The Numeric Control System Research Of 3-RRRT Parallel Manipulator

This dissertation deals with the key issues relevant to the interpolator strategy, velocity transition and the development of open architecture CNC system for the 3-RRRT parallel manipulator.Considering the kinematics characteristics of 3-RRRT parallel manipulator, the interpolation algorithm can be implemented by two steps. In the first step, the tool path is divided into a set of discrete small linear segments along the time axis according to the specified machining accuracy in the Cartesian space. This is followed by the second step that these segments are further interpolated by PVT algorithm in the actuator spaceThe velocity control technique for the different segments is presented based upon the linear acceleration. The transition is analyzed in the paper.According to the open CNC system ideas, the hardware flat in PC and PMAC is built.With the aid of basic concept of software engineering, the 3-RRRT parallel manipulator CNC software system is divided into 7 tasks. Based on the tasks, we construct the program modules.The modules of the system are introduced. The kinematics module and the man-machine module are analyzed in the paper. The use of class in the modules is introduced.According to the specialty of real time in the system, the multitasking of the 3-RRRT parallel manipulator CNC software system is implemented. The PLC together with interrupt technology is integrated using the two rotary buffers allocated in PC and PMAC. The interrupt flow is introduced in the 5th chapter.