Design And Implementation Of Look-ahead Interpolation For Continuous Short Blocks

Micro-lines are often used to fit some kinds of rough curve or complex typesurface. And when machining these micro-lines, its easy to produce some serioussituation, such as the lower efficient, the higher error and so on. So this field isvery worth to study deeply. Compared with many abroad researcher working onthis field from the last century, only a few researcher study on it, and many ofthem just study on the level of theory and is poor of put theory into practice. Inthis paper, I study look-ahead interpolation of micro-lines in view oftwo-dimension, including theory innovation and practical application on MotionControl Card, which is helpfull to improve funcitons of Motion Control Card anddevelop the national industry.From the view of theory, the look-ahead interpolation of continuousmicro-lines is divided into three parts. The first, based on the deep study onstrengthes and shorts of velocity planning of S curve and other curves, especiall y,velocity planning to micro-lines interpolation, this paper puts forward and buildsan model of velocity planning of asymmetric S curve. And face to super shortlines，a higher speed can be got by it. And the result of simulink powerful provesthat this method can get a higher speed of interpolation. The second, according tostudying on the corner smooth handle. The paper puts forward a new method forcorner smooth handle, namely compound handle. And the result of simulinkproves a higher transition speed in corner between two lines can be got. The last,based on the study of lool-ahead control, the paper puts the control intointerpolation of micro-lines, which perfectly balannces the relationship ofefficiency and accuracy of interpolation by discoverying and reasonable handlingdangerous points by pretreating micro-lines, and achieve the higher efficientinterpolation.When the interpolation is transpanted into Motion Control Card to debug, Gcode is translated into these information which can be read by Look-aheadinterpolation by NC Decoder. And the software build a FIFO to save theseinformation and pretreatment data. The whole interpolation system is dividedinto rough interpolation and fine interpolation. And the rough interpolation,TimeDividing Interpolation, is realized by software.Based on the result of simulation, this conclusion can be produced thatLook-ahead control can reduce error and increase average speed, compared with no Look-ahead control.