Patent Description:
A system for providing unusual attitude recovery symbology is provided as defined by claim <NUM>.

Further, unless expressly stated to the contrary, "or" refers to an inclusive or and not to an exclusive "or".

The appearances of the phrase "in some embodiments" in various places in the specification are not necessarily all referring to the same embodiment, and embodiments of the inventive concepts disclosed may include one or more of the features expressly described or inherently present herein, or any combination or sub-combination of two or more such features, along with any other features which may not necessarily be expressly described or inherently present in the instant disclosure.

Embodiments of the concepts disclosed herein are directed generally to a system for providing unusual attitude recovery guidance to an aircraft pilot or crew via symbology displayed via a primary flight display (PFD) or head-down display (HDD), a head-up display (HUD), a head-mounted display (HMD), a stand-by display, or a head-worn display (HWD). The unusual attitude recovery symbology may enable path-based recovery from the unusual attitude condition, while maintaining a flight path vector on a display during the unusual attitude condition. Pitch correction symbology or roll correction symbology may be displayed in response to the detected changes in pitch attitude or detected change in roll attitudes. As will be appreciated, the symbology described herein may provide for enhanced situational awareness and simplified guidance for quickly and efficiently taking steps to recover aircraft of all sizes and configurations from unusual attitude. Unusual attitude roll entry avoidance symbology may also be displayed, the roll entry avoidance displayed to help avoid entry into the unusual attitude condition.

Display symbology is generally described in <CIT>, by Richard Hansen et. al; and <CIT>, by Lenard Noice.

Referring to <FIG>, a system is depicted, in accordance with one or more embodiments of the present disclosure.

An exemplary embodiment of a system <NUM> for providing unusual attitude recovery symbology according to the inventive concepts disclosed herein may include a controller <NUM>, the controller <NUM> including one or more processors <NUM>, and a display element <NUM>, the display element <NUM> including a projector <NUM> (or similar display module) and a combiner <NUM> (or similar display surface). The controller <NUM> may be communicatively coupled to one or more aircraft sensors <NUM> or avionics systems <NUM> of an aircraft in which the system <NUM> is embodied. Similarly, the controller <NUM> may include the one or more aircraft sensors <NUM> (e.g., where the display element <NUM> is embodied as a stand-by instrument). The display element <NUM> may be a primary flight display (PFD), a head-down display (HDD), a head-up display (HUD), a head-mounted display (HMD), a stand-by instrument, or a head-worn display (HWD). The display element <NUM> may be configured to display fully or partially immersive imagery corresponding to the environment surrounding the aircraft. The display element <NUM> may include graphics processors (e.g., a synthetic vision system (SVS)) for generating explanatory symbology related to the environment and merging the symbology with the imagery to generate a combined vision stream displayed via the combiner <NUM>. The processors <NUM> of the controller <NUM> may generate some or all of the symbology of a combined vision stream.

Based on data collected from the aircraft sensors <NUM> or avionics systems <NUM>, the controller <NUM> may determine that the aircraft is in an unusual attitude condition. For example, the unusual attitude condition may be determined based on a pitch or a roll of the aircraft. Such pitch or roll may be determined by one or more of the aircraft sensors <NUM> or the avionics systems <NUM>. Various unusual attitude recovery symbology may then be displayed on the display element <NUM>, by a communicative coupling between the controller <NUM> and the display element <NUM>. As may be understood, the system <NUM> is not intended to be limited to a specific unusual attitude entry condition. In this regard, the roll or pitch at which the unusual attitude condition may be entered will depend on a configuration of the aircraft in which the system <NUM> is installed.

Referring to <FIG>, an exemplary embodiment of a system 100a for providing unusual attitude recovery symbology may be implemented identically to the system <NUM> of <FIG>, wherein when an unusual attitude condition is detected by the controller <NUM> (<FIG>), the system 100a generates unusual attitude symbology on the display surface.

The unusual attitude symbology is displayed relative to a roll scale <NUM>. The roll scale <NUM> remains positioned statically on the display element <NUM> (e.g., in an upper position). By displaying the unusual attitude symbology relative to the roll scale <NUM>, a pilot may visually determine the state of the aircraft with a reduced scan time (e.g., because of the static position). In this regard, as the pilot adjusts a roll of the aircraft, a roll pointer <NUM> is moved about the roll scale <NUM>. By the unusual attitude symbology, the pilot may refer to the roll scale <NUM> to visually determine corrective actions needed to exit an unusual attitude condition.

