Design and implementation of a control system for use of galvanometric scanners in laser micromachining applications

摘要

In the recent years, laser machining technology has been used widely in industrial applications usually with the aim of increasing the production capability of mass production lines - especially for fast marking, engraving type of applications where speed is an important concern - or manufacturing quality of a certain facility by increasing the level of accuracy in material processing applications such as drilling, cutting; or any scientific research oriented work where high precision machining of parts in sub millimeter scale might be required. A galvanometric scanner is a high precision device that is able to steer a laser beam with a mirror attached to a motor, whose rotor angular range is usually limited with tens of degrees in both directions of rotation; and position is controlled either by voltage or current. Due to their lightness, the rotor and the mirror can move very fast, allowing fast marking (burning out) operation with the laser beam. This can be evaluated as a great advantage compared to slower mechanical appliances used for cutting/machining of different materials. This study concentrates on the analysis of galvanometric scanner system components; and the design and implementation of a hardware and software based control system for a dual-axis galvo setup; and their adaptation for use in laser micromachining applications either as a standalone system or a modular subsystem. Analysis part of the thesis work contains: evaluation of dominant laser micromachining techniques, an overview of the galvanometric scanner system based approach and related components (e.g. electromechanical, electrical, optical), understanding of working principles and related simulation work, compatibility issues with the target micromachining applications. Design part of the thesis work includes: the design and implementation of electronic controller board, intermediate drive electronics stage, microcontroller programming for machining control algorithm, interfacing with graphical user interface based control software and production of necessary mechanical parts. The study has been finalized with experimental work and evaluation of obtained results. The results of these studies are promising and motivate the use of laser galvanometric scanner systems in laser micromachining applications.