Detecting device and railroad vehicle

• US 20100026562A1
• Filed: 05/06/2009
• Published: 02/04/2010
• Est. Priority Date: 08/01/2008
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Kato, Naoki, Oho, Shigeru, Hyodo, Akihiko
• Granted Patent: US 7,956,796 B2
• Time in Patent Office: Days
• US Class Current: 342/189
• 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

Location information of a vehicle such as a railroad vehicle and an elevator cage is detected by using a reflection strength change of an electromagnetic wave. A system is configured by 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 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 a change pattern of 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 radio field strength change pattern 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 change pattern of 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 change pattern of 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 change pattern of 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 a change pattern of 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 change pattern of 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 change pattern of 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 change pattern of 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 change pattern of 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.