多点激励功率谱再现振动试验控制研究

Control designs for multi-exciter power spectral density replication vibration tests

通过对多点激励功率谱再现振动试验控制算法研究.设计基于偏相干分析理论的振动试验系统频响矩阵辨识策略,针对系统频响矩阵存在奇异点及系统频响矩阵为长方矩阵情形,设计基于求解频响矩阵广义逆和矩阵最小范数最小二乘解的Moore-Penrose逆系统解耦算法。针对传统差分修正驱动谱控制算法中存在系统功率谱自谱为负数或零值问题,通过引进比例均方根反馈修正算法,设计改进的功率谱均衡控制策略,有效避免功率谱均衡过程中自谱产生负值或零值问题。多点激励功率谱再现振动试验表明,改进的功率谱均衡控制策略对多点激励系统具有可靠、高精度的控制效果。

Through studying the control algorithm for muhi-exciter PSD （power spectral density） replication vibration tests, an identification strategy for the frequency response matrix of a vibration test system based on partial coherence analysis was designed. For situations of singular points existing in a system frequency response matrix and the matrix being rectangular, different system decoupling algorithms were desgined based on the solutions to the matrix generalized inverse and its Moore-Penrose inverse with the minimum norm and least square methods. Aiming at the situation that the system APSD ~ auto-power spectral density） might be negative or zero in the traditional difference correction of the drive spectral control algorithm, an improved PSD equalization control strategy was designed by introducing a proportional RMS feedback correction algorithm. The algorithm could effectively avoid the APSD being negative and zero in the process of PSD equalization. The multi-exciter PSD replication vibration tests showed that the improved PSD equalization control strategy can achieve a reliable, high-precision control effect on a multi-exciter vibrationsystem.