| 3-DOF parallel mechanism becomes a hot spot at home and abroad with a largeworkspace, a simple structure, high manufacturing and assembly precision, easy to controland low cost.2R1T type motion mechanism of3-DOF parallel mechanism is widely used invarious fields to meet the requirements of the people in design goals. This paper mainlystudies3-PSP parallel mechanism which can realize2R1T type motion.First, the paper analyzes the structural characteristics of3-PSP parallel mechanism. Usingtraditional degrees of freedom formulas and screw theory, the degrees of freedom arecalculated and the specific distribution is analyzed. The output motion of3-PSP parallelmechanism is determined as2R1T type motion. It lay the foundation for the later research.Second, the paper studies the kinematics of3-PSP parallel mechanism. Using the closedvector loop method, the inverse kinematic constraint equations of the3-PSP parallelmechanism are established. When the end of output is known, the driving input variables canbe obtained; When given the driver input length, according to the geometric characteristics ofthe moving platform, the position of the end output in relative coordinate system can beobtained. By using the transformation matrix method, the vectors in different coordinatereference can be connected to seek the positive solutions; According to derivation on timeabout the constraint equations of the inverse kinematics. The Jacobian matrix is deduced. Itsvelocity and acceleration are analyzed.Then, the kinematics of3-PSP parallel mechanism is analyzed. According to the Jacobianmatrix, the singularity of the mechanism is analyzed. The result is that there is no singular position. The result lays the foundation for solving the workspace; then, based on the inversesolution, using the boundary search method for the workspace research, the structuralparameters and the length constraints are set, its mathematical modeling is established inMatlab. The reachable workspace is obtained in three-dimensional simulation. The workspacearea rule is analyzed. Finally, using the Jacobian matrix condition number, the dexterity of3-PSP parallel mechanism is analyzed.Finally, the kinematics and dynamics of3-PSP parallel mechanism are simulated. UsingADAMS and UG8.0collaborative simulation technology, the3-PSP parallel mechanism therigid virtual prototype model of3-PSP parallel mechanism is established. Its positive andinverse kinematics is simulated. The spiral curve trajectory output of the end effector can besuccessfully realized. Analyze the driven input velocity and acceleration curve. In determiningthe subject of the end output trajectory, the dynamic simulation with force and no force areproceeded. The power consumption of the driving motor and forces are compared. Theresults provide a theoretical support for selecting driver motor. |
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