SYSTEMS AND METHODS FOR LANDING IDENTIFICATION

• US 20130139590A1
• Filed: 12/06/2011
• Published: 06/06/2013
• Est. Priority Date: 12/06/2011
• Status: Active Grant

• Current Assignee: Goodrich Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Original Assignee: Goodrich Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Cahill, Eric D., Shaw, Michael
• Granted Patent: US 9,688,389 B2
• Time in Patent Office: Days
• US Class Current: 73/494
• CPC Class Codes: B64C 25/00 Alighting gear air-cushion alighting gear B60V3/08
• CPC Class Codes: B64C 25/46 Brake regulators for preventing skidding or aircraft somersaulting
• CPC Class Codes: G01D 5/14 influencing the magnitude of a current or voltage
• CPC Class Codes: G01P 3/44 for measuring angular speed G01P3/56 takes precedence
• CPC Class Codes: H03K 3/0232 Monostable circuits

Abstract

Systems and methods disclosed herein may be useful for use in landing identification. In this regard, a method is provided comprising receiving pulse information over a first time period, wherein the pulse information is indicative of an angular distance traveled by a first wheel, comparing the pulse information to a threshold value, and determining a likelihood of a landing event based upon the comparison. In various embodiments, a system is provided comprising a monstable multivibrator in electrical communication with a metal-oxide-semiconductor field-effect transistor (MOSFET), a resistor-capacitor network in electrical communication with the MOSFET, and a comparator that receives a voltage from the resistor-capacitor network and a reference voltage.

Claims

1. A system comprising:

a monstable multivibrator in electrical communication with a metal-oxide-semiconductor field-effect transistor (MOSFET);

a resistor-capacitor network in electrical communication with the MOSFET; and

a comparator that receives a voltage from the resistor-capacitor network and a reference voltage.

2. The system of claim 1, further comprising a signal conditioner that conditions an input AC signal.

3. The system of claim 2, wherein the resistor-capacitor network comprises two capacitors and two resistors.

4. The system of claim 3, further comprising a voltage follower in electrical communication with the comparator.

5. The system of claim 2, further comprising an external hysteresis circuit.

6. The system of claim 5, wherein the external hysteresis circuit comprises a first resistor coupled to a first terminal of the comparator and a second resistor wired in series with the first resistor.

7. The system of claim 4, wherein the resistor-capacitor network further comprises a node having an average voltage.

8. A method comprising:

triggering a monstable multivibrator in response to a conditioned wheel angular displacement signal;

sinking current, using a metal-oxide-semiconductor field-effect transistor (MOSFET), in response to the triggering;

creating an average voltage at a node from pulsed voltage at a drain of the MOSFET; and

comparing, using a comparator, the average voltage to a reference voltage.

9. The method of claim 8, further comprising conditioning a wheel angular displacement to obtain the conditioned wheel angular displacement signal.

10. The method of claim 8, further comprising buffering the comparator using a voltage follower.

11. The method of claim 8, wherein the creating the average voltage is performed by a resistor-capacitor network.

12. The method of claim 8, further comprising adding hysteresis to the comparator using a resistor.

13. The method of claim 8, further comprising increasing the duty cycle of the MOSFET.

14. The method of claim 13, further comprising decreasing, in response to the increase in the duty cycle of the MOSFET, the average voltage.

15. A landing identification system comprising:

a wheel speed sensor that outputs a signal indicative of angular displacement;

a signal conditioner that receives the signal indicative of angular displacement and outputs a conditioned angular displacement signal;

a monstable multivibrator that receives the conditioned angular displacement signal, wherein the monstable multivibrator is in electrical communication with a wheel angular displacement circuit,

wherein the wheel angular displacement circuit changes state in response to angular displacement above a displacement threshold over a first time period.

16. The landing identification system of claim 15, wherein the displacement threshold is indicative of a speed over 20 knots.

17. The landing identification system of claim 15, wherein the change of state of the wheel angular displacement circuit is provided to another aircraft component.

18. The landing identification system of claim 15, wherein the wheel angular displacement circuit does not state in response to a determination of excessive noise.

19. The landing identification system of claim 15, wherein the wheel speed sensor is a variable reluctance wheel speed sensor.

20. The landing identification system of claim 15, wherein the signal indicative of angular displacement is in AC form.