Abstract: Systems, methods, and apparatus for sensor fault detection and identification using residual failure pattern recognition are disclosed. In one or more embodiments, a method for sensor fault detection and identification for a vehicle comprises sensing, with sensors located on the vehicle, data. The method further comprises performing majority voting on the data for each of the types of data to generate a single voted value for each of the types of data. Also, the method comprises generating, for each of the types of data, estimated values by using some of the voted values. In addition, the method comprises generating residuals by comparing the estimated values to the voted values. Further, the method comprises analyzing a pattern of the residuals to determine which of the types of the data is erroneous to detect and identify a fault experienced by at least one of the sensors on the vehicle.

Abstract: An example method of limiting an aircraft to a pitch axis envelope includes determining aircraft state limits associated with multiple pitch axis variables of an aircraft, determining predicted aircraft states, comparing the predicted aircraft states to the aircraft state limits to produce aircraft state errors, translating the aircraft state errors into a set of positive and negative limit elevator commands, selecting a highest priority positive limit elevator command, selecting a highest priority negative limit elevator command, limiting a primary pitch axis control law elevator command of the aircraft to a value that is less than or equal to the highest priority positive limit elevator command and greater than or equal to the highest priority negative limit elevator command, and controlling the aircraft according to the primary pitch axis control law elevator command limited to the value.

Abstract: A flight control system for an aircraft is disclosed. The flight control system includes one or more processors and a memory coupled to the processors. The memory stores data comprising a database and program code that, when executed by the one or more processors, causes the flight control system to receive as input a plurality of first operating parameters that each represent an operating condition of the aircraft. The flight control system is further caused to determine a drag coefficient and a lift coefficient based on the plurality of first operating parameters. The flight control system is also caused to determine an estimated dynamic pressure based on both the drag coefficient and the lift coefficient.

Abstract: A flight control system for an aircraft is disclosed and includes one or more processors and a memory coupled to the processors. The memory stores data comprising a database and program code that, when executed by the one or more processors, causes the flight control system to receive as input a measured angle of attack that is based on a raw angle of attack and an estimated angle of attack based on a total pressure. The flight control system is further caused to compare the measured angle of attack with the estimated angle of attack to determine an error. In response to determining that the error between the measured angle of attack and the estimated angle of attack exceeds a threshold value, the flight control system determines the presence of a fault with an angle of attack value.

Abstract: A flight control system for an aircraft is disclosed, where the flight control system detects a first common mode pneumatic event. The flight control system includes one or more processors and a memory coupled to the processors. The memory stores data comprising a database and program code that, when executed by the one or more processors, causes the flight control system to receive as input a measured dynamic pressure and an estimated angle of attack. The flight control system is further caused to determine a rate of change of the measured dynamic pressure and compare the rate of change of the measured dynamic pressure with a dynamic pressure threshold value. The flight control system is further caused to determine a rate of change of the estimated angle of attack and compare the rate of change of the estimated angle of attack with a threshold angle of attack.

Abstract: An example method of limiting an aircraft to a pitch axis envelope includes determining aircraft state limits associated with multiple pitch axis variables of an aircraft, determining predicted aircraft states, comparing the predicted aircraft states to the aircraft state limits to produce aircraft state errors, translating the aircraft state errors into a set of positive and negative limit elevator commands, selecting a highest priority positive limit elevator command, selecting a highest priority negative limit elevator command, limiting a primary pitch axis control law elevator command of the aircraft to a value that is less than or equal to the highest priority positive limit elevator command and greater than or equal to the highest priority negative limit elevator command, and controlling the aircraft according to the primary pitch axis control law elevator command limited to the value.