For example, during normal operating conditions the system 100a displays an image on the display surface. The image includes the roll scale <NUM> and the roll pointer <NUM> indicative of a roll of the aircraft, a boresight symbol <NUM>, and a flight path vector <NUM> of the aircraft. As may be understood, the system 100a is limited to such display, and may further include a variety of information, such as, but not limited to, an airspeed indicator <NUM>, an altitude indicator <NUM>, and a horizon <NUM>. The boresight symbol <NUM> provides a longitudinal axis of the aircraft attitude from which various symbology (e.g., a pitch scale, the flight path vector <NUM>, the horizon <NUM>, etc.) is referenced. The flight path vector <NUM> provides a projected path of the aircraft. The pitch scale and the roll scale <NUM> provide an attitude of the aircraft.

Upon detecting an entry of the aircraft into the unusual attitude condition (i.e. an unusual roll condition; and optionally an unusual pitch condition), the controller updates the image displayed on the display element <NUM>. The updated image includes various unusual attitude symbology which is maintained relative to the roll scale <NUM>, such as, but not limited to, an unusual attitude warning indicator <NUM>, a roll recovery arc <NUM>, a roll direction indicator <NUM>, and a pitch direction indicator <NUM>. The unusual attitude symbology may be referenced off the aircraft attitude (e.g., as represented by the boresight symbol <NUM>).

The unusual attitude warning indicator <NUM> may include annunciations, such as, but not limited to, UA, Unusual Attitude, Roll, or Pitch. By the unusual attitude warning indicator <NUM>, a pilot may visually determine the aircraft is in an unusual attitude condition. Once both the unusual roll condition and the unusual pitch condition are corrected, the unusual attitude warning indicator <NUM> may be removed from display element <NUM>.

The roll recovery arc <NUM> presents range of roll angles in relation to the roll scale <NUM>, by which the aircraft may recover from the unusual roll condition. Thus, a pilot may visually determine a stable roll angle for the aircraft by which the aircraft may exit the unusual attitude condition using the roll recovery arc <NUM>. For example, the pilot may visually determine a difference between a current position of the roll pointer <NUM> and the roll recovery arc <NUM>, and based on the visual determination, may adjust the roll pointer <NUM> within the roll recovery arc <NUM>. The range of the roll recovery arc <NUM> may be selected based on the aircraft. For example, <FIG> depicts the roll recovery arc <NUM> as extending from fifteen degrees from level, although this is not intended to be limiting. In embodiments, the roll recovery arc <NUM> may include color information indicative of a status of the roll of the aircraft. For example, the roll recovery arc <NUM> may be a first color (e.g., a red color) indicating an unusual roll condition. When the roll is corrected with the roll recovery arc <NUM>, the roll recovery arc <NUM> may be updated with a second color (e.g., a green or blue color) indicating a roll recovery.

The roll direction indicator <NUM> may indicate a direction of corrective roll by which the aircraft may exit the unusual attitude condition. When the roll of the aircraft comes within the roll recovery arc <NUM>, the roll direction indicator <NUM> may be removed, indicating the aircraft has achieved an acceptable roll. The roll direction indicator <NUM> may be removed after a delay, to prevent pilot disorientation, as will be described further herein. In some embodiments, the roll direction indicator <NUM> may be displayed above the unusual attitude warning indicator <NUM> and below the roll scale <NUM>.

The pitch direction indicator <NUM> may be displayed if the aircraft is undergoing an unusual pitch condition. The pitch direction indicator <NUM> may include a shape. For example, the shape of the pitch direction indicator <NUM> may include a triangle. The triangle-shaped pitch direction indicator <NUM> may be pointed in a direction, corresponding to a pitch direction to recover the aircraft from the UA pitch condition. For example, where the triangle points upwards, a pilot may visually determine the aircraft needs to pitch upwards to recover from the unusual pitch condition. When the pilot has achieved a target pitch attitude, the pitch direction indicator <NUM> may be removed from the image updated on the display element <NUM>, indicating the aircraft has achieved an acceptable pitch. The pitch direction indicator <NUM> may be removed after a delay, to prevent pilot disorientation, as will be described further herein. In some embodiments, the pitch direction indicator <NUM> is displayed below the unusual attitude warning indicator <NUM>.

