System and method for providing thrust guidance related to flight path angle

Abstract

The present invention is entitled "System and method for providing thrust guidance related to flight path angle". The present invention provides a technically improved flight guidance system and method that generates thrust guidance related to potential flight path angles. The thrust guidance is provided as an acceleration command that can be communicated to the pilot in an intuitive manner, such as using acceleration cues on a primary flight display (PFD) system. The acceleration cues provided are uniform in the flight envelope and appear consistent for two basic thrust guidance modes.

Description

Technical Field

[0001] The present invention relates generally to vehicle guidance systems and, more particularly, to flight guidance systems and methods for providing thrust guidance related to flight path angle. Background Art

[0002] The primary flight display (PFD) is centered on the flight path and can easily identify whether the aircraft is creeping or descending (i.e., its trajectory). To change the trajectory, the aircraft's thrust level may need to be changed from the current thrust to the target thrust. In these situations, the pilot may need thrust guidance, and specifically, may need acceleration commands to achieve the target thrust.

[0003] In an automatic flight control system (AFCS) including autopilot (AP) and autothrottle (A / T) speed control functions, there are two basic methods of controlling thrust, which are referred to as thrust guidance modes and include: speed control and thrust control. Therefore, when a pilot requires thrust guidance, the pilot may also expect to receive thrust guidance presented in the same manner regardless of which of the two thrust guidance modes is used.

[0004] Additionally, while some flight guidance systems and methods provide thrust cues, the cues are generally in terms of engine power, engine power error, or throttle position error, and therefore are not particularly intuitive and do not provide an indication of the acceleration represented. Some other common flight guidance systems translate engine power commands into equivalent accelerations, but these implementations typically deliver different acceleration translations in a given flight envelope. Furthermore, most systems present thrust acceleration cues that are very different from one another, depending on which of the two thrust guidance modes they are using.

[0005] Therefore, there is a need for improved flight guidance systems and methods in the art that provide consistent thrust guidance acceleration commands for a basic thrust guidance mode. The desired systems and methods generate acceleration commands for thrust guidance that can be communicated to the pilot in an intuitive manner, such as using prompts on a primary flight display system. In addition, other desirable features and characteristics of the present invention will become apparent from the following detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention. Summary of the invention

[0006] This Summary is provided to describe selected concepts in a simplified form that are further described in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

[0007] In one embodiment, a processor-implemented method for providing thrust guidance on a primary flight display (PFD) of an aircraft is provided. The method includes: receiving an expected airspeed; receiving a current airspeed and a current flight path angle (FPA) from a state data source; receiving a real-time engine thrust (T) level, a real-time throttle level angle (TLA), and a real-time weight from an avionics data source; executing the thrust guider algorithm at a control module including the thrust guider algorithm to thereby perform the following operations: referencing aircraft constraint data to obtain T max and T idle ; Calculate T based on weight and maximum TLA max Projected Potential Flight Path Angle (PPFPA) of real-time TLA TLA ); Calculate T based on weight and minimum TLA idle PPFPA TLA According to T max PPFPA TLA and T idle PPFPA TLA Generate acceleration command (PFPA CMD ); and commanding the PFD to render a symbology representing the acceleration command.

[0008] The present invention also provides a system for providing thrust guidance on a primary flight display (PFD) of an aircraft, the system comprising: an expected airspeed source; a state data source providing a current airspeed and a current flight path angle (FPA); an avionics data source providing a real-time engine thrust (T) level, a real-time throttle level angle (TLA), and a real-time weight; and a control module comprising a processor programmed to: reference aircraft constraint data to obtain T max and T idle ; Calculate T based on weight and maximum TLA max Projected Potential Flight Path Angle (PPFPA) under real-time TLA TLA ); Calculate T based on weight and minimum TLA idle PPFPA TLA According to T max PPFPA TLA and T idle PPFPA TLA Generate acceleration command (PFPA CMD ); and commanding the PFD to render a symbology representing the acceleration command.

[0009] The present invention provides an aircraft embodiment, which includes: a primary flight display (PFD); a desired airspeed source; a state data source, which provides a current airspeed and a current flight path angle (FPA); an avionics data source, which provides a real-time engine thrust (T) level, a real-time throttle level angle (TLA), and a real-time weight; and a thrust seeker control module, which includes a processor, the processor being programmed to: determine a true airspeed error; convert the true airspeed error to a desired acceleration command; and use constraint data to limit the desired acceleration command to generate an acceleration output, wherein the constraint data provides T max and T idle ; Calculate T based on weight and maximum TLA max Projected Potential Flight Path Angle (PPFPA) under real-time TLA TLA ); Calculate T based on weight and minimum TLA idle PPFPA TLA According to T max PPFPA TLA and T idle PPFPA TLA Generate acceleration command (PFPA CMD ); and commanding the PFD to render a symbology representing the acceleration command.

