Method and Apparatus for Aircraft Sensor and Actuator Failure Protection Using Reconfigurable Flight Control Laws

• US 20140005862A1
• Filed: 09/03/2013
• Published: 01/02/2014
• Est. Priority Date: 10/03/2008
• Status: Active Grant

• Current Assignee: Textron Innovations Incorporated (Textron Inc)
• Original Assignee: Bell Helicopter Textron Incorporated (Textron Inc)
• Inventors: Shue, Shyhpyng Jack, Corrigan, John James, Bird, Eric Thomas, Wood, Tommie Lynn, Ewing, Alan Carl
• Granted Patent: US 8,763,950 B2
• Time in Patent Office: Days
• US Class Current: 701/3
• CPC Class Codes: B64C 19/00 Aircraft control not otherwise provided for
• CPC Class Codes: B64C 27/54 Mechanisms for controlling blade adjustment or movement relative to rotor head, e.g. lag-lead movement
• CPC Class Codes: G05B 19/0428 Safety, monitoring G05B19/0423 takes precedence
• CPC Class Codes: G05B 2219/24192 Configurable redundancy
• CPC Class Codes: G05B 2219/25069 Pseudo redundance, eliminate failing element and reconfigure system
• CPC Class Codes: G05B 23/0289 Reconfiguration to prevent failure, e.g. usually as a reaction to incipient failure detection
• CPC Class Codes: G05D 1/0077 using redundant signals or controls
• CPC Class Codes: G05D 1/0858 specially adapted for vertical take-off of aircraft

Abstract

A method and apparatus for reconfiguring flight control of an aircraft during a failure while the aircraft is flying. The method and apparatus provide a control law that is software-implemented and configured to automatically send flight control data to a mixing/mapping matrix. The method and apparatus also provide a reconfiguration management tool configured to communicate with the mixing/mapping matrix in order to safely transfer authority from a failed actuator to a back-up actuator. The method and apparatus also provide a sensor management tool for providing input to the reconfiguration management tool in order to smooth any transient conditions that may occur during reconfiguration. The method and apparatus provide for a way of smoothing any possible transient situation that might otherwise occur by employment of a fader, the fader being used to gradually convert positioning of failed actuators and positioning of reconfigured actuators. An exemplary aircraft for using the method and apparatus of a reconfigurable flight control system is a quad tilt rotor. The quad tilt rotor provides a variety of redundant and back-actuators, as such, having a robust and highly qualified reconfigurable flight control system is very desirable.

Claims

1. A reconfigurable flight control system for reconfiguring flight control of an aircraft during a failure, the aircraft having flight control actuators and sensors, the reconfigurable flight control system comprising:

a control law that is software-implemented and configured to automatically send flight control data to a mixing/mapping matrix;

a reconfiguration management tool configured to communicate with the mixing/mapping matrix in order to safely transfer authority from a failed actuator to a back-up actuator, the reconfiguration management tool comprising;

a risk factor tool for calculating a risk factor, the risk factor being used for determining whether reconfiguration is necessary;

wherein the risk factor is an empirical representation of a control authority of the aircraft, such that a degradation in the control authority effects the risk factor; and

a sensor management tool for providing input to the reconfiguration management tool in order to smooth any transient conditions that may occur during reconfiguration;

wherein the mixing/mapping matrix is configured to dictate the use of a differentiate collective power and a left and right aircraft flap differential, in order to achieve an aircraft yawing control of the aircraft.

2. The reconfigurable flight control system according to claim 1, wherein the risk factor is based upon individual axes.

3. The reconfigurable flight control system according to claim 1, wherein the risk factor takes into consideration a control power level.

4. The reconfigurable flight control system according to claim 1, wherein the reconfiguration management tool further comprises:

a fault/fail detection tool for detecting a failure of at least one of the flight control sensors and actuators.

5. The reconfigurable flight control system according to claim 1, wherein the reconfiguration management tool is configured for determining whether reconfiguration is necessary based upon a quantity of failures.

6. The reconfigurable flight control system according to claim 1, wherein the smoothing any transient conditions that may occur during reconfiguration by the sensor management tool involves the employment of a fader, the fader being used to gradually convert positioning of at least one failed actuator and positioning of at least one reconfigured actuator.

7. The reconfigurable flight control system according to claim 6, wherein the fader is configured to prevent a high amplitude feedback in front of an input side by implementation of a fade block installation.

8. The reconfigurable flight control system according to claim 1, wherein the sensor management tool comprises:

a Kalman filter for interpreting a data from the flight control sensors on the aircraft.

9. A reconfigurable flight control system for reconfiguring flight control of an aircraft in response to a failure, the aircraft having flight control actuators and sensors, the reconfigurable flight control system comprising:

a control law that is software-implemented and configured to automatically send flight control data to a mixing/mapping matrix;

a reconfiguration management tool configured to communicate with the mixing/mapping matrix in order to safely transfer authority from a failed actuator to a back-up actuator, the reconfiguration management tool comprising;

a risk factor tool for calculating a risk factor, the risk factor being used for determining whether reconfiguration is necessary;

wherein the risk factor is an empirical representation of a control authority of the aircraft, such that a degradation in the control authority effects the risk factor; and

a sensor management tool for providing input to the reconfiguration management tool in order to smooth any transient conditions that may occur during the reconfiguring flight control of the aircraft in response to the failure;

wherein the mixing/mapping matrix is configured to mix the usage of the flight control actuators in response to a failing of the failed actuator by employing a first independent actuator system at a first percentage and employing a second independent actuator system at a second percentage, such that the combination of the first independent actuator system and the second independent actuator system produces a differential thrust.

10. The reconfigurable flight control system according to claim 9, wherein the differential thrust is utilized for yaw control.

11. The reconfigurable flight control system according to claim 9, wherein the risk factor takes into consideration a control power level.

12. The reconfigurable flight control system according to claim 9, wherein the reconfiguration management tool further comprises:

a fault/fail detection tool for detecting a failure of at least one of the flight control sensors and actuators.

13. The reconfigurable flight control system according to claim 9, wherein the reconfiguration management tool is configured for determining whether reconfiguration is necessary based upon a quantity of failures.

14. The reconfigurable flight control system according to claim 9, wherein the smoothing any transient conditions that may occur during reconfiguration by the sensor management tool involves the employment of a fader, the fader being used to gradually convert positioning of at least one failed actuator and positioning of at least one reconfigured actuator.

15. The reconfigurable flight control system according to claim 14, wherein the fader is configured to prevent a high amplitude feedback in front of an input side by implementation of a fade block installation.

16. The reconfigurable flight control system according to claim 9, wherein the sensor management tool comprises:

a Kalman filter for interpreting a data from the flight control sensors on the aircraft.

17. A method of automatically reconfiguring flight control of an aircraft, comprising:

detecting a failure of an yaw control actuator;

determining whether reconfiguration is necessary based upon a risk factor;

seamlessly transferring flight control authority from a failed actuator to a back-up actuator;

configuring a back-up actuator to generate differential thrust for yaw control; and

managing the transfer of flight control authority to a back-up actuator with a sensor management tool so as to smooth any transient conditions that may otherwise occur.

18. The method according to claim 17, further comprising;

mixing and mapping the use of actuators by continuously changing the percentage usage of each actuator on the aircraft.