Design And Implementation Of Smooth Transition Algorithm Between Micro Lines Based On Cardinal Spline Curve

With the continuous development of manufacturing industry,aerospace and other industries put forward higher requirements on the accuracy and efficiency of CNC technology.As the most extensive method of processing complex curved surface,micro-segment processing technology has always regarded high-speed and highprecision as important rule.How to achieve a smooth transition between the tiny line segments and improve the machining accuracy and processing efficiency has always been a hot and difficult issue in the CNC industry.If the micro-segment processing is directly processed in accordance,there will be overcuts or abrupt changes at larger corners.Although the direct transition method and arc transition method can alleviate this situation,the direct transition method has some disadvantages such as a low processing speed and difficult to predict transfer points,arc transitions have abrupt changes in curvature at transit points.Therefore,this paper proposes to insert Cardinal spline curves between adjacent small segments to achieve a smooth transition of the speed of the transition.This transition curve not only solves the problem of abrupt acceleration at the transition point during arc transition,but also improves processing efficiency.It is also simpler than complex five spline calculations.At the same time,this spline can be applied not only to the smooth transition of small segments,but also to describe various motion trajectories such as straight lines,arcs,and free curves.The main work of this paper is as follows:Based on the Cardinal spline curve characteristic and corner transition curve vector model,a smooth transition algorithm based on Cardinal spline curve was designed and implemented.The superiority of the algorithm was proved by simulation comparison with direct transition algorithm and arc transition algorithm.In order to realize the overall speed optimization,an adaptive forward-looking control algorithm based on S-curve is designed and implemented.This method no longer uses a fixed number of look-ahead segments to make forward-looking control more flexible and can better adapt to complex and varied trajectories,while the twostage scanning method does not require backtracking iteration calculation when adjusting speed.It only needs to compare the two scans to find the optimal convergence speed,which greatly reduces the calculation time and further meets the real-time requirements of the numerical control system.The algorithm is verified on the blue sky CNC,the experimental results show that the proposed algorithm can realize the smooth transition between the tiny lines and ensure the continuous change of speed and acceleration.