Flight recorder impact safety distance determination and impact safety management method and device

Abstract

The embodiment of the invention discloses a flight recorder impact safety distance determination method, which comprises the following steps: establishing a digital model according to flight recorder parameters, and performing flight recorder aerodynamic characteristic simulation by using the digital model to obtain an air resistance model corresponding to a flight recorder; acquiring the speed and attitude of the flight recorder under the condition that the flight recorder is not ejected; calculating the ejection speed increment of the flight recorder according to the ejection momentum and attitude of the flight recorder; calculating the initial ejection speed of the flight recorder according to the speed of the flight recorder under the non-ejection condition and the ejection speed increment; and according to the ejection initial speed and the air resistance model, calculating an impact safety distance required by the flight recorder to reach a preset speed after the flight recorder is ejected.

Description

Technical Field

[0001] This application relates to the technical field of aircraft avionics, and particularly to a method and device for determining the impact safety distance of a flight recorder and impact safety management. Background Art

[0002] In 2015, ICAO proposed the concept of the global aviation distress and safety system and promoted the work on the technology of the Automatic Ejection Flight Recorder (ADFR). The ADFR is a key device for aircraft safety and is used for accident analysis. The ADFR ejects and separates from the aircraft in case of aircraft distress and should have a certain impact resistance. In the prior art, the impact resistance performance of the ADFR is verified through a strong impact test. The ADFR impacts with the impact surface at the test impact speed, and the ADFR should not be damaged after the impact.

[0003] However, even though the impact performance of the existing ADFR has passed the verification of the strong impact test, the test impact speed cannot cover all situations in case of aircraft distress. In previous aircraft accident data or accident investigations, it has been found that the crash speed of the aircraft exceeds the test impact speed of the ADFR, indicating that in reality, there are situations where the actual impact speed of the ADFR exceeds its test impact speed, and there is a risk that the ADFR may be damaged due to the impact. Summary of the Invention

[0004] Embodiments of this specification provide a method and device for determining the impact safety distance of a flight recorder and impact safety management, so as to solve the technical problem of how to determine the impact safety distance of the flight recorder and manage the impact safety of the flight recorder.

[0005] To solve the above technical problem, the embodiments of this specification provide the following technical solutions:

[0006] Embodiments of this specification provide a method for determining the impact safety distance of a flight recorder. The method includes:

[0007] Establish a digital model according to the flight recorder parameters, and use the digital model to simulate the aerodynamic characteristics of the flight recorder to obtain the air resistance model corresponding to the flight recorder;

[0008] Obtain the speed and attitude of the flight recorder when it is not ejected; calculate the ejection speed increment of the flight recorder according to the ejection momentum and attitude of the flight recorder; calculate the ejection initial speed of the flight recorder according to the speed of the flight recorder when it is not ejected and the ejection speed increment.

[0009] Calculate the impact safety distance required for the flight recorder to reach a preset speed after ejection according to the ejection initial speed and the air resistance model.

[0010] Optionally, the air resistance model includes air resistance coefficients in the horizontal and vertical directions.

[0011] Optionally, the method further includes:

[0012] Calculating the components of the impact safety distance in the horizontal and vertical directions.

[0013] An embodiment of this specification provides a method for managing the impact safety of a flight recorder. The method includes:

[0014] Establishing a digital model based on the flight recorder parameters, and using the digital model to simulate the aerodynamic characteristics of the flight recorder to obtain the corresponding air resistance model of the flight recorder;

[0015] Determining the initial ejection velocity of the flight recorder, and calculating the impact safety distance required for the flight recorder to reach a preset velocity after ejection according to the initial ejection velocity and the air resistance model;

[0016] When a preset condition occurs, obtaining the terrain DEM data around the aircraft, and judging whether the impact safety condition is satisfied according to the terrain DEM data and the impact safety distance.

[0017] Optionally, determining the initial ejection velocity of the flight recorder includes:

[0018] Obtaining the velocity and attitude of the flight recorder when it is not ejected; calculating the ejection velocity increment according to the ejection momentum and attitude of the flight recorder; calculating the initial ejection velocity of the flight recorder according to the velocity of the flight recorder when it is not ejected and the ejection velocity increment.

[0019] Optionally, judging whether the impact safety condition is satisfied according to the terrain DEM data and the impact safety distance includes:

[0020] Determining whether there are obstacles in the target range according to the terrain DEM data to judge whether the impact safety condition is satisfied;

[0021] Wherein, the target range is determined according to the horizontal and vertical components of the impact safety distance.

