Surface contact override landing scheme for a FBW rotary-wing aircraft

• US 20070282493A1
• Filed: 06/02/2006
• Published: 12/06/2007
• Est. Priority Date: 06/02/2006
• Status: Active Grant

• Current Assignee: Sikorsky Aircraft Corporation (Martin Marietta Corporation)
• Original Assignee: Sikorsky Aircraft Corporation (Martin Marietta Corporation)
• Inventors: Fanciullo, Todd M., Morphy, Paul, Stiles, Lorren, Faynberg, Alex
• Granted Patent: US 7,742,846 B2
• Time in Patent Office: Days
• US Class Current: 701/4
• CPC Class Codes: G01C 23/00 Combined instruments indicating more than one navigational value, e.g. for aircraft; Combined measuring devices for measuring two or more variables of movement, e.g. distance, speed or acceleration
• CPC Class Codes: G05D 1/0676 specially adapted for landing
• CPC Class Codes: G05D 1/0858 specially adapted for vertical take-off of aircraft

Abstract

A method of transitioning from a complex response flight state to a ground operation control state. Pilot intent is determined through collective position information to control the transition. An independent cockpit switch activates an emergency surface contact transition function for use with a fly-by-wire (FBW) flight control system. Once the surface contact transition function is active, FBW control laws transition from a fully augmented flight state, through an augmentation deactivation state and into the surface contact state.

Claims

1. A method of transitioning a Fly-By-Wire flight control system to a ground state comprising the steps of:

(A) reducing a flight control augmentation in response to a reduction in a collective pitch position.

2. The method as recited in claim 1, further comprising the step of:

(B) identifying a pilot input which initiates a surface contact transition function prior to said step (A).

3. The method as recited in claim 1, further comprising the steps of:

(a) identifying a pilot input which initiates a surface contact transition function;

(b) identifying a first collective position which is less than a collective position at said step (a); and

(c) disabling a trim follow-up flight control law function in response to said step (b).

4. The method as recited in claim 3, further comprising the steps of:

(d) identifying a second collective position; and

(e) reducing a rate feedback flight control law function in response to said step (d).

5. The method as recited in claim 4, further comprising the steps of:

(f) identifying a third collective position less than the second collective position; and

(g) transitioning the flight control law to a neutral state in response to said step (f).

6. A method of transitioning a Fly-By-Wire flight control system to a ground state comprising the steps of:

(A) identifying a pilot input which initiates a surface contact transition function;

(B) monitoring a collective pitch position; and

(C) reducing a flight control augmentation in a lagged manner in response to a reduction in the collective pitch position.

7. The method as recited in claim 6, wherein said step (C) further comprises:

(a) transitioning a flight control law to a proportional response.

8. The method as recited in claim 6, wherein said step (C) further comprises:

(a) transiting a flight control law to a damped mode.

9. The method as recited in claim 6, wherein said step (C) further comprises:

(a) transiting a feed forward command for a flight control law to a pseudo-proportional mode.

10. The method as recited in claim 6, wherein said step (C) further comprises:

(a) reducing a trim follow-up function of a flight control law.

11. A method of transitioning a Fly-By-Wire flight control system to a ground state comprising the steps of:

(A) initiating a surface contact transition function;

(B) identifying a first collective position which is less than a collective position at said step (A);

(C) reducing a trim follow-up function of a control law in response to said step (B);

(D) identifying a second collective pitch position less than the first collective pitch position;

(E) reducing a rate feedback of the control law in response to said step (D)

(F) identifying a third collective pitch position less than the second collective pitch position; and

(G) transitioning the flight control law to a neutral state in response to said step (F).

12. The method as recited in claim 11, wherein said step (B) further comprises:

(a) holding an integrator of the trim follow-up function to a state at said step (A).

13. The method as recited in claim 12, wherein said step (B) further comprises:

(b) reducing attitude feedback of the control law until disabled after a period of time.

14. The method as recited in claim 11, wherein said step (C) further comprises:

(a) transitioning the flight control law to a proportional response.

15. The method as recited in claim 11, wherein said step (E) further comprises:

(a) reducing the rate feedback of the control law until disabled after a period of time.

16. The method as recited in claim 15, wherein said step (E) further comprises:

(b) operating the control law in a proportional mode with no rate feedback.