APPROACH SYSTEM SELECTION

Systems and methods for approach system selection are provided herein. In certain embodiments, a method includes receiving an approach identifier. Further, the method includes identifying a plurality of approach modes associated with the approach identifier. Additionally, the method includes selecting an approach mode in the plurality of approach modes based on an integrity measure of navigation guidance associated with separate approach modes in the plurality of approach modes. Moreover, the method includes providing the navigation guidance for the selected approach mode to an approach system for guiding a vehicle through an approach for the selected approach mode.

BACKGROUND

Multiple landing systems may be available to provide approach information to aircraft to help the aircraft safely land on a specific runway. The approach information may include course and glidepath guidance that helps the aircraft follow a desired approach path towards the runway. During the approach towards the runway, a flight crew member may tune a receiver or other similar device to a mode, frequency, and/or channel associated with one of the landing systems for the runway. After tuning the receiver to the mode/frequency/channel, the selected landing system is used as the basis for providing navigation guidance to the aircraft in relation to the desired approach path for the runway.

SUMMARY

Systems and methods for approach system selection are provided herein. In certain embodiments, a method includes receiving an approach identifier. Further, the method includes identifying a plurality of approach modes associated with the approach identifier. Additionally, the method includes selecting an approach mode in the plurality of approach modes based on an integrity measure of navigation guidance associated with separate approach modes in the plurality of approach modes. Moreover, the method includes providing the navigation guidance for the selected approach mode to an approach system for guiding a vehicle through an approach for the selected approach mode.

Per common practice, the drawings do not show the various described features according to scale, but the drawings show the features to emphasize the relevance of the features to the example embodiments.

DETAILED DESCRIPTION

The following detailed description refers to the accompanying drawings that form a part of the present specification. The drawings, through illustration, show specific, illustrative embodiments. However, it is to be understood that other embodiments may be used and that logical, mechanical, and electrical changes may be made.

The present disclosure describes systems and methods for selecting approach systems. Some vehicles receive navigation guidance during an approach towards a destination. For example, aircraft may receive approach guidance when approaching a runway. The approach guidance helps the aircraft be at an appropriate decision height when a pilot decides to land or abort the landing attempt.

Many approach systems have been designed that use different methods and equipment to provide approach guidance to aircraft. Because of the different methods and equipment, the different approach systems have different capabilities and are subject to various issues that can impair approach system performance. The present disclosure describes methods and systems for selecting an appropriate approach system that engages with associated approach facilities at a runway, or other destination, based on quality measures of the available approach systems. By selecting an approach system based on a quality measure, the methods and systems described herein may reduce the attention needed from individuals when selecting an approach system, allowing the individuals to focus on landing the aircraft and any emergencies that could arise.

FIG.1is a diagram illustrating an aircraft101approaching a runway103for landing. The term “aircraft,” as used herein, may refer to any vehicle capable of flying, including airplanes, helicopters, drones, rockets, missiles, and the like. Alternatively, while the description may use the term “aircraft,” the teachings described herein may apply to vehicles generally. Vehicles may include automobiles, boats, submarines, among other vehicles. Accordingly, embodiments described herein that apply to aircraft may apply to vehicles generally.

As shown, the aircraft101approaches a runway103for landing. When landing, the path followed by an aircraft101towards a runway103may determine whether the aircraft101can successfully land at the runway103. Accordingly, an aircraft101may follow a feeder route, where the aircraft101moves from the en route structure to an initial approach segment. During the initial approach segment, the aircraft101positions itself for an intermediate or final approach segment. At the final approach segment, the aircraft101follows an approach path105or glidepath down to the runway103. As runways are located at different locations, having different surrounding geography, the approach paths can vary from runway to runway.

Frequently, approach facilities can be installed at or be associated with runways103that support different approach procedure(s). The facilities include ground-based approach facilities109and110or airborne approach facilities107. The facilities provide signals to an approach system on the aircraft to guide the aircraft101along the approach path105. The term “approach system,” as used herein, refers to an integrated system located on a vehicle (like the aircraft101) that exchanges information with the approach facilities to aid the approach of the vehicle towards a particular destination. For example, an approach system may receive signals from the ground-based approach facilities109and110to support an instrument landing system (ILS), a ground-based augmentation system (GBAS) landing system (GLS), or other types of ground-based approach facilities109and110that aid a vehicle during an approach towards a runway103or other destination. Also, an approach system may receive signals from the airborne approach facilities107to support a GLS, a localizer performance with vertical guidance landing system (LPV), or other types of airborne approach facilities107that are designed to aid a vehicle during an approach towards a runway103or other destination.

