Brain O.sub.2 reserve limiter for high performance aircraft

• US 4,821,982 A
• Filed: 04/07/1987
• Issued: 04/18/1989
• Est. Priority Date: 04/07/1987
• Status: Expired due to Fees

• Current Assignee: Air Force Government of The United States of America As Represented By The Secretary
• Original Assignee: United States Of America As Represented By The Secretary Of The Air Force
• Inventors: Van Patten, Robert E.
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): Corl, Rodney
• Application Number:
  US07/035,425
• Time in Patent Office: 742 Days
• Field of Search: 244/75 R, 244/76 R, 244/191, 244/182, 364/433, 364/434
• US Class Current: 244/76.00R
• CPC Class Codes: B64C 13/16 actuated automatically, e.g. responsive to gust detectors
• CPC Class Codes: G05D 1/0066 for limitation of acceleration or stress

Abstract

A method for controlling an aircraft to prevent high G-caused pilot unconsciousness. Data defining a state space of acceleration, rate of change of acceleration and duration of acceleration at maximum acceleration within which an aircraft may be operated without causing pilot unconsciousness is provided to an aircraft intelligent flight control system. The flight control system continuously monitors the past and present state of the aircraft and compares to the surface boundaries of the defined safe state space, Whenever the aircraft exceeds those boundaries, the flight control system intervenes to unload the aircraft to within those boundaries. Additional data and measurements may be added to define an n-dimensional state space. Another embodiment unloads the aircraft to a baseline acceleration. A simplified embodiment is described which compares current acceleration to a preselected value of acceleration. If the current acceleration exceeds the preselected value, the previous acceleration onset rate is compared to a preselected acceleration onset rate. If it exceeds the preselected onset rate, the duration of time the current and immediately past acceleration has exceeded the preselected value of acceleration is determined. If that value is greater than a preselected duration, the flight control system commands the aircraft to perform an unloading maneuver to reduce the G loading on the aircraft to a preselected baseline acceleration.

Claims

1. A method of protecting a pilot from G-induced unconsciousness while piloting an aircraft, comprising the steps of:

(a) providing previously determined data defining a state space comprising acceleration, rate of change of acceleration and duration of acceleration of the aircraft, the state space having previously been determined to be acceptable boundaries of G tolerance for the pilot;

(b) continuously monitoring over time the acceleration and rate of change of acceleration of the aircraft; and

,

(c) comparing the monitored values of acceleration and rate of change of acceleration to said state space and, whenever the boundaries of said state space are exceeded directing the aircraft to perform a maneuver unloading the aircraft to reduce the monitored acceleration and rate of change of acceleration to values within said boundaries.

2. A method of protecting a pilot from G-induced unconsciousness while piloting an aircraft, comprising the steps of:

(a) providing previously determined data defining a state space comprising acceleration, rate of change of acceleration and duration of acceleration, the state space having previously been determined to be acceptable boundaries of G tolerance for the pilot;

(b) providing a preselected baseline acceleration within the boundaries of said state space;

(c) continuously monitoring over time the acceleration and rate of change of acceleration of the aircraft; and

,

(d) comparing the monitored values of acceleration and rate of change of acceleration to said state space and directing the aircraft to perform a maneuver unloading the aircraft to the preselected baseline acceleration whenever the boundaries of said state space are exceeded.

3. A method of protecting a pilot from G-induced unconsciousness while piloting an aircraft, comprising the steps of:

(a) providing preselected values of acceleration, rate of change of acceleration, duration of acceleration above the preselected value of acceleration, and baseline acceleration;

(b) continuously monitoring current values of acceleration and rate of change of acceleration of the aircraft in the vertical z-axis;

(c) storing past values of said acceleration and said rate of change of acceleration for preselected periods of time; and

,

(d) whenever the current value of acceleration exceeds said preselected value of acceleration;

one or more of said past values of rate of change of acceleration exceeds said preselected rate of change of acceleration; and

, the duration of the current value of acceleration exceeding said preselected value of acceleration is greater than said preselected duration, commanding the aircraft to perform a maneuver to unload the aircraft to reduce the acceleration of the aircraft to said baseline value of acceleration, then returning control of the aircraft to the pilot.

4. The method of protecting a pilot from G-induced unconsciousness according to claim 3, wherein the preselected value of acceleration is +6 G in the z-axis. the preselected value of rate of change of acceleration is +2 G/second, the preselected duration above the preselected value of acceleration is 3 seconds, and the value of the baseline acceleration is +6 G in the z-axis.