恒流开式液体静压支承动力学建模及参数辨识方法

Parameter Identification Method and Dynamic Modeling of Open-type Constant Flow Hydrostatic Bearing

针对现有恒流开式液体静压支承线性动力学模型计算偏差较大问题,建立了液体静压支承的非线性动力学模型。基于液体静压支承振动响应,提出应用Fourier级数方法和最小二乘联合方法,识别该非线性动力学模型中的刚度与阻尼。同时,设计了多种阶跃激励作用下的实验工况,应用研制的实验平台,获取了各种工况条件的振动响应。结合液体静压支承的非线性动力学模型和提出的参数辨识方法,得到了液体静压支承的刚度、阻尼参数。在此基础上,对比识别的动力学参数计算的位移响应与实验值,发现理论值与实验值的决定系数都在0.97以上,从而验证了建立的非线性动力学和参数辨识方法的有效性。

Due to the large error of the linear dynamic model for the open-type constant flow hydrostatic bearing,a nonlinear dynamic model of hydrostatic bearing is established.Based on the vibration response of hydrostatic bearings,the Fourier series method and the least square method(LSM)were used to identify the stiffness and damping of the nonlinear dynamic model.Meanwhile,some step excitation experiment were designed,and the vibration responses of various working conditions were obtained by using the developed experimental platform.Combined with the proposed nonlinear dynamic model of hydrostatic bearing and the method of parameter identification,the stiffness and damping of hydrostatic bearing were obtained.On this basis,the theoretical displacement response and experimental displacement were compared.It is found that coefficient of determination between the theoretical and experimental displacement is more than 0.97.Furthermore,this validates the fitness of the nonlinear dynamic model and parameter identification methods.