Traffic information display system

• US 5,583,494 A
• Filed: 04/13/1995
• Issued: 12/10/1996
• Est. Priority Date: 06/13/1991
• Status: Expired due to Term

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation), Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Umezu, Masaharu, Ideno, Hiroaki, Mizutani, Yoshisada
• Primary Examiner(s): SWARTHOUT, BRENT
• Application Number:
  US08/421,030
• Time in Patent Office: 607 Days
• Field of Search: 340/990, 340/995, 340/988, 340/905, 364/444, 364/449
• US Class Current: 340/995.14
• CPC Class Codes: G01C 21/3667 Display of a road map G01C21/3614 takes precedence; guidance using 3D or perspective road maps G01C21/3635
• CPC Class Codes: G09B 29/106 using electronic means

Abstract

The present invention relates to a traffic information display system mounted on a vehicle to provide a map which is easy to see and which permits the driver of the vehicle to recognize the present position of the vehicle, etc. A control means used in this system determines a road on which the vehicle is present, on the basis of an output provided from a present position and direction detecting means, and fetches plural road data including the said road from a map information memory means. Then, the control means transforms the coordinates of start and end points of each road present in the road data into coordinates on a display screen, and provides those coordinates and a command to connect the start and end points using a straight line to a deformed map preparing means. The deformed map preparing means displays the road between each start point and each end point using a straight line, thereby providing a map which is easy to understand for the driver.

Claims

1. A traffic information display system comprising:

a map information memory means having road data involving information which represents start and end points of each road and also having characteristic point data involving coordinates relating to start and end points of each road;

a control means which fetches coordinates of start and end points of roads in a predetermined area from said map information memory means and transforms the fetched coordinates into display coordinates;

a deformed map preparing means which receives the display coordinates of start and end points, sets a straight line between each pair of start and end points and prepares a map for display; and

a display means for displaying the map prepared by the deformed map preparing means,

wherein said control means includes a coordinate normalizing means which transforms the display coordinates of start and end points into intersection coordinates of a plurality of intersections in a nondisplayed lattice superimposed on said display means which are closest to said display coordinates, and thereafter provides the intersectional coordinates to said deformed map preparing means, and

wherein said control means further includes a coordinate shifting means which, when there are two sets of display coordinates which are located on a single intersection of the lattice after a transformation made by said coordinate normalizing means, shifts one set of coordinates to be displayed at another intersection of said lattice.

2. A traffic information display system comprising:

a map information memory means having road data involving information which represents start and end points of each road and also having characteristic point data involving coordinates relating to start and end points of each road;

a control means which fetches coordinates of start and end points of roads in a predetermined area from said map information memory means and transforms the fetched coordinates into display coordinates;

a deformed map preparing means which receives the display coordinates of start and end points, sets a straight line between each pair of start and end points and prepares a map for display; and

a display means for displaying the map prepared by the deformed map preparing means,

wherein said control means includes a coordinate normalizing means which transforms the display coordinates of start and end points into intersection coordinates of a plurality of intersections in a nondisplayed lattice superimposed on said display means which are closest to said display coordinates, and thereafter provides the intersectional coordinates to said deformed map preparing means, and

wherein said control means further includes a display symbol indicating means which, when there are two sets of display coordinates located in a single intersection of the lattice after a transformation made by said coordinate normalizing means, provides a command to display a symbol which indicates that two intersections are displayed at the same display coordinates to said deformed map preparing means, and the deformed map preparing means displays start and end points using symbols in accordance with said command.

3. A traffic information display system including:

a map information memory means having road data involving information which represents start and end points of each road and the type of each road and also having characteristic point data involving coordinates relating to start and end points of each road;

a control means for fetching road data of roads present in a predetermined area, the coordinates of start and end points of each road and the type of the road from said map information memory means, for determining a display width of each road and a symbol size of the start and end points of each road on the basis of the type of the road, for transforming the start and end point coordinates into display coordinates, for determining intersection coordinates of a nondisplayed lattice having spacings larger than the display width of each road and the symbol size of the start and end points of each road, and for performing a coordinate transformation to transform said display coordinates into coordinates closest to intersection display coordinates of the intersections of the lattice;

a deformed map preparing means which receives the coordinates closest to the intersection display coordinates, the display width of each road and the symbol size of the start and end points of each road, then sets a straight line of a width corresponding to the display road width between each pair of start and end points, and prepares a map for display having the start and end points of each road represented by symbols of a size corresponding to the determined symbol size; and

a display means for displaying the map prepared by said deformed map preparing means.

