CN113553049B - Method for converting flight program into AIXM data structure - Google Patents

Abstract

The invention discloses a method for converting a flight program into an AIXM data structure, which comprises the following steps: converting a flight program into 3 UML entity objects of a program, a transition and a flight section; converting the flight path track into a GML model object; and converting the program, transition and leg UML entity objects into AIXM standard aviation data. The method can realize the conversion of the flight program from the graphic information into a standard AIXM data structure.

Description

Method for converting flight program into AIXM data structure

Technical Field

The invention relates to the technical field of data processing, in particular to a method for converting flight program graphics into a standard AIXM data structure.

Background

The flight program is a standard route for an aircraft when flying for take-off or landing. For a long time, the flight program is mainly represented in a graphic mode in each link of design, release and use, the expression mode of structured data is lacked, and computational analysis and automatic mapping cannot be carried out through a computer.

While the onboard navigational database Specification (ARINC 424) provides a way to describe flight procedures in textual code, the ARINC424 code is primarily directed to onboard avionics, and much operational or graphical related information is discarded during the encoding process. And the flight trajectory is restored through the ARINC424 code without a standard method, especially for the traditional flight program, the flight trajectories restored by different methods in the design, release and use processes of the same ARINC424 flight program code may be different.

In recent years, the international civil aviation organization recommends the adoption of the aviation data exchange model (AIXM) as a standard format for aviation data exchange between countries and systems. The AIXM standard defines data models and standard formats of various aviation elements in a Unified Modeling Language (UML), wherein flight program models contain more comprehensive information than ARINC424 codes, and particularly, geometric models such as GM _ ARC, GM _ ARCString, GM _ LineString, GM _ CurveSegment, GM _ Curve and Curve are introduced, so that three-dimensional information such as composition points, ARC centers and radii of flight tracks can be accurately described, and the spatial tracks of flight programs have uniqueness in each link of design, release and use.

At present, a method for converting the flight program from graphic information into an AIXM data structure is lacked at home and abroad, and the method fills the gap. The method can realize the conversion of the flight program from the graph to the standard AIXM data structure, realize the digitization and the standardization of the flight program, and facilitate the calculation, the analysis and the automatic drawing of the flight program by a computer.

Citation document 1: the invention relates to a flight program design system based on performance navigation, a verification platform and a verification method, which are disclosed in China as follows: CN102867073A (CN 102867073B). This document describes a system implementing PBN flight programming and a verification platform, where claim 1 mentions that its system bottom layer is an AIXM-based core database layer, including AIPs and NOTAM. No mention is made of the process or method of AIXM encoding, storage of flight procedures. The claim 1 3) ARINC424 coded output application module that also does not employ AIXM coded output flight procedures. In contrast, the present invention can build an AIXM model and output AIXM format data for all flight procedures including PBN.

Citation document 2: the invention relates to a flight program design system and a verification platform based on performance navigation, which are disclosed in China: CN 202221566U. This citation is similar to citation 1 and does not relate to the AIXM encoding and output method of the flight procedure.

Citation document 3: the invention relates to a method and a device for checking and controlling flight procedure flight path data, which have the following disclosure: CN 111444174A. The cited document refers to a method for restoring a flight trajectory by means of ARINC424 coding. The calculation of the turning radius r mentioned in claim 5 is only obtained by the calculation of the turning gradient and the vacuum speed, and does not consider the key information of the beginning and the end points, the beginning and the end directions and the like of the navigation section. Compared with the method adopting the file, the method adopts the AIXM model to restore the flight track, the radius calculation method considers the starting point and the ending point of the flight segment and the starting and ending positions, the calculation of the coordinates of the circle center is also involved, and the calculation method and the result are more comprehensive and accurate than the method adopting the file.

Citation document 4: the invention relates to a method and a device for making a flight procedure standard chart by data drive, which comprises the following steps: CN 111651537A. The cited document refers to a method and a device for data-driven production of a standard diagram of a flight program. The data recited in the claims does not include a digitized flight program or flight program code, nor does it describe a specific method of converting the flight program into a graphic.

Citation document 5: the invention discloses a local coding method, a local coding device and a local coding storage medium of an AIXM data structure, which are disclosed in the specification: CN 111783397A. This document describes a method of converting a native aviation entity into an AIXM data structure, but does not refer to a specific method of AIXM encoding a flight procedure. In contrast, the present invention provides detailed steps for AIXM encoding of flight procedures.