Abstract: Aircraft and methods and systems for controlling performance of an aircraft. The methods and systems allow the aircraft to meet a performance requirement using a set of aircraft flight data and actuators connected to control surfaces. Performance data for primary and secondary actuators are obtained to select between a primary control law for controlling the primary control surface, a secondary control law for controlling the secondary control surface, and a blended control law that controls the primary and secondary control surfaces together. If the primary control surface cannot meet the aircraft performance requirement using the primary control law, the blended control law is implemented if the primary and secondary control surfaces can be used together to meet the performance requirement; otherwise the secondary control surface is used, using the secondary control law, to meet the aircraft performance requirement.

Abstract: Systems, methods, and apparatus for sensor fault detection and identification using residual failure pattern recognition are disclosed. In one or more embodiments, a method for sensor fault detection and identification for a vehicle comprises sensing, with sensors located on the vehicle, data. The method further comprises performing majority voting on the data for each of the types of data to generate a single voted value for each of the types of data. Also, the method comprises generating, for each of the types of data, estimated values by using some of the voted values. In addition, the method comprises generating residuals by comparing the estimated values to the voted values. Further, the method comprises analyzing a pattern of the residuals to determine which of the types of the data is erroneous to detect and identify a fault experienced by at least one of the sensors on the vehicle.

Abstract: A flight control system for an aircraft is disclosed. The flight control system includes one or more processors and a memory coupled to the processors. The memory stores data comprising a database and program code that, when executed by the one or more processors, causes the flight control system to receive as input a plurality of first operating parameters that each represent an operating condition of the aircraft. The flight control system is further caused to determine a drag coefficient and a lift coefficient based on the plurality first of operating parameters. The flight control system is also caused to determine an estimated dynamic pressure based on both the drag coefficient and the lift coefficient.

Abstract: A flight control system for an aircraft is disclosed and includes one or more processors and a memory coupled to the processors. The memory stores data comprising a database and program code that, when executed by the one or more processors, causes the flight control system to receive as input receive as input a measured angle of attack that is based on a raw angle of attack and an estimated angle of attack based on a total pressure. The flight control system is further caused to compare the measured angle of attack with the estimated angle of attack to determine an error. In response to determining that the error between the measured angle of attack and the estimated angle of attack exceeds a threshold value, the flight control system determines the presence of a fault with an angle of attack value.

Abstract: A flight control system for an aircraft is disclosed, where the flight control system detects a first common mode pneumatic event. The flight control system includes one or more processors and a memory coupled to the processors. The memory stores data comprising a database and program code that, when executed by the one or more processors, causes the flight control system to receive as input a measured dynamic pressure and an estimated angle of attack. The flight control system is further caused to determine a rate of change of the measured dynamic pressure and compare the rate of change of the measured dynamic pressure with a dynamic pressure threshold value. The flight control system is further caused to determine a rate of change of the estimated angle of attack and compare the rate of change of the estimated angle of attack with a threshold angle of attack.

Abstract: A gust compensation system is configured to adaptively reduce gust loads exerted into an aircraft. The gust compensation system may include a first sensor proximate to a front of the aircraft. The first sensor is configured to output a first signal. A second sensor may be distally located from the front of the aircraft. The second sensor is configured to output a second signal. A gust signal sub-system is configured to receive the first and second signals and generate a gust signal based on analysis of the first and second signals. The gust signal sub-system outputs the gust signal and may modify a load parameter signal in response to the gust signal exceeding a load alleviation threshold.

Abstract: A gust compensation system is configured to adaptively reduce gust loads exerted into an aircraft. The gust compensation system may include a first sensor proximate to a front of the aircraft. The first sensor is configured to output a first signal. A second sensor may be distally located from the front of the aircraft. The second sensor is configured to output a second signal. A gust signal sub-system is configured to receive the first and second signals and generate a gust signal based on analysis of the first and second signals. The gust signal sub-system outputs the gust signal and may modify a load parameter signal in response to the gust signal exceeding a load alleviation threshold.

