TAWS false alarm suppression method for special terrain along air route

Abstract

The application provides a TAWS false alarm suppression method for special terrain of an air route, and belongs to the technical field of safety monitoring of transport aircrafts. When a real aircraft air route operation causes a false alarm of a forward-looking warning function due to changes in special terrain of an airport, aircraft data of a false alarm position can be obtained. Based on the data, a false alarm position parameter is generated based on a standard air route through a ground preprocessing method, a threshold is reduced based on specific conditions of the false alarm, and an envelope modulation parameter is generated. Based on the two types of parameters, a false alarm suppression configuration item is generated and configured in a TAWS device. In the calculation process of the TAWS, whether the current aircraft is in the position range where the false alarm occurs is judged according to the aircraft parameters and the false alarm position parameter in the configuration item. If it is in the range, the forward-looking warning threshold is modulated according to the pre-stored alarm threshold modulation value to avoid the occurrence of false alarm.

Description

Technical Field

[0001] This application relates to the field of safety surveillance of transport aircraft, and in particular to a TAWS false alarm suppression method for special terrain along flight routes. Background Technology

[0002] The Terrain Awareness and Warning System (TAWS) provides flight crews with voice and visual warnings of potential, controllable threats of ground collisions, as well as height and situational awareness displays of the surrounding terrain and obstacles. Forward Look-Ahead Warning (FLTA) is a key function of TAWS. Based on the aircraft's current latitude, longitude, altitude, speed, and other flight parameters, as well as terrain elevation and obstacle data stored internally, this function calculates whether there is a possibility of collision with terrain or obstacles along the forward flight path, given the current flight conditions.

[0003] Alarm clearance refers to the height of an aircraft above the terrain or obstacles below it during flight. TAWS devices are designed with alarm thresholds based on typical clearance requirements, and the alarm thresholds are adjusted in different flight phases, such as takeoff, cruise, approach, and landing, to ensure that the aircraft has sufficient protection in each flight phase and to ensure that no false alarms or erroneous alarms are generated during normal takeoff and landing.

[0004] The current threshold design for forward look-ahead warnings mainly focuses on appropriate clearance scaling for different flight phases, but it still has the following drawbacks: When aircraft fly over airports in mountainous or basin areas, there may be abrupt changes in terrain below the flight path. Some airports may also require high-precision flight, such as RNP (Restricted Noise Level) flights, which may lower the permissible altitude. In such cases, setting alarm thresholds according to general rules might calculate a collision between the forward look-ahead warning (FLAD) protection zone and the terrain. However, if the flight path is deemed reasonable according to the airport's flight procedures, a false alarm is generated. Such false alarms can severely impair a pilot's judgment of the safety of the current flight environment and require targeted identification and suppression. Summary of the Invention

[0005] In view of this, this application provides a TAWS false alarm suppression method for special terrain along flight routes, which solves the problems in the prior art and reduces noise alarms to pilots.

[0006] The TAWS false alarm suppression method for special terrain along flight routes provided in this application adopts the following technical solution: A TAWS false alarm suppression method for special terrain along flight routes includes: Step 1, Generating False Alarm Location Parameters: Based on the false alarm results generated by the operating route, the following parameters are stored: the nearby airport code where the false alarm occurred, the latitude and longitude range of the false alarm start point, the latitude and longitude range of the end point, the altitude of the start point, the altitude of the end point, the heading of the false alarm segment, the distance to the FAF point, and the distance to the MAP point. Step 2, Generation of threshold correction parameters: Based on the false alarm position set for the corresponding flight path, the correction data for the side look angle, downward look time, forward look time, and clearance value set for the forward look alarm are parameterized and stored; Step 3, False Alarm Range Identification: In the aircraft ground proximity warning (TAWS), determine whether the current flight position and status are within the range that may generate false alarms on the flight path. If so, use correction data to correct the alarm algorithm.