Citation document 6: the invention discloses a visualization method, a visualization device and a storage medium of an AIXM data structure, and discloses a method for displaying an AIXM data structure, which comprises the following steps: CN 111767336A. This document describes a method of visualizing AIXM data. The invention provides a detailed method for analyzing the geometrical graph of the flight procedure, compared with a visualization method of the flight procedure, which is not involved.

Disclosure of Invention

In order to solve the problems that the current flight program can only be represented in a graph or ARINC424 coding mode, the flight track cannot be accurately restored, automatic calculation and analysis cannot be carried out by means of a computer and the like, the invention provides a method for converting the flight program into an AIXM standard data structure, and meanwhile, the method can generate flight program track data meeting GML standards, so that a computer system can carry out calculation, analysis and automatic drawing on the flight program.

In order to achieve the purpose, the technical scheme of the invention comprises the following steps:

step 1: converting a flight program into 3 UML entity objects of a program, a transition and a flight section;

step 2: converting the flight path of the flight segment into a GML model object;

and step 3: and converting the program, transition and leg UML entity objects into AIXM standard aviation data.

Further, the flight program is converted into 3 UML entity objects of program, transition and flight segment, and the method comprises the following steps:

step 1-1: according to the navigation type, the runway and the flight phase, all components of the flight program are divided into 6 transitions of runway transition, public transition, route transition, approach transition, final approach and missed approach. Wherein, for the approach and departure procedures, the part connecting the runway is divided into runway transitions; dividing the part of the connected airway into airway transitions; and dividing the part which is between the runway transition and the route transition and is shared by a plurality of flight programs into a common transition, and if a certain flight program has no common part with other programs, dividing the whole flight program into the common transition. For the approach procedure, the part between the initial approach positioning point and the middle approach positioning point is divided into approach transition, the part between the middle approach positioning point and the fly-back point is divided into the last approach, and the part behind the fly-back point is divided into fly-back.

Step 1-2: and splitting each transition into a plurality of flight segments according to the flight mode and the termination condition.

Step 1-3: and generating three UML entity objects of a program, a transition and a navigation section. Firstly, dividing flight tracks corresponding to the same waypoint into a flight program for departure and approach programs; and for the approach procedure, dividing the flight trajectories which adopt the same navigation mode and correspond to the same landing runway into a flight procedure. And then, distributing each transition into a corresponding flight program according to the continuity of the flight trajectory, thereby forming a hierarchical structure comprising three stages of the flight program, the transition and the flight section. And finally, generating a flight program object (Procedure), a transition object (ProcedureTransition) and a flight segment object (SegmentLeg) according to the flight program, the transition and the flight segment according to the UML solid model of the AIXM, and assigning values to the attributes of the flight program object (Procedure), the transition object (ProcedureTransition) and the flight segment object (SegmentLeg) one by one according to the model requirements.

Further, the step 1-2 of splitting the transition into the legs further includes:

the flight mode of the split flight segment comprises the following steps: 5 flight modes of direct flight, flight along the azimuth line, flight along the arc line, direct steering and hovering waiting; the termination conditions for the split flight segment are as follows: 5 end conditions of reaching a specific height, reaching a specific point, intercepting a certain navigation station radial line, reaching a specific distance and reaching a specific time.

Further, step 2 of converting the flight path trajectory into a GML model object includes the following steps:

step 2-1: and calculating the geometric parameters of the starting point and the ending point of the track of the flight segment, the circle center of the arc line and the radius.

Step 2-2: and converting the flight path track into objects of GM _ ARC, GM _ ArcString, GM _ LineString, GM _ CurveSegment, GM _ Curve and Curve to generate a GML model object.

Further, the method for calculating the geometric parameters of the flight path track in the step 2-1 comprises the following steps:

the method for calculating the starting point and the tail point of the flight segment comprises the following steps: setting the starting points of the flight program as the starting points and the end points of the initial flight section, setting the starting points of the rest flight sections as the end points of the preorder flight sections, and calculating the end points according to the flight mode and the termination condition. For example, for a flight segment with the end condition of reaching a specific height, the horizontal distance of the starting point and the end point can be obtained by dividing the altitude difference of the starting point and the end point of the flight segment by the climbing rate at the end point, and then the coordinates of the end point can be obtained according to the coordinates of the starting point, the horizontal distance and the flight direction. The calculation mode of the tail point of the navigation section with the termination condition of intercepting a radial line of a certain navigation station, reaching a specific distance and reaching a specific time is similar to the calculation mode, and the coordinates of the tail point can be obtained through geometric calculation.