As mentioned above, the ground-based approach facilities109and110may be associated with the runways103to support the operations of approach systems on aircraft approaching the runways103. For example, the ground-based approach facilities109may be associated with multiple runways103at one airport or runways103at multiple airports, such as ground-based approach facilities used to support GLS approach systems. Additionally, the ground-based approach facilities109may be specific to a particular runway103, such as the ground-based approach facilities110, which may include a glide-slope station110-1and a localizer station110-2with each runway such as those used to support ILS approaches. Additionally, the runways103may be associated with various combinations of ground-based approach facilities109and110and airborne-based approach facilities107to support different combinations of approach systems.

Guidance signals provided by the different airborne approach facilities107and the different ground-based approach facilities109and110may have different levels of accuracy and, potentially, may be affected by different sources of error. For example, GLS and LPV approach systems may use measurements from GNSS satellites107when providing guidance signals. GNSS satellites may be subject to availability issues, such as the loss of signals from a satellite due to blocking of the signals by the aircraft101during maneuvers of the aircraft101. Additionally, environmental issues (such as spoofing, interference, etc.) may affect the integrity of the resultant measurements. ILS approach systems may be sensitive to obstructions, terrain changes, and potential reflections of transmitted signals within a signal broadcast area. Also, an ILS approach system may receive a notice (such as a notice to airman (NOTAM)) indicating that the ground-based approach facilities110are experiencing an outage or limiting the approaches that can be performed by the aircraft101. Because of the different benefits and potential drawbacks provided by different approaches, different approach systems may be desirable for use during different situations.

Typically, when an aircraft101approaches a runway103, the pilot or other crew member may receive instructions from an air traffic controller (ATC) instructing the pilots to use particular approach instructions until the aircraft101arrives at a particular location, where the pilot may then select a particular approach mode. When selecting the approach mode, the pilot or crew may use the approach system on the aircraft to select one of several potential approach modes. After selecting one of the potential approach modes, the pilot or equipment on the aircraft101determines whether or not the selected approach mode is supported by facilities associated with the runway103. If the selected approach mode is supported, the pilot or equipment can then determine whether the selected approach mode provides navigation guidance with sufficient integrity or whether the approach mode can safely guide the aircraft along an approach path. If the selected approach mode is unavailable or fails to provide sufficiently safe guidance, the pilot may use the onboard instrumentation to select another potential approach mode. The pilot may repeat the above-described process for selecting an approach mode and checking if the selected approach mode provides sufficiently safe navigation guidance until the pilot selects an approach mode supported by facilities associated with the runway103that provides sufficiently safe navigation guidance to the aircraft101. This typical approach for selecting approach systems unduly burdens the time and attention of the pilot when preparing the aircraft101for landing on the runway103.

In exemplary embodiments, the aircraft101may have an onboard approach system that allows a pilot to provide just an approach identifier to the approach system to select an approach mode. The approach system uses the approach identifier to acquire information about the approach modes associated with the approach identifier and then determines which of the available approach modes provides navigation measurements with the highest integrity, highest probability of availability, or other quality measure. When the approach system selects the approach mode, the approach system may begin to generate navigation guidance for guiding the aircraft101down the approach path105to land safely on the runway103. As used herein, the term “approach identifier” may refer to information that identifies the approach destination. For example, the approach identifier may identify a runway or other type of approach destination. As used herein, the term “quality measure” may refer to a quantitative measurement of the usability of the navigation guidance provided for a specific approach mode and may include measurements of integrity, accuracy, continuity, and the like.

In exemplary embodiments, implementing an approach system that evaluates the available approach modes for an approach identifier decreases a pilot's workload during a final approach. The reduction of workload may enable the pilot to perform other vital duties related to the planning and execution of the approach of the aircraft101towards the runway103.

FIG.2is a block diagram of a system200for selecting an approach mode. The system200includes an approach system223and an external system225. The approach system223may reside on a vehicle, such as the aircraft101inFIG.1. The approach system223may receive an approach identifier and identify an approach mode for use by a vehicle performing an approach towards a final destination. At times, the approach system223may communicate periodically with one or more external system(s)225. The external system(s)225may provide information to the approach system223regarding the approach modes associated with a particular approach identifier. Alternatively, the external system(s)225may provide approach information regarding multiple approach modes associated with multiple approach identifiers for later use by the approach system223.

