The Research On Dynamic Analysis And Control Method Of High-speed Motion Of Industrial Robots

In modern industry,high-speed motion industrial robots are widely used in automobile,electronics,aerospace and other fields,becoming one of the key devices to promote industrial automation.In the high-speed motion of a robot,the nonlinear dynamics of the robot is significant,and the complex dynamics affect the real-time control of the robot.In addition,joint flexibility can also lead to vibration between the links of the robot.Therefore,the joint flexibility must be fully considered in the dynamics modeling and control of the robot.In this dissertation,a 6-DOF industrial robot is taken as the research object,aiming at the problem that complex dynamics can affect the real-time performance of dynamics-based control,as well as the problem of joint vibration and deformation caused by joint flexibility during high-speed motion,a6-DOF high-speed dynamics model of the robot based on the rigid-body dynamics model by simplifying the dynamics expression and considering the joint flexibility is established.By studying the various factors affecting the dynamic accuracy of the robot during high-speed motion,the computational moment method is used for control,and the optimization of this control method is proposed to improve the dynamic accuracy of the high-speed robot.The main research contents are as follows:Firstly,according to the structure and parameters of the robot,the D-H coordinate system and parameter model of the robot are constructed.The forward and inverse kinematics models of the robot are derived,the matrix expression of the robot end and eight analytical solutions for the inverse kinematics are obtained.The correctness of the established forward kinematic model and inverse kinematic solutions for the robot are verified through various methods,laying a foundation for the study of the robot dynamics.Secondly,the rigid-body dynamics of the robot is analyzed,and the dynamics model of the 6-DOF robot is recursively derived using the Newton-Euler method.The trajectory planning of each joint of the robot is performed,enabling the transition from low-speed to high-speed motion.The inertial terms,centrifugal and Coriolis terms,and gravitational terms in the dynamic expressions are simplified to obtain the simplified dynamics equations for the robot at high speed to meet the real-time control requirements.By comparing the output moments of the drive motors of each joint of the robot,the simplification of the dynamic equations is verified,which provides the theoretical basis for further research on the kinetic characteristics and control methods of the robot in high-speed motion with consideration of the joint flexibility.Then,a flexible joint model of the robot is established,and the dynamic equations of the 6-DOF flexible joint robot are developed considering the joint flexibility.Based on this model,the effect of joint speed on vibration and deformation is studied,and the influence of joint stiffness and damping on joint vibration and deformation during highspeed movement is explored.The computational moment method is used to control the robot with flexible joints,and the effectiveness of the simplified model of the robot is compared and analyzed,and the computational moment method is combined with the fuzzy control to improve the dynamic accuracy of the high-speed robot.Finally,the 6-DOF industrial robot simulation model considering joint flexibility is established using Adams.A control system is established in Simulink,and the simulation of robot control with high-speed motion is carried out by combination of Simulink and Adams.The simulation results show that the optimized computed torque method based on fuzzy theory can effectively improve the control of the robot.