Abstract

Today, laser based micromachining technologies enable the most advanced material manufacturing. Since it has wide range of applications in Microelectronics, medical device, aerospace etc., the accuracy of the process is of utmost significance. The current project proposes a machine vision assisted workstation for laser micromachining. The machine vision system not only has the ability to control the Laser path but also has the ability to locate the starting point of machining. The system was designed and developed from basic components, while MATLAB was used to control the laser direction, and to image the specimen.
To analyse the limitations of the developed system, a rectangular shape was machined. Subsequently, known magnitudes of translational and rotational movements were given to the specimen. The images of machined area were captured before and after transformation. MATLAB algorithm was used to process the images to find the initial point of machined area on the transformed specimen. The laser beam is then guided to that point and the machining is repeated. The specimen was measured under microscope to find the error between the former and latter machined paths. Translational and angular errors were measured for various transformations.
In this study, the challenges and corresponding possible solutions that are encountered in machining complex geometries are addressed. The study proposes mathematical function based and image processing based algorithms to find the machining coordinates and function-based approach was found to be more efficient for complex geometries. Furthermore, the effect of process parameters on the overall quality of the manufacturing are discussed. The COMSOL software was used to model all the effect of laser parameters on the roughness, depth and thickness of machined path. To validate the numerical model, experiments were conducted for different process parameters the results are in good agreement with a simulation results.
The simulated model can be used to estimate the effect of the process parameters before the machining. Since the laser beam can be controlled on the geometry of the specimen and the study demonstrates the minimum possible error, this system can be applied to manufacture and repair wide range of microstructures.