[0007] Optionally, step 1 specifically includes: Step 1.1, Generating the false alarm route location: Obtain the starting latitude and longitude points and the ending latitude and longitude points when the aircraft generates a forward look-ahead warning from the flight recorder. Map these starting latitude and longitude points to the standard aeronautical chart to obtain the false alarm segment start point F-Start and the false alarm segment end point F-End in the standard aeronautical chart. Step 1.2, Generating false alarm airport parameters: Based on the location where the false alarm occurs, record the airport ID, and confirm the distances D-FAF and D-MAP of the FAF point and MAP point from the runway threshold point based on the airport's flight path chart; Step 1.3, Formatting of false alarm location parameters: Based on the false alarm flight path location and false alarm airport parameters, obtain all parameters that support the determination of false alarm location, list them in tabular form, and store them in the configuration items of false alarm parameters in the form of a data structure.

[0008] Optionally, step 2 specifically includes: Step 2.1, Side-Look Angle Correction: Extract the collision information between the terrain and the warning envelope within the detection range ahead of the aircraft's false alarm position. When a collision occurs, reduce the side-look angle, lowering it to a minimum of 0 degrees. Analyze whether the target terrain A causing the false alarm can be eliminated. If it can be eliminated, record the test angle offset. ; Step 2.2, Adjustment of Vertical Threshold: When reducing the side-looking angle cannot effectively suppress false alarms, i.e., when abrupt terrain changes occur below the normal descent path, the downward-looking threshold is reduced. The altitude threshold below the aircraft is composed of the basic warning clearance H1 and the downward-looking height H2, as shown in the formula: , where t d V represents the downward viewing time. h This refers to the vertical velocity of the aircraft as it descends. Reduce the descent time; the adjusted descent time is t.d ’ The generated downward viewing time offset for ; If adjusting the downsight time still fails to meet the suppression requirements, analyze and predict whether there is a collision with the terrain ahead of the flight path at the forwardsight distance. The original forwardsight time was t. f The adjusted forward look time is t. f ’ The generated forward look time offset for: ; If adjusting the downsight time and forwardsight time is ineffective, adjust the basic warning clearance. The original basic warning clearance was H1, and the adjusted clearance is now H1. ’ The corresponding warning baseline net clearance bias for .

[0009] Optionally, in step 3, during the process of determining whether the current flight position and status are within the range where false alarms may occur on the flight path, the current position parameters of the aircraft are compared with the stored false alarm position parameters, and the allowable flight technical error is calculated. Combined with the horizontal and vertical quality factors and magnetic heading angle of the aircraft, it is determined whether the current flight position and status are within the range where false alarms may occur on the flight path.

[0010] Optionally, step 3 specifically includes: Step 3.1: Using the airport search module built into TAWS, and using the aircraft's latitude and longitude and terrain database information, obtain the ID of the nearest airport to the current aircraft. Compare this ID with the false alarm airport ID in the false alarm location parameter to confirm whether it is near a false alarm airport. Step 3.2: Based on Step 3.1, according to the calculated distance to the airport, compare the distances to FAF and MAP points in the parameter items to calculate the allowable flight technical error within the current range; Calculate the technical error F_delta_Y in horizontal flight: ; Where X represents the distance coordinates from the aircraft to the runway threshold. The horizontal deviation of the aircraft from the standard flight path. This is the distance from the aircraft to the final approach positioning point. This is the distance from the aircraft to the go-around point. Calculate the vertical flight technical error F_delta_Z: ; in, This refers to the altitude deviation of the aircraft from the standard flight path. This is the distance from the aircraft to the final approach positioning point. This is the distance from the aircraft to the go-around point. Step 3.3: Based on Step 3.2, and combining the aircraft's horizontal quality factor (HFOM) and vertical quality factor (VFOM), determine whether the aircraft is within the false alarm range. If it is within the false alarm flight path range, apply the relevant threshold bias: Based on the false alarm segment start point F_Start(Lat_FS, Lon_FS), the false alarm segment end point F_End(Lat_FE, Lon_FE), and the aircraft's current latitude and longitude Cur(Lat_Cur, Lon_Cur), the latitude and longitude coordinate system is converted to a rectangular coordinate system using the false alarm segment start point as the reference. The corresponding point is F_Start(X... S ,Y S ), F_End(X E Y E ), Cur (X) Cur , Y Cur ), calculate the lateral deviation of the aircraft from the standard flight path. : ; Based on the false alarm segment distance DIS-F, the aircraft's current position is at the distance DIS-X from the false alarm initiation point, and the false alarm segment initiation point is at altitude H. Start End point height H End Current altitude of the aircraft (H) Cur Calculate the altitude error H of the aircraft deviating from the current standard flight path. Z : ; When the lateral deviation distance is less than or equal to the sum of the flight technical error and the horizontal quality factor, the aircraft is judged to be within the horizontal error range defined by the false alarm route. When the altitude deviation is less than or equal to the sum of the flight technical error and the horizontal quality factor, the aircraft is judged to be within the vertical error range defined by the false alarm route. Based on the current magnetic heading angle of the aircraft, it is compared with the magnetic heading angle of the false alarm route. If it is less than the preset value, it is determined that the magnetic heading angle of the aircraft meets the judgment requirements. When the aircraft is within the horizontal error range defined by the false alarm route and the aircraft is within the vertical error range defined by the false alarm route, the corresponding envelope modulation is performed when it is considered that the aircraft is currently within the false alarm range and the aircraft's magnetic heading angle meets the judgment requirements.