The method for calculating the radius and the circle center of the arc line comprises the following steps:

arc radius:

r=sinα/sinβ*L;

L=acos(sin(lat1)*sin(lat2)+cos(lat1)*cos(lat2)*cos(lon1-lon2))*R；

in the formula, alpha is an included angle between a connecting line of a starting square line and a starting point and a tail point of the navigation segment, beta is an included angle between a connecting line of a stopping square line and a starting point and a tail point of the navigation segment, L is a distance between the starting point and the stopping point of the navigation segment, lat1 and lon1 are coordinates of the starting point of the navigation segment, lat2 and lon2 are coordinates of the tail point of the navigation segment, and R is the radius of the earth;

circle center coordinates:

M=sin((1-r/L)*r)/sin(r)；

N=sin(L)/sin(r)；

a = M*cos(lat1)*sin(lon1) +N*cos(lat2)*sin(lon2)；

b = M*cos(lat1)*sin(lon2) + N*cos(lon2)*sin(lat2)；

c = M*sin(lat1)+ N*cos(lat2)；

lat=atan2(c,sqrt(a*a+b*b))；

lon=atan2(b,a)；

in the formula, lat and lon are circle center latitude and longitude, lat1 and lon1 are coordinates of the starting point of the leg, lat2 and lon2 are coordinates of the ending point of the leg, r is an arc radius, and L is a distance between the starting point and the ending point of the leg.

The invention has the following advantages:

the method can realize the conversion of the flight program from the graph to the AIXM data structure, describe the flight program track in the GML data format and realize the digital conversion of the flight program. The invention solves the defect that the flight program can only be understood and processed manually, and the generated flight program data can be used for the aspects of aviation data exchange, flight program design, calculation and analysis, automatic mapping of a flight chart and the like.

Drawings

FIG. 1 is a diagram of the main steps for converting a flight procedure into an AIXM data structure according to an embodiment of the present invention.

FIG. 2 is a flow chart of a process for converting a flight procedure to an AIXM data structure according to an embodiment of the present invention.

FIG. 3 is a diagram of a Pudong airport departure flight procedure with a conversion process according to an embodiment of the present invention.

FIG. 4 is a diagram of three data models of program, transition, and flight in the AIXM model.

FIG. 5 is the structure diagram of the GM _ Curve model in GML standard (ISO 19107).

Fig. 6 is a schematic diagram of a method for calculating the end point of the flight segment according to the embodiment.

Fig. 7 is a schematic diagram of a process of calculating the center and radius of the arc track of the leg according to the embodiment.

Fig. 8 is a flight procedure trajectory diagram generated by restoring GML data generated in the present embodiment.

Fig. 9 is a schematic diagram of flight procedure AIXM data generated by conversion according to the embodiment.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The flight procedure has been mainly expressed in a graphic manner, although the flight procedure can be encoded by adopting the ARINC424 standard, the ARINC424 encoding cannot contain all information of the flight procedure, and the flight track restored by the ARINC424 encoding has no uniqueness due to the lack of track description information.

Based on the method, the method for converting the flight program into the AIXM data structure can completely convert all information of the flight program into AIXM standard data and simultaneously contains accurate flight track information.

As shown in fig. 1, one embodiment of the present invention comprises the steps of:

step 1: converting a flight program into 3 UML entity objects of a program, a transition and a flight section;

step 2: converting the flight path track into a GML model object;

and step 3: and converting the program, transition and leg UML entity objects into AIXM standard aviation data.

The detailed flow of the method is shown in fig. 2, and includes:

step 1: the flight program is converted into 3 UML solid objects of program, transition and flight segment. The method comprises the following steps:

step 1-1: according to the navigation type, the runway and the flight phase, all components of the flight program are divided into 6 transitions of runway transition, public transition, route transition, approach transition, final approach and missed approach. Wherein, for the approach and departure procedures: dividing the part of the connecting runway into runway transitions; dividing the part of the connected airway into airway transitions; and dividing the part which is between the runway transition and the route transition and is shared by a plurality of flight programs into a common transition, and if a certain flight program has no common part with other programs, dividing the whole flight program into the common transition. For the approach procedure: and dividing the part between the initial approach positioning point and the middle approach positioning point into approach transition, dividing the part between the middle approach positioning point and the missed approach point into the latest approach, and dividing the part behind the missed approach point into missed approach.