[0010] Furthermore, other desirable features and characteristics of the systems and methods will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing background. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The present invention will be described below with reference to the following drawings, wherein like numerals represent like elements, and

[0012] Figure 1 is a block diagram of a thrust seeker system according to an exemplary embodiment;

[0013] Figure 2 is an example thrust versus throttle level constraint diagram according to an exemplary embodiment;

[0014] Figure 3 According to an exemplary embodiment, Figure 1 PFD image generated by the thrust seeker system;

[0015] Figure 4 and Figure 5 is a data flow diagram of a method for providing thrust guidance according to an exemplary embodiment;

[0016] Figure 6 and Figure 7is a graphical representation of the relationship between thrust introducer prompting and PFPA prompting according to an exemplary embodiment; and

[0017] Figure 8 A method for providing thrust guidance on a primary flight display is shown in accordance with an exemplary embodiment. DETAILED DESCRIPTION

[0018] The following specific embodiments are merely illustrative in nature and are not intended to limit the embodiments of the subject matter or the application and use of such embodiments. As used herein, the word "exemplary" means "used as an example, instance or illustration". Therefore, any embodiment described herein as "exemplary" is not necessarily to be understood as being preferred or advantageous over other embodiments. All embodiments described herein are exemplary embodiments provided to enable those skilled in the art to make or use the present invention rather than to limit the scope of the present invention as defined by the claims. In addition, it is not intended to be bound by any theory presented in the foregoing background technology or the following detailed description.

[0019] Exemplary embodiments of the disclosed thrust introducer module ( Figure 1 , 104, also referred to as control module 104 hereinafter) employs a novel thrust seeker algorithm to thereby deliver an enhanced flight guidance system that generates novel acceleration commands for thrust guidance. The novel thrust seeker algorithm implemented as a method and system utilizes the potential flight path angle (PFPA) of the aircraft, thrust (T), throttle level angle (TLA) and weight (W) to generate acceleration commands and further implements a new "thrust seeker prompt" for a primary flight display. Functionally, the new thrust seeker prompt displays to the pilot some interconnected relationships between thrust level, throttle level angle, weight, airspeed, flight path angle and acceleration. In the described embodiment, the thrust seeker algorithm is applied in the context of a primary flight display (PFD) that provides a traditional flight path vector and a traditional flight path angle (FPA) symbol. Although the thrust seeker algorithm is generally implemented as an enhanced aircraft flight platform display system within an aircraft, the concepts presented herein can be deployed in a variety of mobile platforms, such as rotorcraft, spacecraft, etc. Furthermore, the provided systems and methods may be separate from or integrated into a pre-existing mobile platform management system, electronic flight information system (EFIS), or aircraft flight control system (AFCS).

[0020] As outlined, the novel rules and instructions that make up the thrust seeker algorithm (program 162 plus stored variables 164) generate acceleration commands that are uniform and correlated to equivalent flight path angles (FPA). The generated acceleration commands may be a function of velocity error or thrust error and are not dependent on drag values ​​that may be inconsistent. In various embodiments, the generated acceleration commands are rendered as symbols on a display unit in a cockpit display; the symbols objectively provide additional information in an intuitive manner, thereby improving the human-machine interface. The thrust seeker algorithm additionally limits the generated acceleration commands to those that can be supported by the available energy of the aircraft. Thus, the acceleration guidance generated by executing the novel thrust seeker algorithm increases the crew's situational awareness, particularly with respect to the current acceleration capabilities of the aircraft.

[0021] Now turn to Figure 1 In one embodiment, a thrust seeker system 102 (also referred to herein as "system" 102) is generally associated with a mobile platform 100. In various embodiments, the mobile platform 100 is an aircraft and is referred to as aircraft 100. The system 102 includes a control module 104. Although onboard the aircraft 100, the control module 104 is shown as a separate functional block, but in some embodiments, the control module 104 is integrated into a pre-existing mobile platform management system, avionics system, cockpit display system (CDS), flight control system (FCS) or aircraft flight management system (FMS). In some embodiments, the control module 104, the user input device 122, and the display system 120 are configured as a control display unit (CDU). In other embodiments, the control module 104 may be present in an electronic flight bag (EFB) or a portable electronic device (PED) such as a tablet, a cellular phone, etc. In embodiments where the control module is within an EFB or PED, the display system 120 and the user input device 122 may also be part of the EFB or PED.

[0022] The control module 104 may be operably coupled to any combination of the following aircraft systems, which are typically onboard systems: an autopilot system (AP) 106; a source of desired speed 108; a source of real-time (RT) aircraft state data 110; a source of aircraft constraints 112; a source of aircraft configuration data 114, including sensor information and pre-programmed information (equipment settings and weights); a source of throttle 116 settings; a source of thrust level 118 settings; a display system 120; and a user input device 122. In various embodiments, a communication system and structure 126 may reside on the aircraft and be used to communicatively couple the various onboard systems and external sources, such as a source of weather data 50, to the control module 104. The functionality of these aircraft systems and their interactions are described in more detail below.

[0023] In one embodiment, the expected speed 108 is a calibrated airspeed. In one embodiment, the expected speed 108 is a Mach speed. In various embodiments, the expected speed 108 may be provided manually via a user input device 122. In other embodiments, the expected speed 108 may be provided by a flight management system (FMS) in communication with a navigation database. The expected speed 108 may be obtained from a pre-programmed flight plan; in various embodiments, the flight plan provides an expected speed at one of a series of expected geospatial midpoints between takeoff and landing, and may also include performance data associated with each geospatial midpoint (non-limiting examples of performance data include expected navigation data, such as: expected airspeed, expected altitude, expected acceleration, expected flight path angle, etc.).