[0011] Optionally, when performing envelope modulation, based on the test angle offset parameter, downward look time offset parameter, forward look time offset parameter, and clearance offset parameter in the false alarm suppression configuration item, relevant threshold modulation is performed according to the envelope parameter definition to complete forward look alarm suppression.

[0012] In summary, this application includes the following beneficial technical effects: This application proposes an effective solution to the false alarm problem that may arise in Terrain Awareness and Warning Systems (TAWS) when encountering special terrain features such as those below flight paths at airports in mountainous or basin areas. The solution involves generating false alarm location parameters and false alarm threshold modulation parameters based on records of false alarms generated by the flight path, as well as airport and aeronautical chart data. These parameters are then stored in TAWS as a configuration item. This parameter item, in conjunction with the false alarm location determination rules defined in the invention, can effectively calculate whether the aircraft is within the false alarm range based on the false alarm location parameters in the data item and the aircraft's current position information, and perform corresponding false alarm suppression as needed.

[0013] This application can effectively solve the problem of false alarms during normal flights on special airport routes, reduce noise alarms for pilots, and has high application value. Attached Figure Description

[0014] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a diagram illustrating the execution architecture of the false alarm suppression method in this application; Figure 2 The false alarm points on the standard flight path are confirmed based on the false alarm points recorded in the aircraft log. Figure 3 The false alarm airport parameters are confirmed based on the false alarm points recorded by the aircraft. Figure 4 This is a diagram illustrating the horizontal false alarm cause identification and threshold modulation strategy. Figure 5 This is a diagram illustrating the vertical false alarm cause confirmation and threshold modulation strategy. Figure 6 This is a detailed diagram of vertical threshold modulation; Figure 7 This is the logic diagram for determining whether an aircraft is in a false alarm range; Figure 8 This is a diagram showing the calculation of technical errors in horizontal flight. Figure 9 This is a diagram showing the error calculation for vertical flight technology. Figure 10 This is a diagram illustrating the principle of horizontal range determination. Figure 11 This is a diagram illustrating the principle of vertical range determination. Detailed Implementation

[0016] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0017] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. This application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0018] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this application, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using structures and / or functionalities other than one or more of the aspects set forth herein.

[0019] It should also be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this application. The illustrations only show the components related to this application and are not drawn according to the number, shape and size of the components in actual implementation. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0020] Furthermore, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that the described aspects can be practiced without these specific details.

[0021] This application provides a TAWS false alarm suppression method for special terrain along flight routes.

[0022] A TAWS false alarm suppression method for special terrain along flight routes includes: Step 1, Generating False Alarm Position Parameters: Based on the false alarm results generated by the operating route, the following parameters are stored: the nearby airport code where the false alarm occurred, the latitude and longitude range of the false alarm's origin and end points, the altitude of the origin point, the altitude of the end point, the heading of the false alarm segment, the distance to the FAF point, and the distance to the MAP point. FAF stands for Final Approach Fix, and MAP stands for Missed Approach Point.

[0023] Step 2, generation of threshold correction parameters: Based on the false alarm position set according to the corresponding route, the correction data of the side look angle, downward look time, forward look time and clearance value set for the forward look alarm are parameterized and stored.