In certain embodiments, the approach system223may include a management system201and a navigation system203. While illustrated as separate components, the management system201and the navigation system203may operate as the same component. For example, when operating as the same component, the same computational resources may function as the navigation system203and the management system201. Alternatively, separate (either physically separate or through partitioning) computational resources may function as the management system201and the navigation system203. When the management system201and the navigation system203are separately or independently functioning systems, some of the functionality described as being performed by the navigation system203may be performed by the management system201and vice versa.

In exemplary embodiments, the management system201may store information about the travel of a vehicle associated with the approach system223. For example, the management system201may be a communication management unit, a flight management system, or other device for managing and controlling various devices and systems within the approach system223and onboard the vehicle. Further, when the vehicle is an aircraft, the management system201may store flight information, such as flight plans, and manage information received through the various devices on the aircraft. For example, the management system may connect to devices, such as a user interface219and display devices217. Additionally, the management system201may receive navigation solutions and other navigation information from the navigation system203. In some implementations, the management system201receives navigation information from the navigation system203and calculates guidance information related to an approach path. Alternatively, the management system201may receive guidance information from the navigation system203.

As illustrated, the management system201may include a processor205and storage207. The processor205may execute computer-readable instructions that direct the processor205to perform management tasks for the approach system223. For example, as stated above, the management system201may be connected, through various interfaces, to multiple devices within the approach system223and other devices within the vehicle. Accordingly, the processor205may receive data through the various interfaces connected to the management system201. Additionally, the processor205may execute instructions stored in the storage207and store information received through the interfaces in the storage207.

In certain embodiments, the navigation system203is a device that provides information related to the navigation solution of the vehicle. In some embodiments, the navigation system203may measure the motion of the vehicle and calculate a navigation solution for the vehicle based on the measurements. Alternatively, the navigation system203may measure the motion of the vehicle and provide the measurements (fused measurements from multiple sensors, processed measurements, raw measurement data, etc.) to the management system201, where the management system201calculates the navigation solution for the vehicle.

To measure the motion of the vehicle, the navigation system203may include sensors215. The sensors215may be devices that acquire information about the environment and the motion of the vehicle. For example, the sensors215may include global navigation satellite system receivers, IMUs, gyroscopes, accelerometers, barometers, altimeters, velocimeters, thermometers, magnetometers, hygrometers, and other sensors that provide information related to the navigation state of the vehicle.

In further embodiments, the navigation system203may include a processor209. The processor209functions similarly to the processor205in that the processor209executes instructions and processes data received from memory storage devices and other data-producing devices (such as the sensors215).

In certain embodiments, the navigation system203may include a transceiver213, where the transceiver213is designed to receive signals associated with multiple approach modes for facilities located at various destinations to which the vehicle could travel. For example, the transceiver213may be a multi-mode receiver (MMR), an integrated MMR (IMMR), or other devices facilitating communication between an approach system and the vehicle. Additionally, the transceiver213may include multiple receivers that are configured to receive signals from facilities associated with the different approach modes. In some implementations, the transceiver213may include processing capabilities that perform some of the functionality ascribed to the processor209. In particular, the transceiver213may include logic for selecting an approach mode.

In exemplary embodiments, the transceiver213receives GNSS signals. For example, the transceiver213may receive GNSS signals through one or more antennas211to support approach modes that use GNSS measurements. In some implementations, the transceiver213may be tuned to receive one or more VHF Data Broadcast (VDB) signals transmitted from some of the ground-based approach facilities at an airport to provide corrections to the GNSS measurements (such as in ground-based augmentation system (GBAS)). Upon receipt of sufficient GNSS signals from GNSS satellites, the transceiver213, processor209, or processor205may determine the distance between the transceiver213and the GPS satellites and the position of the GPS satellites. Based on the determined distances and positions, along with corrections from a GBAS or a satellite-based augmentation system (SBAS), the processor209determines various navigation parameters that include, for example, aircraft position, groundspeed, and ground track angle. The processor209(or the processor205) may calculate deviations from an intended approach path and distance to threshold at a particular destination using the navigation parameters and corrections.

