基于ARMA模型的磁流变振动系统精确建模与性能研究

为了研究自主研制的磁流变减振器及其振动系统的动态性能,建立了未经简化的磁流变振动系统的动力学四阶系统模型,通过四阶系统分母多项式与时间序列ARMA模型系数的对应关系推导出动态特性参数的计算公式,将不同工况条件下实验检测信号进行傅里叶变换滤去谐振成分,利用公式计算获得了系统动态特性参数,与三阶系统建模比较分析了建模精度以及系统的动态性能。研究分析表明,基于ARMA模型的四阶系统比三阶系统具有更高的模拟精度,尤其在中高工作频率范围优势更为明显,推导得出的动态性能参数的分析为系统选取了合适的工况,分析结果可作为磁流变减振器及振动系统性能预测与评价的依据,其方法可供同类高阶系统动态性能分析推广与借鉴。

Accurate modeling and performance investigation on MR vibration system based on the ARMA model

In order to investigate dynamic performance of the independently developed magnetorheological(MR) damper and its vibration system, the unsimplified four order dynamics model of MR vibration system is set up. Calculation formulas for dynamic performance parameters are deduced through the corresponding relationship between the ARMA model coeffient and the denominator polynomial of transfer function, and the resonant component of experimental detection signal under different working conditions is filtered by FFT. The system dynamic characteristic parameters are obtained by these calculation formulas, and the modeling accuracy and dynamic performance of four order model are analyzed by comparing with three order model. Analysis shows that,the four-order system based on ARMA model exhbits higher modeling accuracy than three order model. Especially, its advantage is more obvious in the higher working frequency range. Calculation and analysis of the derived dynamic performance parameters can select the appropriate condition for the system. Analysis results can be used as the basis of performance prediction and evaluation for the MR damper and vibration system, and the method is available for dynamic performance promotion and reference of the similar higher order system analysis.