[0024] Step 3, False Alarm Range Identification: In the aircraft ground proximity warning (TAWS), determine whether the current flight position and status are within the range that may generate false alarms on the flight path. If so, use correction data to correct the alarm algorithm.

[0025] This invention addresses the problems and shortcomings of existing technologies by stating the technical problem it aims to solve. Existing terrain awareness and warning systems, designed according to standard threshold rules, may generate false alarms when flying specific routes in mountainous or basin-like areas due to abrupt changes in the terrain below. This application proposes a method for identifying and suppressing false alarms. Based on false alarm flight path records, a parameter configuration item is generated, recording the false alarm location and envelope adjustment rules. Using this parameter configuration item, the range of the aircraft's false alarm location is identified in TAWS (Terrain Assurance and Warning System), and corresponding alarm envelope modulation is performed to avoid false alarms.

[0026] like Figure 1As shown, the system architecture for implementing the above method specifically includes a ground preprocessing end and a terrain perception and alarm system end. The ground preprocessing end includes an envelope modulation parameter generation module and a false alarm location parameter generation module. Based on the false alarm location data of the flight path, the ground preprocessing end generates a false alarm suppression configuration item and loads it into the TAWS end. During the flight process, the TAWS end identifies the false alarm location and performs threshold modulation. Specifically, in real aircraft flight path operations, when the forward look-ahead warning function generates false alarms due to special terrain changes at the airport, it can obtain aircraft data at the location of the false alarm. Based on this data, false alarm location parameters are generated based on the standard flight path through ground preprocessing. Based on the specific circumstances of the false alarm, the threshold is reduced, and envelope modulation parameters are generated. Based on the two types of parameters, a false alarm suppression configuration item is generated and configured in the TAWS device. During the calculation process, the TAWS determines whether the current aircraft is within the range where a false alarm might occur based on the aircraft parameters and the false alarm location parameters in the configuration item. If it is within the range, the forward look-ahead warning threshold is modulated according to the pre-stored alarm threshold modulation value to avoid the occurrence of false alarms.

[0027] This application specifically includes the following: like Figure 2 and Figure 3 As shown, step 1, generating false alarm location parameters; Step 1.1, Generating False Alarm Route Locations: The flight recorder can obtain the starting and ending latitude and longitude points when the aircraft generates a forward look-ahead warning. Simultaneously, due to certain flight and positioning errors, these two points need to be mapped to a standard aeronautical chart to obtain the false alarm segment start point F-Start and false alarm segment end point F-End on the standard aeronautical chart. Step 1.2: Generating False Alarm Airport Parameters. Based on the location where the false alarm occurred, record the airport's ID, such as the ICAO code, or a custom ID number from the airport database, and confirm the distances (D-FAF and D-MAP) of the FAF and MAP points from the runway threshold based on the airport's flight path chart. Step 1.3: Formatting of False Alarm Location Parameters. Based on the parameters generated above, all parameters supporting false alarm location determination can be obtained and listed in tabular form. These parameters can be stored in the configuration items of the false alarm parameters as a data structure.

[0028] Table 1 Parameterization Table of False Alarm Locations

[0029] Step 2: Generation of threshold correction parameters. False alarms may be caused by an excessively large horizontal detection range, which causes terrain on both sides below the flight path to enter the detection area and cause false alarms, or by excessive downward detection time or insufficient clearance. For these situations, the priority order of threshold correction is set: first, the side-looking angle is corrected, then the downward and forward looking times in the vertical direction are corrected, and finally the basic clearance is corrected.

