Secure non-contact switch

• US 8,456,792 B2
• Filed: 02/05/2010
• Issued: 06/04/2013
• Est. Priority Date: 02/05/2010
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Peczalski, Andy, Kolavennu, Soumitri, Hall, Jeff, Hanson, Todd
• Primary Examiner(s): Jackson, Stephen W
• Application Number:
  US12/701,497
• Publication Number:
  US 20110193422A1
• Time in Patent Office: 1,215 Days
• Field of Search: 361/179
• US Class Current: 361/179
• CPC Class Codes: G07C 9/00309 operated with bidirectional data transmission between data carrier and locks

Abstract

A redundant non-contact switch reports a status as closed or open for a first member and a second member that move relative to each other between an open state and a closed state. In some embodiments, the redundant non-contact switch includes a wireless authentication (WA) pair and a magnetic pair. The WA pair may include a WA responder attached to one of the first member and the second member, and a WA interrogator attached to the other of the first member and the second member. The WA pair may be configured to register a WA status of closed or open, depending on a WA authentication between the WA responder and the WA interrogator. The magnetic pair may include a magnet attached to one of the first member and the second member, and a magnet sensor attached to the other of the first member and the second member. The magnetic pair may be configured to register a magnetic status of closed or open, depending on whether a magnet distance between the magnet and magnet sensor is beyond a threshold magnet distance. In some instances, the redundant non-contact switch reports the status as closed only if both the WA status is registered as closed and the magnetic status is registered as closed.

Claims

1. A redundant non-contact switch for reporting a status as closed or open for a first member and a second member that move relative to each other between an open state and a closed state, comprising:

a wireless authentication (WA) pair, including;

a WA responder attached to one of the first member and the second member;

a WA interrogator attached to the other of the first member and the second member;

the WA pair configured to register a WA status of closed or open, depending on a WA authentication between the WA responder and the WA interrogator;

a magnetic pair, including;

a magnet attached to one of the first member and the second member;

a magnet sensor attached to the other of the first member and the second member;

the magnetic pair configured to register a magnetic status of closed or open, depending on whether a magnet distance between the magnet and magnet sensor is beyond a threshold magnet distance; and

the redundant non-contact switch configured to report the status as closed only if both the WA status is registered as closed and the magnetic status is registered as closed.

2. The redundant non-contact switch of claim 1, wherein the WA responder requires operational power to perform the WA authentication.

3. The redundant non-contact switch of claim 2, wherein the WA responder wirelessly receives operational power from the WA interrogator, wherein sufficient operational power is received by the WA responder only when a WA distance between the WA responder and the WA interrogator is below a threshold WA distance.

4. The redundant non-contact switch of claim 2, wherein the WA responder, WA interrogator, magnet, and magnet sensor are arranged on the first member and second member such that the magnet distance and WA distance vary as the first member and second member move between the open and closed states.

5. The redundant non-contact switch of claim 1, wherein the magnet sensor includes a magnetically-actuated switch that registers a magnetic status of closed when the magnet is brought within the threshold magnet distance of the magnetically-actuated switch, and a magnetic status of open when the magnet is moved away from the magnetically-actuated switch by more than the threshold magnet distance.

6. The redundant non-contact switch of claim 5, wherein the magnetically-actuated switch, when closed, allows power to be provided to the WA interrogator, and when open, does not allow power to be provided to the WA interrogator.

7. The redundant non-contact switch of claim 1, wherein:

the WA interrogator and the magnet sensor are both attached to the same one of the first member or second member;

the WA responder and the magnet are both attached to the other one of the first member or second member; and

the magnet sensor is configured to allow transmission of a signal by the WA interrogator when the magnetic status is registered closed, and to prevent transmission by the WA interrogator when the magnetic status is registered open.

8. The redundant non-contact switch of claim 1, wherein:

the WA interrogator and the magnet are both attached to the same one of the first member or second member;

the WA responder and the magnet sensor are both attached to the other one of the first member or second member; and

the magnet sensor is configured to allow reception of a signal by the WA responder when the magnetic status is registered closed, and to prevent reception by the WA responder when the magnetic status is registered open.

9. The redundant non-contact switch of claim 1, wherein the WA interrogator includes an inductive power transmit coil and the WA responder includes an inductive power receive coil.