[0022] Optionally, the minimum distance between the projection area boundary of the target range in the horizontal direction and the flight recorder is not less than the horizontal component of the impact safety distance;

[0023] The minimum distance between the projection area boundary of the target range in the vertical direction and the flight recorder is not less than the vertical component of the impact safety distance.

[0024] Optionally, the method further includes:

[0025] Judge whether the flight recorder is detached from the aircraft according to whether the impact safety condition is met.

[0026] An embodiment of this specification provides a device for determining the impact safety distance of a flight recorder. The device includes:

[0027] An aerodynamic performance simulation module for establishing a digital model according to the flight recorder parameters, simulating the aerodynamic characteristics of the flight recorder by using the digital model to obtain an air resistance model corresponding to the flight recorder, and transmitting the air resistance model to the impact deceleration distance calculation module;

[0028] An initial motion state calculation module for determining the ejection initial velocity of the flight recorder and transmitting the ejection initial velocity to the impact deceleration distance calculation module;

[0029] An impact deceleration distance real-time calculation module for calculating the impact safety distance required for the flight recorder to reach a preset velocity after ejection according to the ejection initial velocity and the air resistance model.

[0030] An embodiment of this specification provides a device for managing the impact safety of a flight recorder. The device includes:

[0031] An aerodynamic performance simulation module for establishing a digital model according to the flight recorder parameters, simulating the aerodynamic characteristics of the flight recorder by using the digital model to obtain an air resistance model corresponding to the flight recorder, and transmitting the air resistance model to the impact deceleration distance calculation module;

[0032] An initial motion state calculation module for determining the ejection initial velocity of the flight recorder and transmitting the ejection initial velocity to the impact deceleration distance calculation module;

[0033] An on-board data processing module for providing the data required to determine the ejection initial velocity to the initial motion state calculation module and providing the terrain DEM data around the aircraft to the impact deceleration distance calculation module;

[0034] An impact deceleration distance real-time calculation module for calculating the impact safety distance required for the flight recorder to reach a preset velocity after ejection according to the ejection initial velocity and the air resistance model;

[0035] An impact safety distance real-time judgment module for judging whether the impact safety condition is met according to the terrain DEM data and the impact safety distance.

[0036] At least one of the above technical solutions adopted in the embodiments of this specification can achieve the following beneficial effects:

[0037] The aerodynamic characteristics are simulated through a digital model to obtain the air resistance model corresponding to the flight recorder. According to the ejection initial velocity of the flight recorder and the air resistance model, the impact safety distance of the flight recorder can be determined more accurately.

[0038] After determining the impact safety distance of the flight recorder, when a preset condition occurs, it is judged whether the impact safety condition is satisfied according to the terrain DEM data and the impact safety distance, so as to avoid damage to the flight recorder due to impact, realizing the management of the safety of the flight recorder against impact. Description of the Drawings

[0039] In order to more clearly illustrate the technical solutions in the embodiments of this specification or the prior art, the drawings required for describing the embodiments of this specification or the prior art will be briefly described below. Obviously, only the drawings required for some embodiments of this application are described below. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0040] Figure 1 It is a schematic flowchart of a method for determining the impact safety distance of a flight recorder provided in the first embodiment of this specification.

[0041] Figure 2 It is a schematic flowchart of a method for managing the impact safety of a flight recorder provided in the second embodiment of this specification.

[0042] Figure 3 It is a schematic diagram of the impact safety management stage of the flight recorder in the second embodiment of this specification.

[0043] Figure 4 It is a schematic structural diagram of a device for determining the impact safety distance of a flight recorder provided in the third embodiment of this specification.

[0044] Figure 5 It is a schematic structural diagram of a device for managing the impact safety of a flight recorder provided in the fourth embodiment of this specification. Detailed Embodiments

[0045] In order to enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below with reference to the drawings. Obviously, the embodiments involved in the detailed embodiments are only some embodiments of this application, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the detailed embodiments without creative efforts shall fall within the protection scope of this application.

[0046] The first embodiment of this specification (hereinafter referred to as "Embodiment 1") provides a method for determining the impact safety distance of a flight recorder. The execution subject of Embodiment 1 includes, but is not limited to, a terminal, a server, an operating system, or an application program. That is, the execution subject can be diverse and can be set, used, or transformed according to needs. Additionally, a third-party application program can assist the execution subject in executing Embodiment 1. For example, the method provided in Embodiment 1 can be executed by a server, and a corresponding application program can be installed on a terminal (which can be held by a user). Data transmission can occur between the terminal or the application program and the server to assist the server in executing the method provided in Embodiment 1.