In additional embodiments, the transceiver213may receive VHF, MLS, or other signals from approach facilities. For example, the transceiver213may be tuned to receive VHF signals through the antenna211from a ground station (such as an external system225) associated with a particular approach destination. In some implementations, the transceiver213may receive the VHF and GNSS signals simultaneously through separate antennas211. The VHF signals may include corrections for GNSS signals. Also, the VHF signals may include broadcast information used to define a reference path typically leading to the approach destination.

In further embodiments, the transceiver213may receive radio signals related to an ILS. For example, the transceiver213may be tuned to receive two directional radio signals. One of the radio signals is a localizes signal that provides horizontal guidance, and the other radio signal is a glideslope signal that provides vertical guidance. The processor209or the processor205receives and processes the radio signals to determine the relationship between the vehicle position and the signals.

In certain embodiments, the navigation system203further includes various databases for storing information. As illustrated, the navigation system203stores an approach database221. Additionally, the navigation system203may also store other databases that contain approach models for specific approach modes, such as an LPV database. The approach database221(and other databases) is stored on a memory device on the navigation system203or in the storage207. Further, the approach database221stores approach identifiers and approach information. As used herein, an approach identifier is a code, name, number, or other means for identifying a specific approach destination. Further, “approach information” refers to information describing the approach systems available at an approach destination described by a particular approach identifier. Also, the approach information may include connectivity information that can be used by the processor209to establish communications or receive signals associated with a particular approach mode. For example, the approach database221may store an approach identifier for an approach destination and then associate approach information for that approach destination with the approach identifier.

In exemplary embodiments, the approach database221may be updated to ensure that the approach database221has the information describing at least the approaches used by the associated vehicle. To update the approach database221, to get approach information associated with the region where the vehicle is located, or other subset of the available approach information the approach system223may communicate periodically with an external system225. The external system225may be any system that provides approach information located outside of the vehicle. The external system225may be a ground station, another aircraft, a mobile communication system, an air traffic controller (ATC) center, an airline operation center, or other system that can communicate with the approach system223.

In some embodiments, the external system225includes a transceiver231The transceiver231can transmit and receive communications with the approach system223through an antenna233. Additionally, the external system225includes a processor229. The processor229may function similarly to the processors209and205regarding the execution of instructions. Additionally, the external system225may include storage227, Which stores approach information updates for transmission to connected approach systems223. The processor229communicates with the approach system223through the receiver231to transmit the approach information updates to connected approach systems223.

In certain embodiments, the approach system223may request an update to the approach database221through the transceiver213. In response to the requested update, the external system225may transmit the requested approach information updates to the approach system223. Alternatively, when the approach system223is within a transmission range of the external system225, the external system225may push approach information updates to the approach system223to update the approach database221. Additionally, the external system225may provide approach information updates to the approach database221such that the approach database2211is a copy of a similar approach database stored in the storage227. Alternatively, the external system225provides approach information updates for the data stored in the approach database221, where the approach database221is a subset of the approach information stored in the storage227. Additionally, the external system225may broadcast approach information indicating which approach modes are supported within an associated geographic location.

While the external system225is shown as communicating with the approach system223through a wireless communication link, the external system225may provide approach information updates to the approach database221through any means of data exchange. For example, the external system225may provide approach information updates to the approach database221through a wireless communication link, GateLink, a data-loader, an Ethernet connection, or other forms of communicating data between two different devices.

In certain embodiments, when selecting an approach mode, the management system201(or navigation system203and transceiver213) may receive an approach identifier from the user interface219. The user interface219may be a device through which a user can input an approach identifier. Alternatively, the approach identifier can be received from another device, transmitted from another system (like an ATC center), or identified from the location of the vehicle and approach identifiers associated with the location of the vehicle. The user interface219then provides the approach identifier to the processor209in the navigation system203through the management system201. The processor209uses the approach identifier to look up approach information associated with the approach identifier in the approach database221. Alternatively, some approach systems223may lack an approach database221. When the approach systems223lack an approach database221, the navigation system203may transmit the approach identifier to an external system225, which, in response to receiving the approach identifier, transmits back approach information associated with the approach identifier to the approach system223.

