Patent Application
20190283862
The present disclosure generally relates to flight control systems, and more specifically to a flight control system configured to aid a pilot in controlling an aircraft in the unlikely event that control of primary flight surfaces of the aircraft has been lost.
Modern aircraft have good safety records, and safety incidents involving modern commercial aircraft are very rare. However, there is always a desire to further improve aircraft safety.
In commercial aircraft aviation, rare historic safety incidents have occurred when a total loss of control of the primary aircraft control surfaces, such as the ailerons and the rudder, occurs. There is therefore a need for a flight control system that would assist the pilot of an aircraft in such emergency situations.
This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description section.
In an exemplary embodiment, there is provided a flight control system for an aircraft having multiple engines and a trimmable stabilizer. The flight control system includes at least one sensor for sensing aircraft parameters, for example airspeed, track angle and/or flight path angle. The flight control system further includes a detector for detecting a total loss of control of the primary flight surfaces of the aircraft. The flight control system further includes an emergency flight controller for receiving a pilot input. The emergency flight controller is in operable communication with the at least one sensor and with the detector and is configured to determine thrust targets for the multiple engines and a target stabilizer position for the trimmable stabilizer on the basis of the pilot input and sensed aircraft parameters when the detector detects a total loss of control of the primary flight surfaces of the aircraft. The flight control system also includes a guidance module configured to provide instructions to a pilot as to how to control the engine thrusts toward the thrust targets and as how to control the trimmable stabilizer towards the target stabilizer position.
In another exemplary embodiment, there is provided a method for providing control instructions to a pilot of an aircraft. The method includes detecting, by a detector, a total loss of control of primary flight surfaces of the aircraft and transmitting, by a processor, an emergency signal to an emergency flight controller. The method further includes receiving a pilot input from a pilot. The method further includes determining a target thrust for each engine of the aircraft and a target stabilizer position for a trimmable stabilizer of the aircraft on the basis of the pilot input and sensed aircraft parameters. The method further includes providing instructions to the pilot as to how to control engine thrusts toward the target thrust for each engine and as to how to control a trimmable stabilizer position toward the target trimmable stabilizer position.
In another exemplary embodiment, there is provided an aircraft having multiple engines and a trimmable stabilizer, together with a flight control system. The flight control system includes at least one sensor for sensing aircraft parameters, for example airspeed, track angle and/or flight path angle. The flight control system further includes a detector for detecting a total loss of control of the primary flight surfaces of the aircraft. The flight control system further includes an emergency flight controller for receiving a pilot input. The emergency flight controller is in operable communication with the at least one sensor and with the detector and is configured to determine thrust targets for the multiple engines and a target stabilizer position for the trimmable stabilizer on the basis of the pilot input and sensed aircraft parameters when the detector detects a total loss of control of the primary flight surfaces of the aircraft. The flight control system also includes a guidance module configured to provide instructions to a pilot as to how to control the engine thrusts toward the thrust targets and as how to control the trimmable stabilizer towards the target stabilizer position.
Other desirable features will become apparent from the following detailed description and the appended claims, taken in conjunction with the accompanying drawings and this background.
A more complete understanding of the subject matter may be derived from the following detailed description taken in conjunction with the accompanying drawings, wherein like reference numerals denote like elements, and wherein:
The following detailed description is merely illustrative in nature and is not intended to limit the embodiments of the subject matter or the application and uses of such embodiments. As used herein, the word “exemplary” means “serving as an example, instance, or illustration.” Thus, any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments. All of the embodiments described herein are exemplary embodiments provided to enable persons skilled in the art to make or use the systems and methods defined by the claims. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding Technical Field, Background, Brief Summary or the following Detailed Description.
For the sake of brevity, conventional techniques and components may not be described in detail herein. Furthermore, any connecting lines shown in the various figures contained herein are intended to represent example functional relationships and/or physical couplings between the various elements. It should be noted that many alternative or additional functional relationships or physical connections may be present in an embodiment of the present disclosure.
When a total loss of the primary aircraft control surfaces of an aircraft occurs, it is possible for a pilot to maneuver an aircraft with multiple engines using differential engine thrust. However, maneuvering the aircraft in this manner is usually difficult for a pilot, since the aircraft may respond to thrust changes in a manner the pilot does not expect. Furthermore, controlling an aircraft using thrust alone requires the pilot to manually change the throttle positions for each engine, which increases the amount of work needed from the pilot. Still further, the loss of the primary control surfaces is likely to induce a degree of stress in the pilot. This stress, coupled with the increase in the amount of work needed from the pilot, may increase the likelihood of the pilot making an error in controlling the thrust-controlled aircraft, which could have severe negative consequences.
Embodiments of the present invention provide a flight control system for assisting pilot control of the aircraft in situations where a loss of control of the primary surfaces of the aircraft occurs.
