空间站控制力矩陀螺微振动测试技术

Micro-vibration Testing Technology of Space Station Control Moment Gyroscope

目的分析控制力矩陀螺的微振动扰动特性。方法通过获取陀螺连接点对结构的扰振力输出、关键部位的微振动响应来获取产品的微振动扰动特性,通过隔振的方式对外部环境的干扰进行隔离,进而降低测试的背景噪声,通过运用高精度测试传感器来实现微小扰动力信号、加速度信号的测量,利用结构有限元法及单点激励多点响应的模态分析方法校核系统刚度,进而确定测试频率范围是否满足需求。结果可同时获得空间站控制力矩陀螺连接点处的输出扰振力、质心处的输出扰振力合力、合力矩以及关键部位的微振动响应,可有效隔离外部干扰,扰振力背景噪声的时域信号最大值可控制在0.07 N以内,RMS值在0.02 N以内,加速度信号的时域背景噪声最大值可控制在1.5 mg以内,RMS值在0.1 mg以内。可识别微小扰振信号,加速度传感器分辨率为5×10-5 grms,力传感器的测量分辨率为1×10-2 N,力矩测量分辨率小于1×10-2 N·m。测试频带在320 Hz以内。结论满足型号需求,并投入型号使用。

Objective To analyze the micro-vibration perturbation characteristics of control moment gyroscope. Methods The micro-vibration perturbation characteristics of the CMG were obtained by measuring the force signal at the contact surface and the acceleration signal at the crucial location. The external environment was isolated by means of vibration isolation to reduce the background noise of the test. A high precision test sensor was used to measure micro-vibration force signal and acceleration signal. The stiffness of the system was identified with the structural finite element method and the modal test analysis method of single point excitation multi-point response, to determine whether test frequency range meets the requirements. Results The force signal at the contact surface, the resultant force at the center of mass and the acceleration signal at the crucial location could be measured. External interference could be effectively isolated. Background noise： force signal ≤0.07 N（maximum）, ≤0.02 N（RMS）, acceleration signal≤1.5 mg（maximum）, ≤0.1 mg（RMS）. Micro-vibration signal could also be recognized. Resolution： acceleration 5×10^-5 grms, force 1×10^-2 N, torque 1×10^-2 N·m. The test band was within 320 Hz. Conclusion It meets model requirement and is put into use.