Research On Micro-vibration Of Satelite Platform Based On Transfer Path Analysis Method

At present,China has hundreds of artificial satellites for observation,which are widely used in scientific research,geology and meteorology.However,high-resolution satellite observations are easily affected by the vibration of moving parts such as flywheels and gyroscopes.Micro-vibrations are transmitted to the optical camera through the satellite platform cabin,which affects the imaging quality.At present,the research of satellite microvibration is mainly based on simulation and experiment.For complicated systems,the vibration model established by simulation has many dimensions and a large amount of calculation.The advantage of the transfer path analysis method is that the theoretical model has high versatility,is closer to the actual situation,and is suitable for rapid diagnosis.Therefore,the transfer path analysis method based on the test can be used as an evaluation method for the micro-vibration transfer of the satellite platform,and provides a basis for the vibration suppression of the platform.Firstly,according to the satellite structure,establish the vibration transfer model,plan the transfer path,and select the applicable transfer path method.Determine the main vibration source of the satellite platform,and build a vibration transfer model with three elements of " source path response".According to the structure of the satellite cabin,plan the transmission path from the vibration source to the target camera foundation.Compare the theoretical models of transfer path methods,and select the OTPA（operational transfer path analysis）method which is cycle-short and scalable.Then,an improved OTPA method based on Tikonov regularization is proposed to improve the matrix ill-posed problem in the analysis of OTPA method.Compared with the commonly used truncated singular value method,the regularization method considers both the accuracy of the results and the stability of the balance matrix.The truncated singular value method and the regularization method OTPA algorithm are implemented using MATLAB.A two-path vibration transmission test was carried out on the L-shaped honeycomb panel.The singular values and condition numbers of paths under different truncation thresholds and regularization parameters are compared to verify the effectiveness of the regularized OTPA method for ill-posed problems and higher computational accuracy.Finally,build a test platform and conduct micro-vibration experiments on the satellite,then analyze the contribution of the planned paths through OTPA method.Adopt the PXI hardware solution,and develope the vibration testing and analysis modular system software by using LabVIEW.Build a satellite micro-vibration test platform to test and measure working condition data.Based on the regularized OTPA the transmissibility and contribution of each path are calculated,and the vibration contribution of different paths in the vibration transmission under typical operating conditions is compared in the frequency domain,and the path that has a greater impact on the target camera is determined.