A method and system for evaluating the safety of urban low-altitude air routes considering biological activities

Abstract

The present invention relates to a method and system for assessing the safety of urban low-altitude airways taking into account biological activities, including constructing a spatial three-dimensional grid based on a two-dimensional basic grid divided from ground space, and constructing an index structure; calculating the characteristic information of organisms appearing in each three-dimensional grid in the low-altitude airspace under different scenarios according to the spatiotemporal trajectory information of the organisms' activities in the low-altitude airspace; obtaining the airway routes of aircraft in the low-altitude airspace space, and calculating the relative characteristic information between the organisms and the aircraft in the three-dimensional grid; quantitatively analyzing and calculating the risk of collision in the three-dimensional grid on the airway routes, and obtaining the risk index information of the airway routes; and determining the safety risk assessment results of the low-altitude airway routes. The present invention conducts a comprehensive, precise, dynamic, and systematic quantitative assessment of the safety risks of urban low-altitude airways, and can quantify the safety impact of biological activities in different periods on urban low-altitude airways, and can be used for low-altitude infrastructure site selection, low-altitude airway planning, etc.

Description

Technical Field

[0001] The present invention relates to the technical field of urban low-altitude traffic planning, and in particular to an urban low-altitude route safety assessment method and system taking biological activities into consideration. Background Art

[0002] With the rise of new aircraft such as drones and eVtols, the low-altitude area has gradually become an emerging space for urban transportation. Reasonable planning of urban low-altitude routes can not only improve the safety of aircraft operations and avoid air traffic congestion, but also promote the development of the low-altitude economy and promote the innovation of urban transportation modes. In addition, low-altitude route planning helps to integrate urban space resources, realize the effective connection between ground transportation and air transportation, provide more diversified travel options for urban residents, and enhance the sustainable development capacity of the city. Therefore, it is particularly important to carry out safety assessments of urban low-altitude routes. Existing studies mainly consider factors such as urban buildings, terrain undulations, and weather to assess the safety risks of routes, and then support the planning of low-altitude routes. The main idea is to assess the safety risks of routes around static facilities and the impact of the aircraft itself, but it does not consider the impact of other organisms in the urban airspace, especially the activities of birds on flight. Birds usually fly at an altitude of less than 1000m, with a high degree of overlap with the low-altitude economic zone, and their activity characteristics change with the seasons. These are factors that need to be considered in the process of route planning and safety assessment. In short, the existing urban flight route safety risk assessment methods have the problems of incomplete consideration of factors and incomplete temporal and spatial characteristics. Therefore, it is urgent to study the urban low-altitude route safety assessment method that takes into account the existing biological activity factors in the airspace. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a method and system for evaluating the safety of urban low-altitude routes taking into account biological activities in view of the deficiencies of the above-mentioned prior art.

[0004] The technical solution of the present invention to solve the above technical problem is as follows: A method for evaluating the safety of urban low-altitude routes taking into account biological activities comprises the following steps:

[0005] Based on the two-dimensional basic grid divided by the ground space, a three-dimensional grid in the low-altitude airspace is constructed, and an index structure between the two-dimensional basic grid and the three-dimensional grid is constructed;

[0006] According to the spatiotemporal trajectory information of the organisms in the low-altitude airspace, the characteristic information of the organisms appearing in each three-dimensional grid in the low-altitude airspace under different scenarios is calculated based on the random field model;

[0007] Acquire the route of the aircraft in the low-altitude airspace, determine the spatiotemporal sequence of the three-dimensional grid in the low-altitude airspace corresponding to the route, and calculate the relative characteristic information between the organisms and the aircraft in the three-dimensional grid corresponding to the route in combination with the characteristic information;

[0008] Constructing a collision risk assessment model based on the relative characteristic information, and performing quantitative analysis and calculation on the risk of collision in the corresponding three-dimensional grid on the route, to obtain risk index information of the route;

[0009] The safety risk assessment result of the low-altitude flight route is determined based on the index structure and risk index information between the two-dimensional basic grid and the three-dimensional grid.

[0010] The beneficial effects of the present invention are as follows: the urban low-altitude airway safety assessment method taking biological activities into consideration of the present invention constructs an index structure between the ground two-dimensional basic grid and the low-altitude airspace three-dimensional grid, and calculates the characteristic information of the biological organisms appearing in each three-dimensional grid and the relative characteristic information relative to the aircraft. The risk index information of the aircraft's route is calculated by the collision risk assessment model, and finally the safety risk assessment result of the low-altitude airway is determined based on the index structure. A comprehensive, detailed, dynamic and systematic safety risk quantitative assessment of the urban low-altitude airway is performed, and the safety impact of low-altitude biological activities such as birds at different periods on the urban low-altitude airway can be quantified, and it can be used for low-altitude infrastructure site selection, low-altitude airway planning, urban airspace safety risk assessment and other aspects.

[0011] On the basis of the above technical solution, the present invention can also be improved as follows:

[0012] Further: the two-dimensional basic grid based on the ground space division constructs a three-dimensional grid in the low-altitude airspace space, and constructs an index structure between the two-dimensional basic grid and the three-dimensional grid, specifically including the following steps:

[0013] Based on the ground grid, a regular cube is used to divide the low-altitude airspace space corresponding to the ground grid directly above the ground grid to obtain a three-dimensional grid in the low-altitude airspace space;

[0014] According to the number of the ground grid and the height of the three-dimensional grid, the three-dimensional grid in the low-altitude airspace is marked;

[0015] An index structure between the two-dimensional basic grid and the three-dimensional grid is constructed.

