Dispatch of net of machine tool of Chinese numerical control: System of inchoate numerical control of numerical control machine tool is to use means of interpolation of digital pulse multiplier, through old development, interpolation principle matures ceaselessly, the type of its interpolation method is very much also. Apply relatively extensive interpolation algorithm to be able to become two kinds big at present: Pulse increment interpolation and data sampling interpolation. System of inchoate numerical control of numerical control machine tool is to use means of interpolation of digital pulse multiplier, through old development, interpolation principle matures ceaselessly, the type of its interpolation method is very much also. Will divide from the digital model of generation, once (linear) interpolation, 2 (round, parabola) interpolation and tall second curve interpolation; Will divide from adoption fundamental and computational method, divide the pointwise to be a feature with area differentiate to compare law interpolation again, it is interpolation of digital pulse multiplier with scale multiplication, with digital integral the method undertakes the digital integral interpolation of operation, it is interpolation of vector differentiate law with vector operation, the time split plot design that is a foundation with speed operation, have both pointwise compares the comparison with digital integral feature integration method interpolation, and interpolation of patulous integration method is waited a moment. Apply relatively extensive interpolation algorithm to be able to become two kinds big at present: Pulse increment interpolation and data sampling interpolation. (1) of of pulse increment interpolation the characteristic of algorithm of this kind of interpolation is every time interpolation end produces increment of a journey only, with each the means of pulse is outputted, in machining a process, numerical control device outputs fiducial pulse alignment to every motion coordinate ceaselessly, make each reference axis makes corresponding displacement thereby. Every pulse represented the smallest displacement, because the amount of this pulse alignment decided the displacement of reference axis is measured, and the athletic rate that the frequency of pulse alignment determined reference axis. The implementation method of interpolation of increment of impulse of arteries and veins is simpler, normally only addition and shift can finish interpolation, accordingly it comes true more easily with hardware, and the rate that achieves this kind of operation with hardware circuit is very rapid. At present useful also software finishs this kind of algorithm, but apply to a few medium precision only (0. 01mm) or moderate rate (1 ～ 3m/min) the CNC system of the requirement. (2) of of data sampling interpolation the characteristic of algorithm of this kind of interpolation is interpolation operation cent pace is finished. The first pace is thick interpolation, it is insert between the starting point that gives a curve and terminus a certain number of dot, with a certain number of small straight line segment will approach give a curve, the length L of each small straight line segment is equal, and with give feed speed to concern. Thick interpolation inserts the computation in complementary operation cycle in every, the length L because of this each small straight line segment and feed speed F and interpolation cycle T are concerned, namely L=FT. The characteristic of thick interpolation is given a curve uses a group linear paragraph will approach. The 2nd pace is interpolation of essence of life, it is the redo on the each small straight line segment in thick interpolation cipher out " those who count foothold is close change " the job, this one pace is equivalent to pair of linear pulse increment interpolation. Method of data sampling interpolation applies to closed circuit and the position that half closed circuit is actuating device with electric machinery of servo of straight, communication to control a system. Thick interpolation gives coordinate in the computation inside every interpolation cycle real position increment, and interpolation of essence of life is opposite inside every sampling cycle closed circuit or the positional increment size that feedback of half closed-loop control system answers and the statement position increment size that interpolation outputs undertake sampling. Next the interpolation statement position with cipher out corresponding reference axis and actual feedback position, get both look quite follow error. The basis follows error cipher out is corresponding feed speed of the axis, move with this drive machine tool. In CNC system, method of general thick interpolation has: Interpolation of integral of word of integration method of linear function law, patulous number, even numbers. CNC Milling
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