将高阶累积量谱应用于多点随机振动控制环境试验中,生成时域随机驱动信号。通过建立三阶累积量谱(双谱)与自谱间的幅频与相位转换关系,经时域随机驱动信号验证性生成实验,揭示这层关系的存在。其次在多输入多输出线性系统理论假设前提下...将高阶累积量谱应用于多点随机振动控制环境试验中,生成时域随机驱动信号。通过建立三阶累积量谱(双谱)与自谱间的幅频与相位转换关系,经时域随机驱动信号验证性生成实验,揭示这层关系的存在。其次在多输入多输出线性系统理论假设前提下,根据系统驱动、系统频响、系统响应间线性映射关系,通过双谱与自谱间的幅频与相位转换,经IFFT(iverse fast Fourier transform)变换生成满足试验控制要求的时域随机驱动信号。最后以一悬臂梁为试件,对其进行双输入、双输出随机振动控制环境模拟试验。试验结果表明:将双谱应用于多点随机振动控制试验中生成时域随机驱动信号的方法是可行有效的,同时也验证了双谱能抑制高斯白噪声的特性,这一点可通过所生成驱动信号的概率密度分布特征曲线(部分满足均匀分布)进行体现。展开更多
Both auto-power spectrum and cross-power spectrum need to be controlled in multi-input multi-output （MIMO） random vibration test. During the control process with the difference control algorithm （DCA）, a lower tri...Both auto-power spectrum and cross-power spectrum need to be controlled in multi-input multi-output （MIMO） random vibration test. During the control process with the difference control algorithm （DCA）, a lower triangular matrix is derived from Cholesky decomposition of a reference spectrum matrix. The diagonal elements of the lower triangular matrix （DELTM） may become negative. These negative values have no meaning in physical significance and can cause divergence of auto-power spectrum control. A proportional root mean square control algorithm （PRMSCA） provides another method to avoid the divergence caused by negative values of DELTM, but PRMSCA cannot control the cross-power spectrum. A new control algorithm named matrix power control algorithm （MPCA） is proposed in the paper. MPCA can guarantee that DELTM is always positive in the auto-power spectrum control. MPCA can also control the cross-power spectrum. After these three control algorithms are analyzed, three-input three-output random vibration control tests are implemented on a three-axis vibration shaker. The results show the validity of the proposed MPCA.展开更多
文摘将高阶累积量谱应用于多点随机振动控制环境试验中,生成时域随机驱动信号。通过建立三阶累积量谱(双谱)与自谱间的幅频与相位转换关系,经时域随机驱动信号验证性生成实验,揭示这层关系的存在。其次在多输入多输出线性系统理论假设前提下,根据系统驱动、系统频响、系统响应间线性映射关系,通过双谱与自谱间的幅频与相位转换,经IFFT(iverse fast Fourier transform)变换生成满足试验控制要求的时域随机驱动信号。最后以一悬臂梁为试件,对其进行双输入、双输出随机振动控制环境模拟试验。试验结果表明:将双谱应用于多点随机振动控制试验中生成时域随机驱动信号的方法是可行有效的,同时也验证了双谱能抑制高斯白噪声的特性,这一点可通过所生成驱动信号的概率密度分布特征曲线(部分满足均匀分布)进行体现。
基金National Natural Science Foundation of China （10972104） The Fundamental Research Funds for NUAA（NS2010007）
文摘Both auto-power spectrum and cross-power spectrum need to be controlled in multi-input multi-output （MIMO） random vibration test. During the control process with the difference control algorithm （DCA）, a lower triangular matrix is derived from Cholesky decomposition of a reference spectrum matrix. The diagonal elements of the lower triangular matrix （DELTM） may become negative. These negative values have no meaning in physical significance and can cause divergence of auto-power spectrum control. A proportional root mean square control algorithm （PRMSCA） provides another method to avoid the divergence caused by negative values of DELTM, but PRMSCA cannot control the cross-power spectrum. A new control algorithm named matrix power control algorithm （MPCA） is proposed in the paper. MPCA can guarantee that DELTM is always positive in the auto-power spectrum control. MPCA can also control the cross-power spectrum. After these three control algorithms are analyzed, three-input three-output random vibration control tests are implemented on a three-axis vibration shaker. The results show the validity of the proposed MPCA.
