Navigation system with route determination process capable of determining a desired route readily and quickly

• US 5,430,653 A
• Filed: 10/12/1993
• Issued: 07/04/1995
• Est. Priority Date: 10/12/1992
• Status: Expired due to Fees

• Current Assignee: Masprodenkoh Kabushikikaisha.
• Original Assignee: Masprodenkoh Kabushikikaisha.
• Inventors: Inoue, Nobutaka
• Primary Examiner(s): ZANELLI, MICHAEL J
• Application Number:
  US08/134,575
• Time in Patent Office: 630 Days
• Field of Search: 364/444, 364/460, 364/462, 364/449, 340/988, 340/995, 342/357, 342/457
• US Class Current: 701/210
• CPC Class Codes: G01C 21/34 Route searching; Route guidance

Abstract

A navigation system for a vehicle is provided with a route determination process by which a road is selected and determined as a route according to a designated starting point and a driving direction. The route is indicated on a road map displayed on a screen, and stored. Further routes are automatically determined, intersection by intersection, according to the category of the road determined earlier as a route. Cancellation of the route thus determined is performed intersection by intersection and reported to a user by erasion of the route indication. The road map displayed on the screen always places the last intersection on the determined and uncanceled route at its center, thereby allowing the user to confirm the proceeding of the route determination and the route cancellation process.

Claims

1. A navigation system for a vehicle having a route selection mode and a navigation mode, said system comprising:

displaying means for displaying a road map thereon;

road map data storage means for storing road map data to be displayed on said display means, said road map data including road category type data indicative of a category of each road included in the road map data;

display control means for controlling said display means to display a road map, during route selected and during navigation, according to the road map data stored in said road map data storage means;

input means for inputting a base point and a driving direction when said system is in the route selection mode;

first road selection means for selecting a road to be taken, when said system is in the route selection mode, according to the driving direction and the road map data, from the base point to an intersection with the selected road forming a portion of a selected route;

route indication control means for controlling said display means to indicate on the displayed road map, when aid system is in the route selection mode, the selected road of said first road selection means to be taken on said route;

second road selection means for selecting a next road to be taken on said route, when said system is in the route selection mode, according to the road category type of the selected road and the road map data, from an end of the previously selected road to a next intersection;

first display change control means for displaying the next road on the displayed road map, when said system is in the route selection mode, and for determining whether the next intersection is displayed on the road map currently shown on said display means and, if said first display change control means determines that the next intersection is beyond the currently displayed road map, changing the displayed road map, when said system is in the route selection mode, to a road map including the next intersection with said next intersection being displayed at the center of said display means;

determination means for determining whether or not a next road has been determined by said second road selection means and, if said determination means determines that a next road has been determined, activating said second road selection means to select a further road connected to an end of the previously selected road;

route cancel input means for receiving an input instruction to halt at least one of said first and second road selection means from performing road selection and to cancel at least a portion of the previously selected route; and

route cancel control means for canceling, in response to the input instruction, at least a portion of the previously selected route in response to the input instruction and erasing a corresponding indication of the canceled route from said display means with said erasing proceeding from a last input intersection toward a first input intersection.

2. A navigation system according to claim 1, wherein said navigation system further comprises:

second display change control means for determining whether a last intersection on an uncancelled portion of the previously selected route is displayed on the road map currently displayed on said display means and, if said second display change control means determines that the last intersection is not displayed on the currently displayed road map, changing the displayed road map to a road map including the last intersection.

3. A navigation system according to claim 2, wherein said navigation system further comprises:

route determination resumption means for activating said first road selection means to resume operation upon receipt of an input designating a driving direction, and

recognizing the end of the uncancelled route as a new base point, when one of (1) said determination means determines that said second road selection means has not selected a further road to be taken, and (2) said route cancel control means finishes cancellation of a desired portion of said route in response to an instruction to cancel a portion of the previously selected route.

4. A navigation system according to claim 3, wherein said navigation system further comprises an antenna and a receiver for receiving a transmission signal for indicating, during use, a position and velocity of the vehicle.

5. A navigation system according to claim 3, wherein said road map data storage means is one of an optical disk and a magnetic disk and said display means is one of a cathode ray tube and a liquid crystal screen.

6. A navigation system according to claim 3, wherein said navigation system further comprises a main controller comprising:

a central processing unit;

a ROM;

a RAM;

an input/output port; and

a bus line interconnecting said central processing unit, said ROM, said RAM and said input/output port with one another; and

said main controller communicates with said display control means for controlling said display means.