In embodiments, the controller <NUM> is configured to emphasize or de-emphasize various unusual attitude symbology. For example, where the display element <NUM> is embodied by a device including a color display, the unusual attitude symbology may be emphasized by changing a color of the various unusual attitude symbology (e.g., changing to a red color) and de-emphasize by changing the color (e.g., changing to an amber color). By way of another example, the controller <NUM> may be configured to emphasize the unusual attitude symbology by changing the fill (e.g., changing to a solid fill, cross-hatch, etc.) and de-emphasize the unusual attitude symbology by changing the fill (e.g., changing to a hollow fill). By way of another example, the controller <NUM> may be configured to emphasize the unusual attitude symbology by flashing the unusual attitude symbology. By way of another example, the controller <NUM> may be configured to emphasize the unusual attitude symbology by increasing a brightness of the unusual attitude symbology or decreasing a brightness of surrounding symbology. By way of another example, the controller <NUM> may be configured to emphasize the unusual attitude symbology by increasing a line weight and may be configured to de-emphasize the unusual attitude symbology by decreasing a line weight.

In embodiments, the pitch direction indicator <NUM> may be emphasized (e.g., by a color, a fill type, a flashing, brightness, a line weight, etc.) when a pitch is trending in a wrong direction or otherwise needs immediate correction. If the aircraft does not have enough speed and pitching up would exaggerate the issue, the unusual attitude symbology may provide the operator with conflicting information. For example, if the pitch attitude may lead to a stall condition, the pitch direction indicator <NUM> may be de-emphasized. While the stall information is displayed, the pitch direction indicator <NUM> may include a color (e.g., amber) or a hollow shape fill to de-emphasize pitch correction. If the system has determined there is enough margin to correct for pitch, the pitch direction indicator <NUM> may be emphasized. For example, the pitch direction indicator <NUM> may include a different color (e.g., red) or a solid fill to indicate a pitch correction is needed.

In the event of an unusual pitch condition but no unusual roll condition (or where the unusual roll condition has been recovered), the pitch direction indicator <NUM> may be emphasized (e.g., by a color, a fill type, a flashing, brightness, a line weight, etc.). By the emphasis, a pilot may determine a present step of correcting pitch to get out of the unusual pitch condition. This may be advantageous in complying with current standard operating procedures of correcting for roll and then correcting for pitch.

In embodiments, the controller <NUM> is further configured to update the unusual attitude symbology in response to determining the exit of the aircraft from the unusual attitude condition. For example, the controller may update the unusual attitude symbology after a pre-determined delay. By updating the unusual attitude symbology after the pre-determined delay, pilot disorientation may be reduced. In this regard, should the aircraft rapidly enter and exit the unusual attitude condition, one or more of the roll recovery arc <NUM>, the unusual attitude warning indicator <NUM>, the roll direction indicator <NUM>, or the pitch direction indicator <NUM> may remain displayed. The pre-determined delay may be any suitable amount of time, such as, but not limited to, one-half of a second or more.

In embodiments, an unusual attitude roll entry chevron <NUM> may be displayed prior to entering the unusual attitude condition. The unusual attitude roll entry chevron <NUM> may indicate a roll angle at which point a system may transition to the unusual attitude display. The system may transition into the unusual attitude display when the roll pointer intersects the unusual attitude roll entry chevron <NUM>. By the unusual attitude roll entry chevron <NUM>, a pilot may avoid the unusual attitude condition based on the roll pointer <NUM>.

Referring now to <FIG>, an exemplary embodiment of a system 100b for providing unusual attitude recovery symbology may be implemented identically to the system <NUM> of <FIG>, wherein when an unusual attitude condition is detected by the controller <NUM> (<FIG>), the system 100b generates unusual attitude symbology on the display element <NUM>.

