Research On Reusable Lock And Separation Technology For Space Experimental Unit

With the progress and development of space science and technology,more and more artificial satellites are launched into space.The invalid spacecrafts become space junk,which will severely limit other space missions to carry out,therefore,it is urgent for us to master the technology of on-orbital service to solve the problem of aircraft maintenance.Space and earth transit system can complete the tasks of fuel filling and equipment replacement for the space station.Therefore it is significant to develop space-earth transit technology.The reusable lock and separation technology is the premise and key technology of on-orbital service and space-earth transit,the research of reusable lock and separation technology has become an urgent need for space exploration activities.This thesis is devoted to the study of the scheme of the reusable lock and separation and the optimal design method,and a series of experiment studies on the prototype.Three programs are proposed according to the capture way of the space payload of on orbit service platform and design specifications.The “worm-gear and crank-slider mechanism” is selected based on the principle of misalignment tolerance,lock-separation shock and locking force.The D-H matrix between the arbitrary point of the space payload and the coordinate system of reusable lock and separation device is established,in addition,the mathematical model of the locking torque of the rigid-locking mechanism is completed.The mechanism of the capture,rigid-locking,guide-separation and transmission are detailed designed,and the compentent of these mechanism are selected.The locking torque of the rigid-locking mechanism is optimized,in addition,the selection of the motor,speed reducer and worm-gear are finished.Finite model of experimental unit and reusable lock and separation device is modeled as well as modal analysis is given to attain the relation of locking-force to fundamental frequency.The influence of the deviation of the locking-force can be ignored to fundamental frequency.Mathematic and prediction models are built for locking location,the mapping relationship between locking location and fundamental frequency is achieved by applying neural network method.Tensor Flow algorithm is used to optimize and get the optimal locking locations.The mathematical model of the trajectory of key points of the ball head is completed,misalignment tolerance is analyzed and optimized by the way of the projection of key points.By static analysis,it is achieved that the response with statics structural strength and deformation under preload meets the requirements.In order to complete the design of separation spring,the separation resistance test of electric connector is carried out.The relationship between deformation and force of disk spring is got by tension test machine,the deformation-force curve will used to finish locking torque and locking power simulation.The static analysis and test are carried out,in order to verify the reusable lock and separation device can eliminate maximum error value in the process of locking.With the dynamic simulation of the mechanism movement and the prototype test,the basic functions of the reusable lock and separation device are verified.The fundamental frequency and acceleration response are got by vibration experiments,the space payload is locked reliably under input vibration conditions.In summary,the research results of this paper meet the design specifications,and can supply the reference for the further optimization and improvement of the reusable lock and separation device.