Method and apparatus for estimating behaviors of vehicle using GPS signals

• US 20080027645A1
• Filed: 07/26/2007
• Published: 01/31/2008
• Est. Priority Date: 07/26/2006
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Fujii, Takehito, Tanaka, Hiromichi, Sawada, Mamoru, Okada, Minoru
• Granted Patent: US 7,885,765 B2
• Time in Patent Office: Days
• US Class Current: 701/215
• CPC Class Codes: G01C 21/28 with correlation of data from several navigational instruments

Abstract

A method and an apparatus for estimating behaviors of a vehicle are provided. At least two GPS antennas are located along a longitudinal axis of a vehicle so that speed vectors at the positions where the GPS antennas are located can be determined based on GPS signals received by the GPS antennas. The speed vectors are known to be estimated with high accuracy based on the GPS signals. The positions of the GPS antennas on the local coordinate system are estimated based on such highly accurate speed vectors, so that the estimated positions may also have high accuracy. Based on a line connecting these highly accurate positions of the GPS antennas, an inclination of the longitudinal axis of the vehicle is estimated. Use of the high-accuracy speed vectors enables high-accuracy estimation on the positions of the GPS antennas and the vehicle direction on the local coordinate system.

Claims

1. A method of estimating a direction along which a vehicle runs, the method comprising steps of:

calculating speed vectors at two or more mutually-different positions of the vehicle, respectively, by using GPS (Global Positioning System) signals received by two or more GPS antennas located at the mutually different positions of the vehicle;

calculating positions of the GPS antennas in a local geodetic coordinate on the basis of the calculated speed vectors, the positions of the GPS antennas corresponding to the speed vectors; and

calculating the direction of the vehicle in the local based on the estimated positions of the GPS antennas.

2. The estimating method of claim 1, wherein the two or more mutually-different positions of the vehicle are two positions consisting of a front-side position of the vehicle and a read-side position of the vehicle and the GPS antennas are two in number.

3. The estimating method of claim 2, further comprising a step of calculating reference positions of the GPS antennas by using the calculated speed vectors,

wherein the position calculating step calculates the positions of the GPS antennas in the local geodetic coordinate by integrating the calculated speed vectors with respect to a unit time and displacing the reference positions of the GPS antennas, respectively, by amounts of the integrated speed vectors, the displaced positions corresponding respectively to the positions of the GPS antennas in the local geodetic coordinate.

4. The estimating method of claim 3, further comprising a step of determining whether or not each of the calculated speed vectors is within a predetermined threshold range

wherein, when it is determined that the each of the calculated speed vectors is within a predetermined threshold range, the reference position calculating step includes a step of i) setting a predetermined position of the local geodetic coordinate to a first reference position of one of the two GPS antennas and ii) setting a second reference position of the other of the two GPS antennas by displacing the first position-being-referenced by a distance between the two GPS antennas toward the other GPS antenna from the first position-being-referenced along a direction of the calculated speed vectors.

5. The estimating method of claim 1, further comprising a step of calculating an area spatially occupied in the local geodetic coordinate based on both the calculated direction of the vehicle and a parameter indicative of at least a size of the vehicle.

6. The estimating method of claim 2, further comprising a step of calculating an area spatially occupied in the local geodetic coordinate based on both the calculated direction of the vehicle and a parameter indicative of at least a size of the vehicle.

7. The estimating method of claim 3, further comprising a step of calculating an area spatially occupied in the local geodetic coordinate based on both the calculated direction of the vehicle and a parameter indicative of at least a size of the vehicle.

8. The estimating method of claim 4, further comprising a step of calculating an area spatially occupied in the local geodetic coordinate based on both the calculated direction of the vehicle and a parameter indicative of at least a size of the vehicle.

9. A method of estimating a direction along which a vehicle runs, the method comprising steps of:

calculating speed vectors at two or more mutually-different positions of the vehicle, respectively, by using GPS (Global Positioning System) signals received by two or more GPS antennas located at the mutually different positions of the vehicle; and

calculating the direction of the vehicle in a local geodetic coordinate by performing calculation based on a formula of;

10. The estimating method of claim 9, further comprising a step of calculating reference positions of the GPS antennas by using the calculated speed vectors,

wherein the direction calculating means calculates the direction of the vehicle in the local geodetic coordinate by performing calculation based on a formula of:

11. The estimating method of claim 9, further comprising a step of calculating an area spatially occupied in the local geodetic coordinate based on both the calculated direction of the vehicle and a parameter indicative of at least a size of the vehicle.

12. The estimating method of claim 10, further comprising a step of calculating an area spatially occupied in the local geodetic coordinate based on both the calculated direction of the vehicle and a parameter indicative of at least a size of the vehicle.

13. An apparatus for estimating a direction along which a vehicle runs, comprising:

a speed calculating block calculating speed vectors at two or more mutually-different positions of the vehicle, respectively, by using GPS (Global Positioning System) signals received by two or more GPS antennas located at the mutually different positions of the vehicle;

a position calculating block calculating positions of the GPS antennas in a local geodetic coordinate on the basis of the calculated speed vectors, the positions of the GPS antennas corresponding to the speed vectors; and

a direction calculating block calculating the direction of the vehicle in the local based on the estimated positions of the GPS antennas.

14. The apparatus of claim 13, wherein the two or more mutually-different positions of the vehicle are two positions consisting of a front-side position of the vehicle and a read-side position of the vehicle and the GPS antennas are two in number.

15. An apparatus for estimating a direction along which a vehicle runs, comprising:

a calculating block calculating speed vectors at two or more mutually-different positions of the vehicle, respectively, by using GPS (Global Positioning System) signals received by two or more GPS antennas located at the mutually different positions of the vehicle; and

a calculating block calculating the direction of the vehicle in a local geodetic coordinate by performing calculation based on a formula of;