Position detecting apparatus and method of correcting data therein
First Claim
1. An apparatus for detecting a position in an actual space of an object by imaging said object with an imaging unit, comprising:
- said imaging unit for obtaining an image of a plurality of objects;
a corrective coefficient calculating unit for calculating a corrective coefficient to correct projected coordinates of said objects imaged by said imaging unit; and
a correcting unit for correcting said projected coordinates of said objects by using said corrective coefficient calculated by said corrective coefficient calculating unit, wherein said corrective coefficient calculating unit calculates said corrective coefficient based on a distance between said objects, and a distance from said imaging unit to said objects.
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Accused Products
Abstract
A first object and a second object arranged in an actual space with coordinates (Xn, Zn) and (Xn−D, Zn) are imaged, and respective coordinates x1* and x2* of the first object and the second object in the image are calculated. Then, a coordinate x1 of the first object in the image and a coordinate x2 of the second object in the image are calculated by equations:
x1=F·Xn/Zn
x2=F·(Xn−D)/Zn where F is a design parameter of an imaging unit. An image distortion corrective value α to correct the design parameter F is calculated by equations:
α·x1*=x1
α·x2*=x2
using a difference between the coordinates x1 and x1* and a difference between the coordinates x2 and x2*.
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Citations
6 Claims
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1. An apparatus for detecting a position in an actual space of an object by imaging said object with an imaging unit, comprising:
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said imaging unit for obtaining an image of a plurality of objects;
a corrective coefficient calculating unit for calculating a corrective coefficient to correct projected coordinates of said objects imaged by said imaging unit; and
a correcting unit for correcting said projected coordinates of said objects by using said corrective coefficient calculated by said corrective coefficient calculating unit, wherein said corrective coefficient calculating unit calculates said corrective coefficient based on a distance between said objects, and a distance from said imaging unit to said objects.
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2. An apparatus for detecting a position in an actual space of an object by imaging said object with an imaging unit, comprising:
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said imaging unit for obtaining an image of a plurality of objects;
a position-in-image calculating unit for calculating respective projected coordinates x1* and x2* of a first object and a second object in said image obtained by said imaging unit, said first and second objects being arranged in an actual space with coordinates (Xn, Zn) and (Xn−
D, Zn) so that said first and second objects are away from said imaging unit by a distance Zn and that said first object is away from said second object by a distance D, where said coordinate Xn is arbitrary; and
a corrective coefficient calculating unit for calculating a corrective coefficient α
to correct a design parameter F of said imaging unit,wherein said corrective coefficient calculating unit calculates a coordinate x1 in said image of a design position of said first object and a coordinate x2 in said image of a design position of said second object by equations;
x1=F·
Xn/Zn
x2=F·
(Xn−
D)/Znand then said corrective coefficient calculating unit calculates said corrective coefficient α
by equations;
α
·
x1*=x1
α
·
x2*=x2using a difference between said coordinates x1 and x1* and a difference between said coordinates x2 and x2*, and wherein said design parameter F is corrected to be 1/α
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F with said corrective coefficient α
, and said projected coordinates of said objects imaged by said imaging unit are corrected. - View Dependent Claims (3, 4)
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5. A method of correcting data in an apparatus that detects a position in an actual space of an object by imaging said object with an imaging unit, said method comprising the steps of:
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arranging first and second objects in an actual space with coordinates (Xn, Zn) and (Xn−
D, Zn), respectively, so that said first and second objects are away from said imaging unit by a distance Zn and that said first object is away from said second object by a distance D, where said coordinate Xn is arbitrary, and then obtaining an image of said first and second objects with said imaging unit;
calculating respective projected coordinates x1* and x2* of said first object and said second object in said image;
calculating a coordinate x1 in said image of a design position of said first object and a coordinate x2 in said image of a design position of said second object by equations;
x1=F·
Xn/Zn
x2=F·
(Xn−
D)/Znwhere F is a design parameter of said imaging unit;
calculating a corrective coefficient α
to correct said design parameter by equations;
α
·
x1*=x1
α
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x2*=x2using a difference between said coordinates x1 and x1* and a difference between said coordinates x2 and x2*;
correcting said design parameter F to be 1/α
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F with said corrective coefficient α
, and correcting said projected coordinates of said objects imaged by said imaging unit. - View Dependent Claims (6)
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Specification