[0016] The beneficial effect of the above further scheme is: by dividing the low-altitude airspace space corresponding to the ground grid, a three-dimensional grid in the low-altitude airspace space is obtained, which can facilitate the subsequent determination of the characteristic information of the organisms appearing in each three-dimensional grid based on the spatiotemporal trajectory information of the organisms' activities in the low-altitude airspace. It is also convenient to establish an index structure between the two-dimensional basic grid and the three-dimensional grid, which serves as a reference for the subsequent safety risk assessment results of low-altitude flight routes.

[0017] Further: the step of calculating the feature information of the organisms appearing in each three-dimensional grid in the low-altitude airspace under different scenarios based on the temporal and spatial trajectory information of the organisms' activities in the low-altitude airspace based on the random field model specifically includes the following steps:

[0018] Obtaining vector line information of the spatiotemporal trajectory of biological activities in the low-altitude airspace, determining the spatial position relationship between the spatiotemporal trajectory of biological activities and the three-dimensional grid, and determining the characteristics of individual biological activity trajectories of the spatiotemporal trajectory of biological activities in each three-dimensional grid;

[0019] The characteristic information of the biological groups in each three-dimensional grid is calculated according to the characteristics of the individual biological activity trajectories.

[0020] The beneficial effect of the above further scheme is: the spatial position relationship between the biological activity spatiotemporal trajectory and the three-dimensional grid is accurately determined through the vector line information of the biological activity spatiotemporal trajectory, so that the individual biological activity trajectory characteristics of the biological activity spatiotemporal trajectory in each three-dimensional grid can be calculated with the three-dimensional grid as a reference, which is convenient for subsequent route safety assessment.

[0021] Further: the step of obtaining the vector line information of the spatiotemporal trajectory of biological activities in the low-altitude airspace, determining the spatial position relationship between the spatiotemporal trajectory of biological activities and the three-dimensional grid, and determining the individual biological activity trajectory characteristics of the spatiotemporal trajectory of biological activities in each three-dimensional grid specifically includes the following steps:

[0022] According to the vector line information of the spatiotemporal trajectory of biological activities in the low-altitude airspace, the activity position information of individual organisms is spatialized to obtain the activity sequence composed of the three-dimensional spatiotemporal trajectory points of individual biological activities. , as follows:

[0023] ;

[0024] In the formula, Represents individual organisms a At the moment The three-dimensional space coordinate information of the following;

[0025] Analyze the three-dimensional grid corresponding to the activity sequence composed of the three-dimensional spatiotemporal trajectory points of the individual biological activity to obtain the three-dimensional grid sequence of the individual biological activity , as follows:

[0026] ;

[0027] In the formula, Represents individual organisms a exist The three-dimensional grid of the airspace at the time.

[0028] The three-dimensional grid sequences of all individual biological movements are integrated to obtain the spatiotemporal sequence set of the spatiotemporal trajectory of group biological activities in each three-dimensional grid, as shown in the following formula:

[0029] ;

[0030] in, Represents individual organisms a Active spatial three-dimensional grid spatiotemporal sequence information.

[0031] The beneficial effect of the above further scheme is: according to the vector line information of the spatiotemporal trajectory of biological activities, the activity sequence composed of the three-dimensional spatiotemporal trajectory points of individual biological activities is obtained. , and obtain the three-dimensional grid sequence of individual biological activities based on the three-dimensional grid passed through , and finally obtain the set of spatiotemporal sequences of the spatiotemporal trajectories of group biological activities formed by all individual organisms in each three-dimensional grid.

[0032] Further: the step of calculating the characteristic information of the biological groups in each three-dimensional grid according to the characteristics of the individual biological activity trajectories specifically includes the following steps:

[0033] Taking the three-dimensional grid as the basic statistical unit, the time and space coordinates of the starting point of the individual organism entering the three-dimensional grid are extracted according to the characteristics of the individual biological activity trajectory. and the end time and space coordinates ;

[0034] The moving distance of the individual organism in the three-dimensional grid is calculated according to the starting point space-time coordinates and the end point space-time coordinates of the individual organism entering the three-dimensional grid. , and determine the speed of the individual organism in the three-dimensional grid according to the moving distance and the time difference of entering and leaving , the calculation formula is as follows:

[0035] ;

[0036] In the formula, represents the time when the individual organism enters the end point in the three-dimensional grid, Indicates the time corresponding to the starting point of the individual organism entering the three-dimensional grid;

[0037] Count the speeds of all individual organisms in the three-dimensional grid, and calculate the average speed of the group of organisms in the three-dimensional grid , the calculation formula is as follows:

[0038] ;

[0039] The activity direction of the individual organism in the three-dimensional grid is calculated according to the starting point space-time coordinates and the end point space-time coordinates of the individual organism entering the three-dimensional grid, and the direction vector is obtained. , the calculation formula is as follows:

[0040] ;

[0041] Count the direction vectors of all individual organisms in the three-dimensional grid, and calculate the average direction vector of the group of organisms in the three-dimensional grid ;

[0042] Based on the three-dimensional grid sequence of individual biological activities, the number of organisms appearing in each three-dimensional grid is counted .

[0043] The beneficial effect of the above further solution is that according to the three-dimensional grid sequence of individual biological activities, the number of organisms appearing in each three-dimensional grid can be accurately counted. , according to the characteristics of the individual biological activity trajectory, the starting point space-time coordinates and the end point space-time coordinates of the individual biological entering the three-dimensional grid are extracted, and then the moving distance and moving speed of the individual biological in the three-dimensional grid, as well as the average speed and average direction vector of all individual biologicals are determined, which can be used as the relative characteristic information of calculating the aircraft relative to the biological.

