Patent · US Expired

Curvilinear interpolation system and method

US4648024A · kind A · utility

39Cited by
9References
2Claims
0Family size

Assignee

Inventors

Key dates

Filing dateNov 15, 1984
Grant dateMar 3, 1987
Priority date
Expiry dateNov 15, 2004

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG05B19/41
  • WIPO fieldControl
  • WIPO sectorInstruments

Abstract

A curvilinear interpolation system and method for use in a numerical control apparatus such as a machine tool or a robot having two or more drive axes and movable while effecting linear interpolation on a given curve with a plurality of line segments. For each line segment a curvature K.sub.p of the curve is calculated at a current curve interpolating point P.sub.p, and a curvature K.sub.n calculated at a point P.sub.n on the curve spaced a given search length l.sub.S from the point P.sub.p along the curve. Then, a curvature K.sub.s is set equal to K.sub.p when K.sub.p .gtoreq.K.sub.n and set equal to K.sub.n when K.sub.p <K.sub.n. The curvature K.sub.s is compared with a limit curvature K.sub.L established for determining whether a curve portion is a straight line or an arc for establishing the curve portion as an arc having the curvature K.sub.s when K.sub.s .gtoreq.K.sub.L to approximate the curve portion with a line segment so as to fall within an allowable error t and for establishing the curved portion as a straight line when K.sub.s <K.sub.L to approximate the curve portion with a line segment of a prescribed length. An operative member such as a robot arm is then moved alon…

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.