基于非线性输出频率响应函数的液压管路故障诊断研究

Fault Diagnosis for Hydraulic Pipelines Based on Nonlinear Output Frequency Response Function

航空液压管路系统受到多源激励的影响,在工程应用中经常发生管路系统振动故障。针对长跨距管路系统振动故障定位困难的问题,采用光纤布拉格光栅(Fiber Bragg Grating,FBG)测试技术开展了长跨距管路系统振动信号分布式测量,并提出结合非线性输出频率响应函数(Nonlinear Output Frequency Response Function,NOFRF)分析方法实现液压管路系统卡箍松动和管体碰撞故障的准确定位。采用FBG传感器对长跨距管路系统振动信号进行分布式测量,克服了传统加速度测试过程中的电磁干扰和复杂布线问题;采用NOFRF指标提取卡箍松动和管体碰撞的故障特征,实现了对微弱故障的早期监测和准确定位。试验结果表明,所提方法可有效定位卡箍松动和管体碰撞故障。

Aviation hydraulic pipeline systems are subject to multi-excitations,including base excitation and pump-induced fluid pulsation,leading to pipeline system vibration faults frequently in engineering.In response to the dfficulty in locating vibration faults in long-span pipeline systems,distributed measurement of vibration signals in long-span pipeline systems is carried out by using fiber Bragg grating(FBG)testing technology.Combined with the nonlinear output frequency response function(NOFRF)method,accurate positioning of clamp loosening and pipe collision faults in hydraulic pipeline systems are achieved.In this method,FBG sensors are used for distributed measurement of the vibration signals in the long-span pipeline system,which can overcome problems of electromagnetic interference and complex wiring problems in traditional acceleration testing processes.The NOFRF values obtained from the collected vibration signals are used to determine the locations of loose clamps and pipe collisions,realizing early monitoring and accurate positioning of weak faults.Test results clearly demonstrate that the proposed method can effectively locate clamp looseness and pipe collision faults.