[0024] Real-time (RT) aircraft state data generally refers to navigation system data and inertial data. In some embodiments, the source of RT aircraft state data 110 may be a navigation system, and aircraft state data is sometimes referred to as navigation data. As used herein, "real-time" can be interchanged with current, instantaneous and actual (contrary to expectation). RT state data may include any of the following: instantaneous position (e.g., latitude, longitude, orientation, attitude), instantaneous trajectory (i.e., the direction in which the aircraft is traveling relative to some references), RT flight path angle, RT vertical speed, RT ground speed, RT instantaneous height (or height above ground level), and the current flight phase of aircraft 100. As will be understood in the art, in various embodiments, the source of aircraft state data 110 may include each of the following: aircraft data system (ADS), global positioning system (GPS), inertial reference system (IRS), or radio-based navigation system (e.g., VHF omnidirectional radio range (VOR) or long-range assisted navigation (LORAN)), and may include one or more navigation radio components or other sensors that are appropriately configured to support the operation of FMS. In various embodiments, the RT aircraft state data may be available via the communication system and structure 126 so other components such as the control module 104 and the display system 120 may further process and / or manipulate the aircraft state data.

[0025] The avionics status 124 data generally includes data specific to the components and systems of the aircraft 100, such as data that may be provided by sensors and / or equipment specifications. In one embodiment, the avionics status data may be organized into constraints 112, configurations 114, throttles 116, and thrusts 118. In one embodiment, the constraints 112 may include a preprogrammed starting weight for the aircraft 100. In one embodiment, the constraints 112 may control onboard systems to provide comfort during flight. In one embodiment, the constraints 112 may include a lookup table; in one embodiment, the constraints 112 may also include an aircraft / engine specific lookup table that associates engine thrust (T) levels with each throttle level angle (TLA) setting or position from minimum TLA to maximum TLA. For example, in Figure 2 In the T versus TLA graph 200 shown in FIG. 2 , it can be observed that at the lowest TLA 202 there is an associated minimum thrust T idle 204, and T is fairly flat as TLA increases to TLA 206. From TLA 206 to TLA 208, there is a steeper and more linear positive relationship between TLA and engine thrust T. After TLA 208, T flattens out again, so that as TLA continues to increase to its maximum value (T max ) is close to the maximum value. It will be appreciated that the T versus TLA graph 200 will be different for different aircraft and engines. The information embodied in the T versus TLA graph may be stored as a lookup table in aircraft-specific storage, such as constraints 112.

[0026] return Figure 1 , configuration 114 may represent current (real-time) sensed component and system information and / or status of each of the various onboard avionics systems; specific to the present disclosure, RT aircraft configuration data collectively includes current weight (W), status of aircraft wings, landing gear position, transmission status, airbrake status, wing status, etc.

[0027] Although throttle and thrust can be considered part of configuration 114, for the embodiments herein, we separate them. The throttle 116 setting provides the current (real-time) sensed throttle horizontal angle (TLA) setting. The thrust 118 setting provides the current (real-time) sensed thrust (T) level, generally in the range of idle to maximum. Figure 2 As mentioned, there is a relationship between T and TLA, but it may not be linear.

[0028] During operation, the components of the avionics status data self-report or provide corresponding real-time (RT) performance data and sensory data for further processing. Thus, at least thrust (T) level, weight (W) and throttle level angle (TLA) settings are continuously updated for further processing.

[0029] The source of weather data 50 provides current weather conditions. The control module 104 utilizes some weather conditions, such as wind, effective airspeed, etc.

[0030] In various embodiments, communications between the aircraft 100 subsystems are managed by the communication system and structure 126. The communication system and structure 126 is configured to support instantaneous (i.e., real-time or current) communications between the onboard systems (i.e., navigation system, navigation database, various avionics systems, FMS), the control module 104, and one or more external data sources 122. As functional blocks, the communication system and structure 126 represents the hardware and software supporting communications required for one or more transmitters, receivers, and components of the system 102 to communicate as described herein. In various embodiments, the communication system and structure 126 may have additional communications not directly relied upon herein, such as two-way pilot to ATC (air traffic control) communications via data link; support for the Automatic Dependent Surveillance-Broadcast system (ADS-B); communication management function (CMF) uplink; terminal wireless local area network (LAN) unit (TWLU); instrument landing system (ILS); and any other suitable radio communication system that supports communications between the aircraft 100 and various external sources. In various embodiments, the control module 104 and the communication system and structure 126 also support controller and pilot data link communications (CPDLC), such as through an aircraft communications addressing and reporting system (ACARS) router; in various embodiments, this feature may be referred to as a communications management unit (CMU) or communications management function (CMF). In summary, the communication system and structure 126 may allow the aircraft 100 and control module 104 to receive information that would otherwise be unavailable to the pilot and / or co-pilot using only onboard systems.

[0031] As described in more detail below, the user input device 122 and the control module 104 are cooperatively configured to allow a user (e.g., a pilot, a co-pilot, or a crew member) to interact with the display device 20 and / or other elements of the system 102 in the display system 120. According to an embodiment, the user input device 122 can be implemented as a cursor control device (CCD), a keypad, a touch pad, a keyboard, a mouse, a touch panel (or a touch screen), a joystick, a knob, a line selection key, a voice controller, a gesture controller, or other suitable devices suitable for receiving input from a user. When the user input device 122 is configured as a touch pad or a touch screen, the user input device can be integrated with the display system 120. As used herein, the user input device 122 can be used to modify or upload a program product 166, overwrite a program when it is running, etc. In various embodiments, the display system 120 and the user input device 122 are airborne on the aircraft 100 and are also operably coupled to the communication system and structure 126.

