EP0699894A2
Expired / Lapsed
EP
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Navigation system
Assignee: Aisin AW Co Ltd
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Filing: 1995-07-18
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Granted: —
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Expires: 2015-07-18
Abstract
Abstract In order to calculate the traveling distance and heading of a vehicle in highly accurate fashion, a navigation system is provided with a distance sensor for outputting pulses in proportion to rotation of a wheel, a GPS receiving unit for calculating vehicle speed by GPS reception, acquisition means for acquiring the number of pulses at the same time as GPS reception, distance correction coefficient calculating means for calculating GPS traveling distance from the GPS-reception vehicle speed and a time difference between any two points, and calculating a distance correction coefficient from the GPS traveling distance and a pulse difference between two points, and present position calculating means for calculating present position based upon a corrected distance correction coefficient. In another aspect, the navigation system includes heading calculating means for calculating heading of the vehicle based upon a signal from the receiving means, satellite position sensing means for sensing the position of the satellite based upon the signal from the receiving means, traveling speed sensing means for sensing traveling speed of the vehicle, heading error estimating means for estimating error in the heading, obtained by the heading calculating means, based upon the traveling speed obtained by the traveling speed sensing means and the position of the satellite obtained by the satellite position sensing means, and judging means for judging whether to employ the bearing calculated by the bearing calculating means.
Inventors
- 👤 Shinichi c/o Aisin AW Co. Ltd. Kato
- 👤 Mitsuhiro c/o Aisin AW Co. Ltd. Nimura
- 👤 Masaharu c/o Aisin AW Co. Ltd. Hanasaki
- 👤 Akimasa c/o Aisin AW Co. Ltd. Nanba
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 20:33
CPC Classifications
G; G01; G01C; G01C21/00; G01C21/26; G01C21/28
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
123 words
A navigation system for a vehicle, comprising: distance sensor for outputting pulses the number of which is proportional to rotation of a wheel; a GPS receiving unit for calculating vehicle speed by GPS reception; acquisition means for acquiring the number of pulses from the distance sensor at the same time as GPS reception; distance correction coefficient calculating means for calculating GPS traveling distance from vehicle speed, based upon GPS reception, at each of two arbitrary points, and a time difference between these two points, and calculating a distance correction coefficient from the GPS traveling distance and a difference in the number of pulses between the two points; and present position calculating means for calculating present position based upon a corrected distance correction coefficient.
Claim 2
Dependent Claim
46 words
The system according to claim 1, wherein said present position calculating means calculates the traveling distance by multiplying the difference in the number of pulses between the two points by a distance per pulse, which is preset for each vehicle, and by the distance correction coefficient.
Claim 3
Dependent Claim
39 words
The system according to claim 1 or 2, wherein traveling distance based upon the GPS is calculated by multiplying the average value of vehicle speed, which is based upon GPS reception, at the two points by the time difference.
Claim 4
Dependent Claim
62 words
The system according to claim 2 or 3, wherein said distance correction coefficient calculating means calculates, from the GPS traveling distance and the difference in number of pulses, the number of pulses necessary to advance the vehicle a unit distance, and calculates the distance correction coefficient according to the formula [(unit distance)/(number of pulses necessary to advance one unit distance)]/(distance per pulse)
Claim 5
Independent Claim
108 words
The system according to any one of claims 1 to 4, wherein said GPS receiving unit outputs vehicle speed, time, heading and status, the distance correction coefficient being calculated when the vehicle speed at the two points is greater than a predetermined speed, a change in angle between the two points is less than a predetermined angle, a speed difference between the two points is less than a predetermined speed difference, the time difference between the two points is less than a predetermined time difference, and the two points at which there is reception from the GPS are points at which measurement is performed in the same dimension.
Claim 6
Dependent Claim
152 words
A navigation system for a vehicle, comprising: receiving means for receiving a signal from a satellite; heading calculating means for calculating heading of the vehicle based upon a signal from said receiving means; satellite position sensing means for sensing the position of the satellite based upon the signal from said receiving means; traveling speed sensing means for sensing traveling speed of the vehicle; heading error estimating means for estimating error in the heading, obtained by said heading calculating means, based upon the traveling speed obtained by said traveling speed sensing means and the position of the satellite obtained by said satellite position sensing means; and judging means for judging whether the estimated heading error, which has been estimated by said heading error estimating means, is less than a predetermined value; wherein the heading calculated by said heading calculating means is employed when the estimated heading error is less than the predetermined value.
Claim 7
Dependent Claim
209 words
A navigation system for a vehicle, comprising: receiving means for receiving a signal from a satellite; heading calculating means for calculating heading of the vehicle based upon a signal from said receiving means; satellite position sensing means for sensing the position of the satellite based upon the signal from said receiving means; traveling speed sensing means for sensing traveling speed of the vehicle; heading error estimating means for estimating error in the heading, obtained by said heading calculating means, based upon the traveling speed obtained by said traveling speed sensing means and the position of the satellite obtained by said satellite position sensing means; judging means for judging whether the estimated heading error, which has been estimated by said heading error estimating means, is less than a predetermined value; heading estimating means for estimating heading of the vehicle; correction quantity calculating means for calculating a correction quantity that is for correcting the estimated heading, estimated by said heading estimating means, based upon the heading calculated by said heading calculating means and the estimated heading error estimated by said heading error estimating means; and heading correcting means for correcting the estimating heading, estimated by said heading estimating means, based upon the correction quantity calculated by said correction quantity calculating means.
Claim 8
Dependent Claim
230 words
A navigation system for a vehicle, comprising: receiving means for receiving a signal from a satellite; heading calculating means for calculating heading of the vehicle based upon a signal from said receiving means; satellite position sensing means for sensing the position of the satellite based upon the signal from said receiving means; traveling speed sensing means for sensing traveling speed of the vehicle; heading error estimating means for estimating error in the heading, obtained by said heading calculating means, based upon the traveling speed obtained by said traveling speed sensing means and the position of the satellite obtained by said satellite position sensing means; judging means for judging whether the estimated heading error, which has been estimated by said heading error estimating means, is less than a predetermined value; heading estimating means for estimating heading of the vehicle; correction quantity calculating means which, when it is judged by said judging means that the estimated heading error is less than the predetermined value, is for calculating a correction quantity that is for correcting the estimated heading, estimated by the heading estimating means, based upon the heading calculated by said heading calculating means and the estimated heading error estimated by said heading error estimating means; and heading correcting means for correcting the estimated heading, estimated by said heading estimating means, based upon the correction quantity calculated by said correction quantity calculating means.
References Cited (Backward Citations)
JPH05209756A
Cited
JPH0666577A
Cited
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