Type Synthesis And Compliance Modeling Of Hybrid Compliant Mechanisms For Peg In Hole Assembly

For the requirements of high-efficiency and high-precision peg in hole assembly,this paper proposes a scheme of passive peg in hole assembly with hybrid compliant mechanism,and carries out research on type synthesis,compliance Modeling and peg in hole assembly experiment of hybrid hybrid compliant mechanism.The main results of the full text are as follows:1.Design of peg in hole assembly scheme based on hybrid compliant mechanism.Analyze the force variation of the shaft member during the assembly process of the peg in hole assembly,and condense the design requirements of the assembly system and the error compensation mechanism.Combining the advantages of parallel mechanism and compliant mechanism,a general scheme of peg in hole assembly system based on new hybrid compliant mechanism is proposed.A piece spring is selected as the basic compliant unit of the parallel compliant mechanism,and a method for controlling the deformation of the compliant unit by means of a rigid hinge is proposed.2.Type synthesis of hybrid compliant mechanism.Using instantaneous screw as a mathematical tool to describe the freedom and constraint of motion of the basic compliant unit,a comprehensive method of configuration of the parallel compliant mechanism is proposed to form a general flow,which used for type synthesis of the hybrid compliant mechanism.According to the requirements of shaft hole assembly design,the parallel flexible mechanisms with n R2 T and 3Rn T degrees of freedom are synthesized.The four-degree-of-freedom and five-degree-of-freedom flexible branches of the n R2 T and 3Rn T parallel compliant mechanisms are respectively generated by the instantaneous screw theory.The compliant branch is assembled according to the constraints of the mechanism to obtain a parallel compliant mechanism,preferably a1R2 T and a 3R parallel compliant mechanism combined with a 2R3 T hybrid compliant mechanism.3.Compliance modeling and optimization design of hybrid compliant mechanisms.The simulation experiment is used to analyze the mapping law of the compliance of the hybrid mechanism and the size parameters of the leaf spring.It is known that the mechanism Compliance and the length,width and thickness of the leaf spring are exponentially mapped.Construct a mapping model of line compliance,angular compliance and slice spring size parameters of the hybrid mechanism,use the genetic optimization algorithm to fit the model coefficients.Taking the mass,volume and axial load-bearing capacity of the hybrid compliant mechanism as the optimization target,the mechanism compliance and angular compliance as constraints,constructing a multiobjective optimization model,and optimizing the chip spring scale parameters to make the hybrid compliant mechanism light in weight.Small volume and high axial load carrying capacity.4.Manufacturing and experimental research on hybrid compliant mechanism prototype.Manufacturing physical prototype of hybrid flexible mechanism,The prototype of the hybrid compliant mechanism prototype was tested and it was confirmed that it was 2R3 T degrees of freedom.The compliance of the flexible flexible mechanism is verified.The error between the experimental results and the compliance model is less than 7%,which proves the accuracy of the compliance model.The axial load carrying capacity of the hybrid compliant mechanism is tested,and the physical prototype can withstand an axial pressure of no more than 50 N and an axial tensile force of no more than 100 N.The hybrid compliant mechanism is combined with the UR3 industrial robot to form the peg in gole assembly system,and the R10 and R5 shaft hole assembly experiments are carried out.When the deviation between shaft and hole is 0.1 mm,the peg in hole assembly system can be adjusted within the ?5? and ?2mm error range.The success rate is above 90%,which indicates that the hybrid compliant mechanism can greatly improve the success rate of the peg in hole assembly and reduce the assembly time.This paper starts with the characteristics of peg in hole assembly,systematically studies the type synthesis and compliance modeling method of hybrid compliant mechanism,and verifies the effectiveness of the peg in hole assembly system based on hybrid compliant mechanism through experiments,and lays out the theoretical basis of the peg in hole assembly mechanism.Breaking through key modeling and analysis techniques is of great significance for high-efficiency and high-precision peg in hole assembly.