4. A traffic information display system comprising:

a map information memory means having road data involving information which represents start and end points of each road and also having characteristic point data involving coordinates relating to start and end points of each road;

a control means which fetches coordinates of start and end points of roads in a predetermined area from said map information memory means and transforms the fetched coordinates into display coordinates;

a deformed map preparing means which receives the display coordinates of start and end points, sets a straight line between each pair of start and end points and prepares a map for display; and

a display means for displaying the map prepared by the deformed map preparing means,

wherein said control means includes a coordinate normalizing means which transforms the display coordinates of start and end points into intersection coordinates of a plurality of intersections in a nondisplayed lattice superimposed on said display means which are closest to said display coordinates, and thereafter provides the intersectional coordinates to said deformed map preparing means, and

wherein said control means calculates an angle of each said road relative to a reference direction, replaces said angle with an angle of a closest value out of angles of integer multiples of a predetermined angle, and provides the coordinates of start and end points after the replacement to said deformed map preparing means.

7. A traffic information display system according to claim 4 or claim 6, wherein said control means provides the length of each road to said deformed map preparing means for making a length display on the map for display.

5. A traffic information display system comprising:

a map information memory means having road data involving information which represents start and end points of each road and also having characteristic point data involving coordinates relating to start and end points of each road;

a control means which fetches coordinates of start and end points of roads in a predetermined area from said map information memory means and transforms the fetched coordinates into display coordinates;

a deformed map preparing means which receives the display coordinates of start and end points, sets a straight line between each pair of start and end points and prepares a map for display; and

a display means for displaying the map prepared by the deformed map preparing means,

wherein said control means includes a coordinate normalizing means which transforms the display coordinates of start and end points into intersection coordinates of a plurality of intersections in a nondisplayed lattice superimposed on said display means which are closest to said display coordinates, and thereafter provides the intersectional coordinates to said deformed map preparing means, and

wherein said control means transforms the coordinates of start points and end points so that each segment between a transformed coordinate of a start point and a transformed coordinate of an end point is equal to lengths of other segments.

6. A traffic information display system comprising:

a map information memory means having road data involving information which represents start and end points of each road and also having characteristic point data involving coordinates relating to start and end points of each road;

a control means which fetches coordinates of start and end points of roads in a predetermined area from said map information memory means and transforms the fetched coordinates into display coordinates;

a deformed map preparing means which receives the display coordinates of start and end points, sets a straight line between each pair of start and end points and prepares a map for display; and

a display means for displaying the map prepared by the deformed map preparing means,

wherein said control means includes a coordinate normalizing means which transforms the display coordinates of start and end points into intersection coordinates of a plurality of intersections in a nondisplayed lattice superimposed on said display means which are closest to said display coordinates, and thereafter provides the intersectional coordinates to said deformed map preparing means, and

wherein said control means displays approximations of the lengths of the roads by comparing actual lengths between the start and end points of each road to a plurality of predetermined lengths and by selecting one of said plurality of predetermined lengths having a length closest to that of the actual length for each road; and

said control means provides coordinates of start and end points of said selected one of said plurality of predetermined lengths to said deformed map preparing means.

8. A traffic information display system comprising:

map information memory means having road data involving information which represents start and end points of each road and also having characteristic point data involving coordinates relating to start and end points of each road;

a control means which fetches coordinates of start and end points of roads in a predetermined area from said map information memory means and transforms the fetched coordinates into display coordinates;

a deformed map preparing means which receives the display coordinates of start and end points, sets a straight line between each pair of start and end points and prepares a map for display; and

a display means for displaying the map prepared by the deformed map preparing means, wherein said control means further includes a flashing means which calculates the distance between the present position of the vehicle and either the start point or the end point located ahead of the vehicle on the road on which the vehicle is present, then determines a flashing period proportional to the thus-calculated distance, and provides a symbol display command and a symbol erase command to said deformed map preparing means in accordance with said deformed map preparing means in accordance with said flashing period, and the deformed map preparing means flashes the symbol added to the map for display in accordance with the symbol display command and the symbol erase command.

