| Under the background of ‘Made in China 2025',the developments of industrial robots and intelligent products are also growing rapidly.As an important development field in the new era,robot is also a common mechanical equipment on the production line in the society.At present,many dangerous and high-intensity work can be replaced by robots.With the development of robots,the requirements of the society for robots are also increasing,and they are all developing towards light and fast.Especially in many industries,the position accuracy of robots is very strict,so the error analysis of robots needs to be studied in depth.The robot studied in this paper is different from the robots that seem spider hand,which is widely used in the market.It's drived by linear cylinder,so it has higher intensity and precision.At present,there are few studies on error analysis and compensation and flexible dynamics of this kind of robot.So the kinematics,dynamics and elastodynamics of the robot will be analyzed in this paper.Specific research contents are as follows:(1)Mechanism modeling and kinematics analysis.Firstly,the mechanism of the 3-PUU robot is analyzed,and the solid model is established and the degree of freedom is solved.Then the simplified schematic diagram is made based on the key components of the model.Based on the schematic diagram,the forward and inverse theoretical model of the robot is solved by vector method through coordinate transformation and self-restraint relationship.The original parameters of the robot are packaged because of confidentially.The velocity Jacobian matrix,velocity model and acceleration model are obtained through the analysis of kinematics model.(2)Error modeling and compensation methods study.Firstly,the error model of rigid body mechanism is established based on the inverse kinematics model,and the error Jacobian matrix is obtained.The main and neglected factors affecting the terminal position accuracy are analyzed by sensitivity indicators,and then the sensitivity indicators is verified by Monte Carlo method.The least sensitive error source is ignored by verification.Then the error parameters of the robot are solved by PSO optimization algorithm based on the experimental data.The optimal solution is imported into the original parameters to realize the error compensation of the robot.(3)Dynamics and elastodynamics analysis.Based on the principle of virtual work,the dynamic model of the robot between the active force on the slider and motion of moving platform is built.Using the finite element model of space beam unit and Lagrange equation,the flexible dynamics model of the branched chain is solved,and based on the constraint relationship the flexible dynamics equation of the robot system is solved.(4)Virtual prototype simulation and experiment.Through the simulation of ADAMS and MATLAB,the correctness of the forward kinematics model,inverse kinematics model,speed model and acceleration model of the robot is verified,and the influence degree of each force on the initiative force of the slider is analyzed by simulation.The influence of various error sources for position error on moving platform is analyzed by ADAMS.And the influence of flexibility on the position,speed and acceleration of the robot is solved.The robot is compensated by the optimal error solution that is obtained from the experimental data. |
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