Elevator car position detection device

Patent metadata

Field	Value
Publication number	US-10399817-B2
Application number	US-201314654977-A
Country	US
Kind code	B2
Filing date	Mar 1, 2013
Priority date	Mar 1, 2013
Publication date	Sep 3, 2019
Grant date	Sep 3, 2019

Abstract

In an elevator car position detection device, a magnetic field generator generates an eddy current magnetic field on an identification member, and a magnetic field detector detects the eddy current magnetic field generated on the identification member. The identification member includes a plurality of conductors which are continuously arranged along an ascending and descending direction of a car, and are relatively different in a plate thickness with respect to a skin depth of an eddy current generated by the magnetic field generator on the identification member. A shape of at least a part of a boundary between the adjacent conductors is a straight line or a curve tilted with respect to a direction orthogonal to the ascending and descending direction of the car.

First claim

The invention claimed is:

1. An elevator car position detection device being configured to detect a position of a car by detecting an identification member by a sensor, wherein:
the sensor comprises a magnetic field generator configured to generate an eddy current magnetic field on the identification member and to output a current waveform, a magnetic field detector configured to detect a magnetic field including the eddy current magnetic field generated in the identification member and to output a voltage waveform that includes an eddy current magnetic field component corresponding to the eddy current magnetic field, and a signal processing part connected to the magnetic field detector, wherein the signal processing part includes
an AC magnetic field component removal circuit configured to extract the eddy current magnetic field component from the voltage waveform output by the magnetic field detector and to output a voltage of the eddy current magnetic field component and
a phase difference detection circuit configured to receive the voltage of the eddy current magnetic field component from the AC magnetic field component removal circuit, to receive the output current waveform from the magnetic field generator, and to detect a difference between a phase of the voltage of the eddy current magnetic field component and a phase of the current waveform received from the magnetic field generator;

the identification member comprises a plurality of conductors which are arranged along an ascending and descending direction of the car, and are relatively different in a plate thickness with respect to a skin depth of an eddy current generated by the magnetic field generator on the identification member;
and
the signal processing part identifies, when the sensor detects the identification member, in which of ranges of the plurality of conductors of the identification member the car is positioned based on (1) information on an amplitude of the eddy current magnetic field acquired from an output of the magnetic field detector, and (2) a value of the difference, detected by the phase difference detection circuit, between the phase of the voltage of the eddy current magnetic field component and the phase of the current waveform received from the magnetic field generator.

2. The elevator car position detection device according to claim 1 , wherein the plurality of conductors comprise a conductor larger in the skin depth of the eddy current with respect to the plate thickness and a conductor smaller in the skin depth of the eddy current with respect to the plate thickness.

3. The elevator car position detection device according to claim 1 , wherein the skin depths of the eddy current of the plurality of conductors are changed by using different metal species as materials.

4. The elevator car position detection device according to claim 1 , wherein the boundary comprises a region of an n-th order curve, provided that n≥1.

5. The elevator car position detection device according to claim 1 , wherein the boundary comprises a protruding region that protrudes in the ascending and descending direction of the car at an intermediate part in the direction orthogonal to the ascending and descending direction of the car.

6. The elevator car position detection device according to claim 5 , wherein the protruding region is bilaterally symmetrical.

7. The elevator car position detection device according to claim 5 , wherein a region of the boundary other than the protruding region is parallel with the direction orthogonal to the ascending and descending direction of the car.

8. The elevator car position detection device according to claim 1 , wherein:
a mounting part is mounted on an end of the identification member in the direction orthogonal to the ascending and descending direction of the car, the mounting part being configured to fix the identification member to a hoistway; and
a part in which the plurality of conductors are absent is formed in the end of the identification member on the mounting part side.

9. An elevator car position detection device comprising:
an identification member comprising a plurality of conductors arranged along an ascending and descending direction of an elevator car;
a magnetic field generator configured to generate an eddy current magnetic field in the identification member and to output a current waveform, the plurality of conductors being relatively different in a plate thickness with respect to a skin depth of an eddy current generated by the magnetic field generator on the identification member;
a magnetic field detector configured to detect a magnetic field including the eddy current magnetic field generated in the identification member and to output a voltage waveform that includes an eddy current magnetic field component corresponding to the eddy current magnetic field; and
a signal processing part connected to the magnetic field detector, wherein the signal processing part includes
an AC magnetic field component removal circuit configured to extract the eddy current magnetic field component from the voltage waveform output by the magnetic field detector and to output a voltage of the eddy current magnetic field component; and
a phase difference detection circuit configured to receive the voltage of the eddy current magnetic field component from the AC magnetic field component removal circuit, to receive the current waveform from the magnetic field generator, and to detect a difference between a phase of the voltage of the eddy current magnetic field component and a phase of the current waveform received from the magnetic field generator,

and
wherein the signal processing part identifies, when the magnetic field detector detects the eddy current magnetic field generated in the identification member, in which of ranges of the plurality of conductors of the identification member the car is positioned based on (1) information on an amplitude of the eddy current magnetic field acquired from an output of the magnetic field detector, and (2) a value of the difference, detected by the phase difference detection circuit, between the phase of the voltage of the eddy current magnetic field component and the phase of the current waveform received from the magnetic field generator.

10. The elevator car position detection device according to claim 9 , wherein the plurality of conductors comprise a conductor larger in the skin depth of the eddy current with respect to the plate thickness and a conductor smaller in the skin depth of the eddy current with respect to the plate thickness.

11. The elevator car position detection device according to claim 9 , wherein the skin depths of the eddy current of the plurality of conductors are changed by using different metal species as materials.

12. The elevator car position detection device according to claim 9 , wherein the boundary comprises a region of an n-th order curve, provided that n≥1.

13. The elevator car position detection device according to claim 9 , wherein the boundary comprises a protruding region that protrudes in the ascending and descending direction of the car at an intermediate part in the direction orthogonal to the ascending and descending direction of the car.

14. The elevator car position detection device according to claim 13 , wherein the protruding region is bilaterally symmetrical.

15. The elevator car position detection device according to claim 13 , wherein a region of the boundary other than the protruding region is parallel with the direction orthogonal to the ascending and descending direction of the car.

16. The elevator

Assignees

• Mitsubishi Electric Corp

Inventors

• Inoue Jin
• Kurata Emiko
• Watanabe Yoshimasa
• Shiratsuki Akihide
• Nishizawa Hiroshi
• Nakajima Hajime
• Ishikawa Masahiro

Classifications

• H03K2017/9706

  Inductive element · CPC title

• G01D5/2053

  by a movable non-ferromagnetic conductive element · CPC title

• B66B3/02 Primary

  Position or depth indicators · CPC title

• B66B1/40

  and for correct levelling at landings · CPC title

• B66B1/3492 Primary

  Position or motion detectors or driving means for the detector (B66B1/40, B66B1/50 take precedence; length measuring G01B; speed measuring G01P) · CPC title