Unusual attitude recovery symbology described maintains a position relative to the flight path vector <NUM>. The flight path vector <NUM> dynamically moves about the display element <NUM>, to show the predicted flight path. By maintaining the path-based unusual attitude recovery symbology in the position relative to the flight path vector <NUM>, a pilot may visually determine the state of the aircraft with a reduced scan time from the flight path vector <NUM> and maintain spatial orientation. In this regard, as the pilot adjusts a roll or a pitch of the aircraft, the flight path vector <NUM> may be correspondingly adjusted to indicate a flight path of the aircraft. Unusual attitude recovery symbology is displayed relative to such flight path vector <NUM>. This is advantageous during the unusual attitude condition when the pilot is referencing the flight path vector <NUM>, because time is a key factor in safely exiting the unusual attitude condition.

The unusual attitude recovery symbology may include a pitch direction indicator <NUM>. The pitch direction indicator <NUM> may be identical to the pitch direction indicator <NUM>, except that the pitch direction indicator <NUM> may remain fixed relative to the flight path vector <NUM>. In this regard, the pitch direction indicator <NUM> may be visible by the pilot, without regard to a pitch or a roll of the aircraft, even if, for example, the horizon <NUM> is no longer conformal with the outside scene. Thus, the pitch direction indicator <NUM> may provide situational awareness of a direction to pitch the aircraft so that the pilot may pitch the aircraft back to stable flight (e.g., towards the horizon or a zero pitch line). The pitch direction indicator <NUM> may be displayed if the aircraft is undergoing an unusual pitch condition. The pitch direction indicator <NUM> may include a shape that corresponds to a direction in which the aircraft should be pitched to recover from the unusual pitch condition. For example, the shape of the pitch direction indicator <NUM> may include a triangle. The triangle-shaped pitch direction indicator <NUM> may be pointed in a direction. For example, where the triangle points upwards, a pilot may visually determine the aircraft needs to pitch upwards to recover from the unusual pitch condition. In some embodiments, the pitch direction indicator <NUM> is disposed below the flight path vector <NUM>.

In embodiments, the unusual attitude recovery symbology may include a roll direction indicator <NUM>. The roll direction indicator <NUM> may be identical to the roll direction indicator <NUM>, except that the roll direction indicator <NUM> may remain fixed relative to the flight path vector <NUM>. In some embodiments, the roll direction indicator <NUM> is disposed above the flight path vector <NUM>.

In embodiments, a flight director guidance cue <NUM> may be displayed during an unusual attitude condition. The flight director guidance cue <NUM> may include a shape different from a flight director guidance cue used during normal operating conditions. For example, the flight director guidance cue <NUM> may include a square, diamond, or rectangle. The shape of the flight director guidance cue <NUM> may have a size such that the flight director guidance cue <NUM> may be contained with the flight path vector <NUM>. In this regard, the pilot may adjust the pitch and roll of the aircraft until the flight path vector <NUM> is contained within the flight director guidance cue <NUM>.

The flight director guidance cue <NUM> may also include a pitch reference point <NUM> in a center of the flight director guidance cue <NUM>. By the pitch reference point <NUM>, the pilot may visually determine when the pitch of the aircraft is within a pitch guide <NUM>, such that an unusual pitch condition may be corrected (e.g., bring the nose level). In embodiments, the pitch guide <NUM> may also be displayed. The pitch guide <NUM> indicates a pitch at which the aircraft may recover from the unusual pitch condition. When the pitch reference point <NUM> of the flight director guidance cue <NUM> is beyond the pitch guide <NUM>, the flight director guidance cue <NUM> may be emphasized (e.g., by a color, a fill type, a flashing, brightness, a line weight, etc.) until the pitch reference point <NUM> crosses the pitch guide <NUM>. When the pitch reference point of the flight director guidance cue <NUM> is within a boundary of the pitch guide <NUM>, the unusual pitch condition may be corrected. Thus, a pilot may visually determine an amount of pitch needed by which to correct the unusual pitch condition. The boundary of the pitch guide <NUM> may be represented as a bracket. The pitch guide <NUM> may be positioned at a pitch value where the aircraft is determined to be at a recoverable pitch state. The pitch guide <NUM> may be located above or below the flight path vector <NUM>, depending on the direction of pitch recovery (e.g., located above when the aircraft needs to pitch downwards; located below when the aircraft needs to pitch upwards).