[0044] Further: the step of obtaining the route of the aircraft in the low-altitude airspace, determining the spatiotemporal sequence of the three-dimensional grid in the low-altitude airspace corresponding to the route, and calculating the relative characteristic information between the organisms and the aircraft in the three-dimensional grid corresponding to the route in combination with the characteristic information specifically includes the following steps:

[0045] Obtain the flight path of the aircraft in the low-altitude airspace, and determine the space-time sequence of the three-dimensional grid in the low-altitude airspace corresponding to the flight path , as follows:

[0046] ;

[0047] In the formula, Indicates aircraft at different times aam 1 The three-dimensional grid passed through;

[0048] According to the space-time sequence of the three-dimensional grid in the low-altitude airspace corresponding to the route Determine the average number of organisms present in the three-dimensional grid K and average speed ;

[0049] Taking the aircraft as the reference object, calculate the relative speed between the group of organisms and the aircraft in the three-dimensional grid , the calculation formula is as follows:

[0050] ;

[0051] In the formula, Three-dimensional grid The flying speed of the organism is x, y, z The weight in direction, The aircraft is located in the three-dimensional grid The flight speed within x, y, z Directional weight.

[0052] The beneficial effect of the above further scheme is: the space-time sequence of the three-dimensional grid in the low-altitude airspace corresponding to the route is determined by the route , so that the average number of organisms in the three-dimensional grid can be accurately calculated K and average speed , thereby calculating the relative speed between the group of organisms and the aircraft in the three-dimensional grid , as the input of the subsequent collision risk assessment model, so as to accurately obtain the risk index information of the entire route.

[0053] Further: the step of constructing a collision risk assessment model based on the relative feature information and quantitatively analyzing and calculating the risk of collision in the three-dimensional grid corresponding to the route specifically includes the following steps:

[0054] Assume that the probability of organisms appearing on the route profile satisfies the multi-source normal distribution:

[0055] ;

[0056] In the formula, Indicates that the organism appears The probability of appearing at a position, express X The variance in direction, express Y The variance in direction, express X and Y The correlation coefficient between express X expectations, express Y expectations;

[0057] Considering that the probability distribution characteristics of organisms on the profiles corresponding to different z values ​​of the route change with the change of z value, we set is a variable with z value as parameter, then the corresponding variables at different z values ​​are ;

[0058] Then the probability density function of organisms appearing in different areas of the three-dimensional grid in the low-altitude airspace is:

[0059] ;

[0060] The three-dimensional grid in the area where the flight path of the aircraft is located is calculated according to the probability density function. cuben Probability of endogenous organisms appearing , the calculation formula is:

[0061] ;

[0062] in, a , b , c are the length, width and height of the aircraft respectively;

[0063] Calculate 3D grid cuben The average number of organisms present in K n Calculate the number of possible collisions in a 3D grid , and according to the three-dimensional grid cuben Length of time t n Calculate the risk assessment results , the calculation formula is:

[0064] ;

[0065] ;

[0066] The three-dimensional grid sequence of individual biological activities on the flight path of the aircraft Risk assessment results of all three-dimensional grids in By superimposing them, we can obtain the risk index information of the entire route.

[0067] The beneficial effect of the above further scheme is: by constructing the probability density function of the appearance of organisms in different areas in the three-dimensional grid in the low-altitude airspace based on the multi-source normal distribution, the three-dimensional grid in the area where the aircraft's route is located is accurately calculated according to the probability density function cuben Probability of endogenous organisms appearing , thereby obtaining the risk assessment results and the risk index information of the entire route.

[0068] Further: the step of determining the safety risk assessment result of the low-altitude air route based on the index structure and risk index information between the two-dimensional basic grid and the three-dimensional grid specifically includes the following steps:

[0069] Based on the index structure between the two-dimensional basic grid and the three-dimensional grid and the three-dimensional grid sequence of individual biological activities Determine the 2D grid sequence of the ground , as follows:

[0070] ;

[0071] Based on the two-dimensional grid sequence Neidi n 2D grid Medium crowd activity density Calculate the weight of the impact of ground crowd activities on the danger level of the flight route ;

[0072] According to the weight of the impact of ground crowd activities on the danger level of the flight route Calculate the risk level to the aircraft's entire route , the calculation formula is:

[0073] ;

[0074] in, For the ground n 2D grid The weight of the impact of ground crowd activities on the danger level of air routes, For the n 2D grid The average number of organisms in the corresponding three-dimensional grid, The three-dimensional grid in the area where the aircraft's route is located cuben The probability of the organism appearing, t n For organisms to pass through the three-dimensional grid cuben length of time.

[0075] The beneficial effect of the above further scheme is: the two-dimensional grid sequence of the ground can be determined through the index structure between the two-dimensional basic grid and the three-dimensional grid and the three-dimensional grid sequence of individual biological activities, and then the influence weight of the ground crowd activity on the danger level of the flight route is calculated in combination with the crowd activity density in the ground two-dimensional grid, and then the risk level of the entire route is accurately calculated, completing the safety risk assessment of the city's low-altitude route.

[0076] The present invention also provides an urban low-altitude airway safety assessment system taking into account biological activities, including a construction module, a characteristic information module, a relative characteristic information module, a risk index information module and a safety risk assessment module;

[0077] The construction module is used to construct a three-dimensional grid in the low-altitude airspace space based on the two-dimensional basic grid divided by the ground space, and to construct an index structure between the two-dimensional basic grid and the three-dimensional grid;

[0078] The characteristic information module is used to calculate the characteristic information of organisms appearing in each three-dimensional grid in the low-altitude airspace under different scenarios based on the spatiotemporal trajectory information of the organisms' activities in the low-altitude airspace and the random field model;

[0079] The relative characteristic information module is used to obtain the route of the aircraft in the low-altitude airspace, determine the spatiotemporal sequence of the three-dimensional grid in the low-altitude airspace corresponding to the route, and calculate the relative characteristic information between the organisms and the aircraft in the three-dimensional grid corresponding to the route in combination with the characteristic information;

[0080] The risk index information module is used to construct a collision risk assessment model based on the relative feature information, and to quantitatively analyze and calculate the risk of collision in the corresponding three-dimensional grid on the route to obtain the risk index information of the route;

[0081] The safety risk assessment module is used to determine the safety risk assessment of the low-altitude flight route based on the index structure and risk index information between the two-dimensional basic grid and the three-dimensional grid.