[0032] In various embodiments, the control module 104 is loaded with instructions 160, either alone or as part of a central management computer (CMS) or flight management system (FMS), and is thereby programmed with instructions 160. The control module executes the instructions 160 and thereby draws input data and information to provide real-time flight guidance for the aircraft 100. This real-time flight guidance may be provided to the user via graphics and commands for the display system 120, audio system, etc. For example, the control module 104 may compare the instantaneous (current) position and heading of the aircraft 100 to the prescribed or expected flight plan data for the aircraft 100 and generate display commands to render the image 22 to distinguish these features. The control module 104 may also associate the corresponding airport, its geographic location, the runway (and its corresponding orientation and / or direction), instrument procedures (e.g., approach procedures, arrival routes and procedures, takeoff procedures, etc.), airspace restrictions, and / or other information or attributes associated with the corresponding airport (e.g., width and / or weight restrictions of taxiway paths, surface type of runways or taxiway paths, etc.) with the instantaneous position and heading of the aircraft 100 and / or with the weather data 50.

[0033] The control module 104 generates display commands for the display system 120 to cause the display device 20 to render an image 22 thereon, including various graphical user interface elements, tables, icons, alerts, menus, buttons, and painted images, as described herein. The display system 120 is configured to continuously receive and process display commands from the control module 104. The display system 120 includes a display device 20 for presenting the image 22. In various embodiments described herein, the display system 120 includes a synthetic vision system (SVS), and the image 22 is an SVS image. In an exemplary embodiment, the display device 20 is implemented on one or more electronic display devices configured as any combination of the following: a head-up display (HUD), an alphanumeric display, a vertical status display (VSD), and a lateral navigation display (ND). In various embodiments, the display system 120 includes a primary flight display (PFD).

[0034] The rendering on the display system 120 may be handled by a graphics system, components of which may be integrated into the display system 120 and / or integrated within the control module 104. Display methods include various types of computer-generated symbols, text, and graphic information that represent, for example, pitch, heading, flight path, airspeed, altitude, runway information, waypoints, targets, obstacles, terrain, and required navigation performance (RNP) data in an integrated multi-color or monochrome form. Display methods also include various formatting techniques for visually distinguishing objects and routes among other similar objects and routes. The control module 104 may be considered to display the various images and selectable options described herein. In practice, this may mean that the control module 104 generates a display command, and in response to receiving the display command from the control module 104, the display system 120 displays, renders, or otherwise visually communicates graphic images associated with the operation of the aircraft 100 on the display device 20, and specifically, thrust guidance symbols and graphic images as instructed by the control module 104.

[0035] The control module 104 performs the functions of the system 102. As used herein, the term "module" refers to any device for facilitating communication and / or interaction between elements of the system 102 and performing additional processes, tasks, and / or functions to support the operation of the system 102, as described herein. In various embodiments, the control module 104 can be any hardware, software, firmware, electronic control component, processing logic, and / or processor device, alone or in any combination. According to the embodiment, the control module 104 can be functionally implemented or realized using the following items: a general-purpose processor (shared, dedicated, or group) controller, a microprocessor or a microcontroller that executes one or more software or firmware programs stored or programmed into a memory device; a content addressable memory; a digital signal processor; an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA); any suitable programmable logic device; a combinational logic circuit, including discrete gates or transistor logic; discrete hardware components and memory devices; and / or any combination thereof designed to perform the functions described herein.

[0036] Therefore, in Figure 1, an embodiment of the control module 104 is depicted as an enhanced computer system including a processor 150 and a memory 152. The processor 150 may include any type of processor or multiple processors, a single integrated circuit such as a microprocessor, or any suitable number of integrated circuit devices and / or circuit boards that work together to perform the described operations, tasks, and functions by manipulating electrical signals representing data bits at memory locations in the system memory and other processing of the signals. The memory 152 may include RAM memory, ROM memory, flash memory, registers, a hard disk, or another suitable non-transitory short-term or long-term storage medium capable of storing computer-executable programming instructions or other data for execution. The memory 152 may be located and / or co-located on the same computer chip as the processor 150. Generally speaking, the memory 152 maintains data bits and can be used as storage and / or scratch pads by the processor 150 during operation. The information in the memory 152 may be organized and / or imported from external data sources during the initialization step of the process; the information may also be programmed via the user input device 122. In some embodiments, the database 156 is part of the memory 152. In some embodiments, the instructions 160 , programs 162 , and storage variables 164 are pre-loaded into the memory 152 or database 156 , and thus internal to the control module 104 .

[0037] Program 162 includes the thrust seeker algorithm described previously, which includes rules and instructions that, when executed, convert the processor 150 / memory 152 / database 156 configuration into the control module 104, which performs the functions, techniques, and processing tasks attributed to the operation of the system 102. The novel program 162 and associated storage variables 164 can be stored in a functional form on a computer readable medium such as shown in memory 152. Although the illustrated exemplary embodiment is described in the context of a fully operational computer system, those skilled in the art will recognize that the mechanisms of the present disclosure can be distributed as a program product 166. As a program product 166, the program 162 can be stored and distributed using one or more types of non-transitory computer readable signal bearing media, such as a non-transitory computer readable medium carrying the program 162 and containing additional computer instructions therein for causing a computer processor (such as processor 150) to load and execute the program 162. Such a program product 166 can take a variety of forms, and the present disclosure applies equally regardless of the type of computer readable signal bearing medium used to perform the distribution. Examples of signal bearing media include: recordable media such as floppy disks, hard disks, memory cards, and optical disks, and transmission media such as digital and analog communication links. It should be understood that cloud-based storage and / or other technologies may also be used in certain embodiments.

