Navigation system and vehicle position estimating method

• US 20070078594A1
• Filed: 09/29/2006
• Published: 04/05/2007
• Est. Priority Date: 09/30/2005
• Status: Abandoned Application

• Current Assignee: Alpine Electronics Incorporated (Alps Alpine Co., Ltd.)
• Original Assignee: Alpine Electronics Incorporated (Alps Alpine Co., Ltd.)
• Inventors: Mori, Daishi
• Application Number:
  US11/541,465
• Publication Number:
  US 20070078594A1
• Time in Patent Office: Days
• US Class Current: 701/207
• CPC Class Codes: G01C 21/12 executed aboard the object being navigated; Dead reckoning
• CPC Class Codes: G01C 21/3878 Hierarchical structures, e.g. layering

Abstract

A turning direction calculating unit determines a turning direction of a vehicle based on a change in azimuth of the vehicle. An angular velocity calculating unit calculates an angular velocity of the vehicle. A turning radius calculating unit calculates a turning radius of the vehicle by using the angular velocity and a travel distance of each predetermined time period. A turning radius correcting unit corrects the turning radius so that the turning radius becomes larger by a correction value WL according to a traveling position on a road if the vehicle turns to the left, and corrects the turning radius so that the turning radius becomes smaller by a correction value WR according to a traveling position on a road if the vehicle turns to the right. A vehicle position estimating unit estimates a vehicle position on a center line of the road by using the corrected turning radius.

Claims

1. A vehicle position estimating method for a navigation system to calculate a position of a vehicle and display a map of an area around the vehicle and a vehicle position mark on a display, the method comprising:

providing a sensor to detect a travel distance of the vehicle and an azimuth of the vehicle;

calculating a turning radius of the vehicle by using a signal output from the sensor; and

estimating a vehicle position on a road link by using the turning radius.

2. The vehicle position estimating method according to claim 1, further comprising:

calculating an angular velocity of the vehicle by using a signal output from the sensor; and

calculating the turning radius of the vehicle by using the angular velocity and the travel distance.

3. The vehicle position estimating method according to claim 2, further comprising:

calculating the angular velocity of the vehicle at each of a predetermined travel time period or at each of a predetermined travel distance.

4. The vehicle position estimating method according to claim 2, further comprising:

estimating a vehicle position by determining that the vehicle is traveling straight when the angular velocity is equal to or smaller than a set value; and

estimating a vehicle position by determining that the vehicle is traveling around a curve when the angular velocity is larger than the set value.

5. The vehicle position estimating method according to claim 4, further comprising:

estimating a present vehicle position by calculating respective axial travel components along a straight or curved line of each predetermined time period and adding the respective axial travel components to respective axial components of a previously estimated position.

6. A vehicle position estimating method for a navigation system to calculate a position of a vehicle and display a map of an area around the vehicle and a vehicle position mark on a display, the method comprising:

providing a sensor to detect a travel distance of the vehicle and an azimuth of the vehicle;

determining a turning direction of the vehicle on the basis of a change of the azimuth;

calculating a turning radius R of the vehicle by using a signal output from the sensor;

correcting the turning radius R so that the turning radius R becomes larger by a correction value WL according to a traveling position on a road if the vehicle turns in a first direction and correcting the turning radius R so that the turning radius R becomes smaller by a correction value WR according to a traveling position on a road if the vehicle turns in a direction opposite to the first direction; and

estimating a vehicle position on a road link by using the corrected turning radius.

7. The vehicle position estimating method according to claim 6, further comprising:

calculating an angular velocity of the vehicle by using a signal output from the sensor; and

calculating the turning radius R of the vehicle by using the angular velocity and a travel distance of each of a predetermined time period.

8. The vehicle position estimating method according to claim 7, further comprising:

setting each of the correction values WR and WL to W/4 when a width of the road is W.

9. The vehicle position estimating method according to claim 7, further comprising:

providing a camera to capture an image of a road on which the vehicle is traveling; and

obtaining the correction values WR and WL by determining a distance from a center line of the road to a vehicle traveling position by using the image captured by the camera.

10. The vehicle position estimating method according to claim 7, further comprising:

calculating the angular velocity of the vehicle at each of a predetermined travel time period or at each of a predetermined travel distance.

11. The vehicle position estimating method according to claim 7, further comprising:

estimating a vehicle position by determining that the vehicle is traveling straight when the angular velocity is equal to or smaller than a set value; and

estimating a vehicle position by determining that the vehicle is traveling around a curve when the angular velocity is larger than the set value.

12. The vehicle position estimating method according to claim 7, further comprising:

estimating a present vehicle position by calculating respective axial travel components along a straight or curved line of each predetermined time period and adding the respective axial travel components to respective axial components of a previously estimated position.

13. A navigation processing method for a navigation system to calculate a position of a vehicle and display a map of an area around the vehicle and a vehicle position mark on a display, the method comprising:

providing a sensor to detect a travel distance of the vehicle and an azimuth of the vehicle;

estimating a first vehicle position on an actual traveling line of a road and a second vehicle position on a center line of the road by using a signal output from the sensor and storing the first and second vehicle positions; and

performing navigation control by using the first and second vehicle positions.