[0082] The present invention also provides a computer-readable storage medium storing a computer program, characterized in that when the computer program is executed by a processor, the urban low-altitude route safety assessment method considering biological activities is implemented. BRIEF DESCRIPTION OF THE DRAWINGS

[0083] Figure 1 A schematic diagram of a flow chart of a method for evaluating the safety of urban low-altitude air routes taking into account biological activities according to an embodiment of the present invention;

[0084] Figure 2 A schematic diagram of three-dimensional grid division in low-altitude airspace space constructed based on two-dimensional grid division of ground space according to an embodiment of the present invention;

[0085] Figure 3 A schematic diagram of using a three-dimensional grid sequence to record an aircraft route and airway according to an embodiment of the present invention;

[0086] Figure 4A schematic diagram of the probability density distribution of an individual organism in different cross-sectional areas on its flight path according to an embodiment of the present invention;

[0087] Figure 5 A schematic diagram of a method for calculating the collision probability between the flight activity space range of an individual organism and the influence range of an aircraft according to an embodiment of the present invention;

[0088] Figure 6 The structure diagram of the urban low-altitude airway safety assessment system considering biological activities according to one embodiment of the present invention. DETAILED DESCRIPTION

[0089] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0090] like Figure 1 As shown in FIG. 1 , a method for assessing the safety of urban low-altitude air routes taking into account biological activities includes the following steps:

[0091] S1: Construct a three-dimensional grid in the low-altitude airspace based on the two-dimensional basic grid divided by the ground space, and construct an index structure between the two-dimensional basic grid and the three-dimensional grid;

[0092] S2: Based on the spatiotemporal trajectory information of the organisms in the low-altitude airspace, the feature information of the organisms appearing in each three-dimensional grid in the low-altitude airspace under different scenarios is calculated based on the random field model;

[0093] S3: Acquire the route of the aircraft in the low-altitude airspace, determine the spatiotemporal sequence of the three-dimensional grid in the low-altitude airspace corresponding to the route, and calculate the relative characteristic information between the organisms and the aircraft in the three-dimensional grid corresponding to the route in combination with the characteristic information;

[0094] S4: constructing a collision risk assessment model based on the relative characteristic information, and performing quantitative analysis and calculation on the risk of collision in the corresponding three-dimensional grid on the route, to obtain risk index information of the route;

[0095] S5: Determine the safety risk assessment result of the low-altitude air route based on the index structure and risk index information between the two-dimensional basic grid and the three-dimensional grid.

[0096] The method for assessing the safety of urban low-altitude airways taking biological activities into consideration of the present invention constructs an index structure between a two-dimensional ground basic grid and a three-dimensional grid of low-altitude airspace, calculates the characteristic information of biological organisms appearing in each three-dimensional grid and the relative characteristic information relative to the aircraft, and obtains the risk index information of the aircraft's route and airway by calculating the collision risk assessment model. Finally, the safety risk assessment result of the low-altitude airway and airway is determined based on the index structure, and a comprehensive, detailed, dynamic and systematic quantitative assessment of the safety risks of the urban low-altitude airway and airway is performed. The method can quantify the safety impact of low-altitude biological activities such as birds on urban low-altitude airway and airway at different periods, and can be used for low-altitude infrastructure site selection, low-altitude airway planning, urban airspace safety risk assessment and other aspects.

[0097] In one or more embodiments of the present invention, the two-dimensional basic grid based on the ground space division constructs a three-dimensional grid in the low-altitude airspace space, and constructs an index structure between the two-dimensional basic grid and the three-dimensional grid specifically includes the following steps:

[0098] S11: Based on the ground grid, a regular cube is used to divide the low-altitude airspace space corresponding to the ground grid directly above the ground grid to obtain a three-dimensional grid in the low-altitude airspace space;

[0099] S12: marking the three-dimensional grids in the low-altitude airspace according to the numbers of the ground grids and the heights of the three-dimensional grids;

[0100] S13: constructing an index structure between the two-dimensional basic grid and the three-dimensional grid.

[0101] like Figure 2 As shown, the ground grid (with a side length of m meters) is uniquely identified with reference to the plane coordinate system, such as the number The three-dimensional grid numbering of the airspace above the grid is expressed by adding one dimension to the ground numbering, such as The grid above with a height of 1-N can be marked as That is, the third-digit code is sorted according to the height from the ground to realize the division of the airspace three-dimensional grid and uniquely identify it. The grid index is constructed in combination with the ground grid number.

[0102] By dividing the low-altitude airspace space corresponding to the ground grid, a three-dimensional grid in the low-altitude airspace space is obtained. This makes it convenient to determine the characteristic information of the organisms appearing in each three-dimensional grid based on the spatiotemporal trajectory information of the organisms' activities in the low-altitude airspace. It is also convenient to establish an index structure between the two-dimensional basic grid and the three-dimensional grid, which serves as a reference for the subsequent safety risk assessment results of low-altitude flight routes.

[0103] In one or more embodiments of the present invention, the step of calculating the feature information of the organisms in the low-altitude airspace in different scenes in each three-dimensional grid based on the random field model according to the spatiotemporal trajectory information of the organisms in the low-altitude airspace includes the following steps:

[0104] S21: obtaining vector line information of the spatiotemporal trajectory of biological activities in the low-altitude airspace, determining the spatial position relationship between the spatiotemporal trajectory of biological activities and the three-dimensional grid, and determining the individual biological activity trajectory characteristics of the spatiotemporal trajectory of biological activities in each three-dimensional grid;

[0105] S22: Calculate characteristic information of a group of organisms in each three-dimensional grid according to the characteristics of the activity trajectories of the individual organisms.