[0047] Specifically, the execution subject of Embodiment 1 can be a flight recorder or a device for controlling the flight recorder, such as an airborne device for controlling the ejection of the flight recorder.

[0048] Reference Figure 1 , the method for determining the impact safety distance of the flight recorder provided in Embodiment 1 includes:

[0049] S101: Establish a digital model based on the flight recorder parameters, and use the digital model to simulate the aerodynamic characteristics of the flight recorder to obtain the air resistance model corresponding to the flight recorder;

[0050] In Embodiment 1, a digital model can be established for the flight recorder, including establishing a digital model corresponding to the flight recorder (referred to as the ADFR digital model) based on the flight recorder parameters. Specifically, a CAD digital model corresponding to the flight recorder can be established according to the external dimensions, weight, center of gravity, and moment of inertia of the flight recorder.

[0051] Through the digital model, the aerodynamic characteristics of the flight recorder can be simulated to obtain the air resistance model corresponding to the flight recorder. Among them, the air resistance model can include the air resistance coefficients in the horizontal and vertical directions. Specifically, the digital model can be preprocessed and the calculation domain and grid can be defined, and the resistance in each direction can be obtained through simulation, thereby establishing an air resistance coefficient model, and calculating the corresponding resistance coefficients (including the air resistance coefficients in the horizontal and vertical directions) according to the air resistance coefficient model.

[0052] The above flight recorder parameters (including flight recorder system parameters) can be obtained through appropriate channels, such as from the device manufacturer.

[0053] S103: Obtain the speed and attitude of the flight recorder when it is not ejected; calculate the ejection speed increment of the flight recorder according to the ejection momentum and attitude of the flight recorder; calculate the initial ejection speed of the flight recorder according to the speed of the flight recorder when it is not ejected and the ejection speed increment;

[0054] In the first embodiment, the speed and attitude (including the mounting surface attitude) of the flight recorder in the case of non-ejection can be obtained. For example, in the case of non-ejection, the flight recorder is generally installed at a specific position of the aircraft (including but not limited to an airplane). Therefore, the motion parameters of the aircraft can be obtained through relevant modules of the aircraft (such as an on-board computer). The motion parameters include the attitude of the aircraft, and the attitude of the aircraft includes the mounting surface attitude. Thus, the speed and attitude of the flight recorder in the case of non-ejection can be determined according to the motion parameters of the aircraft. Specifically, the speed in the motion parameters of the aircraft can be used as the speed of the flight recorder in the case of non-ejection. The mounting surface of the flight recorder is consistent with the attitude of the aircraft skin at its mounting position. Therefore, the mounting surface attitude of the flight recorder can be obtained through the attitude of the aircraft.

[0055] According to the ejection momentum and attitude of the flight recorder, the ejection speed increment of the flight recorder can be calculated. Among them, the ejection momentum of the flight recorder can be obtained through appropriate means, such as obtaining it from the equipment manufacturer. The calculation method of the ejection speed increment is as follows: for example, according to the aircraft attitude angle in the attitude of the flight recorder, the rotation matrix for converting the body coordinate system where the flight recorder is located to the geocentric inertial coordinate system is determined. Subsequently, the ejection momentum of the flight recorder in the body coordinate system is converted to the geocentric inertial coordinate system, and the speed increment brought by ejection, that is, the ejection speed increment, is calculated using the momentum equation.

[0056] According to the speed of the flight recorder in the case of non-ejection and the ejection speed increment, the ejection initial speed of the flight recorder can be calculated, that is, the initial speed when the flight recorder ejects.

[0057] S105: Calculate the impact safety distance required for the flight recorder from ejection to reaching a preset speed according to the ejection initial speed and the air resistance model.

[0058] In the first embodiment, according to the ejection initial speed of the flight recorder and the aforementioned air resistance model, the distance required for the flight recorder to reach the preset speed after ejection can be calculated (specifically, according to the ejection initial speed of the flight recorder and the aforementioned air resistance model, the motion trajectory equation of the flight recorder after separation can be obtained from the kinematic formula and Newton's second law, so as to calculate the distance required for the flight recorder to reach the preset speed after ejection). This distance is used as the impact safety distance of the flight recorder. Among them, the preset speed can be set as needed. For example, the highest test impact speed when the flight recorder does not get damaged can be used as the preset speed, that is, when the flight recorder moves at a speed not higher than the preset speed and suffers an impact, the flight recorder will not get damaged.

