Road map management system

• US 7,627,414 B2
• Filed: 07/27/2006
• Issued: 12/01/2009
• Est. Priority Date: 08/03/2005
• Status: Expired due to Fees

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Goto, Masayuki, Yamada, Shinichi
• Primary Examiner(s): Tran; Khoi
• Assistant Examiner(s): JEN, MINGJEN
• Application Number:
  US11/493,903
• Publication Number:
  US 20070032946A1
• Time in Patent Office: 1,223 Days
• Field of Search: None
• US Class Current: 701/93
• CPC Class Codes: G01C 21/3815 Road data
• CPC Class Codes: G01C 21/3841 Data obtained from two or more sources, e.g. probe vehicles
• CPC Class Codes: G01C 21/3844 Data obtained from position sensors only, e.g. from inertial navigation
• CPC Class Codes: G01C 21/3848 Data obtained from both position sensors and additional sensors
• CPC Class Codes: G01C 21/3859 Differential updating map data
• CPC Class Codes: G08G 1/0969 having a display in the form of a map
• CPC Class Codes: G09B 29/00 Maps; Plans; Charts; Diagrams, e.g. route diagram star maps G09B27/04; devices for holding or supporting maps A47B97/02; for computing purposes G06G1/14, G09B1/16; display boards G09F

Abstract

A road map management system is provided as follows: drawing a past-direction distribution map (Image A) and a future-direction distribution map (Image B) using multiple vehicles'"'"' traveling position data collected via a wide area network during a past-direction data collection period and a future-direction data collection period, respectively; comparing the two distribution maps to extract a differential distribution; defining under a predetermined condition as a recently opened or closed road the differential distribution, which is absent from Image A and present in Image B, or present in Image A and absent from Image B, respectively; and reflecting the defined results on the existing road map data to update.

Claims

1. A road map management system comprising:

data collecting means for collecting traveling position data, which indicates traveling positions of a plurality of vehicles having individual terminals, from the terminals;

distribution map generating means for generating at least two distribution maps including a first distribution map generated as an aggregate of points based on traveling position data relative to the plurality of vehicles collected by the data collecting means during an earlier collection period and a second distribution map generated as an aggregate of points based on traveling position data relative to the plurality of vehicles collected by the data collecting means during a later collection period, which has no overlap period with the earlier collection period;

difference map generating means for generating a difference map indicating a difference between the first distribution map and the second distribution map; and

road change defining means for

detecting a differential distribution appearing in the difference map and determined to be present in one of the first distribution map and the second distribution map and absent from another of the first distribution map and the second distribution map, and

defining the detected differential distribution as a road that underwent a change, when the detected differential distribution satisfies a predetermined condition, wherein

the road change defining means defines, as a recently opened road, a differential distribution, which is absent from the first distribution map and present in the second distribution map and is determined to be outside of a road included in road map data after undergoing a map matching process.

2. A road map management system comprising:

data collecting means for collecting traveling position data, which indicates traveling positions of a plurality of vehicles having individual terminals, from the terminals;

distribution map generating means for generating at least two distribution maps including a first distribution map generated as an aggregate of points based on traveling position data relative to the plurality of vehicles collected by the data collecting means during an earlier collection period and a second distribution map generated as an aggregate of points based on traveling position data relative to the plurality of vehicles collected by the data collecting means during a later collection period, which has no overlap period with the earlier collection period;

difference map generating means for generating a difference map indicating a difference between the first distribution map and the second distribution map; and

road change defining means for

detecting a differential distribution appearing in the difference map and determined to be present in one of the first distribution map and the second distribution map and absent from another of the first distribution map and the second distribution map, and

defining the detected differential distribution as a road that underwent a change, when the detected differential distribution satisfies a predetermined condition, wherein

the road change defining means defines, as a recently closed road, a differential distribution, which is present in the first distribution map and absent from the second distribution map and is determined to be on a road included in road map data after undergoing a map matching process.

