的仿真验证方法,搭建了其仿真模型。以某型随车起重机变幅液压系统的工作原理为基础,分析了变幅液压系统常见故障及故障注入方法,选取换向阀阀芯卡死故障进行诊断,通过阀芯液阻控制模块注入阀芯卡死故障,建立其功率键合图模型;其次,利用扩展遍历路径法生成一组解析冗余关系(ARR)的公式,并推导出阈值计算公式,采用MATLAB/Simulink平台搭建的故障诊断仿真模型计算出系统残差;最终,根据残差估计结果,对带有换向阀卡死故障的变幅液压系统进行诊断。通过诊断结果与初始故障注入对比,以及对随车起重机实验台的故障实验结果分析,验证了基于模型的液压系统故障诊断方法的可行性和高效性,为工程机械液压系统的故障诊断提供了新思路,并为预测液压系统剩余寿命奠定基础。

Fault Diagnosis Simulation Method for Luffing Hydraulic System of Truck-mounted Crane

Focus on the diagnosis problem caused by complex components and large fault concealment in hydraulic system, the paper proposes a fault diagnosis method based on model. In order to verify the feasibility of method, the paper further proposes the simulation method of fault diagnosis and builds the fault diagnosis simulation model. Based on the luffing hydraulic system of a certain type of truck crane, firstly, the paper analyzes its common faults and fault injection methods, injects the valve core stuck fault of the directional valve through the valve core hydraulic resistance control module to diagnose and establishes the power bond graph mode. Secondly, the extended traversal path method is used to generate a set of Analytical Redundancy Relation (ARR) formulas, and the threshold calculation mathematical model is derived. The fault diagnosis simulation model based on MATLAB Simulink platform is used to calculate the residual. Finally, according to the residual estimation results, the fault of hydraulic system is diagnosed. The feasibility and efficiency of fault diagnosis method are verified by comparing fault diagnosis with injection and analyzing fault experimental results, which provides a new idea for the fault diagnosis of the hydraulic system of construction machinery and lays a foundation for further prediction of the remaining life of the hydraulic system.