Research On Structure Design And Dynamic Performance Analysis For A Novel Drilling Robot

Industrial robots have advantages of large workspace,good flexibility and so on,which has been widely used in the field of aircraft manufacturing.In this paper,the novel 3-dof robot's body and arm are designed to meet the application requirements of machining.Several end-effectors are designed for the robot,which can realize the multi-function operation of drilling in the field of machining.The dynamic performance of the robot is studied through theoretical and simulation analysis and experimental verification.The research work of this paper is as follows.(1)The structure of the robot is designed according to the functional requirements and working parameters of the robot and complete the selection of driving system through analysis and calculation.The robot's body adopts the dual-motor drive and worm gears transmisson without a reducer,which improves the rigidity and servo performance of the robot's system.The robot arm is a mechanism with the hybrid open and closed chains,which is subjected to more uniform force under the end load and is not affected by the external bending moment load.At the same time,the robot's arm adopts the direct drive motor without a reducer,which is objectively economic and good at dynamic performance.The overall rigidity of the robot is good and the motion accuracy is improved by combining electrical and mechanical anti-backlash.(2)The motion analysis of the robot is carried out.Analyze the relationship between the size parameters of robot's arm,the travel distance and the installation distance of the driving linear actuator and the workspace of the robot,which aims to optimize the robot arm size.Conduct the parametric modeling of robot and finish the dynamic simulation based on the model.At the same time,the relevant performance parameters of the equivalent industrial robot are compared with the robot designed in this paper,by which the advantages of the robot in bearing characteristics are verified.The mechanical model of robot is built and an approximation method for the robot's stiffness calculation is proposed,which can realize the global stiffness analysis of robot workspace.The multi-solution problem of stiffness in the workspace is also analyzed.(3)The kinematic model of the robot is set up and the workspace of the robot is calculated based on Robotics Toolbox.Complete the trajectory planning of robot positioning and linear interpolation in drilling operations.According to the Matlab trajectory planning's results,the relationship between the robot arm's geometrical sizes and the relationship between the rotation angle of the linear actuator motor and the diagonal length,solve the rotation winding number,rotation speed and angular acceleration of the corresponding motor.(4)Complete the design of robot control system and set up a prototype experimental platform.Control the robot to complete the relevant experiments by the optimized PID control algorithm and the correctness of theoretical analysis is verified by the experimental results.According to the the deficiencies in the experiment,the structure of the prototype is optimized and improved and the linear actuator and control system of the prototype are replaced.Build a new generation of prototype platform to conduct relevant experiments and the experimental results are analyzed.