[0030] Step 2 specifically includes: Step 2.1, Side-looking angle correction. Extract the collision information between the terrain and the warning envelope within the detection range ahead of the aircraft's false alarm position, such as... Figure 4 As shown, when a collision occurs, the side-view angle is reduced, and further reduced to a minimum of 0 degrees. The analysis then examines whether the target terrain A that caused the false alarm can be eliminated. If it can be eliminated, the test angle offset is recorded. ; Step 2.2, Adjustment of the vertical threshold. When reducing the side-looking angle cannot effectively suppress false alarms, i.e., when abrupt terrain changes occur below the normal descent path, such as... Figure 5 and Figure 6 As shown, the downward sight threshold is reduced by lowering it. Since the altitude threshold below the aircraft is composed of the basic warning clearance H1 and the downward probe height H2, and the downward probe height is as shown in formula (1): (1); Where t d V represents the downward viewing time. h Let t be the vertical velocity of the aircraft during its descent. Within the normal approach range, this vertical velocity will not pose a danger; therefore, the look-down time can be appropriately reduced. The original look-down time was t. d The adjusted descent time is t d ’ Therefore, the resulting downward time offset As shown in formula (2): (2); If adjusting the downward look-down time still fails to meet the suppression requirements, we analyze and predict whether a collision occurs with terrain ahead of the flight path at the forward look-down distance. This scenario is generally applicable when there are terrain and obstacles ahead of the aircraft's takeoff flight path. The original forward look-down time is t. f The adjusted forward look time is t f ’ The generated forward look time offset As shown in formula (3): (3); If adjusting the downsight time and forwardsight time is ineffective, adjust the basic warning clearance. The original basic warning clearance was H1, and the adjusted clearance is now H1. ’The corresponding warning baseline net clearance bias As shown in formula (4): (4); In summary, the resulting corrections are shown in Table 2: Table 2. Envelope Correction Parameterization Table

[0031] Step 3: Aircraft false alarm range identification; The function of identifying the aircraft false alarm range runs in the TAWS functional software, and its process is as follows: Figure 7 As shown.

[0032] Step 3 specifically includes: Step 3.1: First, use the airport search module built into TAWS to obtain the ID of the nearest airport to the current aircraft using the aircraft's latitude and longitude and terrain database information. Compare this ID with the false alarm airport ID in the false alarm location parameter to confirm whether the aircraft is near a false alarm airport. Step 3.2: Based on Step 3.1, according to the calculated distance to the airport, compare the distances to the FAF and MAP points in the parameter items to calculate the allowable flight technical error for the current range. The specific calculation method is as follows: Calculation of technical error in horizontal flight: like Figure 8 As shown, Figure 8 In the figure, X represents the distance coordinate from the aircraft to the runway threshold. When the aircraft is outside the FAF, the horizontal flight technical error is set to Errory nautical miles. When the aircraft is between the FAF and the MAP, the horizontal flight technical error decreases linearly to 0 nm. When the aircraft is inside the MAP, the horizontal flight technical error is 0. The specific calculation formula for the flight technical error F_delta_Y is shown in (5): (5); in, This refers to the horizontal deviation of the aircraft from the standard flight path. This is the distance from the aircraft to the final approach positioning point. This is the distance from the aircraft to the go-around point. Vertical flight technical error calculation: like Figure 9 As shown, Figure 9 In the figure, X represents the distance coordinate from the aircraft to the runway threshold. When the aircraft is outside the FAF, the horizontal flight technical error is the preset Errorzy feet. When the aircraft is between the FAF and the MAP, the vertical flight technical error is Errorz / 2 feet. The error is 0 when the aircraft is inside the MAP. The specific calculation of the flight technical error F_delta_Z is shown in formula (6): (6); in, This refers to the altitude deviation of the aircraft from the standard flight path. This is the distance from the aircraft to the final approach positioning point. This is the distance from the aircraft to the go-around point. Step 3.3: Based on Step 3.2, and combining the aircraft's horizontal quality factor (HFOM) and vertical quality factor (VFOM), determine whether the aircraft is within the false alarm range. If it is within the false alarm flight path range, apply the relevant threshold bias. The specific calculation method is as follows: Calculation of lateral deviation of aircraft: Based on the false alarm segment start point F_Start(Lat_FS, Lon_FS), the false alarm segment end point F_End(Lat_FE, Lon_FE), and the aircraft's current latitude and longitude Cur(Lat_Cur, Lon_Cur), the latitude and longitude coordinate system is converted to a rectangular coordinate system using the false alarm segment start point as the reference. The corresponding point is F_Start(X... S ,Y S ), F_End(X E Y E ), Cur (X) Cur , Y Cur At this point, the lateral deviation of the aircraft from the standard flight path can be calculated. As shown in formula (7): (7); Aircraft altitude deviation calculation: Based on the false alarm segment distance DIS-F, the distance from the aircraft's current position to the false alarm initiation point DIS-X, and the altitude of the false alarm segment initiation point H, the aircraft's current position is at the false alarm segment initiation point DIS-X. Start End point height H End Current altitude of the aircraft (H) Cur It can calculate the altitude error H of the aircraft deviating from the current standard flight path. Z As shown in formula (8): (8); like Figure 10 As shown, based on the aircraft's lateral deviation distance Horizontal flight technical error The aircraft horizontal quality factor HFOM is determined to be within the horizontal error range defined by the false alarm route when the following conditions are met: the lateral deviation distance is less than or equal to the sum of the flight technical error and the horizontal quality factor, as shown in formula (9).

