一种多输入多输出非高斯随机振动试验方法

摘要

针对传统的多输入多输出高斯随机振动试验难以应用于非高斯问题,提出了一种基于频域逆系统方法的多输入多输出非高斯随机振动试验控制方法.该方法首先通过给定的参考谱和参考峭度生成参考信号,其次根据频域中的输入输出关系生成满足要求的驱动信号.采用相位调节法生成非高斯信号,由于相位调节法不改变原信号的功率谱,因此可实现功率谱与峭度的独立均衡控制;将矩阵幂次算法用于功率谱均衡,并提出了一种类似矩阵幂次算法的峭度均衡算法.最后,对一个三轴振动台台面振动环境进行了控制试验,结果表明,台面加速度响应的功率谱密度被稳定地控制在±3 dB容差限内,响应峭度也被稳定地控制在参考值附近,从而验证了所提方法的有效性与可行性.%A method based on the inverse system method in frequency domain for MIMO non-Gaussian random vibration test is proposed to solve the problem for which the traditional test method cannot be used for the non-Gaussian situation.First,the reference response signals are generated by the specified reference spectra and the reference kurtoses.Then the coupled driving signals are obtained by the relationship between the inputs and the outputs in the frequency domain.The phase regulation method is used to generate the non-Gaussian signals which do not change the spectra of the signals.Thus,the spectra and the kurtoses can be controlled independently and simultaneously.The matrix power control algorithm is introduced for spectrum e-qualization control,and a kurtosis equalization control algorithm is proposed similarly.The results form a three-axis vibration shaker control test shows that the power spectra density of the response acceleration signals are controlled within the ± 3 dB a-larm limits completely,and the kurtoses of the response signals are also stably controlled near the reference kurtoses,which indicate the validity and feasibility of the proposed method.