In an embodiment, an aircraft comprises multiple engines, primary flight surfaces such as ailerons and a rudder, and non-primary flight surfaces, such as a trimmable stabilizer, for example a horizontal stabilizer. In general, non-primary flight surfaces such as a horizontal trimmable stabilizer may still be controlled manually by the pilot in the event of a total loss of control of the primary flight surfaces of the aircraft. The aircraft also comprises a flight control system configured to implement maneuvers commanded by the pilot. That is, suitable software and/or hardware components of the flight control system (such as a processor and a computer-readable storage device) are utilized to implement maneuvers that are input by the pilot.
As shown in
The primary surface control detector 12 is configured to detect a total loss of control of the primary flight surfaces of the aircraft. When a total loss of control of the primary flight surfaces is detected, the primary surface control detector 12 is configured to transmit a signal signifying this total loss of control to the flight management control module 10. When the flight management control module 10 receives this signal, the flight management control module 10 is configured to switch the mode of operation of the flight control system 100 from a normal flight operation mode into a pilot-in-loop emergency control mode. In an embodiment, the switch from the normal flight operation mode into the pilot-in-loop emergency control mode may be performed automatically by the flight management control module 10. In another embodiment, the switch from the normal flight operation mode into the pilot-in-loop emergency control mode may require pilot confirmation, for example via a cockpit button press from the pilot to signify that this switch to the pilot-in-loop emergency control mode may occur.
The flight control system 100 also includes an emergency flight controller 14. The emergency flight controller 14 is configured to receive data from at least one aircraft sensor 20, the data relating to aircraft parameters, for example airspeed, flight path angle or track angle. In an embodiment, the at least one aircraft sensor includes multiple aircraft sensors. The at least one aircraft sensor may be selected from the group of an airspeed indicator, a gyro meter, a global positioning system (GPS) and so on. In an embodiment, the aircraft parameters are sensed by at least one aircraft sensor 20 and are then transmitted to the emergency flight controller 14 via a normal aircraft databus. In another embodiment, the aircraft parameters are sensed by the at least one aircraft sensor 20 and are then transmitted to the emergency flight controller 14 via a separate transmission path, for example via a dedicated emergency databus.
After the pilot-in-loop emergency control mode is initiated, the emergency flight controller 14 is configured to receive information from a flight management system 13. In an embodiment, the information received by the emergency flight controller 14 from the flight management system 13 relates to the aircraft's flight plan. The flight plan is generally pre-determined, but may be changed by a pilot mid-flight using a flight management control panel 16. For example, if a course change or maneuver is desired, the pilot may input a command for a course change or a desired maneuver into the flight management control panel 16, and this change of course or desired maneuver is transmitted to the flight management system 13. The flight management system 13 then transmits the information about the desired change of course or the desired maneuver to the emergency flight controller 14.
Using the aircraft parameters received from the at least one aircraft sensor 20 and the pilot input received from the flight management system 13, the emergency flight controller 14 is configured to determine target throttle positions for each one of the aircraft engines and a target stabilizer position for the trimmable stabilizer for maneuvering the aircraft. For example, the emergency flight controller 14 may determine the target throttle positions and target stabilizer position for a desired maneuver input by the pilot to perform, such as a descent maneuver, a climb maneuver, and so on. In an embodiment, the emergency flight controller 14 is configured to determine instructions to the pilot to maneuver the aircraft according to an original pre-determined flight course stored in the flight management system 13. In another embodiment, the emergency flight controller 14 is configured to determine instructions to the pilot to maneuver the aircraft along an automatically-determined diverted flight course, for example a flight course routed to a nearby safe landing point.
As explained above, the pilot may input a desired maneuver into the flight management control panel 16. For example, the pilot may input into the flight management control panel 16 that an airspeed increase of 10 knots is desired. Using this pilot input and data from the aircraft sensors 20, the emergency flight controller 14 determines target throttle positions for each engine and a target trimmable stabilizer position to maneuver the aircraft so as to achieve this airspeed increase of 10 knots.
After determination of the target throttle positions for each engine and a target trimmable stabilizer position, instructions relating to these target positions are provided to the pilot using a guidance module 17. In an embodiment, the guidance module 17 comprises a display 22 configured to visually display the target positions to the pilot. In an embodiment, the display 22 is part of existing cockpit equipment. In another embodiment, the display 22 may be a remote display, for example on a handheld computing device operably connected to the emergency flight controller 14, such as a laptop or tablet.