[0033] (9); According to the aircraft's altitude deviation from H ZThe vertical flight technical error F_delta_Z and the aircraft vertical quality factor VFOM are determined to be within the vertical error range defined by the false alarm route when the following conditions are met: the altitude deviation is less than or equal to the sum of the flight technical error and the horizontal quality factor, as shown in formula (10). (10); like Figure 11 As shown, the current magnetic heading angle of the aircraft is compared with the magnetic heading angle of the false alarm route. If it is less than a certain range, the aircraft's magnetic heading angle is determined to meet the judgment requirements.

[0034] When all of the above conditions are met, the aircraft is considered to be in the false alarm limit area and corresponding envelope modulation is required.

[0035] When envelope modulation is clearly required, it is performed based on the test angle offset parameters, downward look time offset parameters, forward look time offset parameters, and clearance offset parameters in the false alarm suppression configuration. Figure 4 , Figure 6 The envelope parameters are defined, and relevant threshold modulation is performed to complete the forward look-ahead alarm suppression.

[0036] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A TAWS false alarm suppression method for special terrain along flight routes, characterized in that, include: Step 1, Generating False Alarm Location Parameters: Based on the false alarm results generated by the operating route, the following parameters are stored: the nearby airport code where the false alarm occurred, the latitude and longitude range of the false alarm start point, the latitude and longitude range of the end point, the altitude of the start point, the altitude of the end point, the heading of the false alarm segment, the distance to the FAF point, and the distance to the MAP point. Step 2, Generation of threshold correction parameters: Based on the false alarm position set for the corresponding flight path, the correction data for the side look angle, downward look time, forward look time, and clearance value set for the forward look alarm are parameterized and stored; Step 3, False Alarm Range Identification: In the aircraft ground proximity warning (TAWS), determine whether the current flight position and status are within the range that may generate false alarms on the flight path. If so, use correction data to correct the alarm algorithm. Step 1 specifically includes: Step 1.1, Generating the false alarm route location: Obtain the starting latitude and longitude points and the ending latitude and longitude points when the aircraft generates a forward look-ahead warning from the flight recorder. Map these starting latitude and longitude points to the standard aeronautical chart to obtain the false alarm segment start point F-Start and the false alarm segment end point F-End in the standard aeronautical chart. Step 1.2, Generating false alarm airport parameters: Based on the location where the false alarm occurs, record the airport ID, and confirm the distances D-FAF and D-MAP of the FAF point and MAP point from the runway threshold point based on the airport's flight path chart; Step 1.3, Formatting of false alarm location parameters: Based on the false alarm flight path location and false alarm airport parameters, obtain all parameters that support the determination of false alarm location, list them in the form of a table, and store them in the configuration items of the false alarm parameters in the form of a data structure; Step 2 specifically includes: Step 2.1, Side-Look Angle Correction: Extract the collision information between the terrain and the warning envelope within the detection range ahead of the aircraft's false alarm position. When a collision occurs, reduce the side-look angle, lowering it to a minimum of 0 degrees. Analyze whether the target terrain A causing the false alarm can be eliminated. If eliminated, record the test angle offset. ; Step 2.2, Adjustment of Vertical Threshold: When reducing the side-looking angle cannot effectively suppress false alarms, i.e., when abrupt terrain changes occur below the normal descent path, the downward-looking threshold is reduced. The altitude threshold below the aircraft is composed of the basic warning clearance H1 and the downward-looking height H2, as shown in the formula: , where t d V represents the downward viewing time. h This refers to the vertical velocity of the aircraft as it descends. Reduce the descent time; the adjusted descent time is t. d ’ The generated downward viewing time offset for ; If adjusting the downsight time still fails to meet the suppression requirements, analyze whether there is a collision prediction with the terrain ahead of the flight path at the forwardsight distance. The original forwardsight time was t. f The adjusted forward look time is t. f ’ The generated forward look time offset for: ; If adjusting the downsight time and forwardsight time is ineffective, adjust the basic warning clearance. The original basic warning clearance was H1, and the adjusted clearance is now H1. ’ The corresponding warning baseline net clearance bias for .

