Kinematic Performance Analysis And Precision Study Of LM2226 Loading And Unloading Manipulator

NC Machining is a Machining method that widely used in Manufacturing Industry.The use of manipulators instead of manual operation has become a very common phenomenon in some large manufacturing enterprises.At present,most small and medium enterprises still use manual loading and unloading in NC machining because they can't afford expensive manipulators.In order to improve the production efficiency and automation of small and medium-sized manufacturing enterprises,a kind of economical connecting rod manipulator is designed and developed for automatic loading and unloading of cylindrical parts in NC machine tools.The main contents of the paper are as follows:(1)According to the requirements of the loading/unloading task and the technological process,the technical specifications and the overall scheme of the manipulator are worked out.The number of degrees of freedom of manipulator is 4,and the structure of manipulator is parallelogram joint.The structure of the base,arm,wrist and internal transmission system of the manipulator is designed in detail based on SolidWorks.The 3D model of manipulator is established and the selection of reducers,servo motors and pneumatic components is completed by relevant calculation.According to the process of loading and unloading,the pneumatic loop is designed and the control scheme of S71200-PLC is established.And then the construction of the prototype and the installation of the electric cabinet are completed.(2)In this paper,the kinematics,workspace,singularity,flexibility and dynamics of manipulator are analyzed.The linkage coordinate system of the manipulator is established by D-H parameter method.The forward kinematics analysis of the manipulator is completed,and the homogeneous transformation matrix of the end actuator in the base coordinate system is obtained.The inverse kinematics analysis is carried out by the method of matrix inverse multiplication,and the functional relationship between the joint rotation angle and the terminal pose is obtained under the premise of the known terminal pose matrix.The forward and inverse kinematics analysis is verified by using MATLB/Robotics Toolbox,and the curves of end displacement,joint angle,angular velocity and angular acceleration during the working process from the initial position to the target position are obtained by simulation.The actual workspace of manipulator is solved by Monte Carlo method in MATLAB.The singularity analysis and the singular configuration of the manipulator is solved based on the Jacobian matrix obtained by the differential transformation method.In order to analyze the maneuverability of the manipulator near the singular position,the dexterity of the manipulator is analyzed based on the operational degree and the operable ellipsoid,and the correctness of the singular configuration is further verified.The dynamic analysis of manipulator is accomplished by using the combination of Lagrange method and ADAMS simulation.(3)The error calculation model of manipulator is established by using differential vector and matrix operation.The precision analysis and joint error compensation of the manipulator are completed.The errors generated by each link are converted to the geometric parameters of each link in the generalized linkage coordinates of the manipulator,and the geometric parameter error model of the manipulator is established based on the matrix differential method.The correctness of the established error model is verified by using MATLAB.The input angle error model of manipulator is established by using the method of joint error mutual compensation.And in order to improve the precision of the end of manipulator,the joint errors are compensated by synthesizing the angle value of each joint.