9. A traffic information display system including:

a present position and direction detecting means for detecting a present position and a moving direction of a vehicle;

a map information memory means having road data involving information which represents start and end points of each road and also having characteristic point data involving coordinates of start and end points of each road;

a control means which sets a characteristic point ahead of the road on which the vehicle is present, as a reference intersection, sets characteristic points at opposite ends of roads connected to the reference intersection, as primary intersections, further sets characteristic points at opposite ends of roads connected to any of the primary intersections, as secondary intersections, then selects nine or less intersections out of the reference intersection and the primary and secondary intersections, and transforms the coordinates of the selected intersections into display coordinates;

a deformed map preparing means which receives the display coordinates from said control means, sets a straight line between each pair of start and end points and prepares a map for display having the start and end points represented by symbols; and

a display means for displaying the map prepared by the said deformed map preparing means.

10. A traffic information display system including:

a map information memory means having map data involving information which represents a relation of connection of roads and information which represents a destination of each road;

a control means which retrieves coordinates of roads present in a predetermined area and information representing destinations of the roads, from said map information memory means, and prepares a map for display involving the roads and information representing destinations; and

a display means for displaying the map prepared by said control means, wherein said control means further includes a destination selecting means which, when plural pieces of information indicating destinations are present with respect to a certain road, selects for display one or plural pieces of said information which are of a higher level than a predetermined level; and

a present position and direction detecting means for detecting a present position and a moving direction of a vehicle, and said control means further includes a destination selecting means which calculates the distance between the destination of each road and the present position of the vehicle and selects, for display, information indicating a destination in which the calculated distance is larger than a first reference value and whose degree of importance is higher than a first degree of importance and a destination in which the calculated distance is smaller than a second reference value and whose degree of importance is lower than a second degree of importance.

11. A traffic information display system including:

a map information memory means having map data involving information which represents a relation of connection of roads and information which represents a destination of each road;

a control means which retrieves coordinates of roads present in a predetermined area and information representing destinations of the roads, from said map information memory means, and prepares a map for display involving the roads and information representing destinations; and

a display means for displaying the map prepared by said control means, wherein said control means further includes a destination selecting means which, when plural pieces of information indicating destinations are present with respect to a certain road, selects for display one or plural pieces of said information which are of a higher level than a predetermined level; and

an operating means to which is input a destination, and wherein said control means further includes a specific destination registering means which, when the same destination as the destination input to said operating means is present in the map data, registers said destination, and a specific destination designating means which, when said destination has been registered, determines said destination as a destination for display at the time of displaying the map, while when said destination has not been registered, instructs the retrieval of said map information memory means.

12. A traffic information display system including:

a map information memory means having map data including information which represents relationships indicating whether or not respective roads are connected with other roads and information which represents a relative height of roads with respect to one another, the height of the road representing an amount above ground level of the road;

a control means which, at the time of display, fetches coordinates of roads present in a predetermined area and coordinates of intersections of pairs of roads which have different heights out of the roads present in the predetermined area, from said map information memory means, said pairs of roads having a grade separation portion at which an upper one of said roads passes over a lower one of said roads, said control means then eliminating the grade separation portion of the lower road of said pairs of roads, and then prepares a map for display involving the roads present in the predetermined area; and

a display means for displaying the map prepared by said control means.

13. A traffic information display system including:

a map information memory means having map data including information which represents relationships indicating whether or not respective roads are connected with other roads and roads which run parallel and verticality spaced with respect to one another;

a control means which, at the time of display, fetches coordinates of roads present in a predetermined area and roads which run parallel and vertically-spaced to one another out of the roads present in the predetermined area, from said map information memory means, and prepares a map for display involving the roads present in the predetermined area such that a width of a lower road is displayed wider than an upper road of two roads which run parallel and vertically-spaced with respect to one another; and

a display means for displaying the map prepared by said control means.