Research On Structure Design And Simulation Test Of Six-dimensional Disturbance Force Simulator

With the rapid development of space technology,the imaging performance of space optical loads in earth observation is continuously improved.However,various motion facilities on space vehicles,such as reaction flywheel,refrigeration compressor,solar sail rotating mechanism,control moment gyroscope and so on,will produce micro-vibration.These micro-vibrations,with the characteristics of wide frequency,small amplitude,multi-directional vibration and complex form,have a serious impact on the imaging quality of optical remote sensors on space vehicles.Therefore,in order to further improve the observational performance of space remote sensors,it is necessary to carry out research work on the adaptability of space remote sensors to the micro-vibration environment of satellite platforms,and then study the corresponding technical strategies to overcome or weaken the impact of micro-vibration of satellite platforms on space remote sensors.The adverse effects of imaging quality can improve the observation accuracy.In this paper,a six-dimensional space disturbance force simulator was designed independently for practical engineering needs.The simulator can reproduce multi-dimensional micro-vibration with different spectrum characteristics,which is of great significance.The main contents of this thesis are as follows:Firstly,the characteristics of micro-vibration in space were studied,and the key technologies of micro-vibration at home and abroad,especially the research status of micro-vibration ground simulation technology,was introduced.Secondly,the theoretical model of the single-axis actuator and the whole simulator were established,and the transfer matrix between the disturbance force and the moment generated by the simulator and the excitation force of the single-axis actuator was obtained.Based on the research results and the theoretical model,the design indexes of the six-dimensional disturbance force simulator designed in this paper were determined.The structure design of the single-axis actuator wascompleted,and the modal analysis and frequency response analysis of the single-axis actuator were carried out.The modal analysis value of the actuator satisfied the design index,and the results of frequency response analysis verified the correctness of the theoretical model of the single-axis actuator.The drawing,processing and assembling of the prototype of the actuator principle have been completed.The experimental platform was built and the fundamental frequency test of the single-axis actuator was carried out.The error between the experimental results and the simulation analysis was large.The phenomenon of double fundamental frequency of the actuator was found in the experimental spectrum curve.Through the analysis of the experimental results and the simulation process,the problems in the results of the actuator were found,and then the structure improvement of the single-axis actuator was carried out.The modal analysis of the new single-axis actuator was completed,and the simulation results met the design requirements.The spring stiffness test of the new single-axis actuator was carried out.The experimental results showed that the error between the actual test results and the finite element analysis was only 2.3%.The fundamental frequency test of the new single-axis actuator was carried out.The error between the test results and the simulation results was 2.1%,which verified the correctness of the new structure.Finally,according to the theoretical model of the whole simulator and the design index of this paper,the structure design of the six-dimensional disturbance force simulator was completed.The modal analysis of the whole simulator was carried out,and the results of analysis met the design requirements.The frequency response analysis of the whole simulator was completed.The results were consistent with the theoretical modeling results.The maximum error of disturbance force in all directions was 2.13%,and the maximum error of disturbance moment was 2.65%,which verified the correctness of the theoretical formula.An experimental platform was built to test the performance of the six-dimensional disturbance force simulator.The Experiments showed that the simulator can realize the output of six-dimensional disturbance force.Comparing the experimental results with the theoretical modelingresults,the results show that the maximum errors of disturbance forces and moments in all directions are less than 5%,which verifies the correctness and functional feasibility of the simulator theory and structure.