Jam mitigation in aircraft fly-by-wire systems and related methods

1. A method of controlling an aircraft with a fly-by-wire system, the method comprising:

determining a current position of a pilot cockpit controller of the fly-by-wire system;

determining an amount of pilot input force applied to the pilot cockpit controller;

determining, using a first table of correlations between pilot input force values and positions of the pilot cockpit controller, an expected pilot input force value that corresponds to the current position of the pilot cockpit controller; and

if the amount of pilot input force applied exceeds the expected pilot input force value by a threshold, generating a pilot command based on the amount of pilot input force applied and not the current position of the pilot cockpit controller, wherein generating the pilot command includes:

determining, using the first table of correlations, an expected position of the pilot cockpit controller based on the amount of pilot input force applied;

determining, using a second table of correlations between the positions of the pilot cockpit controller and positions of a movable flight surface of the aircraft, the pilot command corresponding to the expected position of the pilot cockpit controller; and

outputting the pilot command to a flight control logic.

2. The method of claim 1 , wherein determining the amount of pilot input force applied to the pilot cockpit controller is based on a signal from a force sensor coupled to the pilot cockpit controller.

3. The method of claim 2 , wherein determining the current position of the pilot cockpit controller is based on a signal from a position sensor associated with the pilot cockpit controller.

4. The method of claim 1 , wherein the first table of correlations includes a hysteresis band.

5. The method of claim 1 , wherein the threshold is at least 5 percent of the expected pilot input force value.

6. The method of claim 1 , wherein the threshold is between 5 percent and 10 percent of the expected pilot input force value.

7. The method of claim 1 , wherein the pilot cockpit controller is a set of rudder pedals.

8. The method of claim 7 , wherein the pilot command indicates a desired position or deflection of a rudder of the aircraft.

9. A fly-by-wire system for an aircraft, the fly-by-wire system comprising:

a pilot cockpit controller;

a position sensor to detect a position of the pilot cockpit controller;

a force sensor to detect an amount of pilot input force applied to the pilot cockpit controller; and

a flight control computer to:

determine, using a first database of pilot input force values and corresponding pilot cockpit controller positions, an expected pilot input force value corresponding to the position of the pilot cockpit controller detected by the position sensor;

determine whether a difference between the amount of pilot input force applied detected by the force sensor and the expected pilot input force value satisfies a threshold; and

if the difference satisfies the threshold, generate a pilot command based on the amount of pilot input force applied, wherein, to generate the pilot command based on the amount of pilot input force applied, the flight control computer is to:

determine, using the first database, an expected position of the pilot cockpit controller based on the amount of pilot input force applied;

determine, using a second database of the pilot cockpit controller positions and corresponding positions of a movable flight surface of the aircraft, the pilot command corresponding to the expected position of the pilot cockpit controller; and

output the pilot command to a flight control logic.

10. The fly-by-wire system of claim 9 , wherein the pilot cockpit controller is a set of rudder pedals.

11. The fly-by-wire system of claim 10 , wherein the set of rudder pedals are rudder pedals for a pilot or rudder pedals for a co-pilot.

12. The fly-by-wire system of claim 9 , wherein the pilot command is associated with a position of a rudder of the aircraft.

13. The fly-by-wire system of claim 9 , wherein the threshold is at least 5 percent of the expected pilot input force value.

14. The fly-by-wire system of claim 9 , wherein the first database of correlations includes a hysteresis band.

15. The fly-by-wire system of claim 9 , wherein the threshold is between 5 percent and 10 percent of the expected pilot input force value.

16. A flight control computer including a logic circuit to at least:

determine pilot input force applied to a pilot cockpit controller of a fly-by-wire system of an aircraft;

determine, using a first table of correlations between pilot input force values and corresponding pilot cockpit controller positions during normal operation, an expected pilot input force value that corresponds to a current position of the pilot cockpit controller;

determine the pilot input force applied exceeds the expected pilot input force value by a threshold; and

in response to determining the pilot input force applied exceeds the expected pilot input force value by the threshold, determine a pilot command based on the pilot input force applied by:

determining, using the first table of correlations, an expected position of the pilot cockpit controller based on the determined pilot input force applied; and

determining, using a second table of correlations between the pilot cockpit controller positions and positions of a movable flight surface of the aircraft, the pilot command corresponding to the expected position of the pilot cockpit controller.

17. The flight control computer of claim 16 , wherein the first table includes a hysteresis band of the pilot input force values and the corresponding positions of the pilot cockpit controller.

18. The flight control computer of claim 16 , wherein the pilot cockpit controller is a set of rudder pedals.

19. The flight control computer of claim 16 , wherein the threshold is at least 5 percent of the expected pilot input force value.

20. The flight control computer of claim 16 , wherein the movable flight surface is a rudder of the aircraft.