Research On Robotic Peg-in-Hole Precise Assembly Technology Based On Active-Passive Compliance

In recent years,with the rapid development of industrial robot technology and the transformation and upgrading of traditional manufacturing towards intelligent manu-facturing,robots have become an irreplaceable important equipment and means in man-ufacturing.With greater stiffness,a smaller positioning error of robots may generate a larger contact force during precision assembly operations,which probably cause assem-bly failure or more serious problems,damaging the assembled workpiece and robot body.Therefore,it is particularly important for the robot to have a compliant ability with the external environment and be able to perform compliant assembly.In this paper,the compliance of peg-in-hole precision assembly is discussed with the research on the design and performance analysis of compliant device,robot kinematics,vision posi-tioning system,compliant assembly strategy,assembly control framework,and experi-mental verification based on active-passive compliance.The paper first analyzes the characteristics of active and passive compliance,pro-poses design requirements and design indicators,and then conducts structural design of the compliance device and selection of key components.The strength of key compo-nents is checked by using finite element analysis software.We carry out the experi-mental analysis of the system response,and confirm that the designed compliant device can meet the usage requirements after completing the structural construction of the compliant device and the design of the control system.Secondly,in order to reduce the control error of the robot body during the peg-in-hole assembly,the forward and inverse kinematics modeling method of robots is ana-lyzed,the D-H parameters of robots are extracted by the laser tracker,the optimized compensation is performed by the optimization algorithm,and the robot control accu-racy is improved.In addition,a vision-guided positioning system is introduced into the assembly system,whose basic principles are analyzed and experimentally verified.It makes the robot have a certain active sensing ability before contacting the external en-vironment.Thirdly,based on variable compliance center and the advantages of both passive and active compliance,an assembly strategy and a simple assembly control system are designed to improve the assembly efficiency.In addition,the peg-in-hole assembly er-ror of the strategy,which laid the foundation for the peg-in-hole assembly experiment is analyzed in this paper.Finally,a software and hardware platform for robot compliant assembly based on the assembly strategy and control model is built,and the peg-in-hole assembly experi-ments are completed as well.The experimental results verify the correctness of the pro-posed compliant assembly strategy and the feasibility of practical industrial applica-tions.