Research On High Speed And Light Load Direct Drive 4-DOF SCARA Robot

The unique structure of the SCARA makes it the most reliable robot in PTP motion.It is widely used in the electronic and electrical industry.But with the continuous development of 3C electronics industry,the speed and accuracy of assembly are more and more demanding.The performance of SCARA must be further improved to meet the current work requirements.So,a direct drive SCARA with high speed,light load and high precision is designed in this paper.This paper studies from four aspects: robot body design and optimization,kinematics and dynamics analysis,trajectory planning and algorithm design,co-simulation and experimental analysis.In the aspect of ontology design and optimization,the technical parameters of the SCARA are determined in view of the specific tasks and requirements.The mechanical structure and transmission plan of all kinds of SCARA at present are compared and analyzed.The characteristics and advantages of the direct drive robot are expounded,and the transmission scheme of the direct drive robot is determined.The SCARA is established by using Solid Works.According to the working conditions of light load,the AYSYS is used for the finite element analysis and optimization design to reduce the quality of the fuselage and realize the light weight.In terms of kinematics and dynamics,the mathematical model of robot kinematics is established by using the D-H parameter method,and the forward and inverse kinematics solutions are obtained.The simulation is verified through the MATLAB robot toolbox.And then through the Jacobi matrix and the Hessian matrix of the robot,the singularity of the robot are solved.At last,the dynamic model of SCARA is set up accurately according to the direct drive mechanical structure.In the aspect of trajectory planning,the trajectory planning method of joint space and rectangular coordinate space is expounded.Compare all kinds of point to point interpolation algorithms,such as three times polynomial interpolation,five times polynomial interpolation,parabolic transition linear interpolation,'S type' velocity curve interpolation,etc.,analyze their advantages and disadvantages,and extract their essence to remove the dross.Then a new interpolation algorithm,which is more consistent with high speed motion,is proposed in this paper,that is,a linear interpolation algorithm for trigonometric function transition.Combined with the idea of off-line programming,a small line segment interpolation algorithm for a complex curve in a rectangular coordinate space is given.Then ADAMS is used to verify the feasibility and superiority of the above methods.In order to improve the operation precision of the robot,the error source of the robot is analyzed,and the method of error compensation is put forward.In the field of simulation and experiment,the physical model of the SCARA is established according to the previous article.The dynamic characteristics and response characteristics of the robot are analyzed by the combined simulation method of ADAMS and MATLAB and the PID control algorithm.Then we build the hardware control system and software system of the robot,debug and run the SCARA robot,improve the absolute accuracy of the robot by means of calibration,and test its speed,accuracy,dynamic characteristics and other parameters.To prove the advanced nature of the direct drive robot designed in this paper.