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

• US 7,742,846 B2
• Filed: 06/02/2006
• Issued: 06/22/2010
• 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: Morphy, Paul, Fanciullo, Todd M., Faynberg, Alex, Stiles, Lorren
• Primary Examiner(s): Tran; Khoi
• Assistant Examiner(s): MANCHO, RONNIE M
• Application Number:
  US11/446,464
• Publication Number:
  US 20070282493A1
• Time in Patent Office: 1,481 Days
• Field of Search: 701/3, 701/4, 701/7, 701/2, 701/8, 701/911, 701/12.1, 701/14, 701/33, 701/120, 701/301, 244/12.3, 244/223, 244/234, 244/236, 244/181, 244/17.13, 244/17.11, 244/17.23, 244/175, 244/189, 244/190, 244/195, 244/220, 244/235, 364/434, 364/424.01, 340/5.2, 340/945, 340/946, 340/961, 340/963, 340/970, 342/29, 342/30, 342/36, 342/34, 146/33, 146/128
• 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; and

(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).

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. The method as recited in claim 1, wherein reducing the flight control augmentation in response to the reduction in the collective pitch position occurs during aircraft flight.

7. 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,

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

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

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

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

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

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

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

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

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

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

12. 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).

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

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

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

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

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

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

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

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

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

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

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

(a) initiating the surface contact transition function via pilot input.

19. The method as recited in claim 12, wherein said step (A) occurs during aircraft flight.