In certain embodiments, when the processor209acquires the approach information from the approach database221, the processor209may then determine which of the approach modes, described in the approach information, provides guidance having the highest quality measure. For example, the processor209may determine an integrity measure for each of the approach systems. As used herein, an integrity measure may be a measurement of the trustworthiness of the measurements. For example, integrity measurements may include protection levels, exclusion thresholds, and other measurements associated with the integrity of the guidance provided through a particular approach mode. Other types of quality measures may include accuracy measures, continuity measures, and the like. After determining a quality measure for the different approach modes, the processor209may select the approach mode that provides measurements with the most desirable quality measure. For example, the processor209may select the approach mode having the measurements with the highest integrity.

In further embodiments, the processor209may then provide navigation guidance to the management system201. The navigation guidance may include a measurement of the deviations of the vehicle's current path from the intended approach path. Additionally, the navigation guidance may include suggested maneuvers or corrections that can be made to bring the vehicle closer to the intended approach path. Upon receiving the navigation guidance from the processor209, the processor205may provide the navigation guidance for display on one or more display devices217to the user. For example, the display device217may display the navigation guidance information as a relationship between a vehicle's position and the intended approach path.

In exemplary embodiments, after selecting the approach mode having the measurements with the highest quality measure and providing navigation guidance associated with the selected approach mode to the management system201, the processor209may continue to evaluate the different approach modes associated with the approach identifier in the approach database221. For example, the processor209may monitor the quality measure of the selected approach mode. If the quality measure falls below a specified quality threshold (such as a specified integrity threshold), the processor209may select a non-selected approach mode producing measurements with the highest quality measure. Alternatively, the processor209may monitor the quality measure (such as an integrity measure) of the measurements for each of the available approach modes. If the quality measure of measurements from one of the non-selected approach modes exceeds the quality measure of the measurements for the selected approach mode, the processor209may then select the non-selected approach mode to provide navigation guidance.

The processors205,209,229, and other computational devices used in the approach system223, the external system225, or other systems and methods described herein, may be implemented using software, firmware, hardware, or appropriate combinations thereof. In some implementations, a single processor may execute the functionality of any combination of the processor205and the processor209. For example, the functionality of the management system201may be incorporated in the navigation system203, or the functionality of the navigation system203may be incorporated in the management system201, such that the processor205or the processor209performs the processing tasks described above as being performed by processors in the approach system223.

The processors205,209,229, and other computational devices may be supplemented by, or incorporated in, specially-designed application-specific integrated circuits (ASICs) or field programmable gate arrays (FPGAs). In some implementations, the processors205,209, and/or other computational devices may communicate through an additional transceiver with other computing devices outside of the approach system223, such as systems other than the external system225or computing devices associated with other subsystems controlled by the management system201on the vehicle. The processors205,209,229, and other computational devices can also include or function with software programs, firmware, or other computer-readable instructions for carrying out various process tasks, calculations, and control functions used in the methods and systems described herein.

In some embodiments, the functions of the processors205,209, and229are performed by one or more processors. For example, the functionality of the processor205may be performed by multiple processors, such as a processor for communicating with the navigation system203, a separate processor associated with the user interface219, an additional processor for the display devices217, and other processors for other functionality. Similarly, multiple processors may perform the functionality ascribed above to the processor209. For example, a processor may perform calculations for the navigation solution, a separate processor may handle communications with the approach systems, and other processors may perform additional functionality.

The methods described herein may be implemented by computer-executable instructions, such as program modules or components, which are executed by at least one processor, such as the processors205,209, and229. Generally, program modules include routines, programs, objects, data components, data structures, algorithms, and the like, which perform particular tasks or implement particular abstract data types.

Instructions for carrying out the various process tasks, calculations, and generation of other data used in the operation of the methods described herein can be implemented in software, firmware, or other computer-readable instructions. These instructions are typically stored on appropriate computer program products that include computer-readable media used to store computer-readable instructions or data structures. Such a computer-readable medium may be available media that can be accessed by a general-purpose or special-purpose computer or processor, or any programmable logic device. For instance, the storage207, approach database221, and storage227may be examples of a computer-readable medium capable of storing computer-readable instructions and/or data structures. The storage207, approach database221, and storage227may also store navigation information such as maps, terrain databases, magnetic field information, path data, and other navigation information. Additionally, the storage207may store the approach database221, when the management system201and the navigation system203function as an integrated system within the approach system223.