The flight director guidance cue may also include arms <NUM> that are oriented to allow the pilot to correct the roll angle of the aircraft. In this regard, the arms <NUM> may be inverse to a current roll angle of the aircraft. In embodiments, the path-based UA recovery symbology may also include a roll guide <NUM>. The roll guide <NUM> may display a range of roll angles at which the aircraft may recover from the unusual roll condition. When the arms <NUM> of the flight director guidance cue <NUM> are within a boundary of the roll guide <NUM>, the unusual roll condition may be in an acceptable range of roll recovery. The arms <NUM> may have a width, such that the arms <NUM> extend to the roll guide <NUM>. Thus, the arms <NUM> and the roll guide <NUM> may provide the pilot visual representation of roll needed to bring the aircraft level. The roll guide <NUM> may remain fixed relative to a center of the flight director guidance cue <NUM>. The boundary of the roll guide <NUM> may be represented as a portion of a circle or a portion of an ellipse. Similar to the roll recovery arc <NUM>, an arc-length of boundary of the roll guide <NUM> may be based at least in part on an acceptable roll condition of the aircraft.

Once the aircraft has achieved the target pitch and roll, the controller <NUM> may determine that the aircraft has achieved stable flight. Accordingly, the system 100b may transition into normal symbology by removing the various unusual attitude symbology. The flight director guidance cue <NUM> may also transform into a conventional flight director.

Referring now to <FIG>, an exemplary embodiment of the system 100c for providing unusual attitude recovery symbology may be implemented. The system 100c includes various symbology discussed in regard to the system 100a and the system 100b. For example, the system 100c includes the roll scale <NUM>, the roll pointer <NUM>, the boresight symbol <NUM>, the flight path vector <NUM>, the airspeed indicator <NUM> (see <FIG>), the altitude indicator (see <FIG>), the horizon <NUM>, the unusual attitude warning indicator <NUM>, the roll direction indicator <NUM>, the pitch direction indicator <NUM>, the pitch direction indicator <NUM>, the pitch guide <NUM>, the roll direction indicator <NUM>, the flight director guidance cue <NUM>, the roll guide <NUM>, the arms <NUM>, and the pitch reference point <NUM>.

A standard operating procedure for correcting an unusual attitude condition may be for the pilot to correct for roll and then to correct for pitch. The image displayed by the display element <NUM> may include indicators such that the pilot may first correct for roll and then correct for pitch. In this regard, the flight director guidance cue <NUM> may be emphasized (e.g., by a color, a fill type, a flashing, brightness, a line weight, etc.) and the pitch direction indicator <NUM> may be de-emphasized until the unusual roll condition is corrected. For example, the flight director guidance cue <NUM> may be emphasized by a solid fill or a color and de-emphasized by a hollow fill or a color. The emphasis of the flight director guidance cue <NUM> may highlight the roll for the pilot's attention for immediate correction. The roll direction indicator <NUM> and the roll direction indicator <NUM> may then highlight a direction in which to roll when roll correction is a primary command. A difference between the roll pointer <NUM> and the roll recovery arc <NUM> may indicate an amount of roll required to exit the unusual roll condition. Similarly, a difference between the roll guide <NUM> and the arms <NUM> may indicate an amount of roll required to exit the unusual roll condition.

Referring now to <FIG>, the aircraft has exited or otherwise corrected the unusual roll condition (as depicted by the roll pointer <NUM> and the roll recovery arc; as depicted by the arms <NUM> and the roll guide <NUM>) such that pitch correction is not a primary command. Upon exiting the unusual roll condition, the roll direction indicator <NUM> and the roll direction indicator <NUM> may be removed from the image. Additionally, the pitch direction indicator <NUM> and the pitch direction indicator <NUM> may be de-emphasized. The emphasis of the pitch direction indicator <NUM> and the pitch direction indicator <NUM> may highlight the pitch direction for the pilot's immediate attention. Similarly, a difference between the pitch guide <NUM> and the pitch reference point <NUM> may indicate an amount of pitch required to exit the unusual pitch condition.

Referring now to <FIG>, the aircraft has exited the unusual pitch condition (as depicted by the pitch guides <NUM> and the pitch reference point <NUM>). Upon exiting the unusual pitch condition, the unusual attitude warning indicator <NUM>, the pitch direction indicator <NUM>, and the pitch direction indicator <NUM> may be removed from the image. Additionally, the flight director guidance cue <NUM> may be de-emphasized. By the de-emphasized flight director guidance cue <NUM>, the pilot may visually determine that the unusual attitude condition has been exited. The roll recovery arc <NUM> and the flight director guidance cue <NUM> may then remain displayed for a pre-determined delay before being removed from the image, in accordance with one or more embodiments of the present disclosure.