Taking the off-site program diagram of the Pudong airport at Shanghai of FIG. 3 as an example, this diagram depicts two off-site flight programs that take off from four runways of 16L, 16R, 17L, 17R, one terminating at the waypoint SASAN and the other terminating at the waypoint south water section VOR. Setting 4 tracks from the tail ends of the 16L, 16R, 17L and 17R runways to the D298L point as 4 runway transitions according to the division principle; setting the trajectory from point D298L to the nine-pavilion VOR as 1 common transition; two tracks from the nine pavilion VORs to the SASAN and south water-cut VORs, respectively, are set to 2 fairway transitions.

Step 1-2: and splitting each transition into a plurality of flight segments according to different flight modes and different termination conditions. The flight mode of the split flight segment comprises the following steps: 5 flight modes of direct flight, flight along the azimuth line, flight along the arc line, direct steering and hovering waiting; the termination conditions for the split flight segment are as follows: 5 end conditions of reaching a specific height, reaching a specific point, intercepting a certain navigation station radial line, reaching a specific distance and reaching a specific time.

As shown in FIG. 3, the flight path from RWE 16L/16R terminus to D12.0PUD was flown along the 153 degree azimuth line, and the termination condition was that a specific distance (12.0 nautical miles from the PUD platform) was reached, dividing this part of the flight path into a leg; the flight path from point D12.0PUD to the book office VOR is a direct turn, and the end condition is that a certain point (book office VOR) is reached, and the part of the flight path is divided into another flight segment. And each subsequent flight section flies along the azimuth line according to the flying mode, and the ending condition is that the specific point is reached. After the division is completed, each transition comprises a plurality of legs, for example, a runway transition from RWY16L/16R end to D298L point comprises 3 legs (runway end to D12.0PUD, D12.0PUD to courtyard VOR, courtyard VOR to D298L); the common transition from D298L to the nine-pavilion VOR contains 2 legs (D298L to D298F, D298F to the nine-pavilion VOR); the route transition from nine-pavilion VORs to SASAN includes 2 legs (nine-pavilion VORs to EKIMUs, EKIMUs to SASAN).

Step 1-3: and generating three UML entity objects of a program, a transition and a navigation section. Firstly, dividing flight tracks corresponding to the same waypoint into a flight program for departure and approach programs; and for the approach procedure, dividing the flight trajectories which adopt the same navigation mode and correspond to the same landing runway into a flight procedure. And then, distributing each transition into a corresponding flight program according to the continuity of the flight trajectory, thereby forming a hierarchical structure comprising three stages of the flight program, the transition and the flight section. And finally, generating a flight program object (Procedure), a transition object (ProcedureTransition) and a flight segment object (SegmentLeg) according to the UML entity class model of the AIXM, and assigning values to the attributes of the flight program object (Procedure), the transition object (ProcedureTransition) and the flight segment object (SegmentLeg) one by one according to the model requirements.

Referring to fig. 3, all flight paths in the figure can be divided into 2 departure flight programs, one is SASAN from the runway to the waypoint, and the other is VOR from the runway to the south waterside of the waypoint, and the two departure flight programs are named as SASAN and NXD respectively. Wherein, the two flight programs both comprise 4 runway transitions (end of 4 runways to D298L), 1 common transition (D298L to nine kiosks VOR), the departure program SASAN comprises 1 fairway transition (nine kiosks VOR to SASAN), and the departure program NXD comprises 1 fairway transition (nine kiosks VOR to south water section VOR), thereby forming three hierarchies of program, transition, and flight section.

These three hierarchies are then converted into solid objects of the AIXMUML model. As shown in FIG. 4, in the AIXM flight program UML model structure, the 3 boxes Procedure, ProcedureTransition and SegmentLeg on the right side of the figure represent three entity class models of flight program, transition and flight segment, respectively, and the entries in the boxes represent the attributes contained in the model. To which values are assigned in turn, for example:

2 program (Procedure) objects are created with the name attribute set to SASAN and NXD, respectively.

