Compliance Control Research Of The Friction Stir Welding Machine Based On Parallel Mechanism

Friction stir welding is a new type of solid-phase welding technology,which has many adavantages compared with the thermal welding technology,so it has been widely used in the industrial production.The friction stir welding equipment is mainly modified by the milling machine or the series robot,but this does not meet the requirements,when welding the complex space curve on the thick plate.In this paper,the origin,principle and development of the FSW technology are introduced.And it also analyzed the advantages of the friction stir welding technology compared with the hot welding technology.The application of the friction stir welding technology in various industrial fields has been described so far.Secondly,this paper analyzed the robot kinematics and obtained the forward solution and inverse solution of the kinematics and the correctness is verified.Then,the position controller is designed based on the manifold control algorithm.The kinematics of the parallel robot is studied based on the kinematic results obtained before,and the fastness and precision of the algorithm are verified by simulation.The kinematic study of friction stir welding is the basis of the following force control research.In addition,the forging force applied on the workpiece by the stir pin is a very important parameter when the friction stir welding is at work.In order to ensure that the axial forging force of the stir pin is substantially constant during operation,the force control of the friction stir welding must be studied.By means of steady-state error analysis of the traditional impedance control algorithm,under the condition that the error is equal to zero,the parameter online estimation algorithm of the workpiece is obtained.The traditional impedance control algorithm and the parameter online estimation of the workpiece are combined to carry on the compliance control research of the friction stir welding.The united simulation is carried out in Adams and Matlab,and the superiority of the impedance control algorithm based on workpiece parameter online estimation is verified.