[0106] The spatial position relationship between the biological activity spatiotemporal trajectory and the three-dimensional grid can be accurately determined through the vector line information of the biological activity spatiotemporal trajectory. In this way, the characteristics of the individual biological activity trajectory in each three-dimensional grid can be calculated with the three-dimensional grid as a reference, which can serve as the basis for subsequent route safety assessment.

[0107] Specifically, in one or more embodiments of the present invention, the step of obtaining the vector line information of the spatiotemporal trajectory of biological activities in the low-altitude airspace, determining the spatial position relationship between the spatiotemporal trajectory of biological activities and the three-dimensional grid, and determining the individual biological activity trajectory characteristics of the spatiotemporal trajectory of biological activities in each three-dimensional grid specifically includes the following steps:

[0108] S211: The activity location information of individual organisms is spatialized according to the vector line information of the spatiotemporal trajectory of biological activities in the low-altitude airspace, such as Figure 3 As shown, the activity sequence composed of the three-dimensional spatiotemporal trajectory points of individual biological activities is obtained. , as follows:

[0109] ;

[0110] In the formula, Represents individual organisms a At the moment The three-dimensional space coordinate information of the following;

[0111] S212: Analyze the three-dimensional grid corresponding to the activity sequence composed of the three-dimensional spatiotemporal trajectory points of the individual biological activity to obtain the three-dimensional grid sequence of the individual biological activity , as follows:

[0112] ;

[0113] In the formula, Represents individual organisms a exist The three-dimensional grid of the airspace at the time.

[0114] S213: Integrate the three-dimensional grid sequences of all individual biological movements to obtain the set of spatiotemporal sequences of the spatiotemporal trajectories of group biological activities in each three-dimensional grid, as shown in the following formula:

[0115] ;

[0116] in, Represents individual organisms a Active spatial three-dimensional grid spatiotemporal sequence information.

[0117] S214: Obtaining the activity sequence composed of the three-dimensional space-time trajectory points of the individual biological activity according to the vector line information of the space-time trajectory of the biological activity , and obtain the three-dimensional grid sequence of individual biological activities based on the three-dimensional grid passed through , and finally obtain the spatiotemporal sequence set of the spatiotemporal trajectories of the group biological activities formed by all individual organisms in each three-dimensional grid.

[0118] In one or more embodiments of the present invention, the step of calculating the characteristic information of the biological groups in each three-dimensional grid according to the characteristics of the individual biological activity trajectories specifically includes the following steps:

[0119] S221: Three-dimensional grid As the basic statistical unit, the time and space coordinates of the starting point of the individual organism entering the three-dimensional grid are extracted according to the characteristics of the individual biological activity trajectory. and the end time and space coordinates ;

[0120] S222: Calculate the moving distance of the individual organism in the three-dimensional grid according to the starting point space-time coordinates and the end point space-time coordinates of the individual organism entering the three-dimensional grid , and determine the speed of the individual organism in the three-dimensional grid according to the moving distance and the time difference of entering and leaving , the calculation formula is as follows:

[0121] ;

[0122] In the formula, represents the time when the individual organism enters the end point in the three-dimensional grid, Indicates the time corresponding to the starting point of the individual organism entering the three-dimensional grid;

[0123] S223: Count the speeds of all individual organisms in the three-dimensional grid, and calculate the average speed of the group of organisms in the three-dimensional grid , the calculation formula is as follows:

[0124] ;

[0125] S224: Calculate the activity direction of the individual organism in the three-dimensional grid according to the starting point space-time coordinates and the end point space-time coordinates of the individual organism entering the three-dimensional grid, and obtain a direction vector , the calculation formula is as follows:

[0126] ;

[0127] S225: Count the direction vectors of all individual organisms in the three-dimensional grid, and calculate the average direction vector of the group of organisms in the three-dimensional grid ;

[0128] S226: Three-dimensional grid sequence based on individual biological activities, with three-dimensional grid as the basic statistical unit, such as three-dimensional grid The number of organisms in each three-dimensional grid is counted. .

[0129] Based on the three-dimensional grid sequence of individual biological activities, the number of organisms appearing in each three-dimensional grid can be accurately counted. , according to the characteristics of the individual biological activity trajectory, the starting point space-time coordinates and the end point space-time coordinates of the individual biological entering the three-dimensional grid are extracted, and then the moving distance and moving speed of the individual biological in the three-dimensional grid, as well as the average speed and average direction vector of all individual biologicals are determined, which can be used as the relative characteristic information of calculating the aircraft relative to the biological.

[0130] In one or more embodiments of the present invention, the steps of obtaining the route of the aircraft in the low-altitude airspace, determining the spatiotemporal sequence of the three-dimensional grid in the low-altitude airspace corresponding to the route, and calculating the relative characteristic information between the organisms and the aircraft in the three-dimensional grid corresponding to the route in combination with the characteristic information specifically include the following steps:

[0131] S31: Obtain the route of the aircraft in the low-altitude airspace, and determine the space-time sequence of the three-dimensional grid in the low-altitude airspace corresponding to the route , as follows:

[0132] ;

[0133] In the formula, Indicates aircraft at different times aam 1 The three-dimensional grid passed through;

[0134] S32: According to the space-time sequence of the three-dimensional grid in the low-altitude airspace corresponding to the route Determine the average number of organisms present in the three-dimensional grid Kand average speed ;

[0135] S33: Using the aircraft as a reference object, calculate the relative speed between the group of organisms and the aircraft in the three-dimensional grid , the calculation formula is as follows:

[0136] ;

[0137] In the formula, Three-dimensional grid The flying speed of the organism is x, y, z The weight in direction, The aircraft is located in the three-dimensional grid The flight speed within x, y, z Directional weight.

