Method and apparatus for determining absolute position of a tip of an elongate object on a plane surface with invariant features
First Claim
1. A method for determining a pose of an elongate object having a tip contacting a plane surface having an invariant feature, said method comprising:
- a) illuminating said plane surface and said invariant feature with a probe radiation;
b) detecting a scattered portion of said probe radiation returning to said elongate object at an angle τ
to an axis of said elongate object;
c) deriving said pose from a response of said scattered portion to said plane surface and to said invariant feature; and
d) obtaining an absolute position of said tip on said surface from said pose and said invariant feature.
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Accused Products
Abstract
A method and apparatus for determining a pose of an elongate object and an absolute position of its tip while the tip is in contact with a plane surface having invariant features. The surface and features are illuminated with a probe radiation and a scattered portion, e.g., the back-scattered portion, of the probe radiation returning from the plane surface and the feature to the elongate object at an angle τ with respect to an axis of the object is detected. The pose is derived from a response of the scattered portion to the surface and the features and the absolute position of the tip on the surface is obtained from the pose and knowledge about the feature. The probe radiation can be directed from the object to the surface at an angle σ to the axis of the object in the form of a scan beam. The scan beam can be made to follow a scan pattern with the aid of a scanning arrangement with one or more arms and one or more uniaxial or biaxial scanners. Angle τ can also be varied, e.g., with the aid of a separate or the same scanning arrangement as used to direct probe radiation to the surface. The object can be a pointer, a robotic arm, a cane or a jotting implement such as a pen, and the features can be edges, micro-structure or macro-structure belonging to, deposited on or attached to the surface which the tip of the object is contacting.
245 Citations
50 Claims
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1. A method for determining a pose of an elongate object having a tip contacting a plane surface having an invariant feature, said method comprising:
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a) illuminating said plane surface and said invariant feature with a probe radiation; b) detecting a scattered portion of said probe radiation returning to said elongate object at an angle τ
to an axis of said elongate object;c) deriving said pose from a response of said scattered portion to said plane surface and to said invariant feature; and d) obtaining an absolute position of said tip on said surface from said pose and said invariant feature. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26)
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27. An apparatus for determining a pose of an elongate object having a tip contacting a plane surface having an invariant feature, said apparatus comprising:
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a) a source for illuminating said plane surface and said invariant feature with a probe radiation; b) a detector on said elongate object for detecting a scattered portion of said probe radiation returning to said elongate object at an angle τ
to an axis of said elongate object;c) a computing unit for deriving said pose from a response of said scattered portion to said plane surface and to said invariant feature, and for obtaining an absolute position of said tip on said surface from said pose and said invariant feature. - View Dependent Claims (28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46)
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47. An elongate object having a tip contacting a plane surface having an invariant feature, said elongate object comprising:
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a) an emitter on said elongate object for illuminating said plane surface with a probe radiation at an angle σ
to an axis of said elongate object;b) a detector on said elongate object for detecting a scattered portion of said probe radiation returning from said plane surface to said elongate object at an angle τ
to said axis;c) a computing unit for deriving a pose of said elongate object from a response of said scattered portion to said plane surface and to said invariant feature, and obtaining a position of said tip on said plane surface. - View Dependent Claims (48)
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49. A method for determining a position of a tip of an elongate object, said tip contacting a plane surface having an invariant feature, said method comprising:
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a) illuminating said plane surface and said invariant feature with a probe radiation; b) selecting an angle τ
to an axis of said elongate object;c) detecting a scattered portion of said probe radiation arriving at said angle τ
to said elongate object;d) deriving a pose of said elongate object from a response of said scattered portion to said plane surface and to said invariant feature; and e) obtaining said position from said pose and said invariant feature. - View Dependent Claims (50)
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Specification