Creating 7 transition (Proceduretransition) objects, wherein the type attribute of 4 objects is set to RWY to represent runway transition, and the transitionId attribute is set to corresponding runway name; type of 1 object is set to COMMON to represent a COMMON transition, transitionId attribute is set to head and end point name, type of 2 objects is set to EN _ ROUTE to represent an airway transition, and transitionId attributes are SASAN and NXD, respectively.

Create 16 leg (SegmentLeg) objects, taking the leg from D6.0PUD to D298L in fig. 3 as an example: creating a SegmentLeg object, setting the course attribute of the SegmentLeg object to 271 and indicating that the SegmentLeg object flies along the 271-degree azimuth line; the courSEType attribute is MAG _ TRACK, and the azimuth line is in the magnetic direction; the legtypeARINC attribute is CF, C represents that the flight mode of the flight segment is along the azimuth line, and F represents that the termination condition of the flight segment is reaching a specific point; the stardPoint attribute is set to D6.0PUD, which represents the beginning of the leg; endPoint set to D298L indicates the end of leg; and corresponding attributes are given to the values of flying height, speed, time, glide angle and the like.

To this end, UML entity object generation is complete, and then a flight trajectory (Curve) object will be set for the proceduredtransition object. The left-hand Curve box and arrow in FIG. 4 indicate that the Curve object inherits the GM _ Curve class of ISO19107 standard (GML), and FIG. 5 shows the structure of the GM _ Curve class in ISO19107 standard. The following steps will set up the GM _ ARC, GM _ ArcString, GM _ CurveSegment, and GM _ Curve objects and attributes in turn, and create the flight trajectory (Curve) object.

Step 2: and converting the flight path track into a GML model object. The method comprises the following steps:

step 2-1: and calculating the geometric parameters of the starting point, the ending point, the arc center and the radius of the track of the flight segment.

The method for calculating the starting point and the tail point of the flight segment comprises the following steps: setting the starting point and the end point of the initial flight segment as the starting points of the flight program, then calculating the end point of the flight segment according to the termination condition of each flight segment, and taking the end point of the pre-flight segment as the starting point of the subsequent flight segment. For example, for a flight segment with the end condition of reaching a specific height, the horizontal distance of the starting point and the end point can be obtained by dividing the altitude difference of the starting point and the end point of the flight segment by the climbing rate at the end point, and then the coordinates of the end point can be obtained according to the coordinates of the starting point, the horizontal distance and the flight direction. The calculation mode of the tail point of the navigation section with the termination condition of intercepting a radial line of a certain navigation station, reaching a specific distance and reaching a specific time is similar to the calculation mode, and the coordinates of the tail point can be obtained through geometric calculation.

Taking the off-ground flight procedure corresponding to RWY16L/16R in fig. 3 as an example, the starting point of the procedure is the end of the runway RWY16L, the coordinates of the end of the runway are known from the "national aviation documentation", and the point is taken as the starting point and the end point of the initial flight, the 2 nd flight is obtained from the end of RWY16L along the 153 degree azimuth line to the position 12.0 nautical miles away from the purdont PUD stage, and the end point of the flight is obtained by calculating the intersection point of the end of RWY16L along the 153 degree azimuth line and the circular arc with the purdont PUD stage as the center and the radius of 12.0 nautical miles, as shown in fig. 6. Other starting and ending points of the flight segment can be calculated by a similar method.

The method for calculating the circle center and the radius of the arc line of the track of the flight segment comprises the following steps: solving the arc radius according to the spherical triangle sine theorem, and then calculating the center coordinate according to the arc radius; which comprises the following steps:

the arc radius calculation formula is:

r=sinα/sinβ*L;

L=acos(sin(lat1)*sin(lat2)+cos(lat1)*cos(lat2)*cos(lon1-lon2))*R；

wherein alpha is the angle between the connecting line of the starting position line and the starting and ending points of the navigation section, beta is the angle between the connecting line of the ending position line and the starting and ending points of the navigation section, L is the distance between the starting point and the ending point of the navigation section, lat1, lon1, lat2 and lon2 are the longitude and latitude of the starting point and the ending point of the navigation section respectively, and R is the earth radius =6378137 m.

