Navigation apparatus, method for map matching performed in the navigation apparatus, and computer-readable medium storing a program for executing the method
First Claim
1. A navigation apparatus which is mounted on a vehicle, the navigation apparatus being capable of displaying a vehicle'"'"'s location on a digital roadmap on a screen to provide route guidance to a user of the vehicle, the apparatus comprising:
- current position detecting means for detecting a current position of the vehicle;
a database which stores route/map data including at least information of forks in roads, in which the fork information of each of the forks is stored in association with at least two predetermined conditions relating to features of the fork;
imaging means for taking images of a road on which the vehicle is traveling;
means for detecting and monitoring lane markers on the road to obtain detection results, the detection and monitoring being performed by processing the images taken by the imaging means;
first judging means for judging whether or not a fork is located ahead of the current position of the vehicle, the judgment being made based on the route/map data;
retrieval means for retrieving the fork information of the fork from the route/map data, the retrieval being made in a case where the first judging means judges that a fork is located ahead of the current position of the vehicle;
second judging means for judging whether or not the vehicle has entered a specific area that is set with respect to the fork; and
road determining means for determining the road on which the vehicle is traveling after passing the fork or on which the vehicle is going to travel after passing the fork, the determination being made based on the detection results and the predetermined conditions relating to the fork.
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Accused Products
Abstract
A navigation apparatus has a camera for taking images of a road on which the vehicle is traveling; means for detecting and monitoring lane markers on the road by processing the images; and road determining means for determining the road on which the vehicle is traveling just after passing a fork. This road determination is made based on predetermined conditions relating to the fork and the lane markers detected and monitored. According to the structure described above, it is possible for the navigation apparatus to know the road on which the vehicle is traveling immediately after passing the fork. Further, when the vehicle'"'"'s actual location is displayed at a wrong position on the digital road map, the navigation apparatus can correct the position immediately after passing the fork. This is advantageous in that the driver can know its accurate location from the displayed information immediately after passing the fork.
69 Citations
8 Claims
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1. A navigation apparatus which is mounted on a vehicle, the navigation apparatus being capable of displaying a vehicle'"'"'s location on a digital roadmap on a screen to provide route guidance to a user of the vehicle, the apparatus comprising:
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current position detecting means for detecting a current position of the vehicle;
a database which stores route/map data including at least information of forks in roads, in which the fork information of each of the forks is stored in association with at least two predetermined conditions relating to features of the fork;
imaging means for taking images of a road on which the vehicle is traveling;
means for detecting and monitoring lane markers on the road to obtain detection results, the detection and monitoring being performed by processing the images taken by the imaging means;
first judging means for judging whether or not a fork is located ahead of the current position of the vehicle, the judgment being made based on the route/map data;
retrieval means for retrieving the fork information of the fork from the route/map data, the retrieval being made in a case where the first judging means judges that a fork is located ahead of the current position of the vehicle;
second judging means for judging whether or not the vehicle has entered a specific area that is set with respect to the fork; and
road determining means for determining the road on which the vehicle is traveling after passing the fork or on which the vehicle is going to travel after passing the fork, the determination being made based on the detection results and the predetermined conditions relating to the fork. - View Dependent Claims (2, 3, 4, 5, 6)
first means for making the determination when the vehicle is within the specific area; and
second means for making the determination in a case where the third judging means judges that the vehicle has left the specific area.
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3. The navigation apparatus as claimed in claim 2, wherein the predetermined conditions include first and second conditions, in which the first means makes the determination based on the first condition and the detection results obtained when the vehicle is within the specific area, and the second means makes the determination based on the second condition and the detection results obtained when the vehicle is within the specific area.
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4. The navigation apparatus as claimed in claim 2, further comprising fourth judging means for judging whether or not the first means has successfully determined the road, wherein the second means makes the determination in a case where the fourth judging means judges that the first means has not successfully determined the road.
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5. The navigation apparatus as claimed in claim 1, wherein the detection and monitoring means detects the type of each of the lane makers while monitoring lane change performed by the vehicle.
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6. The navigation apparatus as claimed in claim 1, further comprising correcting means for correcting the vehicle'"'"'s position displayed on the digital road map based on the determined road to match the vehicle'"'"'s location on the road to its position on the digital road map.
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7. A method for map matching performed in a navigation apparatus mounted on a vehicle, the navigation apparatus being capable of displaying a vehicle'"'"'s location on a digital road map on a screen and matching the vehicle'"'"'s location on a road to its position on the digital road map, the method comprising the steps of:
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(a) detecting a current position of the vehicle;
(b) taking images of a road on which the vehicle is traveling;
(c) detecting and watching lane markers on the road to obtain detection results, the detection and watching being performed by processing the images taken at the step (b);
(d) judging whether or not a fork is located ahead of the current position of the vehicle based on route/map data stored in a database of the navigation apparatus, the route/map data including at least information of forks in roads, in which the fork information of each of the forks is stored in association which at least two predetermined conditions relating to features of the fork;
(e) retrieving the fork information of the fork from the route/map data in the database, the retrieval being made in a case where it is judged at the step (d) that a fork is located ahead of the current position of the vehicle;
(f) judging whether or not the vehicle has entered a specific area that is set with respect to the fork;
(g) determining the road on which the vehicle is traveling after passing the fork or on which the vehicle is going to travel after passing the fork, the determination being made based on the detection results and the predetermined conditions relating to the fork; and
(h) correcting the vehicle'"'"'s position displayed on the digital road map based on the determined road to match the vehicle'"'"'s location on the road to its position on the digital road map.
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8. A computer-readable medium which stores a program for executing a method for map matching performed in a navigation apparatus mounted on a vehicle, the navigation apparatus being capable of displaying a vehicle'"'"'s location on a digital road map on a screen and matching the vehicle'"'"'s location on a road to its position on the digital road map, the method comprising the steps of:
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(a) detecting a current position of the vehicle;
(b) taking images of a road on which the vehicle is traveling;
(c) detecting and watching lane markers on the road to obtain detection results, the detection and watching being performed by processing the images taken at the step (b);
(d) judging whether or not a fork is located ahead of the current position of the vehicle based on route/map data stored in a database of the navigation apparatus, the route/map data including at least information of forks in roads, in which the fork information of each of the forks is stored in association with at least two predetermined conditions relating to features of the fork;
(e) retrieving the fork information of the fork from the route/map data in the database, the retrieval being made in a case where it is judged at the step (d) that a fork is located ahead of the current position of the vehicle;
(f) judging whether or not the vehicle has entered a specific area that is set with respect to the fork;
(g) determining the road on which the vehicle is traveling after passing the fork or on which the vehicle is going to travel after passing the fork, the determination being made based on the detection results and the predetermined conditions relating to the fork; and
(h) correcting the vehicle'"'"'s position displayed on the digital road map based on the determined road to match the vehicle'"'"'s location on the road to its position on the digital road map.
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Specification