Research On Key Technologies Of Material-based Assembly Of Large Truss Structures

The support of the super-large structure can achieve higher performance index of the aircraft body,but it is limited by the resources such as transportation.At present,the direct launch of the super-large structure cannot be achieved,but the on-orbit construction and regeneration technology scheme can be adopted.The truss structure has the advantages of small size limitation of the load compartment of the carrier and easy assembly in space,which makes it possible to assemble the super-large space structure on the ground and in the rail.This project combines the actual needs of on-orbit service and maintenance,carries out research on the large-scale truss structure in-orbit assembly ground demonstration system,and verifies some key technologies of space large truss structure in-orbit assembly,and provides technical basis for on-orbit assembly.The research on the hexahedron truss is carried out.Firstly,the geometric invariance is verified.Then the structure is optimized.The weight and fundamental frequency are used as constraints.The multivariate linear regression method is used to establish the empirical model expression of the truss weight and the fundamental frequency.The relationship between each factor and the truss mass and the fundamental frequency is predicted.The interaction between the truss weight and the fundamental frequency is studied by orthogonal test method.The optimal combination of the truss fundamental frequency and the optimal truss mass are folded.In the middle of processing,the final truss lightweight indicator reached 4.89%.The truss assembly is carried out by means of material assembly.Based on the technology in the factory,the locking form of the material is optimized.The advantages and disadvantages of several connection forms are compared,and the card form is selected as the material locking structure.Then the design of the cassette structure is carried out.Finally,the ABAQUS software is used to simulate the plugging and unplugging process of the cassette structure,and the assembly experiment is carried out through the production of the sample.The simulation results and experimental results show that the extraction force of the cassette structure is large,indicating The designed cassette structure has better connection performance.Based on the design principle of the system,this paper plans the assembly sequence of the space truss based on the lightweight post-architecture structure,and analyzes the truss assembly process according to the preliminary planning results to determine the composition scheme of the truss assembly system.Finally,the structure design of each unit of the system is introduced.The truss assembly process is simulated and verified.Firstly,the simulation software is screened.The advantages and disadvantages of DELMIA or Tecnomatix are compared.DELMIA is selected as the simulation tool.The sequence and path of the assembly system are calculated by MATLAB,and the path planning result is output.It is imported into DELMIA in txt file format to analyze the accessibility of the assembly resources.During the simulation,the execution end and plane unit expansion module and the expansion assembly unit are found.There is interference problem,and the interference execution collision problem is solved by modifying the execution end size.Finally,after several simulation demonstrations,the robot grabs the parts normally,and there is no interference in the assembly process to verify the rationality of the assembly planning.