[0059] The significance of the impact safety distance is that after the flight recorder is ejected at the initial ejection speed and passes through the impact safety distance, the speed of the flight recorder will be reduced to the preset speed. When the flight recorder is impacted while moving at a speed not higher than the preset speed, the flight recorder will not be damaged. That is to say, after the flight recorder is ejected at the initial ejection speed and passes through the impact safety distance, its speed has been reduced to the preset speed or a lower speed, and the flight recorder will not be damaged when impacted. Therefore, the impact safety distance can also be called the deceleration distance.

[0060] In addition to calculating the impact safety distance required for the flight recorder to reach the preset speed after ejection, the horizontal and vertical components of the impact safety distance can also be calculated, namely the horizontal component and the vertical component.

[0061] The first embodiment can achieve the following beneficial effects:

[0062] Through the digital model for aerodynamic characteristic simulation, the air resistance model corresponding to the flight recorder is obtained. Combining the motion parameters of the aircraft to calculate the initial ejection speed of the flight recorder, based on the initial ejection speed of the flight recorder and the air resistance model, the impact safety distance of the flight recorder can be determined more accurately.

[0063] The second embodiment of this specification (hereinafter referred to as "Embodiment 2") provides a method for flight recorder impact safety management. The execution subject of Embodiment 2 includes but is not limited to a terminal or a server or an operating system or an application program. That is, the execution subject can be various and can be set, used or transformed according to needs. In addition, a third-party application program can assist the execution subject to execute Embodiment 2. For example, the method provided by Embodiment 2 can be executed by the server, and a corresponding application program can be installed on the terminal (the terminal can be held by the user). Data can be transmitted between the terminal or the application program and the server, so as to assist the server to execute the method provided by Embodiment 2.

[0064] In particular, the execution subject of the first embodiment can be a flight recorder or a device for controlling the flight recorder, such as an airborne device for controlling the ejection of the flight recorder.

[0065] Reference Figure 2 , the method for flight recorder impact safety management provided by Embodiment 2 includes:

[0066] S202: Establish a digital model according to the flight recorder parameters, and use the digital model to perform aerodynamic characteristic simulation of the flight recorder to obtain the air resistance model corresponding to the flight recorder;

[0067] Specifically, it can be implemented with reference to S101.

[0068] S204: Determine the ejection initial velocity of the flight recorder, and calculate the impact safety distance required for the flight recorder to reach the preset velocity after ejection according to the ejection initial velocity and the air resistance model;

[0069] In Embodiment 2, the ejection initial velocity of the flight recorder can be determined. Among them, determining the ejection initial velocity of the flight recorder may include: obtaining the velocity and attitude of the flight recorder when it is not ejected; calculating the ejection velocity increment of the flight recorder according to the ejection momentum and attitude of the flight recorder; calculating the ejection initial velocity of the flight recorder according to the velocity of the flight recorder when it is not ejected and the ejection velocity increment. How to determine or calculate the ejection initial velocity of the flight recorder can be specifically implemented with reference to S103.

[0070] The distance required for the flight recorder to reach the preset velocity after ejection can be calculated according to the ejection initial velocity of the flight recorder and the aforementioned air resistance model, and this distance is used as the impact safety distance of the flight recorder. It can be specifically implemented with reference to S105.

[0071] S206: After a preset condition occurs, obtain the terrain DEM data around the aircraft, and determine whether the impact safety condition is met according to the terrain DEM data and the impact safety distance.

[0072] In Embodiment 2, the preset condition can be set in advance. After the preset condition occurs, the terrain DEM data around the aircraft is obtained. For example, the aircraft being in distress or encountering a specific situation can be used as the preset condition. Generally, the preset condition is a condition that requires the flight recorder to be separated from the aircraft, and the specific content of the preset condition is not limited in Embodiment 2. The execution subject of Embodiment 2 can be connected to the aircraft-related equipment and determine whether the preset condition occurs according to the information of the aircraft-related equipment.

[0073] After the preset condition occurs, the current position of the aircraft can be obtained, and then the terrain DEM data around the aircraft (specifically, within a certain range around the aircraft) can be obtained. For example, the terrain DEM data can be collected by the corresponding device of the aircraft, so the terrain DEM data can be obtained through the relevant module of the aircraft (such as the on-board computer).