For example, the arc radius and the center of the circle of the leg from D6.0PUD to D298L in the departure procedure of RWY17L in FIG. 3 are calculated:

according to the above starting and ending point calculation method, the coordinates of the available starting point D6.0PUD are: lat1=31.0744, lon1=121.8136, and end point D298L coordinates: lat2=31.0158, lon2=121.6378, and substituting the formula to calculate L =18388 meters; and alpha is the included angle of the starting position of the navigation section and the connecting line of the first point and the last point =68 degrees, beta is the included angle of the ending position of the navigation section and the connecting line of the first point and the last point =12 degrees, and the radius r =18388 sin68/sin12=4126 meters is calculated.

The calculation formula of the longitude and latitude coordinates of the circle center is as follows:

M=sin((1-r/L)*r)/sin(r)；

N=sin(L)/sin(r)；

a = M*cos(lat1)*sin(lon1) +N*cos(lat2)*sin(lon2)；

b = M*cos(lat1)*sin(lon2) + N*cos(lon2)*sin(lat2)；

c = M*sin(lat1)+ N*cos(lat2)；

lat=atan2(c,sqrt(a*a+b*b))；

lon=atan2(b,a)；

in the formula, lat and lon are respectively circle center latitude and longitude, lat1, lon1, lat2 and lon2 are respectively the longitude and latitude of the first point and the last point of the navigation segment, r is the arc radius, and L is the distance between the starting point and the ending point of the navigation segment.

By substituting the values of r, L, lat1, lon1, lat2 and lon2 into the above formula, the circle center coordinate point latitude lat = 31.063066 and longitude lon = 121.77242 can be calculated.

And obtaining the rotation angle of the arc line according to the difference value of the initial and final directions, and calculating the initial angle and the final angle of the arc line according to the positions of the initial and final points.

The calculation process and the results are shown in fig. 7.

According to the method, geometric parameters such as the starting points and the ending points of all the legs, the circle centers of the arcs, the radiuses and the like are calculated in sequence.

Step 2-2: and sequentially converting the flight path track into objects of GM _ ARC, GM _ ArcString, GM _ LineString, GM _ CurveSegment, GM _ Curve and Curve to form a GML model object.

As shown in fig. 5, converting the segment trajectory into the GM _ Curve model object requires converting the arc trajectory into the GM _ ArcString object and converting the straight trajectory into the GM _ LineString object.

The GM _ ARCString object is composed of GM _ ARC objects, the GM _ ARC objects are established according to the ARC tracks of each flight segment, the center coordinates obtained in the step 2-1 are given to the center attribute of the GM _ ARC, the radius is given to the radius attribute, the start angle and the end angle of the ARC are respectively given to the startOfArc attribute and the endOfArc attribute, the GM _ ARC objects are established, and the GM _ ARCString and GM _ CurveSegment objects are generated by supplementing the attributes.

And then, converting the straight line track into a GM _ LineString object, creating a GM _ LineLength object, assigning the starting point and the end point of each straight line segment to startPoint and endPoint attributes, and connecting all the straight line segments in series to generate the GM _ LineString and GM _ CurveSegment objects.

GM _ CurveSegment objects are created for the straight or arc trajectories of all legs of each transition, and the set of these GM _ CurveSegment objects is set as GM _ Curve objects.

Supplementing the GM _ Curve object with the horitalAccuracy attribute, setting horitalAccuracy =0, and obtaining the Curve object of each transition, which contains the complete flight trajectory of the transition.

All transitional Curve objects are generated and assigned to a transitional object (proceduredtransition), the UML object creation of the flight procedure is completed, and the flight trajectory is defined by the Curve objects in GML format.

And the GML format data can be directly loaded and displayed by most of the graphic platforms through loading the generated flight program track GML data by the graphic platforms. In the embodiment, after the flight program graph in fig. 3 is converted into GML data, the result is displayed on the three-dimensional graph platform as shown in fig. 8.

And step 3: and converting the program, transition and leg UML entity objects into AIXM standard aviation data. The UML objects of the flight program can be converted into an AIXM format XML file according to the XML _ Schema conversion rule of the AIXM standard, wherein the flight program trajectory data in the GML format is contained, as shown in fig. 9.

To this end, the conversion of the flight program from graphical information to AIXM structured data is completed.

