NAVIGATION SYSTEM

• US 20100185390A1
• Filed: 03/18/2008
• Published: 07/22/2010
• Est. Priority Date: 07/04/2007
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: Monde, Yasuhiro, Fujii, Masatoshi, Hayami, Katsuro, Maeda, Atsushi
• Granted Patent: US 8,571,789 B2
• Time in Patent Office: Days
• US Class Current: 701/208
• CPC Class Codes: G01C 21/26 specially adapted for navigation in a road network
• CPC Class Codes: G01C 25/005 initial alignment, calibration or starting-up of inertial devices
• CPC Class Codes: G09B 29/102 using electrical means

Abstract

A navigation system includes: an angular velocity sensor 1 for detecting a change in an advancement direction of a vehicle; a vehicle azimuth calculation unit 13 for calculating a vehicle azimuth on the basis of angular velocity sensor information obtained from the angular velocity sensor; an on-board camera 2 for shooting a periphery of the vehicle; an image recognition unit 19 for recognizing an image obtained from the on-board camera; and an offset voltage correction unit 21 for performing a drift correction on the angular velocity sensor in accordance with an angle error between the vehicle azimuth calculated by the vehicle azimuth calculation unit and a vehicle azimuth determined from a white line on a road recognized by the image recognition unit.

Claims

1. A navigation system comprising:

an angular velocity sensor for detecting a change in an advancement direction of a vehicle;

a vehicle azimuth calculation unit for calculating a vehicle azimuth on the basis of angular velocity sensor information obtained from said angular velocity sensor;

an on-board camera for shooting a periphery of said vehicle;

an image recognition unit for recognizing an image obtained from said on-board camera; and

an offset voltage correction unit for performing a drift correction on said angular velocity sensor in accordance with an angle error between said vehicle azimuth calculated by said vehicle azimuth calculation unit and a vehicle azimuth determined from a white line on a road recognized by said image recognition unit.

10. The navigation system according to claim 1, further comprising a camera use mode switching unit for switching an image from said on-board camera to be used in image recognition by said image recognition unit, or to be used in another application.

11. The navigation system according to claim 10, wherein said other application is rear view image display for displaying a rear image when shift position information obtained from said vehicle indicates reversing.

12. The navigation system according to claim 1, wherein said current position calculation unit includes a positioning accuracy calculation unit for calculating a positioning accuracy of said determined current position of said vehicle,

said navigation system further comprising an on-board camera power supply control unit for ON/OFF-controlling a power supply of said on-board camera in accordance with positioning accuracy information transmitted from said positioning accuracy calculation unit.

2. A navigation system comprising:

an angular velocity sensor for detecting a change in an advancement direction of a vehicle;

a vehicle azimuth calculation unit for calculating a vehicle azimuth on the basis of angular velocity sensor information obtained from said angular velocity sensor;

a global positioning system (GPS) receiver for detecting a current position of a vehicle using the GPS;

a vehicle speed sensor for detecting rotation of a vehicle wheel;

a distance measurement unit for measuring a traveled distance on the basis of vehicle speed pulse information obtained from said vehicle speed sensor;

a map information storage unit for storing map information;

a current position calculation unit for calculating a current position on the basis of GPS information obtained from said GPS receiver, vehicle azimuth information obtained from said vehicle azimuth calculation unit, and distance information obtained from said distance measurement unit, and determining a current position of the vehicle on a map by comparing said calculated current position with said map information read from said map information storage unit;

an on-board camera for shooting a periphery of said vehicle;

an image recognition unit for recognizing an image obtained from said on-board camera; and

a specific road site determination unit for detecting a railroad crossing or an underpass point of a multi-level interchange from said image recognized by said image recognition unit,

wherein said current position calculation unit further corrects said determined current position of said vehicle such that said railroad crossing or said underpass point of a multi-level interchange detected by said specific road site determination unit corresponds to said current position of said vehicle.

3. A navigation system comprising:

an angular velocity sensor for detecting a change in an advancement direction of a vehicle;

a vehicle azimuth calculation unit for calculating a vehicle azimuth on the basis of angular velocity sensor information obtained from said angular velocity sensor;

a global positioning system (GPS) receiver for detecting a current position of a vehicle using the GPS;

a vehicle speed sensor for detecting rotation of a vehicle wheel;

a distance coefficient calculation unit for calculating a vehicle speed pulse coefficient that determines a distance advanced in a single revolution of said vehicle wheel;

a distance measurement unit for measuring a traveled distance on the basis of vehicle speed pulse information obtained from said vehicle speed sensor and said vehicle speed pulse coefficient calculated by said distance coefficient calculation unit;

a map information storage unit for storing map information;

a current position calculation unit for calculating a current position on the basis of GPS information obtained from said GPS receiver, vehicle azimuth information obtained from said vehicle azimuth calculation unit, and distance information obtained from said distance measurement unit, and determining a current position of a vehicle on a map by comparing said calculated current position with said map information read from said map information storage unit;

an on-board camera for shooting a periphery of said vehicle;

an image recognition unit for recognizing an image obtained from said on-board camera; and

an inter-intersection distance calculation unit for calculating a distance between a plurality of intersections detected on the basis of pedestrian crossings recognized by said image recognition unit,

wherein said current position calculation unit further corrects said determined current position of said vehicle on the basis of said inter-intersection distance calculated by said inter-intersection distance calculation unit, and

said distance coefficient calculation unit corrects said vehicle speed pulse coefficient on the basis of said inter-intersection distance calculated by said inter-intersection distance calculation unit.

