Vehicle position recognition apparatus
First Claim
1. A vehicle position recognition apparatus for recognizing the position of a vehicle traveling on a road, comprising:
- at least one magnetic field formation means provided at predetermined positions on the road for forming a magnetic field;
at least one magnetic field strength detection means for detecting the strength of the magnetic field formed by said magnetic field formation means;
vehicle position computation suitability judgment means for judging whether or not the magnetic field strength detected by said magnetic field strength detection means is suitable for position computation of the vehicle; and
vehicle position computation means for detecting the position of the vehicle from the magnetic field strength detected by said magnetic field strength detection means, based on a result of the judgment performed by said vehicle position computation suitability judgment means,wherein said vehicle position computation suitability judgment means comprises;
vertical magnetic field strength detection means for detecting a vertical component of the magnetic field strength obtained by said magnetic field strength detection means;
vertical magnetic field strength comparison means for comparing a space distribution of the vertical magnetic field strength obtained by said vertical magnetic field strength detection means with a space distribution of the vertical component of the magnetic field strength formed by said magnetic field formation means;
maximum vertical magnetic field position detection means for detecting a position of the maximum vertical magnetic field on the space distribution of the vertical magnetic field strength detected by said vertical magnetic field strength detection means;
magnetic field strength change quantity detection means for comparing a vertical magnetic field strength at the maximum vertical magnetic field position detected by said maximum vertical magnetic field position detection means with a magnetic field strength at a position away from the maximum vertical magnetic field position by a predetermined distance and for detecting a change quantity in the magnetic field caused by the distance;
maximum vertical magnetic field strength transition comparison means for comparing the magnetic field strength at the maximum vertical magnetic field position detected by said maximum vertical magnetic field position detection means with a past maximum vertical magnetic field strength detected by said maximum vertical magnetic field position detection means; and
computation suitability judgment means for judging whether or not the detected magnetic field strength is suitable for the position computation of the vehicle, based on results of said magnetic field strength change quantity detection means and said maximum vertical magnetic field strength transition comparison means.
1 Assignment
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Accused Products
Abstract
A vehicle position recognition apparatus comprising one or a plurality of magnetic field formation means 1-1 installed at predetermined positions on a road for forming a predetermined magnetic field, magnetic field strength detection means 1-4 for detecting the magnetic field formed by the magnetic field formation means 1-1, vehicle position computation suitability judgment means 1-5 for judging whether the magnetic field strength, obtained by the magnetic field detection means 1-4, is suitable or not for computing a position of the vehicle, and vehicle position computation means 1-6 for receiving a result of the judgment of the vehicle position computation suitability judgment means 1-5 and for detecting the position of the vehicle by the magnetic field strength detected by the magnetic field strength detection means 1-4.
11 Citations
5 Claims
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1. A vehicle position recognition apparatus for recognizing the position of a vehicle traveling on a road, comprising:
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at least one magnetic field formation means provided at predetermined positions on the road for forming a magnetic field; at least one magnetic field strength detection means for detecting the strength of the magnetic field formed by said magnetic field formation means; vehicle position computation suitability judgment means for judging whether or not the magnetic field strength detected by said magnetic field strength detection means is suitable for position computation of the vehicle; and vehicle position computation means for detecting the position of the vehicle from the magnetic field strength detected by said magnetic field strength detection means, based on a result of the judgment performed by said vehicle position computation suitability judgment means, wherein said vehicle position computation suitability judgment means comprises; vertical magnetic field strength detection means for detecting a vertical component of the magnetic field strength obtained by said magnetic field strength detection means; vertical magnetic field strength comparison means for comparing a space distribution of the vertical magnetic field strength obtained by said vertical magnetic field strength detection means with a space distribution of the vertical component of the magnetic field strength formed by said magnetic field formation means; maximum vertical magnetic field position detection means for detecting a position of the maximum vertical magnetic field on the space distribution of the vertical magnetic field strength detected by said vertical magnetic field strength detection means; magnetic field strength change quantity detection means for comparing a vertical magnetic field strength at the maximum vertical magnetic field position detected by said maximum vertical magnetic field position detection means with a magnetic field strength at a position away from the maximum vertical magnetic field position by a predetermined distance and for detecting a change quantity in the magnetic field caused by the distance; maximum vertical magnetic field strength transition comparison means for comparing the magnetic field strength at the maximum vertical magnetic field position detected by said maximum vertical magnetic field position detection means with a past maximum vertical magnetic field strength detected by said maximum vertical magnetic field position detection means; and computation suitability judgment means for judging whether or not the detected magnetic field strength is suitable for the position computation of the vehicle, based on results of said magnetic field strength change quantity detection means and said maximum vertical magnetic field strength transition comparison means. - View Dependent Claims (2, 3, 4, 5)
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Specification