Research Of Shaft Hole Compliant Assembly Technology Based On Multi-joint Flexible Lightweight Manipulator

Intelligent manufacturing is the development direction of manufacturing automation.Different from the traditional industrial robots,intelligent robots is a fusion of many disciplines,such as mechanical,electronic sensors,computer hardware,software,artificial intelligence and other knowledge,involves many current frontier technology.Intelligent robot technology mainly has two key points:first,the rapid and accurate perception of the environment;the second is to make a reasonable response in real time.Crucially,the coordination of perception and action is the core issue to determine the level of intelligent robot.Among the robot application field,compliant assembly is one of the main research directions of intelligent manufacturing.In the process of assembly,the assembly process and the installation errors are always present,which lead to the failure of automatic assembly.Whether it is based on force sensor feedback control or machine vision control,it is needed to add external high precision and high speed sensing system,which is not conducive to the flexibility of robot application.This paper is based on a robot platform to achieve automatic assembly.The core problem is the force sense control.Make the robot can take the initiative respond the environment force.This paper shows the she assembly of axle hole comprehensive utilizing of assembly technology and robot integrated mechanical flexibility and joint torque sensing,based on the application performance of a lightweight 7-DOF KUKA robot.Discussing the traditional force feedback control method and the control method based on the robot impedance mode.The main research contents of this paper include the research on the automatic assembly of the axle hole of the lightweight manipulator:(1)Building the mechanical model of axle hole assembly process,analyzing the effect of shaft hole relative position on the force acting on the robot,using MATLAB to simulate the assembly process with initial position deviation.(2)According to the characteristics of flexible robot and compliant assembly theory,this paper put forward two kinds of searching hole specific methods:quantitative position compensation base on feedback force and robot compliant mode method.This paper finally designed the specific implementation scheme base on these two methods.(3)Design and machining of the hole shaft parts used in the experiment,according to the actual production requirements.The shaft is installed at the end of robot as controlled object,and set up the experimental environment.The robot system running JAVA offline application,and achieving automatic assembly,so that verify the assembly scheme proposed in this paper.(4)Record key experiment data,and analysis the robot end position and force during the each stage of compliant assembly process to verify the effectiveness of the methods proposed in this paper.