14. The navigation processing method according to claim 13, further comprising:

correcting the first vehicle position on the basis of a GPS position and correcting the second vehicle position on the basis of a map matching process.

15. The navigation processing method according to claim 13, further comprising:

calculating an angular velocity of the vehicle by using a signal output from the sensor;

calculating a turning radius R of the vehicle by using the angular velocity and a travel distance of the vehicle of each predetermined time period and estimating the first vehicle position on the traveling line of the road by using the turning radius R;

correcting the turning radius R so that the turning radius R becomes larger by a correction value WL according to a traveling position on the road if the vehicle turns in a first direction and correcting the turning radius R so that the turning radius R becomes smaller by a correction value WR according to a traveling position on the road if the vehicle turns in a direction opposite to the first direction, and estimating the second vehicle position on the center line of the road by using the corrected turning radius.

16. A navigation system to calculate a position of a vehicle and display a map of an area around the vehicle and a vehicle position mark on a display, the navigation system comprising:

a sensor to detect a travel distance of the vehicle and an azimuth of the vehicle;

an angular velocity calculating unit to calculate an angular velocity of the vehicle by using a signal output from the sensor;

a turning radius calculating unit to calculate a turning radius of the vehicle by using the angular velocity and a travel distance of each predetermined time period; and

a vehicle position estimating unit to estimate a vehicle position on a road link by using the turning radius.

17. The navigation system according to claim 16, wherein the angular velocity calculating unit calculates the angular velocity of the vehicle at each of a predetermined travel time period or at each of a predetermined travel distance.

18. The navigation system according to claim 17, wherein the vehicle position estimating unit estimates a vehicle position by determining that the vehicle is traveling straight when the angular velocity is equal to or smaller than a set value and estimates a vehicle position by determining that the vehicle is traveling around a curve when the angular velocity is larger than the set value.

19. A navigation system to calculate a position of a vehicle and display a map of an area around the vehicle and a vehicle position mark on a display, the navigation system comprising:

a sensor to detect a travel distance of the vehicle and an azimuth of the vehicle;

a turning direction determining unit to determine a turning direction of the vehicle on the basis of a change of the azimuth;

an angular velocity calculating unit to calculate an angular velocity of the vehicle by using a signal output from the sensor;

a turning radius calculating unit to calculate a turning radius R of the vehicle by using the angular velocity and a travel distance of each predetermined time period;

a turning radius correcting unit to correct the turning radius R so that the turning radius R becomes larger by a correction value WL according to a traveling position on a road if the vehicle turns in a first direction and correct the turning radius R so that the turning radius R becomes smaller by a correction value WR according to a traveling position on a road if the vehicle turns in a direction opposite to the first direction; and

a vehicle position estimating unit to estimate a vehicle position on a center line of the road by using the corrected turning radius.

20. The navigation system according to claim 19, further comprising:

a correction value setting unit to set each of the correction values WR and WL to W/4 when a width of the road is W.

21. The navigation system according to claim 19, further comprising:

a camera to capture an image of a road, the camera being provided on the vehicle; and

a correction value obtaining unit to obtain the correction values WR and WL by determining a distance from a center line of the road to a vehicle traveling position by using the image captured by the camera.

22. The navigation system according to claim 19, wherein the vehicle position estimating unit estimates a vehicle position by determining that the vehicle is traveling straight when the angular velocity is equal to or smaller than a set value and estimates a vehicle position by determining that the vehicle is traveling around a curve when the angular velocity is larger than the set value.

23. A navigation system to calculate a position of a vehicle and display a map of an area around the vehicle and a vehicle position mark on a display, the navigation system comprising:

a sensor to detect a travel distance of the vehicle and an azimuth of the vehicle;

a vehicle position estimating unit to estimate a first vehicle position on an actual traveling line of a road and a second vehicle position on a center line of the road by using a signal output from the sensor and store the first and second vehicle positions; and

a navigation control unit to perform navigation control by using the first and second vehicle positions on the basis of a process.

24. The navigation system according to claim 23, further comprising:

a map matching process unit to correct the second vehicle position; and

a GPS position measuring unit to measure a GPS position on the basis of a GPS signal from a satellite,

wherein the vehicle position estimating unit corrects the first vehicle position on the basis of the GPS position.

25. The navigation system according to claim 23, further comprising:

an angular velocity calculating unit to calculate an angular velocity of the vehicle by using a signal output from the sensor,

wherein the vehicle position estimating unit includes;

a first position estimating unit to calculate a turning radius R of the vehicle by using the angular velocity and a travel distance of the vehicle of each predetermined time period and estimate the first vehicle position on the traveling line of the road by using the turning radius R; and

a second position estimating unit to correct the turning radius R so that the turning radius R becomes larger by a correction value WL according to a traveling position on the road if the vehicle turns in a first direction and correct the turning radius R so that the turning radius R becomes smaller by a correction value WR according to a traveling position on the road if the vehicle turns in a direction opposite to the first direction, and estimate the second vehicle position on the center line of the road by using the corrected turning radius.