Suitable computer-readable storage media (such as the storage207, approach database221, and storage227) may include, for example, non-volatile memory devices including semi-conductor memory devices such as Random Access Memory (RAM), Read Only Memory (ROM), Electrically Erasable Programmable ROM (EEPROM), or flash memory devices; magnetic disks such as internal hard disks or removable disks; optical storage devices such as compact discs (CDs), digital versatile discs (DVDs), Blu-ray discs; or any other media that can be used to carry or store desired program code in the form of computer-executable instructions or data structures.

FIGS.3and4contrast the effects of the systems and methods described herein on the process of selecting an approach mode. For example,FIG.3is a sequence diagram illustrating a typical selection of an approach mode. As shown, a crew/management system301interacts with a navigation system303. The crew/management system301may function similarly to the combination of the management system201connected to the display devices217and user interface219inFIG.2, where the management system201receives information from a flight crew member through the user interface219and provides information to the flight crew member through the display devices217.

As illustrated, when approaching an approach destination, the crew/management system301may begin at305by tuning a receiver in the navigation system303to a GLS channel. The navigation system303may then perform step307by checking if deviations from an intended approach path are available for a GLS approach. If there are no deviations, the navigation system303may proceed at307, where the navigation system303notifies the crew/management system301that no deviations are available for a GLS approach. In response to the notification, the crew/management system301may proceed to311, where the crew/management system301tunes the receiver in the navigation system303to an LPV channel. The navigation system303may then perform step313by checking if deviations from an intended approach path are available for an LPV approach. If there are no deviations, the navigation system303may proceed at315, where the navigation system303notifies the crew/management system301that no deviations are available for an LPV approach. In response to the notification, the crew/management system301may proceed to317, where the crew/management system301tunes the receiver in the navigation system303to an ILS channel. The navigation system303may then perform step319by checking if deviations from an intended approach path are available for an ILS approach. If there are deviations, the navigation system303may proceed at321, where the navigation system303provides the deviations to the crew/management system301. After receiving the deviations, the crew/management system301may use the ILS approach mode to follow the intended approach path towards the desired destination.

The process shown inFIG.3is iterative, and, in each iteration, selecting an approach mode can draw a crew member's attention away from other possibly essential tasks so that the crew member can tune the receiver to a different approach system. In contrast to the sequence ofFIG.3,FIG.4is a sequence diagram illustrating the selection of an approach mode in accordance with the present disclosure. As shown, a crew/management system401interacts with a navigation system403. The crew/management system401may function similarly to the combination of management system201connected to the display devices217and user interface219inFIG.2, where the management system201receives information from a flight crew member through the user interface219and provides information to the flight crew member through the display devices217.

As illustrated, when approaching an approach destination, the crew/management system401may begin at405by sending an approach identifier to the navigation system403. The navigation system403may then perform step407by identifying the available approach modes associated with the approach identifier and then evaluating the deviations for the available approach modes that provide measurements with the highest quality measure. The navigation system403then proceeds to409by sending the deviations for the approach mode that have measurements with the highest quality measure to the crew/management system401. The crew/management system401then may use the provided deviations to follow the intended approach path towards the destination. As shown, the process for selecting an approach mode according to systems and methods described in the present disclosure is not iterative and merely calls for a user to input an approach identifier. Thus, the systems and methods described herein provide a crew with more flexibility to attend to other essential tasks when approaching a destination.

FIG.5depicts a flow diagram illustrating an exemplary method500for selecting an approach mode. The method500may be implemented via the techniques described with respect toFIGS.2and4, but may be implemented using other techniques known to one having skill in the art. The blocks of the flow diagram have been arranged in a generally sequential manner to facilitate explanation. But, the arrangement of the blocks is merely exemplary, and the blocks can be arranged in any manner sufficient to provide the functionality described above with respect toFIGS.2and4. For example, the processing associated with the methods described herein (and the blocks shown in the Figures) may occur in a different order (i.e., where at least some of the processing associated with the blocks is performed in parallel, in an event-driven manner, or both).

In certain embodiments, the method500illustrates the process for selecting an approach mode by an approach system, such as the approach system223inFIG.2, and the steps of the method500are described herein with reference to the approach system223. In particular, the method500proceeds at501, where an approach identifier is received. For example, the approach system223may receive an approach identifier from a flight crew member through the user interface219. Further, the method500proceeds at503, where approach modes are identified based on the approach identifier. For example, the approach system223may search an approach database221for the approach identifier or receive the approach identifiers from a broadcast signal from the approach facilities. When the approach system223finds the approach identifier in the approach database221, the approach system223may identify the approach modes associated with the approach identifier as defined in the approach database221.