[0138] Here, the velocity vectors of the aircraft and the biological group are decomposed in the three coordinate axis directions, and the relative speeds are calculated separately, and finally a complete relative velocity vector is synthesized. aam1 The velocity is decomposed in three directions in the three-dimensional rectangular coordinate system, and then the velocity components in the three directions are obtained. After the calculation is completed, the velocity vectors are combined, and finally the result of the vector synthesis in the three directions is calculated, and then the relative velocity and relative direction are calculated. The speed is On this basis, vector decomposition is performed to obtain the velocity information in three directions , using the same method, the flight speed of the organisms in the three-dimensional grid is decomposed to obtain the component speeds in three directions , taking the aircraft as a reference, obtain the velocity information relative to the aircraft Here, the value of relative velocity is expressed by the modulus of the vector, as follows:

[0139] ;

[0140] Determine the spatiotemporal sequence of the three-dimensional grid in the low-altitude airspace corresponding to the route through the route , so that the average number of organisms in the three-dimensional grid can be accurately calculated K and average speed , thereby calculating the relative speed between the group of organisms and the aircraft in the three-dimensional grid , as the input of the subsequent collision risk assessment model, so as to accurately obtain the risk index information of the entire route.

[0141] In one or more embodiments of the present invention, the step of constructing a collision risk assessment model based on the relative feature information and quantitatively analyzing and calculating the risk of collision in the three-dimensional grid corresponding to the route specifically includes the following steps:

[0142] S41: Consider the impact of different meteorological conditions on flight activities, and express the impact of the activities in a unified error, such as Figure 4 As shown in the figure, the probability of organisms appearing on the route profile is assumed to satisfy the multi-source normal distribution:

[0143] ;

[0144] In the formula, Indicates that the organism appears The probability of appearing at a position, express X The variance in direction, express Y The variance in direction, express X and Y The correlation coefficient between express X expectations, express Y The expectation on the two coordinate axes represents the x and y coordinates on the biological observation path. Combined with its change in the Z direction, the probability density distribution of the organism appearing in the three-dimensional grid in the airspace can be obtained.

[0145] S42: Considering that the probability distribution characteristics of organisms on the profiles corresponding to different z values ​​of the route change with the change of z value, set is a variable with z value as parameter, then the corresponding variables at different z values ​​are ;

[0146] Then the probability density function of organisms appearing in different areas of the three-dimensional grid in the low-altitude airspace is:

[0147] ;

[0148] S43: Calculate the three-dimensional grid in the area where the flight path of the aircraft is located according to the probability density function cuben Probability of endogenous organisms appearing ,like Figure 5 As shown, the calculation formula is:

[0149] ;

[0150] in, a , b , care the length, width and height of the aircraft respectively;

[0151] S44: Calculate 3D grid cuben The average number of organisms present in K n Calculate the number of possible collisions in a 3D grid , and according to the three-dimensional grid cuben Length of time t n Calculate the risk assessment results , the calculation formula is:

[0152] ;

[0153] Here, organisms pass through the three-dimensional grid cuben Length of time t n Combined with the relative speed of the creature's flight To calculate it.

[0154] S45: Three-dimensional grid sequence of individual biological activities on the flight path of the aircraft Risk assessment results of all three-dimensional grids in By superimposing them, we can obtain the risk index information of the entire route.

[0155] By constructing the probability density function of the appearance of organisms in different areas of the three-dimensional grid in the low-altitude airspace based on multi-source normal distribution, the three-dimensional grid in the area where the aircraft's route is located is accurately calculated according to the probability density function cuben Probability of endogenous organisms appearing , thereby obtaining the risk assessment results and the risk index information of the entire route.

[0156] In one or more embodiments of the present invention, determining the safety risk assessment result of the low-altitude flight route based on the index structure and risk index information between the two-dimensional basic grid and the three-dimensional grid specifically includes the following steps:

[0157] S51: Based on the index structure between the two-dimensional basic grid and the three-dimensional grid and the three-dimensional grid sequence of individual biological activities Determine the 2D grid sequence of the ground , as follows:

[0158] ;

[0159] S52: Based on the two-dimensional grid sequence Neidi n 2D grid Medium crowd activity density Calculate the weight of the impact of ground crowd activities on the danger level of the flight route ;

[0160] S53: Weighting based on the impact of ground crowd activities on the danger level of the flight route Calculate the risk level to the aircraft's entire route , the calculation formula is:

[0161] ;

[0162] in, For the ground n 2D grid The weight of the impact of ground crowd activities on the danger level of air routes, For the n 2D grid The average number of organisms in the corresponding three-dimensional grid, The three-dimensional grid in the area where the aircraft's route is located cuben The probability of the organism appearing, t n For organisms to pass through the three-dimensional grid cuben length of time.

[0163] The two-dimensional grid sequence on the ground can be determined through the index structure between the two-dimensional basic grid and the three-dimensional grid and the three-dimensional grid sequence of individual biological activities. The weight of the impact of ground crowd activities on the danger level of the flight route is calculated in combination with the crowd activity density in the two-dimensional grid on the ground, and the risk level of the entire route is accurately calculated to complete the safety risk assessment of the city's low-altitude routes.