[0038] In various embodiments, the processor / memory unit of the control module 104 is communicatively coupled (via bus 155) to an input / output (I / O) interface 154 and a database 156. The bus 155 is used to transfer programs, data, status, and other information or signals between the various components of the control module 104. The bus 155 can be any suitable physical or logical means of connecting computer systems and components. This includes, but is not limited to, direct hard-wired connections, fiber optics, infrared, and wireless bus technologies.

[0039] The I / O interface 154 enables the inter-frame control module 104 to communicate, and enables the control module 104 to communicate with other system 102 components, and enables the control module 104 to communicate with external data sources via the communication system and structure 126. The I / O interface 154 may include one or more network interfaces, and may be implemented using any suitable method and device. In various embodiments, the I / O interface 154 is configured to support communication from an external system driver and / or another computer system. In one embodiment, the I / O interface 154 is integrated with the communication system and structure 126 and directly obtains data from an external data source. In addition, in various embodiments, the I / O interface 154 can support communication with a technician, and / or one or more storage interfaces for being directly connected to a storage device (such as a database 156).

[0040] As mentioned, the primary flight display (PFD) helps to easily identify whether the aircraft is creeping or descending. When the FPA cue position is above the horizon, the aircraft is creeping, and when the FPA cue position is below the horizon, the aircraft is descending. As disclosed in U.S. Patent Application Publication No. 15 / 700,416 to Wyatt et al., "AUTOMATIC FLIGHT CONTROL SYSTEMS AND METHODS," adding a potential flight path angle (PFPA) cue to the PFD improves the pilot's recognition of the current energy state of the aircraft. The PFPA cue above / below the FPA cue indicates that the aircraft is accelerating / decelerating along its current flight path or trajectory.

[0041] The novel thrust guidance algorithm providing enhanced features converts the flight guidance system into an enhanced flight guidance system having technical improvements over conventional flight guidance systems having at least the following features: generating a single acceleration command (PFPA) for the thrust guidance T cmd 52), which is common to both thrust guidance modes; and rendering unique and visually distinguishable symbology that represents the acceleration command (described below). Figure 3Thrust seeker cues 306, which are scaled to potential flight path angles (PFPA). During operation, processor 150 loads and executes one or more programs, algorithms, and rules embodied as instructions and application programs 160 contained within memory 152, and thereby controls the general operation of control module 104 and system 102. With specific reference to the processes and tasks described herein, processor 150 loads program 162, which is uniquely programmed with a novel thrust seeker algorithm. Now moving to Figure 3-5 And continue to refer to Figure 1-2 , describing the operation and performance of the thrust seeker system 102.

[0042] exist Figure 3 , a primary flight display (PFD) 300 is shown with a flight path angle cue (FPA) 302. In various embodiments, a potential flight path angle (PFPA) 304 cue represents the flight path angle that can be maintained at the current airspeed. Speed ​​tape 308 is vertical on the left. As mentioned, the thrust seeker control module 104 generates an acceleration command PFPA cmd 52 and associated thrust guide prompt 306. In various embodiments, and as Figure 3 As shown, the thrust guide cue 306 is shaped as half of a hexagon, i.e., 3 adjacent sides of the hexagon, and the cue is scaled to the same unit as the PFPA cue 304 (the middle portion of the vertical hexagon). Figure 3 As shown, PFPA cue 304 is slightly enveloped by thrust director cue 306 that opens to the left: a first side and a third side of thrust director cue 306 are angled toward PFPA cue 304 and slightly envelope PFPA cue 304); thrust director cue 306 is aligned on the same lateral axis as PFPA cue 304. In other embodiments, thrust director cue 306 may have other shapes. It should be understood that control module 104 continuously calculates current acceleration (A) based on the current velocity at the trajectory or flight path angle (FPA) of aircraft 100. FPA ).

[0043] The potential flight path angle (PFPA) 304 represents the flight path angle that can be maintained at the current airspeed. It can be defined using a small angle approximation, as shown in the following formula 1:

[0044]

[0045] Where FPA302 is the flight path angle of the aircraft, a FPA is the acceleration along the flight path angle (also called the trajectory and flight path vector), and g is the acceleration due to gravity. Note that acceleration is the only variable for a given FPA 302, and the current acceleration (aFPA Current) is plugged into Equation 1 to obtain the current PFPA 304. Since the difference between the PFPA and the flight path of the aircraft represents the current acceleration / deceleration, this indicator provides a simple frame of reference for the pilot to manually control the airspeed of the aircraft or to move the aircraft to a desired airspeed at a predetermined acceleration / deceleration.

[0046] As mentioned, there are two basic thrust guidance modes:

[0047] · Speed ​​control mode ; where guidance is provided to maintain the vehicle at a target airspeed.

[0048] · Thrust control mode ; where guidance is provided to keep the aircraft at a fixed engine thrust (based on engine rating and performance values), and the AFCS controls the aircraft's speed.

