Self-position identification apparatus and self-position identification method

• US 7,489,255 B2
• Filed: 06/17/2005
• Issued: 02/10/2009
• Est. Priority Date: 06/17/2004
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Sonoura, Takafumi
• Primary Examiner(s): Zimmerman; Brian A
• Assistant Examiner(s): Syed; Nabil H
• Application Number:
  US11/154,570
• Publication Number:
  US 20050283309A1
• Time in Patent Office: 1,334 Days
• Field of Search: 340/825.36, 340/825.49, 340/825.34, 340/572.1, 340/5.2, 318/568.12, 318/568.16, 700/253, 700/254, 901/46, 701/207, 701/209
• US Class Current: 340/8.1
• CPC Class Codes: G01S 15/89 for mapping or imaging
• CPC Class Codes: G01S 15/931 of land vehicles
• CPC Class Codes: G05D 1/0246 using a video camera in combination with image processing means
• CPC Class Codes: G05D 1/0255 using acoustic signals, e.g. ultra-sonic singals sonar systems designed for anti-collision purposes G01S15/93
• CPC Class Codes: G05D 1/0272 comprising means for registering the travel distance, e.g. revolutions of wheels measuring distance traversed on the ground by vehicles, e.g. using odometers G01C22/00

Abstract

A position identification apparatus includes a storage section storing a position-unique information database containing, each position on a field and unique information generated from the signal strength of the reflected wave at the position in association with each other, an ultrasonic transmission section originating an ultrasonic wave assigned identification information, an ultrasonic reception section receiving the reflected wave of the ultrasonic wave, a unique information generation section generating signal unique information from the reflected wave, and a position identification section making a comparison between the signal unique information generated by the unique information generation section and the unique information included in the position-unique information database and identifying the current position.

Claims

1. A self-position identification apparatus comprising:

(a) a storage device storing position association unique information associating position coordinates and unique information indicating a unique feature amount associated with the position coordinates;

(b) a transmission device transmitting a detection signal assigned identification information;

(c) a reception device receiving a reflection signal corresponding to the detection signal transmitted by said transmission device;

(d) a generation device generating signal unique information based on a unique position from the reflection signal received by said reception device; and

(e) an identification device comparing between the signal unique information generated by said generation device and the unique information associated with the position coordinates included in the position association unique information and indentifying a current position,

wherein;

(f) said identification device compares between the signal unique information generated by said generation device and the unique information included in the position association unique information stored in said storage device;

(g) the identification device calculates the correlation value indicating the correlation between the position coordinates associated with the unique information and the current position;

(h) the identification identifies the current position based on the calculated correlation value;

(i) said identification device complements a correlation value at a position different from the position coordinates from the calculated correlation value;

(j) the identification device calculates a distribution of the correlation values corresponding to the position coordinates; and

(k) the identification device identifies the crest of the distribution of the correlation values as the current position.

2. The self-position identification apparatus according to claim 1, wherein said identification device compares between the signal unique information generated by said generation device and the unique information associated with the position coordinates included in the position association unique information, and

wherein the unique information contained in the signal is closest to the unique information associated with the position.

3. The self-position identification apparatus according to claim 1, further comprising:

a filtering device removing noise from the reflection signal received by said reception device.

4. The self-position identification apparatus according to claim 3 wherein the filtering device removes noise from the reflection signal based on a reference time predetermined for an elapsed time from transmission of the detection signal by said transmission device to reception of the reflection signal by the reception device.

5. The self-position identification apparatus according to claim 4 wherein the filtering device removes noise from the reflection signal based on a plurality of reference times.

6. The self-position identification apparatus according to claim 1,wherein said transmission device includes a plurality of transmission sections annularly disposed each transmission section transmitting the detection signal having directivity and wherein

said reception device includes a plurality of reception sections annually disposed each reception section receiving the reflection signals corresponding to the detection signals transmitted from the transmission sections.

7. The self-position identification apparatus according to claim 1, wherein said transmission device includes a transmission section rotating on an axis,

wherein the transmission device transmits the detection signal having directivity at every arbitrary angle,

wherein said reception device includes a reception section rotating on the axis, and

wherein the reception device receives the reflection signal corresponding to the detection signal transmitted from said transmission section.

8. The self-position identification apparatus according to claim 1, further comprising:

a reflection device radially reflecting the detection signal transmitted from a direction and reflecting the reflection signal in the direction, wherein the detection signal transmitted from said transmission device is transmitted radially through the reflection device, and

wherein said reception device receives the reflection signal through the reflection device.

9. The self-position identification apparatus according to claim 6, wherein said storage device stores the unique information in association for each angle information indicating an angle between the reception direction receiving the reflection signal in the position coordinates and a previously stored initial direction as the position association unique information,

wherein said generation device generates signal unique information associated with angle information calculated from the reception direction receiving the reflection signal by the reception section and a reference direction of the reception section,

wherein said self-position identification apparatus further includes a device,

wherein the device compares between the signal unique information generated by said generation device and the unique information included in the position association unique information, and

wherein the device calculates a relative angle between the initial direction and the reference direction on the basis of angle information associated with the unique information closest to the generated signal unique information.

10. The self-position identification apparatus according to claim 1 wherein said storage device stores the position coordinates and the signal unique information generated by said generation device, associated with the position coordinates in association as the position association unique information.

11. The self-position identification apparatus according to claim 1, further comprising:

a removal device removing the reflection signal based on identification information of the reflection signal received by said reception device.

12. The self-position identification apparatus according to claim 11 wherein the identification information assigned to the detection signal is a signal with the transmission interval coded, and

the identification information of the reflection signal is a signal with the reception interval coded.

13. The self-position identification apparatus according to claim 1 wherein said storage device stores reference position coordinates and feature information indicating the feature of the reference position coordinates in association with each other as reference position feature information, and

wherein said self-position identification apparatus further includes:

a detection device detecting environment information at the current position;

an extraction device extracting current position feature information indicating the feature of the current position from the environment information detected by the a detection device; and

a determination device comparing between the current position feature information extracted by the extraction device and the feature information included in the reference position feature information and determining whether or not the current position is the reference position.

14. The self-position identification apparatus according to claim 1, further comprising:

an update device updating the current position identified by said identification device and the signal unique information generated by said generation device in association with each other in the position association unique information stored in said storage device.

17. The self-position identification apparatus according to claim 6, wherein each transmission section simultaneously transmits the detection signal having directivity.

15. A self-position identification method comprising:

(a) storing with a storage device position association unique information provided by associating position coordinates and unique information indicating a unique feature amount associated with the position coordinates;

(b) transmitting a detection signal assigned identification information;

(c) receiving a reflection signal corresponding to the transmitted detection signal;

(d) generating with a generation device signal unique information based on a unique position from the received reflection signal;

(e) comparing with an identification device between the generated signal unique information and the unique information associated with the position coordinates included in the position association unique information;

(f) identifying a current position;

(g) comparing the signal unique information generated by said generation device and the unique information included in the position association unique information stored in said storage device, and

(h) calculating the correlation value indicating the correlation between the position coordinates associated with the unique information and the current position; and

wherein;

(i) said identification device complements a correlation value at a position different from the position coordinates from the calculated correlation value;

(j) the identification device calculates a distribution of the correlation values corresponding to the position coordinates, and

(k) the identification device identifies the crest of the distribution of the correlation values as the current position.

16. The self-position identification method according to claim 15 wherein, when the current position is identified, the position coordinates associated with the unique information closest to the signal unique information among the pieces of the unique information included in the position association unique information is identified as the current position, while the signal unique information generated at said generation step and the unique information associated with the position coordinates included in the position association unique information are compared.