多自由度非高斯随机振动控制

发布时间：2018-10-14 18:38

【摘要】：在振动试验台上进行多自由度(MDOF)随机振动激励时,传统的控制方法生成的驱动信号及试验台的响应信号都是高斯信号。但真实的振动干扰信号多是超高斯的;而相比于高斯激励,亚高斯激励可降低驱动信号的最大幅值。为实现多自由度亚高斯和超高斯振动控制,提出一种多自由度非高斯随机振动控制方法,该方法采用系统辨识解决系统耦合问题,而后通过选择特殊的相位生成非高斯伪随机驱动信号,再经过时域随机化得到真随机非高斯驱动信号。基于Hexapod平台的多自由度微振动试验台的亚高斯和超高斯实验表明,在试验台的响应功率谱(PSD)满足工程中常用的±3dB精度的同时,亚高斯驱动信号的最大幅值相比于高斯驱动信号的最大幅值降低了20%以上;超高斯响应信号的峭度与参考峭度的误差在0.2之内。实验结果验证了所提方法的有效性。
[Abstract]:The driving signal generated by the traditional control method and the response signal of the test bed are both Gao Si signals when the multi-degree-of-freedom (MDOF) random vibration excitation is carried out on the vibration test-bed. But the real vibration disturbance signal is mostly ultra high, and compared with Gao Si excitation, the subGao Si excitation can reduce the maximum value of driving signal. In order to realize the multi-degree-of-freedom sub-Gao Si and super-high degree vibration control, a multi-degree-of-freedom non-Gao Si random vibration control method is proposed. The system identification method is used to solve the coupling problem of the system. Then the non-Gao Si pseudorandom driving signal is generated by selecting a special phase, and then the true random non-Gao Si driving signal is obtained by time domain randomization. The sub-Gao Si and ultra-high degree experiments of the multi-degree-of-freedom micro-vibration test rig based on Hexapod platform show that the response power spectrum (PSD) of the test bench can meet the 卤3dB accuracy commonly used in engineering, at the same time, The maximum value of subGao Si driving signal is 20% lower than that of Gao Si driving signal, and the error between the kurtosis and reference kurtosis is within 0.2. The experimental results show that the proposed method is effective.
【作者单位】：北京航空航天大学宇航学院;中国工程物理研究院总体工程研究所;
【分类号】：TB535

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