[0049] Advantageously, the new thrust seeker algorithm provides the same PFPA for each of these situations. cmd 52 and thrust guider prompt 306, regardless of which of the two thrust guidance modes is used. In addition, the thrust guider algorithm implements a unique acceleration limiting technique so that the provided PFPA cmd 52 and thrust director cues 206 are ensured to be achievable given the current engine, its current maximum and minimum throttle level angles, and the current aircraft configuration. Acceleration limiting is performed by system 102 as described below.

[0050] Referring back to Equation 1, PFPA is defined as the current FPA plus the acceleration / deceleration along the current flight path. PFPA 304 may also be defined using a small angle approximation and thrust (T) and drag (D), as shown below in Equation 2:

[0051]

[0052] Where T represents the thrust at the current throttle level angle (TLA), D is the current drag of the aircraft, and W is the current weight of the aircraft. Solving this side of Equation 2 requires that T and D be available in the current aircraft configuration.

[0053] As mentioned, for a given FPA 302, acceleration may be a variable with a range. To obtain the acceleration a of the aircraft 100 at a given FPA 302, FPA Range limits require the use of the T limits of the aircraft 100 (which are engine constraints) to project potential flight path angles. For a given TLA, the projected potential flight path angle is denoted as PPFPA TLAIn other words, for any given throttle level angle (TLA), the projected potential flight path angle (PPFPA) TLA ) can be calculated according to Formula 3.

[0054]

[0055] In Formula 3, the subscript “proj” is used to indicate the projected value. TLA represents the projected potential flight path angle at a given throttle level angle, T TLA It represents the thrust at a given throttle horizontal angle, D Proj It means that once T is achieved TLA is the projection drag acting on the aircraft, and W is the weight of the aircraft.

[0056] As mentioned, T can be easily projected across the throttle quadrant, for example, using a lookup table to obtain Figure 2 , (for example, this may be pre-programmed aircraft-specific data provided by the aircraft manufacturer) to obtain T max and T idle However, projecting the drag, D, is more complex and requires high-fidelity data from the aircraft manufacturer, which is not always available. This creates technical problems in generating a meaningful drag, D component. By deriving Proj PPFPA TLA The new thrust seeker algorithm solves this technical problem. To achieve this, first write Formula 3 in the form shown in Formula 4 below:

[0057]

[0058] As used herein, T TLA_Actual is the current thrust T at TLA, and D Actual is the current resistance. Using the relationship shown in Formula 2, we can rewrite the first term of the formula as shown in Formula 5 below:

[0059]

[0060] In most operating situations, D Proj With D Actual The error between is small and can be considered minimal. In addition, as the vehicle thrust (T) approaches the new or commanded thrust T TLA When D Proj With D Actual The error between is reduced to essentially zero. Therefore, we can approximate the PPFPA at a given TLA without using the resistance D component, as shown in the following Equation 6:

[0061]

[0062] Therefore, using Equation 6, the new thrust seeker algorithm is calculated by targeting T TLA_proj Insertion maximum thrust (T max ) to estimate T max Under PPFPA TLA And by targeting T TLA_proj Insertion idle thrust (T idle ) to estimate T idle Under PPFPA TLA In one embodiment, the estimated PPFPA TLA The value represents the acceleration / deceleration limit that the aircraft 100 can achieve (i.e., the maximum PPFPA TLA and minimum PPFPA TLA ), the aircraft is given its current engines, its current maximum and minimum TLA, and the current aircraft weight. In one embodiment, the estimated PPFPA TLA The value represents the acceleration / deceleration limit that the aircraft 100 can achieve (i.e., the maximum PPFPA TLA and minimum PPFPA TLA ), the aircraft is given its current engines, its current maximum and minimum TLA, and the current aircraft configuration.

[0063] The control module 104 including the thrust seeker algorithm executes the thrust seeker algorithm to thereby adjust the thrust according to the estimated PPFPA TLA Value generation PFPA cmd 52 and associated thrust guider prompt 206. The calculations are done differently for speed control mode and thrust control mode.

[0064] For the speed control mode, the system 102 uses the speed control scheme shown in the data flow diagram 400 to generate the PFPA acceleration command PFPA cmd 52, which is a function of the velocity error, such as Figure 4 The first step of the speed control scheme is to calculate the expected speed and the target speed V target The speed error between V 402 and the actual or real-time speed V 404 (whether calibrated airspeed or Mach number, which is responsive to the pilot's selection) and converts the speed error to an equivalent true airspeed error 407. The actual or real-time speed V 404 may be derived from an air data system (ADS), IRS, or other avionics sensor system. Filtering 406 may be performed based on the actual or real-time speed V 404 determined by available onboard sensors to provide appropriate noise suppression.

[0065] In process 408, the control module 104 converts the true airspeed error 407 into a desired acceleration command 410. Process 408 refers to aircraft specific constraints for gains to handle the true airspeed error 407. In one embodiment, the gain is a fixed value. In one embodiment, the gain is a function of the following terms: weight, center of gravity, and altitude. The output of process 408 (desired acceleration command 410) is a delta acceleration per unit speed error. The desired acceleration command 410 is input to the acceleration limit process 412.

