Study Of Teaching Programming System For 3-Dimension Laser Processing Based On PMAC

This dissertation presents the research on teaching programming system of 3-Dimension(3D) laser processing based on PMAC open NC platform.A new teaching programming system with higher efficiency and precision is developed based on the ideas of Reverse Engineering (RE), borrowed-machine measuring. Key technologies include digitalizing collection device, layouts of teaching points, algorithm of obtaining Surface Normal Vector (SNV), fitting of discrete teaching point and so on.A teaching digitalizing collection device is developed, which adopts touch sensor head. The device can translate the inching feed teaching programming into the semi-automatically one. Aiming at the difficulty of arranging teaching points, a new and simple strategy is used for selecting points in the man-machine interactive mode. It satisfied well the requirements of efficiency and precision by adding points in real time according to bow height of the reconstructed free carve. The SNV measuring is translated into points measuring by using of a method of Differential Geometry; the latter is far easier than the former. Moreover, an algorithm for getting SNV is proposed.Aiming at the moving axes frame model of 5-axes laser processing machine, the algorithm is researched to keep the "focus constant". In addition, the accelerating and decelerating control algorithm is studied to ensure the high machining quality. Discrete teaching points are fitted by cubic B-spline in PMAC SPLINE motion programming mode.Finally teaching man-machine interface is programmed by invoking PCOMM32 offered by PMAC in MATLAB environment. Function include the choice and measurement of teaching points on laser processing trajectory, obtaining of Surface Normal Vector, simulation of processing trajectory, and automatically generating of PMAC...