Apparatus and method for measuring forward direction of vehicle
First Claim
1. An apparatus for measuring a running direction of a vehicle having a body, comprising:
- a) a geomagnetic direction sensor, mounted to the vehicle, which is so constructed and arranged as to detect a direction of geomagnetism in a form of two directional component data mutually orthogonal to each other on a horizontal plane of the vehicle and producing an output;
b) first means for deriving a running direction of the vehicle on the basis of a direction toward a coordinate position indicated by the two directional component data from coordinates of a center position of an output circle derived from said geomagnetic direction sensor;
c) second means for determining whether or not there is a disturbance due to magnetization on the body of the vehicle from said output of said geomagnetic direction sensor;
d) third means for calculating, when said second means determines that said disturbance exists, a peak direction and a peak quantity of said disturbance and a value of a center of an output circle derived before said disturbance and producing parameters representative of said peak direction, said peak quantity and said value of the center of the output circle derived before said disturbance, respectively;
e) fourth means for selecting and setting optimum coefficients out of previously derived coefficients for said parameters produced by said third means;
f) fifth means for combining each of said parameters produced by said third means with each of said coefficients selected and set by said fourth means to provide a quantity of magnetization on the body of the vehicle; and
g) sixth means responsive to said quantity of magnetization for deriving a coordinate value of a center of an output circle derived after said disturbance.
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Abstract
An apparatus and method for measuring a forward direction of a vehicle in which to derive a coordinate position of a center (Ox, Oy) of a directional circle derived from an output of a geomagnetic direction sensor after a magnetization on a vehicle body occurs, the magnetization on the vehicle body is determined from the output of the geomagnetic direction sensor installed in the vehicle and each parameter of a peak quantity (Xmax, Ymax), peak direction (Dx, Dy), and a center value of an output circle before the present disturbance occurs is calculated, optimum coefficients are selected and set according to each parameter from among the previously derived coefficients, a magnetization quantity is calculated from each parameter and each optimum coefficient using a linear combination technique, and the coordinate position of the center of the output circle after the magnetization on the vehicle body occurs from the derived magnetization quantity.
45 Citations
14 Claims
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1. An apparatus for measuring a running direction of a vehicle having a body, comprising:
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a) a geomagnetic direction sensor, mounted to the vehicle, which is so constructed and arranged as to detect a direction of geomagnetism in a form of two directional component data mutually orthogonal to each other on a horizontal plane of the vehicle and producing an output; b) first means for deriving a running direction of the vehicle on the basis of a direction toward a coordinate position indicated by the two directional component data from coordinates of a center position of an output circle derived from said geomagnetic direction sensor; c) second means for determining whether or not there is a disturbance due to magnetization on the body of the vehicle from said output of said geomagnetic direction sensor; d) third means for calculating, when said second means determines that said disturbance exists, a peak direction and a peak quantity of said disturbance and a value of a center of an output circle derived before said disturbance and producing parameters representative of said peak direction, said peak quantity and said value of the center of the output circle derived before said disturbance, respectively; e) fourth means for selecting and setting optimum coefficients out of previously derived coefficients for said parameters produced by said third means; f) fifth means for combining each of said parameters produced by said third means with each of said coefficients selected and set by said fourth means to provide a quantity of magnetization on the body of the vehicle; and g) sixth means responsive to said quantity of magnetization for deriving a coordinate value of a center of an output circle derived after said disturbance. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. An apparatus for measuring a running direction of a vehicle having a body, comprising:
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a) a geomagnetic direction sensor for detecting geomagnetic direction components on a horizontal plane of the vehicle mutually perpendicular to each other and producing an output describing a directional circle having a center coordinate position of said directional circle and a direction from said center coordinate position to a coordinate position indicated by both geomagnetic directional components; b) first means for determining whether or not there is a distrubance due to magnetization on the body of the vehicle from said output of said geomagnetic direction sensor; c) second means for calculating, when said first means determines that said disturbance exists, a peak direction and a peak quantity of said disturbance, and a value of a center of an output circle derived before said distrubance and producing parameters representative of said peak direction, said peak value, and said value of the center of the output circle before said disturbance, respectively; d) third means for selecting and setting optimum coefficients for said parameters produced by said second means out of previously derived coefficients; e) fourth means for combining each of said parameters produced by said second means with each of said coefficients selected and set by said third means to provide a quantity of magnetization on the body of the vehicle; and f) fifth means responsive to said quantity of magnetization for deriving a coordinate value of a center of an output circle derived after said disturbance. - View Dependent Claims (13)
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14. A method for measuring a running direction of a vehicle having a body, comprising the steps of:
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a) providing a geomagnetic direction sensor, mounted to the vehicle, which is so constructed and arranged as to detect a direction of the geomagnetism in a form of two directional component data mutually orthogonal to each other on a horizontal plane of the vehicle and producing an output; b) deriving a running direction of the vehicle on the basis of a direction toward a coordinate position indicated by the two directional component data from coordinates of a center position of an output circle derived from said geomagnetic direction sensor; c) determining whether or not there is a disturbance due to magnetization on the body of the vehicle from said output of said geomagnetic direction sensor; d) calculating, when it is determined that said disturbance exists, a peak direction and a peak quantity of said disturbance and a value of a center of an output circle derived before said disturbance and producing parameters representative of said peak direction, said peak quantity and said value of the center of the output circle derived before said disturbance, respectively; e) selecting and setting optimum coefficients out of previously derived coefficients for said parameters produced in step d); f) combining each of said parameters with each of said coefficients to provide a quantity of magnetization; and g) deriving, responsive to said quantity of magnetization, a coordinate value of a center of an output circle derived after said disturbance.
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Specification