[0066] The acceleration limiting process 412 receives the desired acceleration command 410 and applies acceleration limits to it using constraint data. In various embodiments, the constraint data used to apply acceleration limits include aircraft weight, engine performance data, throttle level angle (TLA) minimum value, throttle level angle (TLA) maximum value, idle thrust (T idle ), maximum thrust (T max ) etc., to generate output based thereon. In various embodiments, the constraint data includes a T pair TLA table; Figure 2 As mentioned, T vs. TLA is not linear. Therefore, the acceleration limiting process 412 acts as a pre-programmed acceleration limiter because it references existing constraints rather than sensors. In various embodiments, the acceleration limiting process 412 may be any combination of: representing a relaxation / comfort modification (e.g., for commercial flights where passengers expect a smooth ride with gentle transitions), representing an aircraft-specific or mission-specific requirement, from the flight guidance system, and uploaded and stored in the memory 152 as part of the program 162 and storage variables 164. Depending on the embodiment, any one or more may apply: the acceleration limiting process 412 may be modified for each application, may be modified to employ variable acceleration limits at different parts of the velocity envelope, and may be modified to employ variable acceleration limits based on the phase of flight.

[0067] After the acceleration limiting process 412 that generates the acceleration output, the acceleration output is translated into a delta flight path angle (ΔFPA) in process 414. In operation 416, the control module 104 adds the ΔFPA to the reference FPA to obtain an unrestricted potential flight path command. The reference FPA may be determined based on the coupling state to the autopilot / autopilot system and may be set to one of the following: an FPA command from the autopilot system, a filtered FPA, or a raw FPA. Process 414 and operation 416 represent a specific implementation of Formula 1 above.

[0068] In process 418, the output of operation 416 is subjected to the real-time available acceleration limit. Process 418 utilizes the maximum thrust (T max ) under PPFPA TLAand idling thrust (T idle ) under PPFPA TLA (Equation 6), and acceleration limiting is performed on them based on the sensed current configuration 114. In one example, real-time available acceleration limiting in process 418 is required when the flight path angle of the aircraft plus the required thrust change required by the thrust vector exceeds the PPFPA; in this case, the PFPA command will be limited by the PPFPA.

[0069] Before being commanded and displayed on the PFD, the output of process 418 undergoes display filtering at 420. Display filtering at 420 involves reducing jitter, thereby improving the human-machine interface and thereby improving the pilot handling quality of the displayed thrust director cues 306.

[0070] For thrust control mode, generally speaking, the pilot will want to use PPFPA max The acceleration of the crawling flight and the PPFPA min The acceleration of the downward flight. Figure 2 As shown, even if TLA is flipped from the minimum value to the maximum value instantaneously, a delay time can be observed in the transition of the thrust T to which the speed responds. The system 102 adopts the thrust control scheme shown in the data flow diagram, in which it generates a PPFPA (PPFPA) of the target thrust. target 504) and the PFPA acceleration command (PFPA cmd 52) Drive to the calculated PPFPA target 504. In various embodiments, the PPFPA target 504 is the acceleration output from process 412 described above.

[0071] At the initialization of the thrust control mode shown in the data flow diagram 500, the integrator 502 is initialized to the current PFPA 304 and driven to the target PPFPA (PPFPA 506) via the first order delay response (K 506). target 504) to allow for modification of the speed of the transition. The time constant K 506 is a variable. In various embodiments, K 506 is a function of each of the flight conditions, measured (ie, actual, real-time, current) acceleration, or the like. In addition, the aircraft 100 is ahead of the PFPA cmd 52 (such as may occur in uncoupled operation, creep to down, or down to creep transition), the PFPA compensation term 508 provides a mechanism to speed up the transient filter. As with the speed control mode, the PFPA cmd 52 is bounded by the available acceleration (PPFPA limit per Equations 6 and 7).

[0072] Figure 6 and Figure 7 306 is shown as what is visually communicated to the pilot by the new thrust director cue 306. Figure 6 , thrust vector prompt 306 is above PFPA prompt 304, indicating that thrust must be increased. Figure 7 In FIG. 3 , thrust vector prompt 306 is below PFPA prompt 304, indicating that thrust must be reduced. Figure 6 and Figure 7 , if the FPA 202 is depicted below the PFPA cue 204, the aircraft 100 is accelerating, as shown in FIG. Figure 2 however, if FPA 202 is depicted above PFPA cue 204, then aircraft 100 is decelerating.

[0073] Reference now Figure 8 , and continue to refer to Figure 1-7 , a flow chart of a method 800 for providing thrust guidance according to various exemplary embodiments is provided. For illustrative purposes, the following description of the method 800 may be combined with Figure 1-7 Reference is made to the elements mentioned above. In practice, portions of method 800 may be performed by different components of the described system. It should be understood that method 800 may include any number of additional or alternative tasks, Figure 8 The tasks shown in the method 800 need not be performed in the order shown, and the method 800 may be incorporated into a more comprehensive procedure or method having additional functionality not described in detail herein. In addition, the tasks shown in the method 800 may be omitted from the implementation of the method 800 if the intended overall functionality remains intact. Figure 8 One or more of the tasks shown in .

[0074] The method begins and at 802, the control module 104 is initialized. As mentioned above, initialization may include uploading or updating instructions and applications 160, programs 162, storage variables 164 such as T vs. TLA lookup tables, etc. Initialization at 802 may also include identifying weather information sources 50 and / or external signals and the communication protocols used with each thereof.