2. The TAWS false alarm suppression method for special terrain along flight routes according to claim 1, characterized in that, In step 3, during the process of determining whether the current flight position and status are within the range where false alarms may occur on the flight path, the current position parameters of the aircraft are compared with the stored false alarm position parameters, and the allowable flight technical error is calculated. Combined with the horizontal and vertical quality factors and magnetic heading angle of the aircraft, it is determined whether the current flight position and status are within the range where false alarms may occur on the flight path.

3. The TAWS false alarm suppression method for special terrain along flight routes according to claim 2, characterized in that, Step 3 specifically includes: Step 3.1: Using the airport search module built into TAWS, and using the aircraft's latitude and longitude and terrain database information, obtain the ID of the nearest airport to the current aircraft. Compare this ID with the false alarm airport ID in the false alarm location parameter to confirm whether it is near a false alarm airport. Step 3.2: Based on Step 3.1, according to the calculated distance to the airport, compare the distances to FAF and MAP points in the parameter items to calculate the allowable flight technical error within the current range; Calculate the technical error F_delta_Y in horizontal flight: ； Where X represents the distance coordinates from the aircraft to the runway threshold. The horizontal deviation of the aircraft from the standard flight path. This is the distance from the aircraft to the final approach positioning point. This is the distance from the aircraft to the go-around point. Calculate the vertical flight technical error F_delta_Z: ； Where X represents the distance coordinates from the aircraft to the runway threshold. This refers to the altitude deviation of the aircraft from the standard flight path. This is the distance from the aircraft to the final approach positioning point. This is the distance from the aircraft to the go-around point. Step 3.3: Based on Step 3.2, and combining the aircraft's horizontal quality factor (HFOM) and vertical quality factor (VFOM), determine whether the aircraft is within the false alarm range. If it is within the false alarm flight path range, apply the relevant threshold bias: Based on the false alarm segment start point F_Start(Lat_FS, Lon_FS), the false alarm segment end point F_End(Lat_FE, Lon_FE), and the aircraft's current latitude and longitude Cur(Lat_Cur, Lon_Cur), the latitude and longitude coordinate system is converted to a rectangular coordinate system using the false alarm segment start point as the reference. The corresponding point is F_Start(X... S ,Y S ), F_End(X E Y E ), Cur (X) Cur Y Cur ), calculate the lateral deviation of the aircraft from the standard flight path. : ; Based on the distance of the false alarm segment The distance of the aircraft's current position from the false alarm starting point Altitude H of the starting point of the false alarm segment Start End point height H End Current altitude of the aircraft (H) Cur Calculate the altitude error H of the aircraft deviating from the current standard flight path. Z : ； When the lateral deviation distance is less than or equal to the sum of the flight technical error and the horizontal quality factor, the aircraft is judged to be within the horizontal error range defined by the false alarm route. When the altitude deviation is less than or equal to the sum of the flight technical error and the horizontal quality factor, the aircraft is judged to be within the vertical error range defined by the false alarm route. Based on the current magnetic heading angle of the aircraft, it is compared with the magnetic heading angle of the false alarm route. If it is less than the preset value, it is determined that the magnetic heading angle of the aircraft meets the judgment requirements. When the aircraft is within the horizontal error range defined by the false alarm route and the aircraft is within the vertical error range defined by the false alarm route, the corresponding envelope modulation is performed when it is considered that the aircraft is currently within the false alarm range and the aircraft's magnetic heading angle meets the judgment requirements.

4. The TAWS false alarm suppression method for special terrain along flight routes according to claim 3, characterized in that, When performing envelope modulation, based on the test angle offset parameters, downward look time offset parameters, forward look time offset parameters, and clearance offset parameters in the false alarm suppression configuration item, relevant threshold modulation is performed according to the envelope parameter definition to complete forward look alarm suppression.

Images