[0074] In the second embodiment, it is possible to determine whether the impact safety condition is met based on the terrain DEM data and the impact safety distance of the flight recorder. Specifically, determining whether the impact safety condition is met based on the terrain DEM data and the impact safety distance of the flight recorder may include: determining whether there are obstacles (including but not limited to the ground or mountains) within the target range according to the terrain DEM data to determine whether the impact safety condition is met; wherein, the target range is determined according to the horizontal component and the vertical component of the impact safety distance. For example, if it is determined according to the terrain DEM data that there are no obstacles within the target range, it is determined that the impact safety condition is met; if it is determined according to the terrain DEM data that there are obstacles within the target range, it is determined that the impact safety condition is not met.

[0075] Preferably, the minimum distance between the boundary of the projection area of the target range in the horizontal direction and the flight recorder is not less than the horizontal component of the impact safety distance; the minimum distance between the boundary of the projection area of the target range in the vertical direction and the flight recorder is not less than the vertical component of the impact safety distance. The target range is a cylinder, the projection of the bottom circle of the target range on the horizontal plane is centered on the position of the flight recorder and has a radius equal to the horizontal component of the impact safety distance; the height of the target range is twice the vertical component of the impact safety distance, and the midpoint of the height of the target range is the position of the flight recorder.

[0076] Of course, when a preset situation occurs, the flight recorder is generally still moving with the aircraft. Therefore, the above-mentioned target range is not a fixed spatial range, but a spatial range that surrounds the flight recorder and moves with the movement of the flight recorder.

[0077] After the target range is delimited according to the above requirements, when the flight recorder is separated from the aircraft by means of ejection or the like, it will not be damaged by encountering an obstacle impact within the target range. When the flight recorder reaches the boundary of the target range, the movement distance of the flight recorder is not less than the impact safety distance, and the movement speed of the flight recorder is not greater than the above-mentioned preset speed. After that, even if the flight recorder encounters an impact again (such as hitting the ground or falling into water or reaching the impact position), it will not be damaged. That is to say, under the condition of meeting the impact safety condition, the flight recorder will not be damaged due to being impacted whether it is within the target range or beyond the target range after being separated from the aircraft.

[0078] As mentioned above, when the preset situation occurs, the aircraft is generally still in motion, so the terrain DEM data around the aircraft can be continuously obtained to continuously determine whether the impact safety conditions are met. Determine whether the flight recorder is detached from the aircraft based on whether the impact safety conditions are met. Specifically, if the impact safety conditions are met, the flight recorder is detached from the aircraft by an appropriate method such as ejection; if the impact safety conditions are not met, wait until the impact safety conditions are met before detaching the flight recorder by an appropriate method such as ejection. For example, if the impact safety conditions are judged to be met at a certain moment, it means that there are no obstacles within the target range at this time, and the flight recorder will not encounter obstacles from the time it detaches from the aircraft to the time it reaches the boundary of the target range, and the flight recorder can be detached from the aircraft.

[0079] Combine the following Figure 3 , exemplarily illustrating the application of Embodiment 1 and Embodiment 2:

[0080] In this example, the ADFR installation stage, normal flight stage, and distress stage are explained.

[0081] a) ADFR installation phase: obtain ADFR parameters (i.e., system parameters), and establish an ADFR digital model based on the ADFR parameters; use the ADFR digital model to simulate the ADFR aerodynamic characteristics to obtain an ADFR air resistance model, including the air resistance coefficients in the horizontal and vertical directions.

[0082] b) Normal flight phase: Obtain aircraft motion parameters, and obtain the attitude and speed of the ADFR installation surface in real time, that is, the attitude and speed of the ADFR when it is not ejected. Calculate the ADFR speed increment caused by the ejection based on the ADFR ejection momentum and the ADFR attitude. Calculate the ADFR ejection initial speed in real time by combining the ADFR speed when it is not ejected and the speed increment caused by the ejection; Calculate the distance required to decelerate to the preset speed after ejection (that is, the impact safety distance) and the horizontal and vertical components of this distance based on the ADFR ejection initial speed and its air resistance model.

[0083] Distress phase: When the aircraft is in distress (a preset condition), an ADFR ejection signal is generated. The aircraft's current position and the terrain DEM data near the aircraft are obtained in real time. Based on the terrain DEM data, it is determined in real time whether there are obstacles in the horizontal and vertical component ranges of the impact safety distance centered on the aircraft's flight recorder (belonging to the target range) (i.e., a hazard analysis is performed in the horizontal and vertical directions). If there are no obstacles, it means that the current distance between the ADFR and the impact position is not less than the impact safety distance, and the impact safety conditions are met, and the ADFR can be ejected from the aircraft.