[0164] like Figure 6 As shown, the present invention also provides an urban low-altitude airway safety assessment system taking into account biological activities, including a construction module, a characteristic information module, a relative characteristic information module, a risk index information module and a safety risk assessment module;

[0165] The construction module is used to construct a three-dimensional grid in the low-altitude airspace space based on the two-dimensional basic grid divided by the ground space, and to construct an index structure between the two-dimensional basic grid and the three-dimensional grid;

[0166] The characteristic information module is used to calculate the characteristic information of organisms appearing in each three-dimensional grid in the low-altitude airspace under different scenarios based on the spatiotemporal trajectory information of the organisms' activities in the low-altitude airspace and the random field model;

[0167] The relative characteristic information module is used to obtain the route of the aircraft in the low-altitude airspace, determine the spatiotemporal sequence of the three-dimensional grid in the low-altitude airspace corresponding to the route, and calculate the relative characteristic information between the organisms and the aircraft in the three-dimensional grid corresponding to the route in combination with the characteristic information;

[0168] The risk index information module is used to construct a collision risk assessment model based on the relative feature information, and to quantitatively analyze and calculate the risk of collision in the corresponding three-dimensional grid on the route to obtain the risk index information of the route;

[0169] The safety risk assessment module is used to determine the safety risk assessment of the low-altitude flight route based on the index structure and risk index information between the two-dimensional basic grid and the three-dimensional grid.

[0170] The present invention also provides a computer-readable storage medium storing a computer program, characterized in that when the computer program is executed by a processor, the urban low-altitude route safety assessment method considering biological activities is implemented.

[0171] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for assessing the safety of urban low-altitude air routes taking into account biological activities, characterized in that: The steps include: Based on the two-dimensional basic grid divided by the ground space, a three-dimensional grid in the low-altitude airspace is constructed, and an index structure between the two-dimensional basic grid and the three-dimensional grid is constructed; According to the spatiotemporal trajectory information of the organisms in the low-altitude airspace, the characteristic information of the organisms appearing in each three-dimensional grid in the low-altitude airspace under different scenarios is calculated based on the random field model; Acquire the route of the aircraft in the low-altitude airspace, determine the spatiotemporal sequence of the three-dimensional grid in the low-altitude airspace corresponding to the route, and calculate the relative characteristic information between the organisms and the aircraft in the three-dimensional grid corresponding to the route in combination with the characteristic information; Constructing a collision risk assessment model based on the relative characteristic information, and performing quantitative analysis and calculation on the risk of collision in the corresponding three-dimensional grid on the route, to obtain risk index information of the route; Determine the safety risk assessment result of the low-altitude flight route based on the index structure and risk index information between the two-dimensional basic grid and the three-dimensional grid; The step of constructing a collision risk assessment model based on the relative feature information and quantitatively analyzing and calculating the risk of collision in the three-dimensional grid corresponding to the route specifically includes the following steps: Assume that the probability of organisms appearing on the route profile satisfies the multi-source normal distribution: ； In the formula, Indicates that the organism appears The probability of appearing at a position, express X The variance in direction, express Y The variance in direction, express X and Y The correlation coefficient between express X expectations, express Y expectations; Considering that the probability distribution characteristics of organisms on the profiles corresponding to different z values ​​of the route change with the change of z value, we set is a variable with z value as parameter, then the corresponding variables at different z values ​​are ; Then the probability density function of organisms appearing in different areas of the three-dimensional grid in the low-altitude airspace is: ； The three-dimensional grid in the area where the flight path of the aircraft is located is calculated according to the probability density function. cuben Probability of endogenous organisms appearing , the calculation formula is: ； in, a , b , c are the length, width and height of the aircraft respectively; Calculate 3D grid cuben The average number of organisms present in K n Calculate the number of possible collisions in a 3D grid , and according to the biological through the three-dimensional grid cuben Length of time t n Calculate the risk assessment results , the calculation formula is: ； The three-dimensional grid sequence of individual biological activities on the flight path of the aircraft Risk assessment results of all three-dimensional grids in By superimposing them, we can obtain the risk index information of the entire route.

2. The urban low-altitude air route safety assessment method considering biological activities according to claim 1 is characterized in that: The method of constructing a three-dimensional grid in the low-altitude airspace space based on the two-dimensional basic grid divided on the ground space and constructing an index structure between the two-dimensional basic grid and the three-dimensional grid specifically includes the following steps: Based on the ground grid, a regular cube is used to divide the low-altitude airspace space corresponding to the ground grid directly above the ground grid to obtain a three-dimensional grid in the low-altitude airspace space; According to the number of the ground grid and the height of the three-dimensional grid, the three-dimensional grid in the low-altitude airspace is marked; An index structure between the two-dimensional basic grid and the three-dimensional grid is constructed.

3. The urban low-altitude air route safety assessment method considering biological activities according to claim 1 is characterized in that: The method of calculating the feature information of the organisms appearing in each three-dimensional grid in the low-altitude airspace under different scenarios based on the random field model according to the spatiotemporal trajectory information of the organisms' activities in the low-altitude airspace specifically includes the following steps: Obtaining vector line information of the spatiotemporal trajectory of biological activities in the low-altitude airspace, determining the spatial position relationship between the spatiotemporal trajectory of biological activities and the three-dimensional grid, and determining the characteristics of individual biological activity trajectories of the spatiotemporal trajectory of biological activities in each three-dimensional grid; The characteristic information of the biological groups in each three-dimensional grid is calculated according to the characteristics of the individual biological activity trajectories.

4. The urban low-altitude air route safety assessment method considering biological activities according to claim 3 is characterized in that: The step of obtaining the vector line information of the spatiotemporal trajectory of biological activities in the low-altitude airspace, determining the spatial position relationship between the spatiotemporal trajectory of biological activities and the three-dimensional grid, and determining the individual biological activity trajectory characteristics of the spatiotemporal trajectory of biological activities in each three-dimensional grid specifically includes the following steps: According to the vector line information of the spatiotemporal trajectory of biological activities in the low-altitude airspace, the activity position information of individual organisms is spatialized to obtain the activity sequence composed of the three-dimensional spatiotemporal trajectory points of individual biological activities. , as follows: ； In the formula, Represents individual organisms a At the moment The three-dimensional space coordinate information of the following; Analyze the three-dimensional grid corresponding to the activity sequence composed of the three-dimensional spatiotemporal trajectory points of the individual biological activity to obtain the three-dimensional grid sequence of the individual biological activity , as follows: ； In the formula, Represents individual organisms a exist The three-dimensional grid of the airspace at the time, The three-dimensional grid sequences of all individual biological movements are integrated to obtain the spatiotemporal sequence set of the spatiotemporal trajectory of group biological activities in each three-dimensional grid, as shown in the following formula: ； in, Represents individual organisms a Active spatial three-dimensional grid spatiotemporal sequence information.