10. The redundant non-contact switch of claim 9, wherein the magnetic pair is configured to allow power transmission from the inductive power transmit coil of the WA interrogator to the inductive power receive coil of the WA responder when the magnetic status is registered closed, and to prevent power transmission from the inductive power transmit coil of the WA interrogator to the inductive power receive coil of the WA responder when the magnetic status is registered open.

11. A secure non-contact switch, comprising:

a wireless authentication (WA) pair including a WA responder and a WA interrogator, the WA pair configured to register a WA status of closed or open, the WA status depending on a WA authentication between the WA responder and the WA interrogator; and

a magnetic pair including a magnet and a magnet sensor, the magnetic pair configured to register a magnetic status of closed or open, the magnetic status depending on a magnet distance between the magnet and magnet sensor;

the secure non-contact switch configured to report a closed status only if both the WA status is registered as closed and the magnetic status is registered as closed.

12. The secure non-contact switch of claim 11, wherein the WA authentication depends, in part, on a WA distance between the WA responder and the WA interrogator.

13. The secure non-contact switch of claim 12, wherein the WA responder requires operational power to perform the WA authentication.

14. The secure non-contact switch of claim 13, wherein the WA responder wirelessly receives operational power from the WA interrogator, wherein sufficient operational power is received by the WA responder only when a WA distance between the WA responder and the WA interrogator is below a threshold WA distance.

15. The secure non-contact switch of claim 11, wherein the magnet sensor is configured to affect the operation of the WA pair.

16. A method for redundantly assessing an open or closed status of a non-contact switch, the non-contact switch including a wireless authentication (WA) pair that includes a WA responder and a WA interrogator, and a magnetic pair that includes a magnet and a magnet sensor, the method comprising:

registering a magnetic status of the magnet pair as open or closed;

attempting a WA authentication if the magnetic status is closed and preventing the WA authentication if the magnetic status is open, the attempting step including the steps of;

broadcasting a interrogation signal from the WA interrogator;

receiving the interrogation signal by the WA responder;

replying with a response signal by the WA responder after receiving the interrogation signal;

receiving the response signal by the WA interrogator; and

determining if the response signal matches a known identification code; and

reporting the status of the non-contact switch as closed only if the response signal matches the known identification code.

17. The method of claim 16, wherein the magnet sensor includes a magnetic relay switch, and the preventing step includes having the magnetic relay switch prevent at least one of the steps of broadcasting the interrogation signal and receiving the interrogation signal.

18. The method of claim 16, wherein the registering step includes finding the magnetic status to be closed if the magnet is within a threshold distance of the magnet sensor.

19. The method of claim 16, wherein the step of broadcasting a interrogation signal includes powering an inductive power transmit coil, and the step of receiving the interrogation signal includes receiving energy inductively with an inductive power receive coil from the inductive power transmit coil, the receiving energy being sufficient to power the step of replying with the response signal.

20. The method of claim 16, wherein the non-contact switch further includes a bypass disarming key having a bypass WA responder with a bypass identification code, and further wherein the step of reporting the status of the non-contact switch further includes reporting the status of the non-contact switch as closed if the non-contact switch determines that a response signal from the bypass WA responder matches a known bypass identification code.

21. The method of claim 16, further comprising the step of logging information about one or more attempted status changes of the non-contact switch.

22. A redundant non-contact interlock switch for reporting an interlock status as closed or open for a first member and second member that move relative to each other between an open state and a closed state, comprising:

a magnetic switch that is registered as closed when the first member and the second member are in the closed state;

a wireless authentication (WA) pair including a WA responder and a WA interrogator, the WA pair registered as closed when;

the first member and the second member are in the closed state; and

the WA responder and the WA interrogator successfully complete a WA authentication; and

the redundant non-contact interlock switch is configured to report the interlock status as closed only if both the WA pair is registered as closed and the magnetic status is registered as closed.

23. A secure non-contact switch, comprising:

an inductive power transmission pair including an inductive power transmit coil and an inductive power receive coil, the inductive power receive coil only receiving sufficient operational power from the inductive power transmit coil when the transmit and receive coils are positioned within a threshold distance of each other; and

a wireless authentication (WA) pair including a WA interrogator and a WA responder, the WA responder requiring sufficient operational power from the inductive power receive coil to provide an authenticating response to an interrogation from the WA interrogator;

the secure non-contact switch reporting a status of closed only if the authenticating response received by the WA interrogator from the WA responder matches an expected authenticating response.