| US 7,616,806 B2 | ||
| Position detecting apparatus and method of correcting data therein | ||
| Nobuharu Nagaoka, Nasukarasuyama (Japan); Masakazu Saka, Utsunomiya (Japan); and Masahito Watanabe, Utsunomiya (Japan) | ||
| Assigned to Honda Motor Co., Ltd., Tokyo (Japan) | ||
| Filed on Nov. 23, 2005, as Appl. No. 11/287,577. | ||
| Claims priority of application No. 2004-347705 (JP), filed on Nov. 30, 2004. | ||
| Prior Publication US 2006/0115117 A1, Jun. 01, 2006 | ||
| Int. Cl. G06K 9/00 (2006.01); G06K 9/46 (2006.01); G06K 9/66 (2006.01); G06K 9/40 (2006.01); H04N 15/00 (2006.01); H04N 13/00 (2006.01); H04N 13/02 (2006.01); G01B 11/14 (2006.01); G01D 18/00 (2006.01); G12B 13/00 (2006.01) | ||
| U.S. Cl. 382—154 [382/103; 382/106; 382/153; 382/190; 382/275; 348/47; 348/118; 348/148; 356/614; 250/252.1] | 7 Claims |
| 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*=x2
using 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.
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