Referring now to <FIG>, a system <NUM> is described in accordance with one or more embodiments of the present disclosure.

The unusual attitude roll direction indication is represented on the flight path vector <NUM> by a roll error tape <NUM>. The roll error tape <NUM> is displayed when the aircraft is experiencing an unusual roll condition. The roll error tape <NUM> includes an arc extending from one or more tips of the flight path vector <NUM> (e.g., where the tip is representative of a wing of the aircraft). For example, the roll error tape <NUM> may include two arcs extending from the tips of the flight path vector <NUM>, where each of the two arcs are in either a clockwise or counter-clockwise orientation. In this regard, the orientation of the two arcs represents a direction in which to roll the aircraft to correct for the unusual roll condition. The roll error tape <NUM> may also include one or more tic marks <NUM>, the tic mark <NUM> representative of a degree of roll. For example, the roll error tape <NUM> may include the tic mark <NUM> for every five degrees, up to or greater than fifteen degrees. The roll error tape <NUM> may also be displayed on various other symbology, such as, but not limited to, the boresight symbol <NUM>.

In embodiments, video (e.g., enhanced vision system (EVS), synthetic vision system (SVS), combined vision system (CVS), or enhanced flight vision system (EFVS)) may remain displayed by the display element <NUM> during the unusual attitude condition. The video may remain displayed because the display format remains conformal between normal attitude and unusual attitude conditions. The video may provide the pilot with additional situational awareness of the environment in order to quickly and safely return to stabilized flight (while avoiding any obstacles).

In embodiments, the various unusual attitude symbology may be displayed via the combiner <NUM> or display surface as monochrome or colored symbols, depending on, e.g., whether the display element <NUM> (<FIG>) is a PFD/HDD, HUD, HMD, stand-by display, or HWD. The unusual attitude symbology may be further modified according to human factors considerations. For example, various of the unusual attitude symbology may be implemented as flashing symbols, solid, and/or with a color. Furthermore, a brightness of the display element displaying the various unusual attitude symbology or the other symbology may be adjusted (either brighter or darker) to be more easily identified by the pilot. By adjusting the brightness intensity, non-critical information may be less bright on the display, while critical information is at full-brightness.

In embodiments, a v-bar or another form of a cross-bar may be provided on a head-down primary flight display during the unusual attitude condition to provide unusual attitude recovery guidance.

In embodiments, a digital representation of an amount of pitch or roll angle required to recover from an unusual attitude condition may be presented on the display element <NUM>. The digital representation may be in addition to the various unusual attitude symbology described herein. By the digital representation, the pilot may determine a numerical amount of pitch or roll needed to correct the unusual attitude condition.

Claim 1:
A system (<NUM>;100a;100b;<NUM>) for providing unusual attitude recovery symbology, comprising:
at least one avionics display element (<NUM>) configured to display an image associated with an aircraft, the image including at least:
a roll scale (<NUM>);
a roll pointer symbol (<NUM>) configured to move about the roll scale, the roll pointer symbol representative of a current roll of the aircraft;
a flight path vector; and
a boresight symbol (<NUM>); and
at least one controller (<NUM>) coupled to the avionics display element, the controller including at least one processor (<NUM>) configured to:
determine an entry of the aircraft into an unusual attitude condition, the unusual attitude condition including an unusual roll condition based on a roll of the aircraft; and
update the image in response to determining the entry of the aircraft to the unusual attitude condition, the updated image further comprising unusual attitude symbology displayed relative to the roll scale, the unusual attitude symbology comprising:
an unusual attitude warning indicator (<NUM>); and
a roll recovery arc (<NUM>) presenting a range of roll angles on the roll scale at which the aircraft may recover from the unusual roll condition, such that the unusual roll condition may be recovered from by positioning the roll pointer symbol within the range of roll angles on the roll scale;
characterized in that the controller is further configured to update the image with a roll error tape (<NUM>), the roll error tape including at least one arc extending from one or more tips of the flight path vector, the at least one arc representative of a direction in which to roll the aircraft to correct for the unusual roll condition.