Model- predictive parameter and path planning in laser cutting

Abstract

Although industrial lasers exhibit high potential for material, geometric, process and volume flexibility, in practice laser processing is still limited to repetitive, high rate operations. This is mainly due to the trail-and-error calibrations involved in obtaining an acceptable operating condition wherever changes in workpiece thickness, material, geometry, and dimensional accuracy on quality are imposed. As an alternative to manual calibration, this paper presents a predictive planning model for straight and curved path cutting based on an analytical energy balance solution, given constraints for material removal rate, taper angles, kerf width and kerf centerline shifting. The effects of three-dimensional heat conduction, phase change, and reflected beam energy are considered for a piece-wise, planar cutting front. By using an analytical model, real-time estimates of the cutting front geometry can be developed. A sequential optimization scheme is used for determining laser power, cutting velocity, and laser-path compensation. Initial case studies for laser cutting of polymethyl-methacrylate (PMMA) are presented.Although industrial lasers exhibit high potential for material, geometric, process and volume flexibility, in practice laser processing is still limited to repetitive, high rate operations. This is mainly due to the trail-and-error calibrations involved in obtaining an acceptable operating condition wherever changes in workpiece thickness, material, geometry, and dimensional accuracy on quality are imposed. As an alternative to manual calibration, this paper presents a predictive planning model for straight and curved path cutting based on an analytical energy balance solution, given constraints for material removal rate, taper angles, kerf width and kerf centerline shifting. The effects of three-dimensional heat conduction, phase change, and reflected beam energy are considered for a piece-wise, planar cutting front. By using an analytical model, real-time estimates of the cutting front geometry can be developed. A sequential optimization scheme is used for determining laser power, cutting velocity, and ...