[0084] Embodiment 2 can achieve the following beneficial effects:

[0085] After determining the impact safety distance of the flight recorder, when a preset condition occurs, based on the terrain elevation data near the aircraft and the impact safety distance, it is determined in real time whether the impact safety condition is met, and it is judged whether it is safe for the flight recorder to eject at the current moment. If the flight recorder detaches from the aircraft when the impact safety condition is met, the flight recorder will not be damaged due to the impact. In this way, the control of the ejection timing of the flight recorder and the management of the safety against impact are realized, that is, the safety of the flight recorder is maximally guaranteed, and the problem that the speed of the flight recorder exceeds the preset speed when it is impacted after ejection is avoided, improving the survival probability of the flight recorder.

[0086] Moreover, the influence of the operating conditions of the aircraft on the initial ejection speed of the flight recorder and the influence of the actual distance between the flight recorder and the potential impact surface on the deceleration effect of the flight recorder are considered. For example, whether there is a potential impact surface (including potential obstacles) within the target range, whether the distance between the flight recorder and the potential impact surface meets the impact safety distance, and whether the flight recorder can decelerate to the preset speed before encountering the potential impact surface. Since these factors are comprehensively considered to determine whether the impact safety condition is met and then the ejection timing of the flight recorder is controlled, it is possible to more accurately judge whether the flight recorder can be ejected and more effectively manage the safety of the flight recorder against impact.

[0087] In particular, since it is not necessary to make the flight recorder detach from the aircraft immediately after the preset condition occurs, but only after the impact safety condition is met, before the flight recorder detaches from the aircraft, the flight recorder can save and record flight data to the maximum extent, which is beneficial to maximizing the role of the flight recorder.

[0088] The third embodiment of this specification provides a device for determining the impact safety distance of a flight recorder corresponding to the method described in the first embodiment, which can be used to execute the method described in the first embodiment.

[0089] Refer to Figure 4 , the device provided by the third embodiment includes:

[0090] An aerodynamic performance simulation module, which is used to establish a digital model according to the flight recorder parameters, perform aerodynamic characteristic simulation of the flight recorder using the digital model to obtain an air resistance model corresponding to the flight recorder, and transmit the air resistance model to the impact deceleration distance calculation module;

[0091] An initial motion state calculation module, which is used to determine the initial ejection speed of the flight recorder and transmit the initial ejection speed to the impact deceleration distance calculation module;

[0092] An impact deceleration distance real-time calculation module, configured to calculate the impact safety distance required for the flight recorder to reach a preset speed after ejection according to the initial ejection speed and the air resistance model.

[0093] The following further describes each module of the third embodiment:

[0094] (1) Aerodynamic performance simulation module (or ADFR aerodynamic performance simulation module)

[0095] Establish an ADFR digital model according to the ADFR parameters (which can be provided by the ADFR device manufacturer), obtain the air resistance coefficients of the ADFR in the horizontal and vertical directions through start-up characteristic simulation, and construct an air resistance model (or aerodynamic model). Transmit the ADFR air resistance model to the impact deceleration distance calculation module.

[0096] (2) Initial motion state calculation module (or ADFR initial motion state calculation module)

[0097] Calculate the initial ejection speed of the ADFR according to the speed increment caused by ejection to the ADFR (which can be provided by the ADFR device manufacturer), and the current aircraft attitude and speed, and transmit the initial ejection speed to the impact deceleration distance calculation module.

[0098] (3) Impact deceleration distance real-time calculation module

[0099] Establish a kinematic equation of the ADFR after ejection separation from the ADFR air resistance model and the real-time calculated initial ejection speed of the ADFR, calculate the distance required for the ADFR to decelerate to the preset speed (i.e., the impact safety distance), and the horizontal and vertical components of this distance.

[0100] Each module in the third embodiment can be connected in a suitable manner. For the content not detailed in the third embodiment, refer to the first embodiment. The third embodiment can achieve the same beneficial effects as the first embodiment.

[0101] The fourth embodiment of this specification provides a flight recorder impact safety management device corresponding to the method described in the second embodiment, which can be used to execute the method described in the second embodiment.

