Continuous Micro Line Blocks Reconstruction & Interpolation Algorithm of CNC System

Aiming at the low accuracy of profile caused by large deviation between machined trajectory and designed profile,and the low surface quality and the vibration in machining process induced by discontinuity of velocity direction on the knot of micro-line blocks when using the algorithm of micro-line machining without curve reconstruction of micro line blocks,a continuous micro line blocks real time curve reconstruction and interpolation algorithm is presented for micro-line machining to realize high speed and high accuracy complex surface machining in computerized numerical control(CNC). The algorithm includes micro-line blocks real time spline reconstruction & recursive interpolation algorithm,and establishes conditions of reconstructed spline curve which can be directly interpolated recursively under condition of acc/dec(acceleration and deceleration) in interpolation process.As the experiment shows,in which a sample is manufactured,the new algorithm can ensure that contour accuracy of curve machining reaches micrometer level,meanwhile,the machining speed is 2～2.4 times the speed of the origin algorithm.The result indicates that by using real time curve reconstruction micro-line machining algorithm,not only the machining efficiency can be improved,because speed planning with acc/dec can be made only once in entire reconstructed curve range,but also trajectory feedrate can be joined smoothly,so trajectory is fair and surface quality is fine.Plus,by making use of reconstructed spline curve suitable for recursive interpolation,the conflict between accuracy and computing speed of machining process using complicate algorithm is balanced,therefore machining accuracy can be promoted.