In further embodiments, the method500proceeds at505, where the availability of valid deviations is checked for the identified approach modes. For instance, the approach system223may identify the deviations from the intended approach path for the different approach modes identified in the approach database221as being associated with the approach identifier.

Additionally, the method500proceeds at507, where an approach mode is selected based on an integrity measure. For example, the approach system223may evaluate the input signals and vehicle position to determine which approach mode would achieve the highest integrity. When the approach system223identifies the preferred approach mode, the navigation system may then select the identified approach mode as the source for approach path deviations. As discussed above, the use of an integrity measure is an example of a type of quality measure.

In alternative embodiments, when the approach mode is selected at507, the approach system223may provide the viability of the available approach modes, as determined by the approach system223to a user (such as a pilot or crew member) through the display devices217and/or user interface219. The approach system223may also communicate the relative preference of the available approach modes in relation to one another. A pilot or other crew members can use instrumentation (such as the user interface219) to select one of the available approach modes based on the provided information. As part of selecting one of the approach modes, the pilot or other crew member may request that an ATC center authorize the selected approach mode. Alternatively, the pilot or other crew member may also evaluate whether a specific approach mode commanded by an ATC center is feasible for an aircraft. Additionally, the viability of the available approach modes, as determined by the approach system223may be transmitted to the made available to the ATC center. In response to the transmission of available approach modes, the ATC center may request that the pilot or other crew member select one of the available approach modes. The embodiment allows the possibility for the ATC to request the pilot or other crew member to select an approach system that the aircraft's navigation system203has determined is suitable to the approach.

Moreover, the method500proceeds at509, where deviations and details of the selected approach mode are provided for guiding a vehicle along an approach path. For example, the approach system223may provide the deviations and other details to the management system201and the flight crew for guiding the vehicle along the intended approach path.

In additional embodiments, the method500proceeds at511, where the integrity measure of the selected approach mode is evaluated during the use of the selected approach mode. For example, the approach system223may continue to evaluate the integrity measure of the deviations provided by the selected approach mode while the deviations are being used to guide the vehicle along the intended approach path. Also, the approach system223may evaluate the integrity measure of the available deviations provided by the non-selected approach mode(s). The method500then proceeds at513, where a determination is made as to whether the integrity measure of the selected approach mode remains satisfactory. For example, the approach system223may determine that the integrity measure of the selected approach mode is satisfactory if the integrity measure is above a specified level. Alternatively, the approach system223may determine the integrity measure of the deviations associated with the selected approach mode are satisfactory if the integrity measure is above the integrity measure of the deviations provided by the non-selected approach mode(s). If the integrity measure is satisfactory, the method500returns to509, where the deviations are still used for guiding the vehicle along an intended approach path. If the integrity measure is unsatisfactory, the method500returns to505, where the availability of valid deviations are checked for the identified approach modes.

FIG.6depicts a flow diagram illustrating an exemplary method600for selecting an approach mode. The method600may be implemented via the techniques described with respect toFIGS.2,4, and5, but may be implemented using other techniques known to one having skill in the art. The blocks of the flow diagram have been arranged in a generally sequential manner to facilitate explanation. But, the arrangement of the blocks is merely exemplary, and the blocks can be arranged in any manner sufficient to provide the functionality described above with respect toFIGS.2,4, and5. For example, the processing associated with the methods described herein (and the blocks shown in the Figures) may occur in a different order (i.e., where at least some of the processing associated with the blocks is performed in parallel, in an event-driven manner, or both).

In certain embodiments, the method600proceeds at601, where an approach identifier is received. Further, the method600proceeds at603, where a plurality of approach modes associated with the approach identifier are identified. Additionally, the method600proceeds at605, where an approach mode in the plurality of approach modes is selected based on the quality measure of navigation guidance associated with each of the plurality of approach modes. Moreover, the method600proceeds at607, where the navigation guidance for the selected approach mode is provided to an approach system.

EXAMPLE EMBODIMENTS

Example 1 includes a method comprising: receiving an approach identifier; identifying a plurality of approach modes associated with the approach identifier; selecting an approach mode in the plurality of approach modes based on an integrity measure of navigation guidance associated with separate approach modes in the plurality of approach modes; and providing the navigation guidance for the selected approach mode to an approach system for guiding a vehicle through an approach for the selected approach mode.

