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 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 separate from each other and 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 c 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 using the design parameter F determined based on a design focal length (f) of the imaging unit and a design pixel pitch (p) of the imaging unit and equations;
x1=F·
Xn/Zn
x2=F·
(Xn−
D)/Zn and then said corrective coefficient calculating unit calculates said corrective coefficient α
by equations;
α
·
x1*=x1
α
·
x2*=x2using said coordinates x1 and x1* and said coordinates x2 and x2*, andwherein said design parameter F is corrected to be 1/α
·
F with said corrective coefficient α
, and said projected coordinates of said objects imaged by said imaging unit are corrected.
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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
7 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:
-
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 separate from each other and 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; anda corrective coefficient calculating unit for calculating a corrective coefficient c 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 using the design parameter F determined based on a design focal length (f) of the imaging unit and a design pixel pitch (p) of the imaging unit and 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 said coordinates x1 and x1* and said coordinates x2 and x2*, and wherein said design parameter F is corrected to be 1/α
·
F with said corrective coefficient α
, and said projected coordinates of said objects imaged by said imaging unit are corrected.- View Dependent Claims (2, 3, 6, 7)
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4. 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 separate 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 using a design parameter F determined based on a design focal length (f) of the imaging unit and a design pixel pitch (p) of the imaging unit and equations;
x1=F·
Xn/Zn
x2=F·
(Xn−
D)/Zncalculating a corrective coefficient α
to correct said design parameter by equations;
α
·
x1*=x1
α
·
x2*=x2using said coordinates x1 and x1* and said coordinates x2 and x2; correcting said design parameter F to be 1/α
·
F with said corrective coefficient α
, and correcting said projected coordinates of said objects imaged by said imaging unit, and wherein said steps are effected by a programmed computer.- View Dependent Claims (5)
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Specification