5. The urban low-altitude air route safety assessment method considering biological activities according to claim 3 is characterized in that: The step of calculating the characteristic information of the biological groups in each three-dimensional grid according to the characteristics of the individual biological activity trajectories specifically comprises the following steps: Taking the three-dimensional grid as the basic statistical unit, the time and space coordinates of the starting point of the individual organism entering the three-dimensional grid are extracted according to the characteristics of the individual biological activity trajectory. and the end time and space coordinates ; The moving distance of the individual organism in the three-dimensional grid is calculated according to the starting point space-time coordinates and the end point space-time coordinates of the individual organism entering the three-dimensional grid. , and determine the speed of the individual organism in the three-dimensional grid according to the moving distance and the time difference of entering and leaving , the calculation formula is as follows: ； In the formula, represents the time when the individual organism enters the end point in the three-dimensional grid, Indicates the time corresponding to the starting point of the individual organism entering the three-dimensional grid; Count the speeds of all individual organisms in the three-dimensional grid, and calculate the average speed of the group of organisms in the three-dimensional grid , the calculation formula is as follows: ； The activity direction of the individual organism in the three-dimensional grid is calculated according to the starting point space-time coordinates and the end point space-time coordinates of the individual organism entering the three-dimensional grid, and the direction vector is obtained. , the calculation formula is as follows: ； Count the direction vectors of all individual organisms in the three-dimensional grid, and calculate the average direction vector of the group of organisms in the three-dimensional grid ; Based on the three-dimensional grid sequence of individual biological activities, the number of organisms appearing in each three-dimensional grid is counted .

6. The urban low-altitude air route safety assessment method considering biological activities according to claim 1 is characterized in that: The step of obtaining the route of the aircraft in the low-altitude airspace, determining the spatiotemporal sequence of the three-dimensional grid in the low-altitude airspace corresponding to the route, and calculating the relative characteristic information between the organisms and the aircraft in the three-dimensional grid corresponding to the route in combination with the characteristic information specifically includes the following steps: Obtain the flight path of the aircraft in the low-altitude airspace, and determine the space-time sequence of the three-dimensional grid in the low-altitude airspace corresponding to the flight path , as follows: ； In the formula, Indicates aircraft at different times aam 1 The three-dimensional grid passed through; According to the time-space sequence of the three-dimensional grid in the low-altitude airspace corresponding to the route Determine the average number of organisms present in the three-dimensional grid K and average speed ; Taking the aircraft as the reference object, calculate the relative speed between the group of organisms and the aircraft in the three-dimensional grid , the calculation formula is as follows: ； In the formula, Three-dimensional grid The flying speed of the organism is x, y, z The weight in direction, The aircraft is located in the three-dimensional grid The flight speed within x, y, z Directional weight.

7. The urban low-altitude air route safety assessment method considering biological activities according to any one of claims 1 to 6, characterized in that: Determining the safety risk assessment result of the low-altitude flight route based on the index structure and risk index information between the two-dimensional basic grid and the three-dimensional grid specifically includes the following steps: Based on the index structure between the two-dimensional basic grid and the three-dimensional grid and the three-dimensional grid sequence of individual biological activities Determine the 2D grid sequence of the ground , as follows: ； Based on the two-dimensional grid sequence Neidi n 2D grid Medium crowd activity density Calculate the weight of the impact of ground crowd activities on the danger level of the flight route ; According to the weight of the impact of ground crowd activities on the danger level of the flight route Calculate the risk level to the aircraft's entire route , the calculation formula is: ； in, For the ground n 2D grid The weight of the impact of ground crowd activities on the danger level of air routes, For the n 2D grid The average number of organisms in the corresponding three-dimensional grid, The three-dimensional grid in the area where the aircraft's route is located cuben The probability of the organism appearing, t n For organisms to pass through the three-dimensional grid cuben length of time.

8. A system for assessing the safety of urban low-altitude air routes taking into account biological activities, applied to any of the methods for assessing the safety of urban low-altitude air routes taking into account biological activities described in 1-7, characterized in that: It includes a construction module, a characteristic information module, a relative characteristic information module, a risk index information module and a security risk assessment module; The construction module is used to construct a three-dimensional grid in the low-altitude airspace space based on the two-dimensional basic grid divided by the ground space, and to construct an index structure between the two-dimensional basic grid and the three-dimensional grid; The characteristic information module is used to calculate the characteristic information of organisms appearing in each three-dimensional grid in the low-altitude airspace under different scenarios based on the spatiotemporal trajectory information of the organisms' activities in the low-altitude airspace and the random field model; The relative characteristic information module is used to obtain the route of the aircraft in the low-altitude airspace, determine the spatiotemporal sequence of the three-dimensional grid in the low-altitude airspace corresponding to the route, and calculate the relative characteristic information between the organisms and the aircraft in the three-dimensional grid corresponding to the route in combination with the characteristic information; The risk index information module is used to construct a collision risk assessment model based on the relative feature information, and to quantitatively analyze and calculate the risk of collision in the corresponding three-dimensional grid on the route to obtain the risk index information of the route; The safety risk assessment module is used to determine the safety risk assessment result of the low-altitude flight route based on the index structure and risk index information between the two-dimensional basic grid and the three-dimensional grid.

9. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the urban low-altitude route safety assessment method taking into account biological activities as described in any one of claims 1 to 7 is implemented.

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