Research On Parallel Mechanism Of Position Adjustment And Overlapping About Large Thin Shell

In recent years,China's comprehensive national strength has been gradually improved,the space industry has achieved rapid development,and the automatic assembly level of space equipment has become increasingly high.Based on space large cylindrical thin-wall parts assembly automation requirements,used for automatic assembly of posture adjustment and suit the equipment configuration of research,put forward a new type of 5-U(RRP)S/8(U)PU parallel mechanism as the posture adjustment and the suit,and the agency for the corresponding theoretical analysis and size optimization,to build a 3 d virtual model,and making the physical prototype experiment validation.The research lays a foundation for the orientation adjustment of large thin shell components and the practical development of automatic equipment for suits,which has important theoretical significance and practical application value.The following research and analysis are carried out.(1)Determine the configuration design requirements for the adjustment of position and posture of large thin shell components and the suit.In view of the engineering background and requirements of the large thin shell parts set,the system components of the equipment are determined,and the parallel mechanism is used for posture adjustment and the set part,and the degree of freedom of the parallel mechanism is determined.(2)The pose adjustment and the configuration design of the suit parallel mechanism are carried out.And determine the degree of freedom and mechanism configuration.According to the design goal of high rigidity and high precision of the mechanism,the branch chains are configured and designed.For passive branched chains,different schemes are proposed by means of the type synthesis method,and the optimal structure is selected by comparison.For active branched chains,the final structure is obtained by means of configuration evolution.Finally,the mechanism configuration of 5-U(RRP)S/(8U)PU was determined,and its assembly conditions,freedom degree calculation and driving pair selection were determined.(3)Kinematics analysis of a novel 5-U(RRP)S/(8U)PU parallel mechanism is carried out.It mainly includes the calculation of positivity and antithesis,the calculation of velocity jacobian matrix by spiral theory,the analysis of workspace theory and examples,the singularity analysis,the calculation and analysis of static stiffness matrix.This part is divided into the following work to lay a theoretical foundation,especially for the prototype control provides the output and input displacement correlation equation,velocity correlation equation and other control functions.(4)Dimension optimization of a novel 5-U(RRP)S/(8U)PU parallel mechanism are carried out.The size of the mechanism is an important factor affecting the stiffness of the structure.The optimization includes the structural size optimization based on genetic algorithm and the joint geometric size optimization based on simulated annealing algorithm by ANSYS and MATLAB.(5)Three-dimensional modeling,virtual simulation verification and prototyping are carried out.According to the results of the theoretical analysis and optimize the size and on the basis of certain practical engineering using Solidedge software for 3 d modeling,and import the ADAMS software to the simulation,degrees of freedom movement characteristics,such as including mechanism was verified through with 5-UPS/8(U),comparing the PU parallel mechanism in the end to verify the new 5-U(RRP)S/8(U)PU stiffness and accuracy of the parallel mechanism to meet the design requirements and has greatly improved.