Numerical Control System Development Of A Novel4-DOF Parallel Mechanism

To meet the requirements of inner wall welding of huge pipe-like parts, a novel4-DOF parallel mechanism is investigated, which has a compact structure and canreach the desired positions more quickly. The contents of this thesis mainly includekinematic analysis, virtual prototype design, and open numerical control (NC) systemdevelopment of the mechanism.(1) Kinematic analysis. The topology of the2-UPS/RPU parallel mechanism isanalyzed briefly. The kinematic equations of the mechanism are derived by virtual ofthe closed-loop vector method. The inverse and the forward position solutions areobtained respectively.(2) Virtual prototype design. The virtual prototype of the mechanism is set up bymeans of commercial software. The reachable workspace is searched by taking intoaccounts of the engineering constraints. The rigid-body dynamics of the virtualprototype is simulated, and servo motor parameters of the active limbs are estimated.(3) Hardware development of the NC system. By integrating a human-machineinterface (HMI) and a Turbo PMAC Clipper controller, the hardware of open NCsystem is designed and established for the parallel mechanism.(4) Software development of the NC system. Main functions of the NC system areproperly divided into different levels, and core software modules are programmed,including HMI, HOME, JOG, AUTO, etc.The validity of the aforementioned accomplishments has been proved by motioncontrol experiments of physical prototype of the2-UPS/RPU mechanism.