Dynamics Optimization Design On Parallel CNC Cutter Grinding Machine Tool

Parallel machine tool is a new type of machine tool. It is characterized by high ratio of stiffness to mass, high speed, good parts-modularizing and low manufacturing cost. Research institutions worldwide had done much research on parallel milling machining center. In order to develop our novel parallel CNC cutter grinding machine tool, the dissertation carried out theoretical research on this field and then designed the machine. After an extensive literature survey, the following work had been accomplished. Firstly, a complete kinematics analysis about Stewart platform had been done. When rotary joints adapted in the parallel mechanism, each single chain was a 6-DOF serial mechanism in which movement of parts were very complex. Considering the single chain of Stewart platform, a group of kinematics equations and its'close-form solutions are gained. Subsequently, velocity and acceleration of a single chain were investigated. The relationships of velocity and acceleration between joint-space and task-space were presented. The first derivative matrix (Jacobian matrix) and second derivative matrix of single chains were constructed. On the base of single chine kinematics, velocity and acceleration of parallel mechanism were analyzed. Relationships of velocity and acceleration between platform and actuator were derived. As the result of simulation, displacement, velocity and acceleration curve of leg's parts were drawn. A suggestion on how long the step would be adapted for an accurate motion of platform was given also. Method in this dissertation overcame the difficulty in analyzing the spherical joints that are combined with three rotary joints. Secondly, author deduced dynamics equations by Newton-Euler method. High efficiency is the character of Newton-Euler approach. So a complete dynamics model is formed by the method. The model not only included the mass and gravity of legs and...