Mechanical Analysis Of Compliant Assembly Of OM2 Components Based On Peg-hole Positioning

This subject comes from the major scientific research project of national SG-III project,which mainly develops ICF laser device for the study of nuclear reaction,and the requirements for laser device is high,to ensure the multi laser beam focusing to the target ball point to trigger a nuclear reaction.Therefore,the OM2 assembly,as an important laser guiding device on the target ball,has high assembly requirements.OM2 component is divided into four parts,by the rectangular section of the shaft hole connection,the total length of about 11 m,total weight of about 5t.Using traditional assembly methods,it is difficult to assemble large size and high quality components while satisfying the requirements of high precision in complex environment.Thus,a new assembly method--the hybrid compliant assembly is adopted in this paper.The mechanical analysis of the assembly process of the axle hole is carried out based on the location of the axle hole.Compliant assembly contains active compliance assembly and passive compliant assembly,wherein the active compliance assembly effect due to the sensor,and the layout of the form,the large size of the parts compared to the small size of the parts on the accuracy of the sensor,the types and the number are put forward higher requirements,more difficult to achieve.The passive compliant device not only has high precision corresponding high rigidity,but also has certain flexibility,which leads to its strong specificity,low practicability and limited scope of application.According to the characteristics of the OM2 component and the compliant assembly,this paper designs scheme of hybrid compliant assembly mechanical sensor and compliant spring for OM2 based on component assembly,wherein the active compliance system for shaft hole location and angle pose adjustment for passive compliant displacement deviation adjustment,the system only need to provide against the force,soft spring will be deformed in the chamfer of the force,so that the axis toward the axis direction of the moving hole to complete the assembly.On the one hand,the assembly scheme reduces the requirement of sensors in active compliance,simplifies the control system,and on the other hand makes the system with high assembly accuracy.In this paper,the motion of compliant mechanism with six degrees of freedom is planned,and the mechanical analysis model of OM2 component installation condition is established.On this basis,the relationship between the force of the force sensor,the interaction force between the shaft and the hole and the position and attitude of the OM2 assembly in the active compliant assembly is calculated.Thus the judgment scheme of the relative position of the axle hole is summed up.The scheme can separately distinguish the contact forms of the shaft relative hole with one point contact,two point contact,three point contact or side contact,and judge that there is no four contact between the rectangular shaft and the hole.At the same time,the position adjustment strategy based on Xie Guofang formula for Euler angle is designed by using the information detected by force sensor,and the stiffness of compliant spring is calculated.Finally,the ADAMS dynamic simulation software is used to simulate the movement process of the OM2 assembly in the bore hole compliant assembly process,which verifies the feasibility of the theoretical results.