Example 2 includes the method of Example 1, wherein the approach identifier identifies a runway.

Example 3 includes the method of any of Examples 1-2, wherein the navigation guidance comprises deviations from an intended approach path for the selected approach mode.

Example 4 includes the method of any of Examples 1-3, wherein identifying the plurality of approach modes associated with the approach identifier comprises acquiring approach information from an approach database stored in one or more storage devices on the vehicle.

Example 5 includes the method of Example 4, further comprising: receiving approach information updates; and updating the approach database with the approach information updates.

Example 6 includes the method of any of Examples 1-5, wherein identifying the plurality of approach modes comprises: transmitting the approach identifier to an external system; and receiving approach information from the external system, wherein the approach information identifies the plurality of approach modes associated with the approach identifier.

Example 7 includes the method of any of Examples 1-6, further comprising evaluating the selected approach mode based on the integrity measure while the vehicle uses the navigation guidance for the selected approach mode.

Example 8 includes the method of Example 7, wherein evaluating the selected approach mode comprises monitoring the integrity measure of the selected approach mode, wherein a second approach mode is selected when the integrity measure of the selected approach mode is below a specified integrity threshold.

Example 9 includes the method of any of Examples 7-8, wherein evaluating the selected approach mode comprises: continuing to monitor the integrity measure of the separate approach modes; and selecting a different approach mode in the plurality of approach modes over the selected approach mode based on the integrity measure for the plurality of approach modes.

Example 10 includes the method of any of Examples 1-9, wherein selecting an approach mode further comprises providing an assessment of the suitability of each of the plurality of approach modes.

Example 11 includes a system comprising: one or more processors on a vehicle; and at least one receiver coupled to the one or more processors; wherein the one or more processors executes computer-executable instructions that direct the one or more processors to: receive an approach identifier; identify a plurality of approach modes associated with the approach identifier; select an approach mode in the plurality of approach modes based on a quality measure of navigation guidance associated with separate approach modes in the plurality of approach modes; provide the navigation guidance for the selected approach mode to an approach system for guiding the vehicle through an approach for the selected approach mode; and evaluate the selected approach mode based on the quality measure while guiding the vehicle through an approach associated with the selected approach mode.

Example 12 includes the system of Example 11, further comprising a storage device having an approach database stored thereon, wherein approach information is stored on the approach database.

Example 13 includes the system of Example 12, wherein the computer-executable instructions further direct the one or more processors to update the approach database with approach information updates received from an external system through the at least one receiver.

Example 14 includes the system of any of Examples 12-13, wherein the computer executable instructions direct the one or more processors to identify the approach information by identifying the approach information in the approach database.

Example 15 includes the system of any of Examples 12-14, wherein the computer executable instructions direct the one or more processors to identify the approach information by: transmitting the approach identifier to an external system; and receiving the approach information from the external system, wherein the approach information identifies the plurality of approach modes associated with the approach identifier.

Example 16 includes the system of any of Examples 11-15, wherein the quality measure is an integrity measure of the navigation guidance.

Example 17 includes the system of any of Examples 11-16, wherein the computer executable instructions direct the one or more processors to evaluate the selected approach mode by: monitoring the quality measure of the selected approach mode; and when the quality measure is below a specified level, selecting a different approach mode based on the quality measure of non-selected approach modes in the plurality of approach modes.

Example 18 includes the system of any of Examples 11-17, wherein the computer executable instructions direct the one or more processors to evaluate the selected approach mode by: continuing to monitor the quality measure of the separate approach modes; and selecting a second approach mode in the plurality of approach modes over the selected approach mode based on the quality measure for the plurality of approach modes.

Example 19 includes the system of any of Examples 11-18, wherein the navigation guidance comprises at least one of deviations and distance to threshold from an intended approach path for the selected approach mode.

Example 20 includes a system comprising: one or more processors on a vehicle; and at least one receiver coupled to the one or more processors; wherein the one or more processors executes computer-executable instructions that direct the one or more processors to: receive an approach identifier; identify a plurality of approach modes associated with the approach identifier; select an approach mode in the plurality of approach modes based on an integrity measure of navigation guidance associated with separate approach modes in the plurality of approach modes; provide the navigation guidance for the selected approach mode to an approach system for guiding the vehicle through an approach for the selected approach mode; and evaluate the selected approach mode based on the integrity measure while guiding the vehicle through the selected approach.