| Cube Sat has made rapid progress in technology,showing explosive growth in number,and has repeatedly put forward innovative concepts in technology and application.Its open design concept,cluster application mode,and diversified development mode have been unanimously recognized by scholars at home and abroad.However,the traditional Cube Sat is mostly based on technical tests and verification,usually 1U-3U.The satellite uses a considerate canvas,with limited energy,and the onboard load and function are single.There is little systematic research on the operational Cube Sat with high resolution and high functional density.Secondly,the traditional separation mechanism mostly uses the belt to connect and separate the satellite and the rocket.However,due to the smaller volume and weight of the satellite,the single-machine layout is more compact.The traditional belt separation mechanism has no space to connect with the Cube Sat,and the impact of the traditional unlocking method on the Cube Sat is unbearable.Therefore,based on a certain type of high resolution,high functional density,12 U batch production Cube Sat of "Jilin No.1",this paper has carried out systematic research work around the integrated optimization design of satellite and separation mechanism,the integrated analysis of launch and inorbit coupling dynamics,and ground test verification.The main work of this paper is as follows:1.First,the theoretical basis of structural optimization is discussed,and then the index requirements of the satellite and its separation mechanism are clarified.Based on the modular and standardized concept of Cube Sat,combined with the design experience of the Jilin No.1 series of satellites,the layout and configuration design of the whole satellite is carried out with the guidance of the general assembly to adapt to batch production.Based on the concept of genetic algorithm,the integrated optimization design of the main bearing structure of the combination of satellite and separation mechanism is carried out based on the factors of launch mechanics,single machine response,and mass.According to the constraint conditions of the satellite and separation mechanism,the motion system of low impact separation mechanism is designed in detail.2.The coupling dynamics of the satellite launch phase are analyzed in an integrated way.Firstly,the simulation theory in the process of contact and satellite separation is introduced,and then the dynamic integration analysis of the separation mechanism and satellite assembly in the launch phase is carried out,including frequency response analysis and random response analysis.The analysis results meet the design requirements;Secondly,Cube Sat has limited energy.To ensure that the satellite can quickly enter the orientation mode to the sun after separation,the integrated dynamic modeling of the satellite and the separation mechanism combination is carried out.Based on the reasonable setting of the contact collision model parameters and friction model parameters,the integrated dynamic simulation model with clearance is established,and the attitude parameters of the satellite after separation are analyzed,The effects of separation spring stiffness and satellite centroid deviation on separation attitude are studied.3.The micro-vibration problem of the satellite in orbit is studied.Firstly,the vibration isolation theory is studied,and then the flywheel disturbance characteristics are analyzed.Based on the Kistler Table micro-vibration test system,the flywheel disturbance force and disturbance torque are tested,and the spectrum characteristics of the measured disturbance data are analyzed.Based on the principle of vibration isolation,a dual-vibration isolation scheme of the whole satellite camera and flywheel is proposed,the whole satellite finite element model from the disturbance source to the optical system is established,and the integrated integration of the whole satellite finite element model,the optical system and the attitude control system are carried out,so as to obtain the full-link integrated analysis method of the transfer characteristics of the performance indicators from the flywheel disturbance source to the load.The integrated analysis method is used to simulate and analyze the dual vibration isolation scheme,predict the effectiveness of the entire satellite dual vibration isolation scheme,and provide effective support and feedback for the micro-vibration suppression scheme.4.Based on the principle prototype of the satellite and the separation mechanism,the ground simulation tests of the launch phase and the in-orbit phase were carried out to verify the effectiveness of the design.First of all,in order to verify the reliability of the structural design scheme of the satellite and separation mechanism combination and test whether the combination structure can withstand the harsh mechanical environment of the launch segment,the launch segment dynamics simulation test was carried out,and the acceptance level sine and random vibration tests were carried out on the whole satellite.The test results verified that the scheme design was reasonable and feasible.Secondly,the separation performance of the separation mechanism in the launch section was tested to verify the reliability of the separation mechanism under vacuum high and low-temperature conditions after the vibration test.For the satellite separation process,a gravity compensation platform is built,and the separation velocity and angular velocity of the satellite separation process are collected to verify the reliability of the separation attitude of the separation mechanism.At last,a micro-vibration simulation test platform based on acceleration sensors was built for the micro-vibration in the orbit segment,and the effect of vibration disturbance on the optical load pixel offset when the three-way flywheel worked alone under the condition of dual vibration isolation was tested.The in-orbit verification link of the satellite was innovatively added,and the dual-vibration isolation scheme was verified in orbit. |
PDF Full Text Request