3. A road map management system comprising:

data collecting means for collecting traveling position data, which indicates traveling positions of a plurality of vehicles having individual terminals, from the terminals;

distribution map generating means for generating at least two distribution maps including a first distribution map generated as an aggregate of points based on traveling position data relative to the plurality of vehicles collected by the data collecting means during an earlier collection period and a second distribution map generated as an aggregate of points based on traveling position data relative to the plurality of vehicles collected by the data collecting means during a later collection period, which has no overlap period with the earlier collection period;

difference map generating means for generating a difference map indicating a difference between the first distribution map and the second distribution map; and

road change defining means for

detecting a differential distribution appearing in the difference map and determined to be present in one of the first distribution map and the second distribution map and absent from another of the first distribution map and the second distribution map, and

defining the detected differential distribution as a road that underwent a change, when the detected differential distribution satisfies a predetermined condition,

wherein the first distribution map is generated in accordance with

$\mathrm{la}<br><br><br><br>\left(\mathrm{xn},\mathrm{yn}\right)=\underset{t=T-\mathrm{\Delta <br><br>}<br><br><br><br>t<br><br><br><br>1}{\overset{T}{\sum <br><br>}}<br><br><br><br>\left(\mathrm{Image}<br><br><br><br>\mathrm{data}<br><br><br><br>\left(\mathrm{xn},\mathrm{yn}\right)\right);<br><br>$

where Ia(xn, yn)=the actual traveling position data at points (xn, yn),

T=a branch point in time which is between the earlier collection period and the later collection period,

the second distribution map is generated in accordance with

$l<br><br><br><br>b<br><br><br><br>\left(\mathrm{xn},\mathrm{yn}\right)=\underset{t=T}{\overset{T+\mathrm{\Delta <br><br>}<br><br><br><br>t<br><br><br><br>2}{\sum <br><br>}}<br><br><br><br>\left(\mathrm{Image}<br><br><br><br>\mathrm{data}<br><br><br><br>\left(\mathrm{xn},\mathrm{yn}\right)\right);<br><br>$

and

the difference map is generated in accordance with

Δ

I(xn,yn)=|Ia(xn,yn)−

Ib(xn,yn)|.

4. A road map management system comprising:

a data collection unit that collects traveling position data, which indicates actual traveling positions of different vehicles having individual terminals, from the terminals;

a distribution map generation unit that generates, responsive to the actual traveling positions from different vehicles collected by the data collection unit, at least two distribution maps including a first distribution map generated using actual traveling position data collected by the data collection unit during an earlier collection period and a second distribution map generated using actual traveling position data collected by the data collection unit during a later collection period, which has no overlap period with the earlier collection period;

a difference map generation unit, responsive to the first and second distribution maps, that generates a difference map indicating a difference in the actual traveling positions between the first distribution map and the second distribution map; and

a road change definition unit that

detects a differential distribution appearing in the difference map and determined to be present in one of the first distribution map and the second distribution map and absent from another of the first distribution map and the second distribution map, and

defines the detected differential distribution as a road that underwent a change, when the detected differential distribution satisfies a predetermined condition,

the first and second distribution maps reflecting a distribution of aggregated actual traveling positions of different vehicles,

wherein the first distribution map is generated in accordance with

$\mathrm{la}<br><br><br><br>\left(\mathrm{xn},\mathrm{yn}\right)=\underset{t=T-\mathrm{\Delta <br><br>}<br><br><br><br>t<br><br><br><br>1}{\overset{T}{\sum <br><br>}}<br><br><br><br>\left(\mathrm{Image}<br><br><br><br>\mathrm{data}<br><br><br><br>\left(\mathrm{xn},\mathrm{yn}\right)\right);<br><br>$

where Ia(xn, yn)=the actual traveling position data at points (xn, yn),

T=a branch point in time which is between the earlier collection period and the later collection period,

the second distribution map is generated in accordance with

$l<br><br><br><br>b<br><br><br><br>\left(\mathrm{xn},\mathrm{yn}\right)=\underset{t=T}{\overset{T+\mathrm{\Delta <br><br>}<br><br><br><br>t<br><br><br><br>2}{\sum <br><br>}}<br><br><br><br>\left(\mathrm{Image}<br><br><br><br>\mathrm{data}<br><br><br><br>\left(\mathrm{xn},\mathrm{yn}\right)\right);<br><br>$

and

the difference map is generated in accordance with

Δ

I(xn,yn)=|Ia(xn,yn)−

Ib(xn,yn)|.