Detecting device and railroad vehicle

• US 7,956,796 B2
• Filed: 05/06/2009
• Issued: 06/07/2011
• Est. Priority Date: 08/01/2008
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Kato, Naoki, Oho, Shigeru, Hyodo, Akihiko
• Primary Examiner(s): Gregory; Bernarr E
• Application Number:
  US12/453,304
• Publication Number:
  US 20100026562A1
• Time in Patent Office: 762 Days
• Field of Search: 342 1- 11, 342 27- 51, 342 61- 65, 342 70- 72, 342/118, 342/125, 342/175, 342/195, 342450-465, 180167-169
• US Class Current: 342/46
• CPC Class Codes: B61L 25/025 Absolute localisation, e.g. providing geodetic coordinates
• CPC Class Codes: B61L 25/026 Relative localisation, e.g. using odometer
• CPC Class Codes: G01S 13/04 Systems determining presence of a target based on relative movement of target G01S13/56
• CPC Class Codes: G01S 13/88 Radar or analogous systems specially adapted for specific applications electromagnetic prospecting or detecting of objects, e.g. near-field detection, G01V3/00
• CPC Class Codes: G01S 7/412 based on a comparison between measured values and known or stored values

Abstract

A system according to the invention detects location information of a vehicle by using a reflection strength change of an electromagnetic wave. The system incorporates a radiowave transmitter which emits a first radiowave, positional markers which generate unique reflection strengths and patterns of temporal changes in the reflection strength from the emitted first radiowave at respective absolute positions, a radiowave receiver which receives a second radiowave reflected by the positional marker and converts the second radiowave into a signal format for extracting location information to output the same, and a marker recognition device which obtains a location of the vehicle from the output of the radiowave receiver. Accordingly, a highly-precise location specification with a resolution smaller than or equal to 1 cm and a highly-reliable location specification which is not affected by slip and slide of the vehicle'"'"'s wheels can be realized.

Claims

1. A detection device mounted on a vehicle for detecting location information of the vehicle, the detection device comprising:

a radiowave transmitter emitting a first radiowave;

a radiowave receiver receiving a second radiowave that is a radiowave reflected by hitting against an object; and

a recognition device detecting the location information of the vehicle based on changes in a radio field strength of the second radiowave.

2. The detection device according to claim 1, wherein the first radiowave is an electromagnetic wave of a millimeter wave band.

3. The detection device according to claim 1, wherein the radiowave receiver includes a rectifier and smoothing circuit, and converts the second radiowave into a DC (Direct Current) signal by the rectifier and smoothing circuit to output the same.

4. The detection device according to claim 1, wherein the recognition device includes a location information table containing installation position information of the object, and compares the changes in radio field strength of the second radiowave and the location information table to detect a position information of the vehicle.

5. The detection device according to claim 1, wherein the recognition device includes a location information table containing installation position information of the object, and refers to the location information table with indexing by a data stream obtained from the changes in the radio field strength of the second radiowave to specify a location of the vehicle.

6. The detection device according to claim 1, wherein the recognition device includes a location information table containing installation position information of the object, and classifies the changes in the radio field strength of the second radiowave into a plurality of radio field strength levels with taking a predetermined threshold as a criterion, counts a number of times the changes in the radio field strength of the second radiowave is classified to a specific radio field strength level, and refers to the location information table with indexing by the counted number to specify a location of the vehicle.

7. The detection device according to claim 1, wherein the object is a plurality of radiowave reflecting materials separately arranged along a track of the vehicle.

8. The detection device according to claim 1, wherein the object is formed by a combination of one or more radiowave reflecting materials and one or more radiowave absorbent materials.

9. The detection device according to claim 8, wherein the object is formed with a combination of shapes of the radiowave reflecting materials and the radiowave absorbent materials different to each other.

10. The detection device according to claim 1, wherein the vehicle is a railroad vehicle or an elevator cage.

11. A railroad vehicle mounting a detection device for detecting location information, wherein the detection device comprises:

a radiowave transmitter emitting a first radiowave;

a radiowave receiver receiving a second radiowave that is a radiowave reflected by hitting against an object; and

a recognition device detecting location information of a vehicle based on changes in a radio field strength of the second radiowave.

12. The railroad vehicle according to claim 11, wherein the first radiowave is an electromagnetic wave of a millimeter wave band.

13. The railroad vehicle according to claim 11, wherein the radiowave receiver includes a rectifier and smoothing circuit, and converts the second radiowave into a DC signal by the rectifier and smoothing circuit to output the same.

14. The railroad vehicle according to claim 11, wherein the recognition device includes a location information table containing installation position information of the object, and compares the changes in the radio field strength of the second radiowave and the location information table to detect a position information of the vehicle.

15. The railroad vehicle according to claim 11, wherein the recognition device includes a location information table containing installation position information of the object, and refers to the location information table with indexing by a data stream obtained from the changes in the radio field strength of the second radiowave to specify a location of the vehicle.

16. The railroad vehicle according to claim 11, wherein the recognition device includes a location information table containing installation position information of the object, and classifies the changes in the radio field strength of the second radiowave into a plurality of radio field strength levels with taking a predetermined threshold as a criterion, counts a number of times the changes in the radio field strength of the second radiowave is classified to a specific radio field strength level, and refers to the location information table with indexing by the counted number to specify a location of the vehicle.

17. The railroad vehicle according to claim 11, wherein the object is a plurality of radiowave reflecting materials separately arranged along a track of the vehicle.

18. The railroad vehicle according to claim 11, wherein the object is formed by a combination of one or more radiowave reflecting materials and one or more radiowave absorbent materials.

19. The railroad vehicle according to claim 18, wherein the object is formed with a combination of shapes of the radiowave reflecting materials and the radiowave absorbent materials different to each other.