Research On Look-Ahead Velocity Planning Algorithm Of Laser Cutting

In the operation of laser cutting CNC system,due to the influence of sharp point and high curvature point in the path curve,improper control of feed rate can cause surface punching of numerical control parts,mechanical jitter,or over-cutting.Therefore,an improved Look-Ahead velocity planning algorithm is proposed to realize the smooth transition of the velocity at these dangerous points,and the processing efficiency is improved by nearly 40 percent.In view of that acceleration and deceleration velocity control algorithm,the velocity constraint algorithm of continuous small line segment connection point and the adaptive Look-Ahead velocity planning algorithm,the paper study on these three aspects.The acceleration and deceleration velocity control algorithm is the basis for the Look-Ahead velocity planning algorithm.The paper first studies the implementation principle of the traditional acceleration and deceleration control algorithm,and analyzes and compares its advantages and disadvantages.Based on the deceleration characteristics of numerical control system,an asymmetrical trapezoidal acceleration and deceleration velocity control algorithm is creatively proposed based on the traditional trapezoidal acceleration and deceleration velocity control algorithm.The processing path curve is usually treated as discrete and continuous small continuous line segment connected end to end.This paper expounds the different transition forms and corresponding velocity constraint equations at the connection points of line segments,using the velocity constraint algorithm in the direct transition form of the connection points,and makes a concise analysis of the error of the algorithm.The design and implementation process of the adaptive Look-Ahead velocity planning algorithm are described in detail,including the basic principle analysis of the Look-Ahead strategy,the automatic capture of the number of Look-Ahead stages in the process,and the optimization and modification of the starting and ending velocity of the continuous small line segment.The dynamic Look-Ahead of feed rate is realized,and the position of the deceleration point can be predicted accurately,and the feed rate can be accelerated and decelerated in real time.At the end of the paper,the calculated data and experimental simulation are obtained by adopting the adaptive velocity planning algorithms for local machining curves.Compared of Look-Ahead velocity planning,the one which did not adopt Look-Ahead velocity planning algorithm and the one with fixed two Look-Ahead stages,the correctness of the improved Look-Ahead velocity planning algorithm is verified.