Kinematics Research And Precision Analysis Of 3-PSP Micro-parallel Mechanism

3-DOF parallel mechanism as the combination of planar mechanism and spatial agency,it was studied more widely than other kinds of robots.With the advantages of simple structure,low cost of manufacture,easy operation and high accuracy,it has been widely used in many fields.Compared with other 3-DOF parallel mechanism,3-PSP is particular for the compatible linkage which is combination a prismatic joint and a spherical joint.The compatible linkage not only reduces the number of motion pairs but also improves the precision of the mechanism.The paper launched study about the 3-PSP parallel mechanism on the following topics:First,it analyzes the kinematics.Use the “closed-loop” method setting up the inverse kinematics formulation.When the inputs of the driving rods are given,the pose of the moving platform can be obtained by the inverse kinematics formulation.Direct kinematics of the robot is also solved by utilizing geometrical approach and the rotation matrix.Next,analyze the velocity and acceleration of the mechanism.Differentiate the inverse kinematics formulation with respect to time.Then get the velocity formulation and the Jacobian matrix of the mechanism.Analyze the singularity of the mechanism by the Jacobian matrix.Get the acceleration formulation by differentiating the velocity formulation with respect to time.Research the workspace of the mechanism by the inverse kinematics formulation.In this paper,we utilized the numerical searching method to write the program,and then via MATLAB,we printed the results.Then,simulate the kinematics of the mechanism by ADAMS and SolidWorks.Establish the three dimension model of the mechanism by SolidWorks.Load the model into ADAMS,which can analyze the displacement,velocity,angular velocity,acceleration,angular acceleration of the parallel mechanism.Output the curves after analyzing and analyze the kinematics performance of the parallel robot.Last,this paper presented an efficient method that simplified the complex subject.Through the theoretical analysis,it can be observed that the impact of the ball,the chute and the rod on the accuracy of moving platform decreased in order.The conclusion was verified by the experiment.The theory analysis result is more reasonable because of the error source ranges were obtained by measurement.The theoretical analysis and the result of experiment are in well agreement which show the correctness of the proposed experiment method made the experiment that mounted the laser on the top of the parallel mechanism,which it's more convenient to measure the parameter.This experiment method transformed the pose error from three-dimensional space to two-dimensional plane.Thus,paper's conclusion can as a reference for improving the precision of the parallel pertinently.