Systems and methods for solenoid state determination

Patent metadata

Field	Value
Publication number	US-9640311-B1
Application number	US-201615006351-A
Country	US
Kind code	B1
Filing date	Jan 26, 2016
Priority date	Jan 26, 2016
Publication date	May 2, 2017
Grant date	May 2, 2017

Abstract

Systems and methods for controlling a solenoid may include measuring a current flowing through a solenoid, and detecting characteristics of the current flowing through the solenoid. The characteristics may be used to determine a state of the solenoid. Characteristics of the current comprise may include local extrema of the current, rate of change of the current, and/or discrete values of the current. The solenoid may comprise a bistable device.

First claim

What is claimed is:

1. A method for controlling a solenoid, comprising:
measuring a current flowing through the solenoid;
detecting characteristics of the current flowing through the solenoid to determine a state of the solenoid;
applying an electric signal to the solenoid to activate the solenoid; and
ending the electric signal to the solenoid in response to the characteristics of the current flowing through the solenoid indicating the state of the solenoid, wherein the state of the solenoid indicates that the solenoid has changed position.

2. The method of claim 1 , wherein the characteristics of the current comprise at least one of a local extrema of the current, a rate of change of the current, or a discrete value of the current.

3. The method of claim 1 , further comprising identifying a first derivative of the current to detect the solenoid is moving.

4. The method of claim 1 , wherein the solenoid comprises a bistable device.

5. A brake control system, comprising:
a control unit; and
a solenoid electronically coupled to the control unit,
wherein the control unit is configured to monitor a current passing through the solenoid,
wherein the control unit is configured to detect characteristics of the current flowing through the solenoid to determine a state of the solenoid,
wherein the solenoid is configured to move in response to the control unit turning on an electric signal; and
wherein the state of the solenoid indicates that the solenoid has changed position.

6. The brake control system of claim 5 , wherein the solenoid comprises a bistable device.

7. The brake control system of claim 6 , wherein the control unit comprises a memory and a processor.

8. The brake control system of claim 6 , further comprising an electromechanical actuator (EMA) mechanically coupled to the solenoid, wherein the solenoid is configured to lock the EMA.

9. The brake control system of claim 8 , further comprising a brake stack, wherein the solenoid is configured to lock the EMA with the EMA applying a force to the brake stack.

10. An article of manufacture including a non-transitory, tangible computer readable storage medium having instructions stored thereon that, in response to execution by a processor, cause a brake system to perform operations comprising:
measuring a current flowing through a solenoid;
detecting characteristics of the current flowing through the solenoid to determine a state of the solenoid; and
applying an electric signal to the solenoid to activate the solenoid, wherein the state of the solenoid is changing positions.

11. The article of claim 10 , wherein the state of the solenoid indicates that the solenoid has changed position.

12. The article of claim 10 , wherein the characteristics of the current comprise at least one of a local extrema of the current, a rate of change of the current, or a discrete value of the current.

13. The article of claim 10 , wherein the solenoid comprises a bistable device.

Assignees

• Goodrich Corp

Inventors

• Kordik Michael
• Summers Paul

Classifications

• H01F7/1844 Primary

  Monitoring or fail-safe circuits (for relays H01H47/002) · CPC title

• B60T8/1703

  for aircrafts · CPC title

• H01F7/064 Primary

  Circuit arrangements for actuating electromagnets (circuit arrangements for obtaining special operating characteristics H01F7/18; driving circuits for electromagnets making use of a switching regulator H01H47/325) · CPC title

• B60T2270/406

  Test-mode; Self-diagnosis · CPC title