7. A method of selecting a route for navigating a roadway comprising the steps of:

displaying a road map on a display means;

storing road map data to be displayed on said display means during route selection in a road map data storage means, said road map data including road category type data indicative of a category of each road included in the road map data;

controlling with a display control means, said display means, to display a road map during route selection according to the road map data stored in said road map data storage means;

inputting a base point and a driving direction with an input means during route selection;

selecting, according to the driving direction and the road map data, with a first road selection means during route selection, a road to be taken from the base point to an intersection with the selected road forming a portion of a selected route;

controlling said display means, with a route indication control means, to indicate on the displayed road map, during route selection, the road selected by said first road selection means;

selecting, according to the road category type of the selected road and the road map data, with second road selection means during route selection a next road to be taken as a further road to be taken on said selected route from end of the previously selected road to a next intersection;

determining during route selection, with a first display change control means, whether the next intersection is displayed on the road map currently displayed on said display means and, if said first display change control means determines that the next intersection is beyond the currently displayed road map, changing the display road map to a road map including the next intersection;

determining during route selection, with a determination means, whether or not a next road has been determined by said second road selection means and, if said determination means determines that a next road has been determined, again activating said second road selection means to select a further road connected to an end of the previously selected road;

receiving during route selection, with a route cancel input means, an input instruction to halt at least one of said first and said second road selection means from performing road selection and to cancel at least a portion of the previously selected route;

canceling during route selection, in response to the input instruction, with a route cancel control means at least a portion of the previously selected route in response to the input instruction and erasing a corresponding indication of the canceled route from said display means;

determining during route selection, with a second display change control means, whether a last intersection on an uncancelled portion of the previously selected route is displayed on the road map currently displayed on said display means and, if said second display change control means determines that the last intersection is not displayed on the currently displayed road map, changing the displayed road map to a road map including the last intersection; and

resuming during route selection, with a route determination resumption means, operation of said first road selection means upon receipt of an input designating a driving direction, and recognizing the end of the uncancelled route as a new base point, when one of (1) said determining means determines that said second road selection means has not determined a further road to be taken and (2) said route cancel control means finishes cancellation of a portion of said route in response to an instruction to cancel a portion of the previously selected route.

8. A method of selecting a route for navigating a roadway according to claim 7, wherein said navigation system further comprises the step of:

retrieving, using said first display change control means, upon determining that the next intersection is not on the currently displayed road map, a central map unit, including the next intersection, and three peripheral map units, and preparing a new current road map from all four retrieved map units with the next intersection located at the center of said current road map, said retrieved road map is substantially the size of said display means, and said three peripheral map units lie adjacent said central map unit and in said driving direction.

9. A navigation system for a vehicle having a route selection mode and a navigation mode, said system comprising:

display means for displaying a road map thereon;

road map data storage means for storing road map data to be displayed on said display means, said road map data including road category type data indicative of a category of each road included in the road map data;

display control means for controlling said display means to display a road map, during route selection and during navigation, according to the road map data stored in said road map data storage means;

input means for inputting a base point and a driving direction when said system is in the route selection mode;

first road selection means for selecting a road to be taken, when said system is in the route selection mode, according to the driving direction and the road map data, from the base point to an intersection with the selected road forming a portion of a selected route;

route indication control means .for controlling said display means to indicate on the displayed road map, when said system is in the route selection mode, the selected road of said first road selection means to be taken on said route;

second road selection means for selecting a next road to be taken on said route, when said system is in the route selection mode, according to the road category type of the selected road and the road map data, from an end of the previously selected road to a next intersection;

first display change control means for displaying the next road on the displayed road map, when said system is in the route selection mode, and for determining whether the next intersection is displayed on the road map currently shown on said display means and, if said first display change control means determines that the next intersection is beyond the currently displayed road map, changing the displayed road map, when said system is in the route selection mode, to a road map including the next intersection with said next intersection being displayed at the center of said display means; and

wherein said first display change control means, upon determining that the next intersection is not on the currently displayed road map, retrieves a central map unit, including the next intersection, and three peripheral map units, and prepares a new current road map from all four retrieved map units with the next intersection located at the center of said current road map, and said retrieved road map is substantially the size of said display means.

10. A navigation system according to claim 9, wherein said three peripheral map units lie adjacent said central map unit and in said driving direction.