The operation of the flight control system 100 will now be explained in more detail with respect to the flowchart of
If the pilot had previously input a desired maneuver prior to a total loss of control of the primary surfaces, or if the pilot subsequently commands a maneuver after the indication that the pilot-in-loop emergency control has been initiated, the emergency flight controller 14 determines target throttle positions for each one of the engines of the aircraft and a target trimmable stabilizer position for the trimmable stabilizer on the basis of the pilot input and the sensed aircraft parameters from the aircraft sensors 20. The emergency flight controller 14 then transmits this information to the guidance module 17. The guidance module 17 displays the target throttle positions and the target trimmable stabilizer position to the pilot 23 in the form of instructions. In an exemplary embodiment, these instructions are provided in the form of visual action cues, as will be explained in more detail below.
After receiving the instructions from the guidance module 17, the pilot 23 then uses a throttle control 21 to adjust the throttle positions of each one of the engines 24 and uses a stabilizer control 26 to adjust the position of the trimmable stabilizer toward the instructed target trimmable stabilizer position. The aircraft parameters correspondingly change in reaction to the pilot's adjustments. The change in the aircraft parameters is shown in
If the pilot inputs a desired maneuver into the flight management control panel 16, the emergency flight controller 14 then determines updated target throttle positions for each one of the engines of the aircraft and an updated target stabilizer position on the basis of the pilot input and the changed sensed aircraft parameters 28.
In an embodiment, in order to reduce the amount of information presented to the pilot and thereby reduce the likelihood that the pilot erroneously controls the throttles or trimmable stabilizer position in a manner that is not in accordance with that instructed by the emergency flight controller 14, the guidance module 17 may display the instructions to the pilot in the form of visual action cues.
Examples of visual action cues are shown in
In scenario T2 of
In scenario T3 of
Notably, in the exemplary embodiments of
When the pilot adjusts the throttle position in accordance with the indicated visual action cue, the sensed aircraft parameters provided to the emergency flight controller 14 change. The emergency flight controller 14 then re-calculates the desired throttle change and, on the basis of the aircraft parameters and information from the flight management control panel 16, the information presented to the pilot is updated. For example, the emergency flight controller 14 may initially provide visual action cues to instruct for the throttle positions of each one of the left and right engines to be increased (as per T2 of
Turning to
In an embodiment, further information may be presented to the pilot through the appearance of a characteristic of the icon 51 of the visual action cue. In some exemplary embodiments, a size, color, shape or other characteristic of the icon 51 may indicate a degree of speed of adjustment required in the throttle adjustment. For example, a red-colored icon 51 may indicate to the pilot that a relatively quick adjustment of the throttle position is required, whereas a green icon 51 may indicate to the pilot that a relatively slower or smoother adjustment of the throttle position may be performed.
Turning to
In scenario S1 of
Turning to
Similarly, in scenario S5 of
Similarly, in scenario S6 of
Turning to
Similarly, in scenario S8 of
Similarly, in scenario S9 of
In an embodiment, the icon 61 may display additional information to the pilot. For example, the length of the icon 61 may indicate the amount of adjustment of the horizontal stabilizer required. In one embodiment, the visual action cue icon is an arrow icon 61, and the guidance module 17 is configured to display the base of the arrow icon 61 at a position proximate to the marker 60 indicating the present position of the horizontal stabilizer, for example at −7.5. The guidance module 17 is further configured to display the tip of the arrow icon 61 proximate to the target position of the horizontal stabilizer, for example at 0.0. In this manner, the information presented to the pilot is displayed in an easy-to-interpret manner, thereby reducing the likelihood of the pilot erroneously adjusting the horizontal stabilizer in an undesired manner
Specific examples as to how the visual action cues are displayed to the pilot will now be explained with reference to
With reference to
Turning to the flowchart of
At step 1200, a detector detects a total loss of control of primary flight surfaces of an aircraft and transmits an emergency signal to an emergency flight controller. The aircraft has multiple engines and a trimmable stabilizer. At step 1202, a pilot input is transmitted to the emergency flight controller. The pilot input relates to a desired maneuver of the aircraft, for example a tracking command, an airspeed change or a flight path angle change. Upon receiving the pilot input, at step 1204 the emergency flight controller determines a target thrust for each engine of the aircraft and a target trimmable stabilizer position for the trimmable stabilizer on the basis of the pilot input and sensed aircraft parameters in order to perform the desired maneuver and transmits these targets to a guidance module. At step 1206, the guidance module provides instructions to the pilot as to how to control engine thrusts toward the target thrust for each engine and as to how to control a trimmable stabilizer position toward the target trimmable stabilizer position. In an embodiment, the target throttle position for each engine and the target stabilizer position are displayed to the pilot in the form using at least one visual action cue.
While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the disclosure in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing the exemplary embodiment or exemplary embodiments. It should be understood that various changes can be made in the function and arrangement of elements without departing from the scope of the disclosure as set forth in the appended claims and the legal equivalents thereof.