Abstract: A method for vertical gust suppression due to turbulence for an aircraft having at least one of direct lift control surfaces or pitch control surfaces. The method includes sensing atmospheric turbulence, measuring the sensed atmospheric turbulence to generate turbulence data, generating a command based on the turbulence data, and applying the command to aircraft controls to actuate the direct lift control surfaces or the pitch control surfaces based on the turbulence data. Therefore, an aircraft response to the actuation of the direct lift control surfaces or the pitch control surfaces reduces a vertical acceleration, a pitch acceleration, a pitch rate, a pitch attitude or a structural load of the aircraft due to the turbulence. Thus, the method reduces the effects of vertical gusts of wind on the aircraft, improves the comfort level for aircraft passengers and crew, and reduces diversions the aircraft may take to avoid the turbulence.

Abstract: A method for controlling control surfaces. A position limit is identified for movement of a control surface based on a load limit set for the control surface and a number of vehicle current operation parameters to form an identified position limit. Responsive to receiving a command to move the control surface on a vehicle to a new position, the control surface is commanded to move to a position within the identified position limit.

Abstract: A method for controlling control surfaces. A position limit is identified for movement of a control surface based on a load limit set for the control surface and a number of vehicle current operation parameters to form an identified position limit. Responsive to receiving a command to move the control surface on a vehicle to a new position, the control surface is commanded to move to a position within the identified position limit.

Abstract: A computer implemented method, apparatus, and computer usable program product for symmetric and anti-symmetric control of aircraft flight control surfaces to reduce wing-body loads. Commands are sent to symmetrically deploy outboard control surfaces to shift wing air-loads inboard based on airplane state and speed brake deployment. Surface rate retraction on a wing with peak loads is limited to reduce maximum loads due to wheel checkback accompanied by utilization of opposite wing control surfaces to retain roll characteristics. Airloads are shifted inboard on a swept wing to move the center of pressure forward, thereby reducing the tail load required to perform a positive gravity maneuver. In a negative gravity maneuver, speed brakes are retracted, thereby reducing the positive tail load and reducing the aft body design loads. High gain feedback commands are filtered from wing structural modes above one hertz by a set of linear and non-linear filters.

Abstract: A method for controlling control surfaces. A position limit is identified for movement of a control surface based on a load limit set for the control surface and a number of vehicle current operation parameters to form an identified position limit. Responsive to receiving a command to move the control surface on a vehicle to a new position, the control surface is commanded to move to a position within the identified position limit.

Abstract: A computer implemented method, apparatus, and computer usable program product for symmetric and anti-symmetric control of aircraft flight control surfaces to reduce wing-body loads. Commands are sent to symmetrically deploy outboard control surfaces to shift wing air-loads inboard based on airplane state and speed brake deployment. Surface rate retraction on a wing with peak loads is limited to reduce maximum loads due to wheel checkback accompanied by utilization of opposite wing control surfaces to retain roll characteristics. Airloads are shifted inboard on a swept wing to move the center of pressure forward, thereby reducing the tail load required to perform a positive gravity maneuver. In a negative gravity maneuver, speed brakes are retracted, thereby reducing the positive tail load and reducing the aft body design loads. High gain feedback commands are filtered from wing structural modes above one hertz by a set of linear and non-linear filters.

Abstract: A method for vertical gust suppression due to turbulence for an aircraft having at least one of direct lift control surfaces or pitch control surfaces. The method includes sensing atmospheric turbulence, measuring the sensed atmospheric turbulence to generate turbulence data, generating a command based on the turbulence data, and applying the command to aircraft controls to actuate the direct lift control surfaces or the pitch control surfaces based on the turbulence data. Therefore, an aircraft response to the actuation of the direct lift control surfaces or the pitch control surfaces reduces a vertical acceleration, a pitch acceleration, a pitch rate, a pitch attitude or a structural load of the aircraft due to the turbulence. Thus, the method reduces the effects of vertical gusts of wind on the aircraft, improves the comfort level for aircraft passengers and crew, and reduces diversions the aircraft may take to avoid the turbulence.