System and Method for Monitoring Relay Contacts

Patent metadata

Field	Value
Publication number	US-2015137819-A1
Application number	US-201414520473-A
Country	US
Kind code	A1
Filing date	Oct 22, 2014
Priority date	Oct 31, 2013
Publication date	May 21, 2015
Grant date	—

Abstract

A system and method are disclosed for monitoring at least one relay contact. The system may include an emitter adapted for communication with a relay contact and configured to emit a signal, and a receiver adapted for communication with the relay contact and configured to detect a signal emitted by the emitter. The system may further include a controller adapted for communication with the emitter and receiver, and configured to determine an open or closed state of the relay contact. The controller may control the emitter to emit a signal, may determine a closed state of the relay contact if the receiver detects the signal, and may determine an open state of the relay contact if the receiver fails to detect the signal.

First claim

What is claimed is:

1 . A system for monitoring at least one relay contact, the system comprising:
an emitter adapted for communication with a first side of a first relay contact and configured to emit a signal; a first receiver adapted for communication with a second side of the first relay contact and configured to detect a signal emitted by the emitter; and a controller adapted for communication with the emitter and the first receiver, the controller configured to determine an open or a closed state of the first relay contact; wherein the controller controls the emitter to emit a signal, the controller determines a closed state of the first relay contact if the first receiver detects the signal, and the controller determines an open state of the first relay contact if the first receiver fails to detect the signal.

2 . The system of claim 1 wherein the controller controls the emitter to emit the signal around a rail voltage of the first relay contact after a relay coil is driven in order to open the first relay contact or prior to closing the first relay contact.

3 . The system of claim 1 wherein the emitter is further adapted for communication with a first side of a second relay contact, the system further comprising:
a second receiver adapted for communication with a second side of the second relay contact and configured to detect a signal emitted by the emitter, wherein a signal emitted by the emitter comprises a first component and a second component different than the first component;
wherein the controller is further adapted for communication with the second receiver and configured to determine an open or a closed state of the second relay contact, and wherein the controller controls the emitter to emit a signal, the controller determines a closed state of the second relay contact if the second receiver detects the signal, and the controller determines an open state of the second relay contact if the second receiver fails to detect the signal.

4 . The system of claim 3 wherein the first component has a first frequency, the second component has a second frequency different than the first frequency, the first receiver is configured to detect the first component, and the second receiver is configured to detect the second component.

5 . The system of claim 3 wherein the signal comprises first and second signals, the first signal having the first component and the second signal having the second component, the first receiver is configured to detect the first component, and the second receiver is configured to detect the second component.

6 . The system of claim 3 wherein the first component has a first amplitude, the second component has a second amplitude different than the first amplitude, the first receiver is configured to detect the first component, and the second receiver is configured to detect the second component.

7 . The system of claim 3 wherein the first component has a first digital identifier, the second component has a second digital identifier different than the first digital identifier, the first receiver is configured to detect the first component, and the second receiver is configured to detect the second component.

8 . A system for monitoring a first relay contact and a second relay contact, each of the first and second relay contacts having a first side and a second side, the system comprising:
an emitter adapted for communication with the first side of each of the first and second relay contacts and configured to emit a signal; a receiver adapted for communication with the second side of each of the first and second relay contacts and configured to detect a signal emitted by the emitter; and a controller adapted for communication with the emitter and the receiver, the controller configured to determine an open or a closed state of each of the first and second relay contacts; wherein the controller controls the emitter to emit a signal having a first component and a second component different than the first component, the controller determines a closed state of the first relay contact and an open state of the second relay contact if the receiver detects only the second component of the signal, the controller determines a closed state of the second relay contact if the receiver detects the first component of the signal, and the controller determines an open state of both the first relay contact and the second relay contact if the receiver fails to detect both the first and second components of the signal.

9 . The system of claim 8 wherein the first component of the signal has a frequency that is substantially attenuated by a battery and/or a DC-link impedance, and the second component of the signal has a frequency that is non-substantially attenuated by a battery and a DC-link impedance.

10 . The system of claim 9 wherein the first component is a lower frequency signal, L(f), the second component is a higher frequency signal, H(f), and the frequency of the signal emitted by the emitter, S(f), is defined by the equation S(f)=L(f)+H(f).

11 . The system of claim 10 wherein a signal detected by the receiver, R(f), is defined by the equation R(f)=K 2 *L(f)+K 2 *H(f)+K 1 *H(f), where K i =0 if a relay has an open state and K i =1 if a relay has a closed state, for i=1, 2.

12 . A method for monitoring at least one relay contact, the method comprising:
emitting a signal; determining a closed state of a first relay contact if a first receiver detects the signal; and determining an open state of the first relay contact if the first receiver fails to detect the signal.

13 . The method of claim 12 wherein the signal is emitted around a rail voltage of the first relay contact after a relay coil is driven to open the first relay contact or prior to closing the first relay contact.

14 . The method of claim 12 further comprising:
determining a closed state of a second relay contact if a second receiver detects the signal; and
determining an open state of the second relay contact if the second receiver fails to detect the signal;
wherein the signal comprises a first component and a second component different than the first component.

15 . The method of claim 14 wherein the first component has a first frequency, the second component has a second frequency different than the first frequency, the first receiver is configured to detect the first component, and the second receiver is configured to detect the second component.

16 . The method of claim 14 wherein the signal comprises first and second signals, the first signal having the first component and the second signal having the second component, the first receiver is configured to detect the first component, and the second receiver is configured to detect the second component.

17 . The method of claim 14 wherein the first component has a first amplitude, the second component has a second amplitude different than the first amplitude, the first receiver is configured to detect the first component, and the second receiver is configured to detect the second component.

18 . The method of claim 14 wherein the first component has a first digital identifier, the second component has a second digital identifier different than the first digital identifier, the first receiver is configured to detect the first component, and the second receiver is configured to detect the second component.

19 . A method for monitoring a first relay contact and a second relay contact, the method comprising:
emitting a signal having a first component a

Assignees

• Lear Corp

Inventors

• Giordano Federico
• Ferre Fabregas Antoni

Classifications

• H01H1/0015

  Means for testing or for inspecting contacts, e.g. wear indicator (measuring circuits G01R31/3274) · CPC title

• G01R31/333

  Testing of the switching capacity of high-voltage circuit-breakers {; Testing of breaking capacity or related variables, e.g. post arc current or transient recovery voltage} · CPC title

• G01R31/327

  Testing of circuit interrupters, switches or circuit-breakers · CPC title

• G01R31/3278 Primary

  of relays, solenoids or reed switches (measuring contact resistance G01R27/205; high voltage magnetic switches G01R31/3271, G01R31/333; testing electric windings G01R31/72; monitoring of fail safe circuits H01H47/002) · CPC title

• G01R31/006

  on road vehicles, e.g. automobiles or trucks (testing of ignition installations peculiar to internal combustion engines F02P17/00) · CPC title