4. A navigation system comprising:

an angular velocity sensor for detecting a change in an advancing direction of a vehicle;

a vehicle azimuth calculation unit for calculating a vehicle azimuth on the basis of angular velocity sensor information obtained from said angular velocity sensor;

a global positioning system (GPS) receiver for detecting a current position of a vehicle using the GPS;

a vehicle speed sensor for detecting rotation of a vehicle wheel;

a distance measurement unit for measuring a traveled distance on the basis of vehicle speed pulse information obtained from said vehicle speed sensor;

a map information storage unit for storing map information;

a current position calculation unit for calculating a current position on the basis of GPS information obtained from said GPS receiver, vehicle azimuth information obtained from said vehicle azimuth calculation unit, and distance information obtained from said distance measurement unit, and determining a current position of a vehicle on a map by comparing said calculated current position with said map information read from said map information storage unit;

an on-board camera for shooting a periphery of said vehicle;

an image recognition unit for recognizing an image obtained from said on-board camera; and

a road deviation determination unit for determining whether or not said vehicle has deviated from a traveling road by detecting a change in the movement of traffic other than said vehicle on a periphery of said vehicle that is recognized by said image recognition unit,

wherein said current position calculation unit further corrects said determined current position of said vehicle on the basis of said determination by said road deviation determination unit as to whether or not said vehicle has deviated from said traveling road.

5. The navigation system according to claim 4, wherein said change in the movement of said traffic other than said vehicle on said periphery of said vehicle that is detected by said road deviation determination unit indicates a longitudinal direction flow or a lateral direction flow of said traffic in an image pattern recognized by said image recognition unit.

6. A navigation system comprising:

an angular velocity sensor for detecting a change in an advancement direction of a vehicle;

a vehicle azimuth calculation unit for calculating a vehicle azimuth on the basis of angular velocity sensor information obtained from said angular velocity sensor;

a global positioning system (GPS) receiver for detecting a current position of a vehicle using the GPS;

a vehicle speed sensor for detecting rotation of a vehicle wheel;

a distance measurement unit for measuring a traveled distance on the basis of vehicle speed pulse information obtained from said vehicle speed sensor;

a map information storage unit for storing map information;

a current position calculation unit for calculating a current position on the basis of GPS information obtained from said GPS receiver, vehicle azimuth information obtained from said vehicle azimuth calculation unit, and distance information obtained from said distance measurement unit, and determining a current position of a vehicle on a map by comparing said calculated current position with said map information read from said map information storage unit;

an on-board camera for shooting a periphery of said vehicle;

an image recognition unit for recognizing an image obtained from said on-board camera; and

a parking lot entrance/exit determination unit for detecting a specific object indicating a parking lot entrance/exit recognized by said image recognition unit,

wherein said current position calculation unit further corrects said determined current position of said vehicle on the basis of said specific object detected by said parking lot entrance/exit determination unit.

7. The navigation system according to claim 6, wherein said specific object indicating said parking lot entrance/exit detected by said parking lot entrance/exit determination unit includes a brightness change in a parking lot gate or said parking lot entrance/exit.

8. A navigation system comprising:

an angular velocity sensor for detecting a change in an advancement direction of a vehicle;

a vehicle azimuth calculation unit for calculating a vehicle azimuth on the basis of angular velocity sensor information obtained from said angular velocity sensor;

a global positioning system (GPS) receiver for detecting a current position of a vehicle using the GPS;

a vehicle speed sensor for detecting rotation of a vehicle wheel;

a distance measurement unit for measuring a traveled distance on the basis of vehicle speed pulse information obtained from said vehicle speed sensor;

a map information storage unit for storing map information;

a current position calculation unit for calculating a current position on the basis of GPS information obtained from said GPS receiver, vehicle azimuth information obtained from said vehicle azimuth calculation unit, and distance information obtained from said distance measurement unit, and determining a current position of a vehicle on a map by comparing said calculated current position with said map information read from said map information storage unit;

an on-board camera for shooting a periphery of said vehicle;

an image recognition unit for recognizing an image obtained from said on-board camera; and

a traveling road determination unit for detecting a specific object indicating a road recognized by said image recognition unit, said navigation system being characterized in that

said current position calculation unit further corrects said determined current position of said vehicle on the basis of said specific object indicating said road, detected by said traveling road determination unit.

9. The navigation system according to claim 8, wherein said specific object indicating said road, detected by said traveling road determination unit, includes a support column of an elevated road, illumination in a tunnel, and a balustrade of a bridge.