基于分形理论的自动舵液压阀故障诊断方法研究

Research on fault diagnosis method for auto pilot hydraulic valve based on fractal theory

针对自动舵液压阀工作过程中存在的非线性问题,提出一种以阀芯位移信号分形特征为判据的故障诊断方法,并研究了分形特征参数——关联维数的计算方法和参数的选择。在建立液压阀数学模型的基础上,对液压阀正常和故障进行仿真,通过确定时间延迟、嵌入维数和无标度区,计算阀芯位移数据的关联维数。结果表明:不同状态的关联维数值具有明显的可分性,可以定量表征液压阀的工作状态,进而达到装备故障诊断的目的。

In order to solve valve, a fault diagnosis the nonlinear problems in the working process of autopilot hydraulic method by choosing the fractal characteristic volume of valve＇s displacement signal as a criterion has been proposed, and the calculation of fractal characteristics parameter called correlation dimension is studied. And the choice of its calculation parameters is also analyzed. The states of normal and fault are simulated based on the mathematics model of hydraulic valve. The correlation dimension of valve displacement data is calculated after confirming delay time, implanted dimension and range＇ without scale. The result showed that correlation dimension of different states can be separated clearly and can quantificationally represent different working states for the purpose of equipment fault diagnosis.