US4648024A
Expired / Lapsed
US
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Curvilinear interpolation system and method
Assignee: Mitsubishi Electric Corp
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Filing: 1984-11-15
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Granted: 1987-03-03
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Expires: 2004-11-15
Abstract
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 p of the curve is calculated at a current curve interpolating point P p , and a curvature K n calculated at a point P n on the curve spaced a given search length l S from the point P p along the curve. Then, a curvature K s is set equal to K p when K p ≧K n and set equal to K n when K p <K n . The curvature K s is compared with a limit curvature K 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 s when K s ≧K 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 s <K 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 along a path defined by the plurality of line segments thereby calculated.
Inventors
- 👤 Kiyotaka Kato
- 👤 Michitaka Oshima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 23:32
CPC Classifications
G; G05; G05B; G05B19/00; G05B19/02; G05B19/18; G05B19/41
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
240 words
A curvilinear interpolation system for use in a numerical control apparatus such as a machine tool or a robot having two or more drive axes and capable of moving a movable member while effecting linear interpolation on a given curve with a plurality of line segments, comprising: means for calculating a curvature K p of said curve at a current curve interpolating point P p ; means for calculating a curvature K n near range of a point P n on said curve spaced a given search length S from the point P p along the curve; means for setting K s =K p when K p ≧K n and setting K s =K n when K p <K n ; means for comparing said curvature K s with a limit curvature K L established for determining whether a curve portion is a straight line or an arc, for establishing said curve portion as an arc having said curvature K s when K s ≧K L to approximate said curve portion with a line segment so as to fall within an allowable error t and for establishing said curve portion as a straight line when K s <K L to approximate said curve portion with a line segment of a prescribed length, so as to define all of said plurality of line segments; and means for moving said movable member along a path defined by said plurality of line segments.
Claim 2
Dependent Claim
240 words
A curvilinear interpolation system for use in a numerical control apparatus such as a machine tool or a robot having two or more drive axes and capable of moving a movable member while effecting linear interpolation on a given curve with a plurality of line segments, comprising: means for calculating a curvature K p of said curve at a current curve interpolating point P p ; means for calculating a curvature K n near range of a point P n on said curve spaced a given search length S from the point P p along the curve; means for setting K s =K p when K p ≧K n and setting K s =K n when K p <K n ; means for comparing said curvature K s with a limit curvature K L established for determining whether a curve portion is a straight line or an arc, for establishing said curve portion as an arc having said curvature K s when K s ≧K L to approximate said curve portion with a line segment so as to fall within an allowable error t and for establishing said curve portion as a straight line when K s <K L to approximate said curve portion with a line segment of a prescribed length, so as to define all of said plurality of line segments; and means for moving said movable member along a path defined by said plurality of line segments.
Claim 3
Dependent Claim
223 words
A curvilinear interpolation method for use in a numerical control apparatus such as a machine tool or a robot having two or more drive axes and capable of moving a movable member while effecting linear interpolation on a given curve with a plurality of line segments, comprising the steps of: (1) for each line segment: calculating a curvature K p of said curve at a current curve interpolating point P p ; calculating a curvature K n near range of a point P n on said curve spaced a given search length S from said point P p along said curve; setting K s =K p when K p ≧K n and setting K s =K n ; comparing said curvature K s with a limit curvature K L established for determining whether a curve portion is a straight line or an arc for establishing said curve portion as an arc having said curvature K s when K s ≧K L to approximate said curve portion with a line segment so as to fall within an allowable error t and for establishing said curve portion as a straight line when K s <K L to approximate said curve portion with a line segment of a prescribed length; and (2) moving an operative member along a path defined by said plurality of line segments.
Claim 4
Dependent Claim
223 words
A curvilinear interpolation method for use in a numerical control apparatus such as a machine tool or a robot having two or more drive axes and capable of moving a movable member while effecting linear interpolation on a given curve with a plurality of line segments, comprising the steps of: (1) for each line segment: calculating a curvature K p of said curve at a current curve interpolating point P p ; calculating a curvature K n near range of a point P n on said curve spaced a given search length S from said point P p along said curve; setting K s =K p when K p ≧K n and setting K s =K n ; comparing said curvature K s with a limit curvature K L established for determining whether a curve portion is a straight line or an arc for establishing said curve portion as an arc having said curvature K s when K s ≧K L to approximate said curve portion with a line segment so as to fall within an allowable error t and for establishing said curve portion as a straight line when K s <K L to approximate said curve portion with a line segment of a prescribed length; and (2) moving an operative member along a path defined by said plurality of line segments.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-03-02 | 1990-09-01 | 1991-03-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-03-02 | 1994-09-01 | 1995-03-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-03-02 | 1998-09-01 | 1999-03-03 | $7700.00 | Window Closed / Lapsed |