Road data generating method for use in an on-board navigation system

• US 4,982,332 A
• Filed: 03/29/1989
• Issued: 01/01/1991
• Est. Priority Date: 06/27/1988
• Status: Expired due to Fees

• Current Assignee: Pioneer Electronics (USA) Incorporated (Pioneer Corporation)
• Original Assignee: Pioneer Electronics (USA) Incorporated (Pioneer Corporation)
• Inventors: Saito, Masaki, Kashiwazaki, Takashi
• Primary Examiner(s): Black, Thomas G.
• Application Number:
  US07/330,272
• Time in Patent Office: 643 Days
• Field of Search: 364/449, 364/447, 364/450, 364/454, 340/990, 340/995
• US Class Current: 701/208
• CPC Class Codes: G01C 21/3815 Road data
• CPC Class Codes: G01C 21/3844 Data obtained from position sensors only, e.g. from inertial navigation
• CPC Class Codes: G08G 1/096827 where the route is computed onboard

Abstract

A road data generating method for use in an on-board navigation system. Points on roads in a map are expressed in numerical form and memorized as map data previously, and co-ordinates of the present position of the vehicle and the compass direction of the movement of the vehicle are detected and the distance to a point on a road nearest to the present position and the angle of the road at that point are determined on the basis of the map data, as decision values for the generation of road data, every time a certain distance is traveled by the vehicle. Judgment is made as to whether or not there already is registered learning data in the vicinity of the present position when the decision values exceed the predetermined values, and standard deviations of the distance and the angle with respect to the registered learning data are calculated when there is the registered learning data. The registered learning data is registered as the road data if the standard deviations are equal to or smaller than predetermined values.

Claims

1. A new road data generating method for adding new roads into a map database for use in an on-board navigation system mounted in a vehicle, comprising the steps of:

previously expressing points on roads in a map in numerical form and memorizing them as map data;

detecting co-ordinated of a present position of the vehicle and compass direction of the movement of the vehicle and determining the distance to a point on a road nearest to the present position and the angle of said road at said point on the basis of said map data, as decision values for the generation of road data, every time a certain distance is traveled by the vehicle;

registering learning data depending on whether or not said decision valued exceed predetermined values;

judging as to whether or not there already is registered learning data in the vicinity of the present position when said decision values exceed said predetermined values;

calculating standard deviations of said distance and said angle with respect to said registered learning data when there is said registered learning data; and

registering said registered learning data as said new road data if said standard deviations are equal to or smaller than predetermined values.

2. A new road data generating method as claimed in claim 1, wherein said step of registering learning data comprises steps of:

registering co-ordinate data of the present position as locus data on condition that an error angle of the present value of the compass direction of the movement of the vehicle with respect to a previous value of the compass direction is greater than a predetermined angle, if there is no learning data when said decision values exceed said predetermined values; and

registering said locus data as learning data if registration of the locus data has been made beforehand, when said decision values are equal to or smaller than said predetermined values.

3. A new road data generating method as claimed in claim 2, wherein a magnitude of said error angle of the present value of the compass direction of the movement of the vehicle with respect to a previous value of the compass direction is judged every time the vehicle travels a second certain distance which is longer than said certain distance.

4. A new road data generating device for adding new roads into a map database for use in an on-board navigation system mounted in a vehicle, comprising:

first means for detecting compass direction of the movement of the vehicle;

means for sensing distance travelled by the vehicle;

second means for detecting present position of the vehicle;

first memory means for storing map data;

second memory means for storing newly generated road data;

means for processing data received from said first memory means, first and second detecting means and sensing means to produce map data representing present position of the vehicle and if said new road data is detected, storing said new road data in said second memory means; and

display means for displaying map data received from said processing means.

5. A new road data generating device as claimed in claim 4, wherein said means for processing comprises:

means for receiving said data from said sensing means, first memory means and first and second detecting means;

means for calculating distance travelled by the vehicle and detecting new road data from data received from said receiving means;

first means for storing processing programs used by said calculating means; and

second means for storing information for executing said processing programs stored in said first storing means.