Research On On-orbit Identification Of Modal Parameters For Large-scale Solar Panel

With the increasing demand of energy for spacecraft, solar panel, as an energyresource device, is improving towards large scale structure and miniaturization ofdensity. Large-scale solar panel is easy to vibrate persistently and hard to stop in a shortperiod of time, which affects the system stability. Therefore, it is necessary to getaccurate modal parameters for vibration control. However, the previous method ofground experiment and finite element hardly satisfy the requirement of accuracy. Aboveall, this paper designed a plan to identify the modal parameters for solar panel on orbit:optimize the sensors with Ant Colony Optimization (ACO), and identify theacceleration signal with Stochastic Subspace Identification (SSI) through establishmentof theoretical model and finite element modal.Firstly, structural dynamic model for semi-rigid structural of solar panel isestablished, and on the basis of simplified condition, vibration frequency equation ofsolar panel is derived; then modal and frequency response analysis is made with thesoftware MSC.Patran; and the theoretical frequency compared to the finite one to getmutual authentication.Secondly, discuss the minimum acceleration sensor number of layout underrepeated frequency; at the same time, design optimal criterion on the basis of energyand vectorial angle to get high signal-to-noise ratio and identifiable signal. Under theabove optimization criteria, bring in ACO to make optimal collocation and build thesimulation.Lastly, time domain identification method-SSI was used to identify modalparameter of large solar panel on the condition that stimulating source is hard to know.First of all, the state space equation is established as mathematical model ofidentification method, then, the process of SSI-COV and SSI-DATA is introduced andthe system order is determined by the singular entropy increment. Finally, thecorrectness and feasibility of SSI is verified by the simulation.