Aircraft Wheel Speed Sensor

• US 20140266156A1
• Filed: 03/13/2013
• Published: 09/18/2014
• Est. Priority Date: 03/13/2013
• Status: Active Grant

• Current Assignee: Woodward Incorporated
• Original Assignee: Woodward Incorporated
• Inventors: Warner, Stephen B.
• Granted Patent: US 9,482,686 B2
• Time in Patent Office: Days
• US Class Current: 324/163
• CPC Class Codes: G01P 3/465 by using dynamo-electro tachometers or electric generator
• CPC Class Codes: G01P 3/481 of pulse signals
• CPC Class Codes: G01P 3/488 delivered by variable reluctance detectors

Abstract

In some aspects of what is described herein, an aircraft wheel speed sensor system includes a pair of conductors coupled between an electro-mechanical system and a control system. The control system is configured to apply a carrier voltage signal to the pair of conductors and to detect a modulated current signal on the pair of conductors. The electro-mechanical system includes a stator and a rotor that moves upon rotation of an aircraft wheel. The stator includes a winding disposed about the rotor. The winding is configured to produce the modulated current signal on the pair of conductors in response to movement of the rotor. The modulated current signal has a frequency that is dependent on a rotational speed of the aircraft wheel.

Claims

1. A method of sensing aircraft wheel speed, the method comprising:

applying a carrier voltage signal to a pair of conductors coupled to a stator winding, the stator winding disposed about a rotor that moves upon rotation of an aircraft wheel, the stator winding configured to render a modulated current signal on the pair of conductors in response movement of the rotor, the modulated current signal having a frequency that is dependent on a rotational speed of the aircraft wheel; and

detecting the modulated current signal.

2. The method of claim 1, comprising isolating the modulated current signal from the carrier voltage signal.

3. The method of claim 1, wherein the carrier voltage signal is a single-frequency voltage signal.

4. The method of claim 1, wherein the modulated current signal is a variable-frequency-modulation to the carrier voltage signal.

5. The method of claim 1, wherein the frequency of the modulated current signal is temperature independent.

6. The method of claim 1, comprising:

generating a square wave logic signal having the frequency of the modulated current signal; and

providing the square wave logic signal to an aircraft control system.

7. The method of claim 1, comprising determining a speed of the aircraft wheel based on the detected modulated current signal.

8. An aircraft wheel speed sensor system comprising:

a pair of conductors coupled between an electro-mechanical system and a control system;

the control system configured to apply a carrier voltage signal to the pair of conductors and to detect a modulated current signal on the pair of conductors; and

the electro-mechanical system including;

a rotor that moves upon rotation of an aircraft wheel; and

a stator that includes a winding disposed about the rotor, the winding configured to render the modulated current signal by modulating current on the pair of conductors in response to movement of the rotor, the modulated current signal having a frequency that is dependent on a rotational speed of the aircraft wheel.

9. The aircraft wheel speed sensor system of claim 8, the stator comprising major stator teeth, the winding including a plurality of coils wound in series about the major stator teeth.

10. The aircraft wheel speed sensor system of claim 9, the stator comprising minor stator teeth extending toward the rotor from the major stator teeth.

11. The aircraft wheel speed sensor system of claim 10, the rotor comprising rotor teeth extending toward the minor stator teeth.

12. The aircraft wheel speed sensor system of claim 11, the stator comprising minor stator slots between adjacent pairs of the minor stator teeth, each minor stator tooth being narrower than its two neighboring minor stator slots, the rotor comprising rotor slots between adjacent pairs of the rotor teeth, each rotor tooth being narrower than its two neighboring rotor slots.

13. The aircraft wheel speed sensor system of claim 11, wherein magnetic interactions between the minor stator teeth and the rotor teeth produce the modulated current signal on the winding.

14. The aircraft wheel speed sensor system of claim 8, the rotor comprising a shaft that is mechanically coupled to the aircraft wheel.

15. The aircraft wheel speed sensor system of claim 8, wherein the electro-mechanical system does not include permanent magnets.

16. The aircraft wheel speed sensor system of claim 8, wherein electrical coupling between the electro-mechanical system and the control system is provided by only the pair of conductors.

17. A method of sensing aircraft wheel speed, the method comprising:

receiving a carrier voltage signal at a stator winding disposed about a rotor that moves upon rotation of an aircraft wheel, the carrier voltage signal being received from a pair of conductors external to the electric machine; and

rendering a modulated current signal on the pair of conductors in response to movement of the rotor, the modulated current signal having a frequency that is dependent on a rotational speed of the aircraft wheel.

18. The method of claim 17, further comprising isolating the modulated current signal from the carrier voltage signal.

19. The method of claim 17, wherein the carrier voltage signal is a single-frequency voltage signal.

20. The method of claim 17, wherein the modulated current signal is a variable-frequency-modulation to the carrier voltage signal.

21. The method of claim 17, wherein the maximum voltage amplitude of the modulated current signal is constant for a range of aircraft wheel rotational speeds.

22. An aircraft wheel speed sensor system comprising:

an electro-mechanical system electrically coupled to a control system by at most a pair of conductors, the electro-mechanical system including a stator without permanent magnets and a rotor without permanent magnets, the stator including a winding configured to render a signal on the pair of conductors, the signal having;

a frequency that varies based on a rotational velocity of an aircraft wheel; and

a peak amplitude that remains constant as the rotational velocity approaches zero; and

the control system configured to detect the signal on the pair of conductors.