[0102] Refer to Figure 5 , the device provided in the fourth embodiment includes:

[0103] An aerodynamic performance simulation module, configured to establish a digital model according to the flight recorder parameters, perform aerodynamic characteristic simulation of the flight recorder using the digital model to obtain the corresponding air resistance model of the flight recorder, and transmit the air resistance model to the impact deceleration distance calculation module;

[0104] An initial motion state calculation module, configured to determine the ejection initial velocity of the flight recorder and transmit the ejection initial velocity to the impact deceleration distance calculation module;

[0105] An airborne data processing module, configured to provide the data required to determine the ejection initial velocity to the initial motion state calculation module, and provide the terrain DEM data around the aircraft to the impact deceleration distance calculation module;

[0106] An impact deceleration distance real-time calculation module, configured to calculate the impact safety distance required for the flight recorder to reach a preset velocity after ejection according to the ejection initial velocity and the air resistance model;

[0107] An impact safety distance real-time judgment module, configured to judge whether the impact safety condition is satisfied according to the terrain DEM data and the impact safety distance.

[0108] The following further describes each module of the fourth embodiment:

[0109] (1) Aerodynamic performance simulation module (or ADFR aerodynamic performance simulation module)

[0110] Establish an ADFR digital model according to the ADFR parameters (which can be provided by the ADFR device manufacturer), obtain the air resistance coefficients of the ADFR in the horizontal and vertical directions through aerodynamic characteristic simulation, and construct an air resistance model (or aerodynamic model). Transmit the ADFR air resistance model to the impact deceleration distance calculation module.

[0111] (2) Initial motion state calculation module (or ADFR initial motion state calculation module)

[0112] Calculate the ejection initial velocity of the ADFR according to the velocity increment caused by the ejection to the ADFR (which can be provided by the ADFR device manufacturer), and the aircraft attitude and velocity at the current moment provided by the airborne data processing module, and transmit the ejection initial velocity to the impact deceleration distance calculation module.

[0113] (3) Airborne data processing module

[0114] Obtain the aircraft attitude and velocity and the digital elevation model (DEM) data of the terrain around the aircraft from the aircraft, provide the required information such as the aircraft attitude and velocity information to the ADFR initial motion state calculation module, and provide the terrain DEM data around the aircraft to the impact safety distance judgment module.

[0115] (4) Impact deceleration distance real-time calculation module

[0116] Based on the ADFR air resistance model and the ADFR ejection initial velocity calculated in real time, establish the kinematic equation after ADFR ejection separation, calculate the distance required for the ADFR to decelerate to the preset velocity (i.e., the impact safety distance), and the components of this distance in the horizontal and vertical directions.

[0117] (5) Impact safety distance real-time judgment module

[0118] According to the DEM data of the terrain near the aircraft, in real time judge whether there are obstacles in the horizontal and vertical component ranges of the distance required to decelerate to the preset velocity, so as to judge whether the impact will cause damage to the ADFR.

[0119] The following combines Figure 3 , and exemplarily illustrates the applications of the third and fourth embodiments:

[0120] In this example, it is described from the stages of ADFR installation, normal flight, and distress.

[0121] a) ADFR installation stage: Obtain the ADFR parameters (i.e., system parameters), and establish the ADFR digital model according to the ADFR parameters; use the ADFR digital model to conduct ADFR aerodynamic characteristics simulation to obtain the ADFR air resistance model, including the air resistance coefficients in the horizontal and vertical directions.

[0122] b) Normal flight stage: Obtain the aircraft motion parameters from the on-board data processing module, and in real time obtain the attitude and velocity of the ADFR installation surface, that is, the attitude and velocity of the ADFR when it is not ejected. According to the ADFR ejection momentum combined with the ADFR attitude, calculate the ADFR velocity increment brought by the ejection. Combine the velocity of the ADFR when it is not ejected and the velocity increment brought by the ejection to calculate the ADFR ejection initial velocity in real time; according to the ADFR ejection initial velocity and its air resistance model, calculate in real time the distance required for it to decelerate to the preset velocity after ejection (i.e., the impact safety distance), and the components of this distance in the horizontal and vertical directions.

[0123] Distress stage: When the aircraft distress is triggered (belonging to the preset situation), generate an ADFR to-be-ejected signal. Obtain the current position of the aircraft and the DEM data of the terrain near the aircraft from the on-board data processing module in real time, and in real time judge whether there are obstacles (i.e., conduct a risk analysis in the horizontal and vertical directions) in the horizontal and vertical component ranges of the impact safety distance centered on the flight recorder of the aircraft (belonging to the target range). If there are no obstacles, it means that the distance between the current ADFR and the impact position is not less than the impact safety distance, meeting the impact safety conditions, and the ADFR can be ejected from the aircraft.

[0124] The modules in the fourth embodiment can be connected in a suitable manner. For the content not detailed in the fourth embodiment, refer to the second embodiment. The fourth embodiment can achieve the same beneficial effects as the second embodiment.

