Vehicle navigation system

• US 5,155,688 A
• Filed: 10/18/1990
• Issued: 10/13/1992
• Est. Priority Date: 10/24/1989
• Status: Expired due to Term

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Noda, Hiroshi, Yoshitoshi, Yo, Goto, Hirofumi, Tanaka, Ichiro
• Primary Examiner(s): Lall, Parshotam S.
• Assistant Examiner(s): Pipala, Edward J.
• Application Number:
  US07/599,600
• Time in Patent Office: 726 Days
• Field of Search: 364/449, 364/454, 364/444, 364/447, 364/457, 364/460, 340/988, 340/995, 342/357, 342/457
• US Class Current: 701/221
• CPC Class Codes: G01C 21/30 Map- or contour-matching
• CPC Class Codes: G01S 19/49 whereby the further system is an inertial position system, e.g. loosely-coupled
• CPC Class Codes: G01S 19/50 whereby the position solution is constrained to lie upon a particular curve or surface, e.g. for locomotives on railway tracks

Abstract

In a vehicle location detecting system having a self-contained type location detecting section for determining the accumulation type location data, a satellite navigation type location detecting section for determining the satellite type location data from satellite navigation data, a synthesizing section calculates synthetic location data from the accumulation type location data and the satellite navigation type location data. An on-road location determining section determines an on-road location of the vehicle in accordance with the synthetic location data and road map data stored in a road map memory. A display sectin displays the on-road location determined by the on-road location determining section.

Claims

1. A vehicle location detecting system provided in a vehicle for detecting the location thereof, comprising:

self-contained type location detecting means for calculating accumulation-type location data based on motion signals from sensors mounted on said vehicle;

satellite navigation type location detecting means for calculating satellite-type location data from satellite location data transmitted by a plurality of satellites constituting a global positioning system (GPS) navigation system;

memory means for storing accumulation-type location data calculated by said self-contained type location detecting means;

means for selecting accumulation-type location data from said memory means which is closest to said calculated satellite-type location data;

synthesizing means for calculating synthetic location data based on the selected accumulation-type location data from said memory means and said calculated satellite-type location data;

a road map memory for storing road map data;

on-road location detecting means for calculating an on-road location of said vehicle based upon said synthetic location data and said road map data; and

display means for displaying the calculated on-road location of said vehicle.

2. A system according to claim 1, wherein said synthesizing means comprises means for calculating a weighted mean of the accumulation type location data and the satellite navigation type location data.

3. A system according to claim 1, further comprising:

an on-road location data memory for storing on-road location data determined by said on-road location determining means;

evaluating means for calculating an evaluation function for each of the on-road location data stored in said on-road location data memory; and

selecting means for selecting on-road location data having the highest evaluation function from among the stored on-road location data, and erasing unselected on-road location data from said on-road location data memory;

wherein said display means displays the on-road location data that is selected by said selecting means.

4. A system according to claim 1, wherein said self-contained type location detecting means comprises:

travel distance detecting means for detecting a travel distance of the vehicle;

direction detection means for detecting a travel direction of the vehicle; and

accumulation type location data calculating means for calculating the location of the vehicle from the travel distance and the direction.