Vehicular traveling direction measuring system
First Claim
1. A system comprising:
- a geomagnetic sensor for sequentially deriving two directional component data of the geomagnetism around a vehicle, the two directions corresponding to said two directional component data, being orthogonal to each other on a horizontal plane;
first means for deriving a traveling direction of the vehicle based on a direction toward a coordinate position defined by said two directional component data from a first coordinate position of a center of a corresponding output circle;
second means for deciding whether a magnetization level on a vehicle body is shifted from a first level to a second level based on said two directional component data;
third means for storing a first group of said two directional component data;
fourth means for storing a second group of said two directional component data;
fifth means for deriving a second coordinate position as a preliminarily corrected value of said first coordinate position based on said first group of the data, said second coordinate position derived for said first magnetization level in response to a negative decision of said second means;
sixth means for deriving a third coordinate position as a preliminarily corrected value of said first coordinate position based on said second group of the data, said third coordinate position derived for said second magnetization level in response to a positive decision of said second means;
seventh means for deriving a first value indicative of accuracy of said second or third coordinate position;
eighth means for deriving a second value which is variable depending on a variation in the magnetization level on the vehicle body;
ninth means for calculating a fourth coordinate position as a finally corrected value of said first coordinate position based on said second or third coordinate position anda latest value of said fourth coordinate position, said latest value derived in a prior calculation executed by said ninth means, by using a rate derived from said first and second values, said rate determining an amount of displacement of said 5 fourth coordinate position between said latest value and said second or third coordinate position so as to determine a point of said fourth coordinate position.
1 Assignment
0 Petitions
Accused Products
Abstract
A system measures a traveling direction of a vehicle based on a direction toward a coordinate position defined by outputs of a geomagnetic sensor from a first coordinate position of a center of a corresponding output circle. The system utilizes a preliminary coordinate position as a preliminarily corrected value of the first coordinate position, a first value indicative of accuracy of the preliminary coordinate position and a second value which is variable depending on a variation in a magnetization level on a vehicle body. The system derives a finally corrected value of the first coordinate position based on the preliminary coordinate position and a latest value of the finally corrected value which has been derived in a prior execution of the system, by changing a rate which determines a point of the current finally corrected value between the latest finally corrected value and the preliminary coordinate position.
36 Citations
22 Claims
-
1. A system comprising:
-
a geomagnetic sensor for sequentially deriving two directional component data of the geomagnetism around a vehicle, the two directions corresponding to said two directional component data, being orthogonal to each other on a horizontal plane; first means for deriving a traveling direction of the vehicle based on a direction toward a coordinate position defined by said two directional component data from a first coordinate position of a center of a corresponding output circle; second means for deciding whether a magnetization level on a vehicle body is shifted from a first level to a second level based on said two directional component data; third means for storing a first group of said two directional component data; fourth means for storing a second group of said two directional component data; fifth means for deriving a second coordinate position as a preliminarily corrected value of said first coordinate position based on said first group of the data, said second coordinate position derived for said first magnetization level in response to a negative decision of said second means; sixth means for deriving a third coordinate position as a preliminarily corrected value of said first coordinate position based on said second group of the data, said third coordinate position derived for said second magnetization level in response to a positive decision of said second means; seventh means for deriving a first value indicative of accuracy of said second or third coordinate position; eighth means for deriving a second value which is variable depending on a variation in the magnetization level on the vehicle body; ninth means for calculating a fourth coordinate position as a finally corrected value of said first coordinate position based on said second or third coordinate position and a latest value of said fourth coordinate position, said latest value derived in a prior calculation executed by said ninth means, by using a rate derived from said first and second values, said rate determining an amount of displacement of said 5 fourth coordinate position between said latest value and said second or third coordinate position so as to determine a point of said fourth coordinate position. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
-
-
16. A system comprising:
-
a geomagnetic sensor for sequentially deriving two directional component data of the geomagnetism around a vehicle, the two directions corresponding to said two directional component data, being orthogonal to each other on a horizontal plane; first means for deriving a first traveling direction of the vehicle based on a direction toward a coordinate position defined by said two directional component data from a first coordinate position of a center of a corresponding output circle; second means for deriving a variation in a traveling direction of the vehicle base on data output from a non-geomagnetic second sensor, said second sensor outputting said data without being affected by the geomagnetism around the vehicle; third means for deriving a second traveling direction of the vehicle based on said variation derived by said second means; fourth means for deciding whether a magnetization level on a vehicle body is shift from a first level to a second level based on said two direction component data; fifth means for storing a first group of said two directional component data; sixth means for storing a second group of said two directional component data; seventh means for storing a third group of said two directional component data and corresponding data of said second traveling direction of the vehicle; eighth means for deriving a second coordinate position as a preliminarily corrected value of said first coordinate position based on said first group of the data, said second coordinate position derived for said first magnetization level in response to a negative decision of said fourth means; ninth means for deriving a third coordinate position as a preliminarily corrected value of said first coordinate position based on the data stored in said seventh means, said third coordinate position derived for said second magnetization level in response to a positive decision of said fourth means; tenth means for deriving a first value indicative of accuracy of said second coordinate position; eleventh means for deriving a second value indicative of accuracy of said third coordinate position; twelfth means for deriving a fourth coordinate position as a preliminarily corrected value of said first coordinate position based on said second group of the data, said fourth coordinate position derived for said second magnetization level when said second value is less than a first predetermined level; thirteenth means for deriving a third value indicative of accuracy of said fourth coordinate position; fourteenth means for deriving a fourth value which is variable depending on a variation in the magnetization level on the vehicle body; fifteenth means for calculating a fifth coordinate position as a finally corrected value of said first coordinate position based on said second or third or fourth coordinate position and a latest value of said fifth coordinate position, said latent value derived in a prior calculation executed by said fifteenth means, by using a rate derived from said first or second or third value and said fourth value, said rate determining an amount of displacement of said fifth coordinate position between said latest value and said second or third or fourth coordinate position so as to determine a point of said fifth coordinate position between said latest value and said second or third or fourth coordinate position. - View Dependent Claims (17, 18, 19, 20, 21, 22)
-
Specification