Development Of 3-UPU Parallel Mechanism CNC System Based On PMAC Card

Since 1965 parallel mechanism appeared, due to its high rigidity, strong bearing capacity, exact orientation, easy to achieve high speed has aroused wide cancern. The numerical control system is the central direct system of the parallel mechanism also is one of the core technologies in modern industry, has been widely used in high-end equipment manufacturing and advanced industrial production field. Therefore the research of parallel mechanism CNC system development has great significance and good application prospect.In this paper, the numerical control system of 3-UPU parallel mechanism is the object of study, the following four aspects are explained in detail:(1) The kinematics analysis of 3-UPU parallel mechanism. According to the 3-UPU parallel mechanism we build the coordinate system and then calculate the degrees of freedom. The derivation of forward and inverse position analysis used the homogeneous coordinate transformation method and then derived Jacobian matrix also analysis singularity of machine. All of the above will provides a theoretical basis for the design of the CNC system.(2) 3-UPU parallel mechanism CNC system hardware set up. According the design concept of open CNC system we built the hardware system framework which use IPC + PMAC as the core, then choose appropriate IPC, PMAC motion controller and servo system for CNC system, followed by hardware system integration and design of the parallel mechanism operating table, drawing electrical system wiring diagram and wiring table for the control system and then accomplish the task of hardware system design.(3) 3-UPU parallel mechanism CNC system software implementation. Software system development is divided into two parts: the PC software development main write three parts program which contain the communication module, trajectory generation module and human-computer interaction interface module. PMAC Software development part introduces programming tools, write kinematic motion program and PLC program.(4) 3-UPU parallel mechanism CNC system no-load debugging. Firstly, configure the CLIPPER and servo driver with the reasonable parameters. Then adjust the PID parameters of servo system. Finally use the typical curve trajectory to verify the feasibility of numerical control system.