Method for detecting map matching position of vehicle in navigation system

• US 7,197,392 B2
• Filed: 10/12/2004
• Issued: 03/27/2007
• Est. Priority Date: 10/20/2003
• Status: Expired due to Fees

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Jung, Mun Ho, Yi, Dong Hoon, Lee, Han Sung
• Primary Examiner(s): Zanelli; Michael J.
• Application Number:
  US10/964,028
• Publication Number:
  US 20050085995A1
• Time in Patent Office: 896 Days
• Field of Search: None
• US Class Current: 701/208
• CPC Class Codes: G01C 21/30 Map- or contour-matching

Abstract

The present invention relates to a method for detecting a map matching position of a vehicle in a navigation system, wherein coordinates of a current vehicle location are obtained from navigation messages received by a GPS receiver using a general line equation for obtaining an intersection point between an arbitrary line and a perpendicular line drawn from an arbitrary point to the line, and the current vehicle location is matched to coordinates found through orthogonal projection on a link on a digital map closest to the obtained coordinates of the current vehicle location. The current vehicle location is detected from the navigation messages received by the GPS receiver, the detected current vehicle location is matched on the digital map to obtain coordinates P₀ of the current vehicle location, the digital map is searched to find a road link closest to the obtained coordinates P₀ of the current vehicle location, coordinates P₁ and P₂ of both end points of the searched road link are obtained, the orientation of line P₁P₂ defined by the coordinates P₁ and P₂ of the obtained road link is checked on the digital map, coordinates P of an intersection point of a perpendicular line drawn from the obtained coordinates P₀ to line P₁P₂ are obtained, and the current vehicle location is matched to the obtained coordinates P of the intersection point.

Claims

1. A method for detecting a map matching position of a vehicle in a navigation system, comprising the steps of:

(a) obtaining, by a control unit, coordinates (P₀) of a current vehicle location using navigation messages received by a GPS receiver and detection signals of sensors installed on the vehicle;

(b) searching map data to find one link to which the coordinates (P₀) of the current vehicle location obtained in step (a) will be matched, and obtaining coordinates (P₁, P₂) of both end points of the link;

(c) putting the coordinates (P₀) of the current vehicle location and the coordinates (P₁, P₂) of both end points of the link into a predetermined formula to obtain coordinates (P) of an intersection point of the perpendicular line connecting perpendicular line () to a line () defined by the coordinates (P₁, P₂) of both end points of the link obtained in step (b); and

(d) determining the coordinates of the current vehicle location to be the coordinates (P) of the intersection point obtained in step (c).

2. The method as claimed in claim 1, wherein the link found in step (b) is a link on the map data closest to the coordinates (P₀) of the current vehicle location.

3. The method as claimed in claim 1, wherein the coordinates (P) of the intersection point obtained in step (c) are calculated from the following formula:

$\left(\begin{array}{c}p\\ q\end{array}\right)=\frac{1}{a^{\mathrm{\prime <br><br>}}<br><br>b-{\mathrm{ab}}^{\mathrm{\prime <br><br>}}}<br><br>\left(\begin{array}{c}{b}^{\mathrm{\prime <br><br>}}<br><br>c-{\mathrm{bc}}^{\mathrm{\prime <br><br>}}\\ c^{\mathrm{\prime <br><br>}}<br><br>a-{\mathrm{ca}}^{\mathrm{\prime <br><br>}}\end{array}\right)$

where p and q are x- and y-axis coordinate values of the coordinates (P) of the intersection point obtained in step (c), respectively, and a, b, c, a′

, b′ and

c′

are coefficients of an equation for line (), ax+by+c=0, and an equation for line (), a′

x+b′

y+c′

=0.

4. The method as claimed in claim 1, wherein if the orientation of the line () is vertical on a digital map, the coordinates (P) of the intersection point obtained in step (c) is determined to be (x₁, y₀), where x₁ is x-axis coordinate values of the coordinates (P₁, P₂), and y₀ is a y-axis coordinate value of the coordinates (P₀).

5. The method as claimed in claim 1, wherein if the orientation of the line () is horizontal on a digital map, the coordinates (P) of the intersection point obtained in step (c) is determined to be (x₀, y₁), where x₀ is an x-axis coordinate value of the coordinates (P₀), and y₁ is y-axis coordinate values of the coordinates (P₁, P₂).