After the flight program is converted into the AIXM data through the method, GML data can be directly loaded by drawing software or software for displaying and simulating the flight program to generate graphs, geometric calculation is not needed, and the display results of all platforms are consistent. However, the flight program encoded by ARINC424 does not explicitly define the flight trajectory, and the geometric parameters of the flight trajectory need to be calculated every time the flight trajectory is displayed, so that the efficiency is reduced, and the graphs generated by different platforms through calculation may not be consistent. It can be seen that the flight procedure AIXM data generated by the method has advantages over ARINC424 encoded data.

The above description is only one embodiment of the present invention, and is not intended to limit the present invention in any way, and all simple modifications, equivalent changes and modifications made to the above embodiments according to the technical spirit of the present invention still belong to the protection scope of the technical solution of the present invention.

Claims (5)

1. A method of converting a flight procedure to an AIXM data structure, comprising the steps of:

step 1: converting a flight program into 3 UML entity objects of a program, a transition and a flight section; firstly, for departure flight procedures and approach flight procedures, dividing flight trajectories corresponding to the same waypoints into a program, and for approach flight procedures, dividing flight trajectories which adopt the same navigation mode and correspond to the same landing runway into a program; then, according to the continuity of the flight path, splitting the program into a plurality of transitions, and splitting the transitions into a plurality of flight sections, thereby forming a hierarchical structure comprising the program, the transitions and the flight sections step by step; finally, generating a flight program object, a transition object and a flight segment object according to the program, the transition and the flight segment according to the UML entity model of the AIXM, and assigning values to the attributes of the flight program object, the transition object and the flight segment object one by one;

step 2: converting the flight path track into a GML model object;

and step 3: and converting the program, transition and leg UML entity objects into AIXM standard aviation data.

2. The method of claim 1, wherein step 1 comprises the steps of:

step 1-1: dividing flight procedures into 6 transitions of runway transition, public transition, route transition, approach transition, final approach and missed approach;

step 1-2: splitting the transition into flight segments according to a flight mode and a termination condition;

step 1-3: and generating three UML entity objects of a program, a transition and a navigation section.

3. The method of converting a flight procedure to an AIXM data structure of claim 2, wherein steps 1-2 further comprise:

the leg is split in 5 flight modes of straight flight, flight along the azimuth line, flight along the arc, direct steering and waiting for hovering and 5 termination conditions of reaching a specific altitude, reaching a specific point, intercepting a certain navigation station radial line, reaching a specific distance and reaching a specific time.

4. The method of claim 1, wherein step 2 comprises the steps of:

step 2-1: calculating geometric parameters of starting and ending points of a track of the flight segment, the circle center of the arc line and the radius;

step 2-2: and converting the flight path track into objects of GM _ ARC, GM _ ArcString, GM _ LineString, GM _ CurveSegment, GM _ Curve and Curve to generate a GML model object.

5. The method of converting a flight procedure to an AIXM data structure of claim 4, wherein step 2-1 further comprises:

setting the starting point and the end point of the initial flight segment as the starting points of a flight program, setting the starting points of the subsequent flight segments as the end points of the preorder flight segments, and calculating the end points according to the flight mode and the termination condition;

calculating the arc radius:

r=sinα/sinβ*L;

L=acos(sin(lat1)*sin(lat2)+cos(lat1)*cos(lat2)*cos(lon1-lon2))*R；

in the formula, alpha is an included angle between a connecting line of a starting square line and a starting point and a tail point of the navigation segment, beta is an included angle between a connecting line of a stopping square line and a starting point and a tail point of the navigation segment, L is a distance between the starting point and the stopping point of the navigation segment, lat1 and lon1 are coordinates of the starting point of the navigation segment, lat2 and lon2 are coordinates of the tail point of the navigation segment, and R is the radius of the earth;

calculating the coordinates of the circle center:

M=sin((1-r/L)*r)/sin(r)；

N=sin(L)/sin(r)；

a = M*cos(lat1)*sin(lon1) +N*cos(lat2)*sin(lon2)；

b = M*cos(lat1)*sin(lon2) + N*cos(lon2)*sin(lat2)；

c = M*sin(lat1)+ N*cos(lat2)；

lat=atan2(c,sqrt(a*a+b*b))；

lon=atan2(b,a)；

in the formula, lat and lon are circle center latitude and longitude, lat1 and lon1 are coordinates of the starting point of the leg, lat2 and lon2 are coordinates of the ending point of the leg, r is an arc radius, and L is a distance between the starting point and the ending point of the leg.

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