[0125] The above are only the embodiments of this specification and are not intended to limit this application. For those skilled in the art, various changes and modifications can be made to this application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of this application shall be included within the scope of the claims of this application.

Claims

1. A method for determining the impact safety distance of a flight recorder, characterized in that, The method includes: Establishing a digital model based on the flight recorder parameters, and performing aerodynamic characteristic simulation of the flight recorder by using the digital model to obtain an air resistance model corresponding to the flight recorder; Obtaining the speed and attitude of the flight recorder when it is not ejected; calculating the ejection speed increment of the flight recorder according to the ejection momentum and attitude of the flight recorder; calculating the ejection initial speed of the flight recorder according to the speed of the flight recorder when it is not ejected and the ejection speed increment; Calculating the impact safety distance required for the flight recorder to reach a preset speed after ejection according to the ejection initial speed and the air resistance model.

2. The method according to claim 1, characterized in that, The air resistance model includes air resistance coefficients in the horizontal direction and the vertical direction.

3. The method according to claim 1, wherein The method further includes: Calculating the horizontal and vertical components of the impact safety distance.

4. Flight recorder shock safety management method, characterized in that, The method includes: Establishing a digital model based on the flight recorder parameters, and performing aerodynamic characteristic simulation of the flight recorder by using the digital model to obtain an air resistance model corresponding to the flight recorder; Determining the ejection initial speed of the flight recorder, and calculating the impact safety distance required for the flight recorder to reach a preset speed after ejection according to the ejection initial speed and the air resistance model; When a preset condition occurs, obtaining the terrain DEM data around the aircraft, and judging whether the impact safety condition is satisfied according to the terrain DEM data and the impact safety distance.

5. The method according to claim 4, characterized in that, Determining the ejection initial speed of the flight recorder includes: Obtaining the speed and attitude of the flight recorder when it is not ejected; calculating the ejection speed increment of the flight recorder according to the ejection momentum and attitude of the flight recorder; calculating the ejection initial speed of the flight recorder according to the speed of the flight recorder when it is not ejected and the ejection speed increment.

6. The method according to claim 4, characterized in that Judging whether the impact safety condition is satisfied according to the terrain DEM data and the impact safety distance includes: Determining whether there are obstacles in the target range according to the terrain DEM data to judge whether the impact safety condition is satisfied; Wherein, the target range is determined according to the horizontal and vertical components of the impact safety distance.

7. The method according to claim 6, wherein The minimum distance between the boundary of the projection area of the target range in the horizontal direction and the flight recorder is not less than the horizontal component of the impact safety distance; The minimum distance between the boundary of the projection area of the target range in the vertical direction and the flight recorder is not less than the vertical component of the impact safety distance.

8. The method according to claim 4, characterized in that, The method further includes: Judging whether the flight recorder detaches from the aircraft according to whether the impact safety condition is satisfied.

9. Flight recorder impact safety distance determination device, characterized in that, The device includes: An aerodynamic performance simulation module, configured to establish a digital model according to the flight recorder parameters, perform aerodynamic characteristic simulation of the flight recorder by using the digital model to obtain an air resistance model corresponding to the flight recorder, and transmit the air resistance model to the impact deceleration distance calculation module; An initial motion state calculation module, configured to determine the ejection initial speed of the flight recorder and transmit the ejection initial speed to the impact deceleration distance calculation module; An impact deceleration distance calculation module, configured to calculate the impact safety distance required for the flight recorder to reach a preset speed after ejection according to the initial ejection speed and the air resistance model.

10. Flight recorder impact safety management device, characterized in that, The device includes: An aerodynamic performance simulation module, configured to establish a digital model based on the flight recorder parameters, perform aerodynamic characteristic simulation of the flight recorder using the digital model to obtain the air resistance model corresponding to the flight recorder, and transmit the air resistance model to the impact deceleration distance calculation module; An initial motion state calculation module, configured to determine the initial ejection speed of the flight recorder and transmit the initial ejection speed to the impact deceleration distance calculation module; An airborne data processing module, configured to provide the data required to determine the initial ejection speed to the initial motion state calculation module and provide the terrain DEM data around the aircraft to the impact deceleration distance calculation module; An impact deceleration distance real-time calculation module, configured to calculate the impact safety distance required for the flight recorder to reach a preset speed after ejection according to the initial ejection speed and the air resistance model; An impact safety distance real-time judgment module, configured to judge whether the impact safety condition is satisfied according to the terrain DEM data and the impact safety distance.

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