Map data providing device

• US 20070271036A1
• Filed: 05/17/2007
• Published: 11/22/2007
• Est. Priority Date: 05/19/2006
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Atarashi, Yasutaka
• Granted Patent: US 7,949,466 B2
• Time in Patent Office: Days
• US Class Current: 701/211
• CPC Class Codes: G01C 21/3837 Data obtained from a single source
• CPC Class Codes: G01C 21/3844 Data obtained from position sensors only, e.g. from inertial navigation
• CPC Class Codes: G01C 21/3889 Transmission of selected map data, e.g. depending on route
• CPC Class Codes: G01C 21/3896 Transmission of map data from central databases

Abstract

Vehicular swept path data and electronic map data representing a road map are compared with each other to compute correction information that represents the amount of deviation of the electronic map data from the vehicular swept path data with respect to each predetermined block. The electronic map data is corrected using the computed correction information, and the corrected electronic map data is provided.

Claims

1. A map data providing device, comprising:

a vehicle position detecting unit configured to detect an absolute position of a vehicle;

a storing unit configured to store absolute positions of the vehicle detected by the vehicle position detecting unit while the vehicle runs as vehicular swept path data pertaining to the vehicle;

a correction information computing unit configured to compare the vehicular swept path data with electronic map data representing a road map and compute correction information representing an amount of deviation of the electronic map data from the vehicular swept path data with respect to each predetermined block;

a first correcting unit configured to correct the electronic map data using the correction information computed by the correction information computing unit; and

a first map data providing unit configured to provide the electronic map data corrected by the first correcting unit.

2. The map data providing device of claim 1,

wherein the correction information computing unit computes, as the correction information, an offset correction amount that represents a movement vector by which a specific point contained in the vehicular swept path data is pulled onto a road contained in the electronic map data in map matching and a rotation correction amount that represents an angle formed by a vehicular swept path line obtained from the vehicular swept path data and a road contained in the electronic map data corresponding to the vehicular swept path line, and

wherein the first correcting unit corrects the electronic map data using the offset correction amount and the rotation correction amount.

3. The map data providing device of claim 1, comprising:

a first determining unit configured to determine whether or not a swept path reliability, which is a reliability of the vehicular swept path data, is equal to or higher than a map reliability, which is a reliability of the electronic map data,

wherein when it is determined by the first determining unit that the swept path reliability is equal to or higher than the map reliability, the correction information computing unit compares the vehicular swept path data with the electronic map data to compute the correction information of the each predetermined block, the first correcting unit corrects the electronic map data using the correction information, and the map data providing unit provides the corrected electronic map data.

4. The map data providing device of claim 3,

wherein the vehicle position detecting unit detects the absolute position by receiving radio waves transmitted from GPS satellites, and

wherein the first determining unit determines whether or not the swept path reliability is equal to or higher than the map reliability, wherein the swept path reliability is defined using information indicating a distribution of the GPS satellites contained in the received radio waves, wherein the map reliability is defined using plane position standard deviation that represents an error in plane position observed during surveying for the electronic map data.

5. The map data providing device of claim 1, comprising:

a second determining unit configured to determine whether or not the vehicular swept path in the block corresponding to the absolute position of the vehicle is contained in the vehicular swept path data;

a block selecting unit configured, when it is determined by the second determining unit that the vehicular swept path corresponding to the absolute position of the vehicle is not contained in the vehicular swept path data, to select three or more blocks that exist around the absolute position of the vehicle and have the correction information;

an interpolating unit configured to interpolate the correction information of the blocks selected by the block selecting unit to obtain the correction information for the absolute position of the vehicle;

a second correcting unit configured to correct electronic map data using the correction information obtained by interpolating by the interpolating unit; and

a second map data providing unit configured to provide the electronic map data corrected by the second correcting unit.

6. The map data providing device of claim 5, comprising:

a third determining unit configured to determine whether or not a reliability of the electronic map data is lower than a predetermined reference value,

wherein when it is determined by the second determining unit that the vehicular swept path corresponding to the absolute position of the vehicle is not contained in the vehicular swept path data and it is determined by the third determining unit that the reliability of the electronic map data is lower than the predetermined reference value, the block selecting unit selects three or more blocks that exist around the absolute position of the vehicle and have the correction information.

7. The map data providing device of claim 5, comprising:

a fourth determining unit configured to determine whether or not blocks selected by the block selecting unit exist in a predetermined range relative to the absolute position of the vehicle,

wherein when it is determined by the fourth determining unit that the blocks selected by the block selecting unit exist in the predetermined range, the interpolating unit interpolates the correction information of the blocks selected by the block selecting unit to obtain the correction information for the absolute position of the vehicle.

8. The map data providing device of claim 5, comprising:

a transmitting unit configured to transmit the correction information computed by the correction information computing unit to a central facility; and

a correction information requesting unit configured to request the correction information from the central facility at which the correction information transmitted by the transmitting unit is accumulated,

wherein the interpolating unit interpolates the correction information transmitted from the central facility in response to the request from the correction information requesting unit to obtain the correction information for the absolute position of the vehicle, and

wherein the second correcting unit corrects the electronic map data using the correction information transmitted from the central facility in response to the request from the correction information requesting unit.

9. A method for correcting map data, comprising:

detecting an absolute positions of a vehicle;

storing absolute positions of the vehicle detected while the vehicle runs as vehicular swept path data pertaining to the vehicle;

comparing the vehicular swept path data with electronic map data representing a road map to thereby compute correction information representing an amount of deviation of the electronic map data from the vehicular swept path data with respect to each predetermined block;

correcting the electronic map data using the computed correction information; and

providing the corrected electronic map data.