US 4,796,191 A · Vehicle navigational system and method

Abstract

A vehicle navigational system and method for tracking a vehicle, including a programmed computer, sensors for sensing the distance traveled and heading of the vehicle, and a stored map data base identifying a map of an area over which the vehicle is moving, in which the computer calculates and advances dead reckoned positions of the vehicle in response to distance and heading data, provides data identifying a contour of equal probability containing the dead reckoned positions and having a probability of containing the actual location of the vehicle, derives multiparameters from the map data base, and updates a given dead reckoned position and the contour using a highly developed vehicle navigational algorithm if a more probable dead reckoned position exists based upon the given dead reckoned position, the contour and the derived multi-parameters.

Claims78

Dependent claims

Apparatus for providing information to improve the accuracy of tracking a vehicle movable over streets in a given area, comprising:

(a) first means for providing data identifying respective positions of the vehicle, each position having an accuracy relative to an actual location of the vehicle and one of said positions being a current position, and for providing data identifying a measured heading of the vehicle;
(b) second means for providing a map data base of the streets;
and
(c) means for deriving any of a plurality of parameters in dependence on one or more respective positions of the vehicle and the streets of the map data base to determine if a more probable current position exists, wherein one of said parameters is the measured heading of the vehicle as compared with the headings of the streets of the map data base.

1 more element

Apparatus for automatically tracking a vehicle movable about streets of an overall given area, comprising:

(a) first means for providing first data identifying respective dead reckoned positions of the vehicle as the vehicle moves about the streets, each dead reckoned position having a certain accuracy and one of the dead reckoned positions being a current position;
(b) second means for providing second data identifying an estimate of the accuracy of the respective dead reckoned positions in the form of a contour containing the respective dead reckoned positions of the vehicle and approximating a probability of containing the actual location on the vehicle, the contour changing as the vehicle moves about the streets;
(c) third means for providing a map data base of the streets of the given area;
and
(d) means for updating the current dead reckoned position of the vehicle to an updated current dead reckoned position corresponding to a more probable point on one of the streets in response to said first data identifying the current dead reckoned position, said second data identifying the contour associated with the current dead reckoned position, and said map data base.

2 more elements

A system for automatically tracking a vehicle movable on streets of a given area, comprising:

(a) first means for providing first data being respective dead reckoned positions of the vehicle, one of the dead reckoned positions being current dead reckoned position, including
(i) means for generating data identifying the distance traveled by the vehicle, and
(ii) means for generating data identifying the heading of the vehicle;
(b) second means for providing second data identifying and estimate of the accuracy of the respective dead reckoned positions in the form of a contour of equal probability containing the respective dead reckoned positions of the vehicle and approximating a probability of containing the actual location of the vehicle, the contour changing as the vehicle moves on the streets;
(c) means for providing third data identifying a map data base of the streets of the given area;
(d) means for determining lines-of-position corresponding to the streets in response to the map data base, in which one or more lines-of-position are substantially parallel to the heading of the vehicle and intersect the contour associated with the current dead reckoned position, one of which may be a most probable line-of-position corresponding to a street on which the vehicle most probably is moving;
(e) means for updating the current dead reckoned position to an updated current dead reckoned position corresponding to a point on the most probable line-of-position;
and
(f) means for updating the contour associated with the current dead reckoned position to an updated contour upon updating the current dead reckoned position, in which the contour containing the respective dead reckoned positions expands in size as the vehicle moves to reflect a decreased accuracy in the respective dead reckoned positions until the updated dead reckoned position is produced and then contracts in size to reflect the increased accuracy of the updated dead reckoned position as compared to the current dead reckoned position, the expanding contour and contracted contour having approximately the same probability of containing the actual location of the vehicle.

6 more elements

A vehicle navigational system for automatically tracking a motor vehicle movable over streets of a given area identified by a map, the vehicle navigational system being installable on the vehicle, comprising:

(a) first means for sensing the distance traveled by the motor vehicle and for generating distance data;
(b) second means for sensing the heading of the motor vehicle and for generating heading data;
(c) means for storing a map data base identifying of the streets;
(d) means for displaying the map and a motor vehicle symbol movable relative to the displayed map;
and
(e) programmed computer means for:
(i) providing data identifying respective dead reckoned positions of the motor vehicle in response to the distance data and the heading data, one of the dead reckoned positions being a current dead reckoned position;
(ii) providing data identifying a contour containing the respective dead reckoned positions, the contour expanding from one dead reckoned position to another dead reckoned position as the vehicle moves until the current dead reckoned position is updated;
(iii) determining lines-of-position corresponding to respective streets in response to the map data base, one of which may be a most probable line-of-position corresponding to a street over which the motor vehicle may be moving, the most probable line-of-position being substantially parallel to the heading of the motor vehicle, intersecting the contour associated with the current dead reckoned position and being connected to a next preceding most probable line-of-position corresponding to a next preceding updated current dead reckoned position;
(iv) updating the current dead reckoned position to an updated dead reckoned position on a more probable point on the most probable line-of-position in response to the current dead reckoned position, the contour associated with the current dead reckoned position and the most probable line-of-position;
(v) updating the contour associated with the current dead reckoned position to an updated contour containing the updated dead reckoned position in response to the contour associated with the current dead reckoned position and the most probable line-of-position;
and
(vi) controlling said displaying means to display the map in response to the map data base and to display the motor vehicle symbol in response to the data identifying the respective dead reckoned positions.

10 more elements

Dependencies are inferred from the claim text.

Vehicle navigational system and method

Life of this patent

Vehicle navigational system and method

Life of this patent

Abstract

Claims78