Vehicle position detecting apparatus
First Claim
1. A vehicle position detecting apparatus comprising:
- road data recording means for recording road data composed of linear road portions;
reading means for reading out the recorded road data from said road data recording means;
present position detecting means for detecting a present position of a vehicle;
vehicle bearing detecting means for detecting a progress bearing corresponding to a progress direction of the vehicle at the present position; and
map matching means for receiving outputs of said reading means, said present position detecting means, and said vehicle bearing detecting means, wherein said map matching means comprises;
degree of similarity calculating means for retrieving linear road portions from the recorded road data which are close to the detected present position of the vehicle, and calculating a degree of similarity value for each of the retrieved linear road portions on the basis of the present position and the progress direction of the vehicle, wherein the degree of similarity value reflects a degree of similarity between a bearing of the retrieved linear road portion and a running history of the vehicle; and
position correcting means comprising;
degree of similarity judgement means for receiving an output of said degree of similarity calculating means and for judging whether the degree of similarity value calculated for each of the retrieved linear road portions is larger than a predetermined value; and
section measurement means for receiving an output of said degree of similarity judgement means and measuring either a distance traveled by the vehicle or a time period which is passed during a period the degree of similarity value for a single retrieved linear road portion is continuously judged to be larger than the predetermined value;
said position correcting means corrects the present position of the vehicle on the single retrieved linear road portion when either the measured distance is greater than a predetermined distance or the measured time period is greater than a predetermined time period.
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Accused Products
Abstract
The navigation apparatus gives, to a map match processing portion, the measured present location and progress bearing of the vehicle with the use of the position bearing measuring portion for each predetermined period. The map match processing portion reads out the road data about the road close to the measured present position from the memory apparatus to effect the map match processing with respect to each link in accordance with the road data for correcting the measured present position. The correcting operation is effected only when the frequency, where the similarity degree with respect to the measured present position and progress bearing at this time is judged to be larger than the predetermined threshold value, is larger than the predetermined constant Ck. The road data are visually displayed on the visual displaying region of the displaying apparatus. The predetermined diagrams are displayed in a superimposed manner, in the corrected present position, on the road data visually displayed.
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Citations
8 Claims
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1. A vehicle position detecting apparatus comprising:
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road data recording means for recording road data composed of linear road portions; reading means for reading out the recorded road data from said road data recording means; present position detecting means for detecting a present position of a vehicle; vehicle bearing detecting means for detecting a progress bearing corresponding to a progress direction of the vehicle at the present position; and map matching means for receiving outputs of said reading means, said present position detecting means, and said vehicle bearing detecting means, wherein said map matching means comprises; degree of similarity calculating means for retrieving linear road portions from the recorded road data which are close to the detected present position of the vehicle, and calculating a degree of similarity value for each of the retrieved linear road portions on the basis of the present position and the progress direction of the vehicle, wherein the degree of similarity value reflects a degree of similarity between a bearing of the retrieved linear road portion and a running history of the vehicle; and position correcting means comprising; degree of similarity judgement means for receiving an output of said degree of similarity calculating means and for judging whether the degree of similarity value calculated for each of the retrieved linear road portions is larger than a predetermined value; and section measurement means for receiving an output of said degree of similarity judgement means and measuring either a distance traveled by the vehicle or a time period which is passed during a period the degree of similarity value for a single retrieved linear road portion is continuously judged to be larger than the predetermined value; said position correcting means corrects the present position of the vehicle on the single retrieved linear road portion when either the measured distance is greater than a predetermined distance or the measured time period is greater than a predetermined time period. - View Dependent Claims (2)
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3. A vehicle position detecting apparatus comprising:
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road data recording means for recording road data composed of linear road portions; reading means for reading out the recorded road data from said road data recording means; present position detecting means for detecting a present position of the vehicle; vehicle bearing detecting means for detecting a progress bearing corresponding to a progress direction of the vehicle at the present position; and map matching means for receiving outputs of said reading means, said present position detecting means, and said vehicle bearing detecting means, wherein said map matching means comprises; road retrieving means for retrieving linear road portions from the recorded road data which are connected with an end portion of a linear road portion to which a past present position of the vehicle belongs; road distinguishing means for receiving an output of said road retrieving means and distinguishing the retrieved linear road portions into upstream side road portions which have a direction that is reverse to the progress direction of the vehicle and into downstream side road portions which have a same direction as the progress direction of the vehicle; degree of similarity calculating means for receiving an output of said road retrieving means and calculating a degree of similarity value for each of retrieved road portions on the basis of the present position and the progress direction of the vehicle, wherein the degree of similarity value reflects a degree of similarity between a bearing of the retrieved linear road portion and a running history of the vehicle; degree of similarity reducing means for receiving an output of said road distinguishing means and said degree of similarity calculating means, and reducing the degree of similarity value for each of the upstream side road portions; and position correcting means for receiving an output of said degree of similarity reducing means and correcting the present position of the vehicle on a correcting candidate point of one of the retrieved linear road portions which has a largest degree of similarity value. - View Dependent Claims (4)
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5. A vehicle position detecting apparatus comprising:
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road data recording means for recording road data composed of linear road portions; reading means for reading out the recorded road data from said road data recording means; present position detecting means for detecting a present position of a vehicle; vehicle bearing detecting means for detecting a progress bearing corresponding to a progress direction of the vehicle at the present position; and map matching means for receiving outputs of said reading means, said present position detecting means, and said vehicle bearing detecting means, wherein said map matching means comprises; road retrieving means for retrieving linear road portions from the recorded road data which are near the detected present position of the vehicle; correcting candidate point setting means for receiving outputs of said road retrieving means and setting correcting candidate points on the retrieved linear road portions in a predetermined manner; and degree of similarity calculation accumulating means for receiving outputs of said correcting candidate point setting means, calculating a degree of similarity value for each of the correcting candidate points on the basis of a distance between the present position of the vehicle and each of the correcting candidate points and on the basis of a bearing difference between the bearing of each of the retrieved linear road portions to which each of the correcting candidate point belongs and a progress bearing of the vehicle, wherein the degree of similarity value indicates a degree of similarity between the retrieved linear road portions to which each of the correcting candidate points belong and a running history of the vehicle, and accumulating degree of similarity values obtained from past corrected present positions of each of the correcting candidate points with the current degree of similarity value calculated for each of the correcting candidate points, respectively; wherein a correcting candidate point having a largest accumulated degree of similarity value is considered the present position of the vehicle. - View Dependent Claims (6, 7, 8)
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Specification