[0075] At 804, current aircraft state data including at least current airspeed and current flight path angle (FPA) is received. At 806, avionics data is received from one or more avionics 120 sources. In various embodiments, the avionics data includes constraints 112, configuration 114 information (including at least aircraft weight), throttle 116 level angle (TLA), and thrust 118 level (T).

[0076] An aircraft-specific and / or engine-specific thrust versus throttle level angle (T versus TLA) lookup table is consulted at 808. This lookup table conveys a specific relationship between throttle level angle and associated engine thrust, and is typically non-linear.

[0077] At 810, T is calculated based on the weight and the maximum TLA. max Projected Potential Flight Path Angle (PPFPA) of real-time TLA TLA At 812, T is calculated based on the weight and the minimum TLA. idle Under PPFPA TLA These calculated values ​​are projected values ​​that are a function of the information in the T vs. TLA lookup table, the aircraft weight, and the given real-time TLA.

[0078] At 814, according to T max Under PPFPA TLA and T idle Under PPFPA TLA Generate acceleration command (PFPA CMD At 816 , method 800 renders a representation of the PFPA on the primary flight display. CMD After 816, method 800 may end or return to 804.

[0079] It should be understood that the thrust introducer system 102 may be used with Figure 1 The thrust seeker system 102 may be integrated with an existing flight management system (FMS), flight control system (FCS), or cockpit displays in the aircraft 100 .

[0080] Thus, the exemplary embodiments discussed above provide a method for implementing a method for generating acceleration commands PFPA for all thrust guidance modes. cmd 52. These commands are then displayed on the same lateral axis as the potential flight path acceleration cues 204 on the primary flight display. The thrust seeker algorithm also provides acceleration limits for its commands based on the available energy of the aircraft in its current aircraft configuration. Acceleration-limited PFPA cmd The 52 scheme does not require drag to calculate acceleration limits, allowing the functionality to be deployed into aircraft that do not have high-fidelity drag data available, such as in the case of compound applications. The thrust seeker method and system 102 will improve the pilot's ability to control aircraft speed in uncoupled operations and increase the pilot's awareness of the acceleration / deceleration available in the current aircraft configuration. In addition, the thrust seeker scheme can be used as an outer loop of an autothrottle to translate flight path acceleration commands into desired throttle positions to achieve automatic speed or thrust control.

[0081] Although at least one exemplary embodiment has been presented in the aforementioned specific embodiments of the present invention, it should be understood that there are a large number of variations. It should also be understood that an exemplary embodiment or multiple exemplary embodiments are only examples and are not intended to limit the scope, applicability or configuration of the present invention in any way. On the contrary, the aforementioned specific embodiments will provide a convenient roadmap for implementing the exemplary embodiments of the present invention for those skilled in the art. It should be understood that, without departing from the scope of the present invention as set forth in the appended claims, various changes may be made to the functions and arrangements of the elements described in the exemplary embodiments.

Claims

1. A processor-implemented method for providing thrust guidance on a primary flight display (PFD) of an aircraft, the method comprising: Receive expected airspeed; Receive the current airspeed and the current flight path angle FPA from the status data source; receiving from an avionics data source real-time engine thrust T level, real-time throttle level angle TLA, constraint data including a thrust T versus throttle level angle TLA table, and real-time weight; The thrust seeker algorithm is executed at a control module including the thrust seeker algorithm to thereby perform the following operations: Calculating an airspeed error between an expected airspeed and a current airspeed, and converting the airspeed error into an equivalent true airspeed error; converting the equivalent true airspeed error into a desired acceleration command for achieving the desired airspeed, wherein the desired acceleration command is an acceleration limited by constraint data from the thrust T versus throttle horizontal angle (TLA) table to generate an acceleration output; translating the acceleration output into an incremental flight path angle FPA; Add the delta FPA to the reference FPA to obtain an unlimited potential flight path command; Reference the vehicle constraint data to obtain T max and T idle , where T max is the maximum thrust and T idle It is the idling thrust; Calculate T based on weight and maximum TLA max Projected potential flight path angles under real-time TLA PPFPA TLA ; Calculate T based on weight and minimum TLA idle PPFPA TLA ; By using the unlimited potential flight path command as the unlimited potential flight path command, T max PPFPA TLA and T idle PPFPA TLA The function generates the acceleration command PFPA by limiting the available acceleration in real time CMD ; commanding the PFD to render symbology representing a PFPA advisory indicating an FPA that can be maintained at the current airspeed; as well as The PFD is commanded to render symbology representing the acceleration command, wherein the symbology representing the acceleration command is scaled to the same units as the PFPA cue, and wherein a flight path angle cue representing the current flight path angle is further rendered on the PFD. The method of claim 1 , wherein the constraint data further comprises a comfort modification.

3. The method according to claim 1, further comprising: Display filtering is preformed before rendering the acceleration commands.

4. The method of claim 3, wherein the symbology representing the acceleration command is a thrust vector cue shaped as 3 adjacent sides of a hexagon.

5. A system for providing thrust guidance on a primary flight display (PFD) of an aircraft, comprising: Expected airspeed source; A state data source, which provides the current airspeed and the current flight path angle FPA; an avionics data source providing real-time engine thrust T level, real-time throttle level angle TLA, constraint data (112) including a thrust T versus throttle level angle TLA table, and real-time weight; and A control module comprising a processor programmed to, when instructed, perform the method of any one of the preceding claims.

Images