Low-altitude penetration rapid planning method based on real-time valley detection

Abstract

The invention relates to a low-altitude penetration rapid planning method based on real-time valley detection, and belongs to the technical field of air route planning. Comprising the steps of performing feasible node expansion according to an initial position and an azimuth angle range of a helicopter to obtain a plurality of expansion nodes; obtaining a plurality of extended line segments based on the plurality of extended nodes, calculating intervisibility of the extended line segments, and abandoning non-intervisibility extended line segments; calculating the pitch angle of the extended line segment based on the elevation value of the extended node; calculating the pitch cost of the extended line segment according to the pitch angle of the extended line segment; calculating the cost of the extended line segment from valleys on two sides; calculating the distance cost from the extended node to the end point based on the planned end point position; obtaining a comprehensive cost based on the three costs; and selecting the extension node corresponding to the minimum value of the comprehensive cost, and taking the extension node as the next extension starting point to continue to extend the node until the extension node and the planning end point position meet the requirements. The safe and rapid valley following route in the penetration stage is provided for the helicopter, and the task execution safety and success rate are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of route planning, and in particular relates to a low-altitude penetration rapid planning method based on real-time valley detection. Background Art

[0002] Helicopters are usually used in mountain combat environments. The complex terrain features can provide conditions for helicopters to penetrate covertly, but can also pose a potential threat to their flight safety. With the increasing amount of information received, processed and transmitted, as well as the dynamic nature of the air / ground combat space itself, relying solely on the onboard ground proximity warning system combined with the pilot's operational response is far from meeting the requirements of flight safety and mission objectives. Summary of the invention

[0003] The technical problems to be solved by the present invention are:

[0004] In order to avoid the shortcomings of the prior art, the present invention provides a low-altitude penetration rapid planning method based on real-time valley detection. It is used to solve the problem that the existing route planning method cannot detect valleys in real time, and plan a terrain following / terrain avoidance route for the helicopter to safely reach the mission end point, providing conditions for the next step of executing the attack / reconnaissance mission.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] A low-altitude penetration rapid planning method based on real-time valley detection, characterized by comprising:

[0007] Obtain the initial position and azimuth range of the helicopter, and expand feasible nodes according to the initial position and azimuth range of the helicopter to obtain multiple expansion nodes;

[0008] Based on the multiple extended nodes, multiple extended line segments are obtained, the intervisibility of each extended line segment is calculated, and the extended line segments without intervisibility are discarded based on the intervisibility;

[0009] Acquire elevation values ​​of multiple extended nodes, and calculate the pitch angle of the extended line segment corresponding to the extended node based on the elevation value of each extended node; calculate the pitch cost of the extended line segment corresponding to the extended node according to the pitch angle of each extended line segment;

[0010] Calculate the cost of the valleys on both sides of the extended line segment corresponding to each extended node;

[0011] Get the planned end point location, and calculate the distance cost between the extended node and the end point based on the planned end point location and the extended node;

[0012] Calculate the comprehensive cost of each extended node based on the pitch cost, valley cost and distance cost of each extended node;

[0013] Select the expansion node corresponding to the minimum comprehensive cost and use it as the next expansion starting point to continue expanding nodes until the expansion node and the planned end point position meet the requirements;

[0014] Connect the initial position of the helicopter, the expansion node with the minimum comprehensive cost, and the planned end point to determine the valley line following route.

[0015] A further technical solution of the present invention is as follows: the feasible node expansion is performed according to the initial position and azimuth range of the helicopter, using the following formula:

[0016] Ax=Sx+200×cos(α)

[0017] Az=Sz+200×sin(α)

[0018] Among them, Ax and Az are the coordinates of the extended nodes, Sx and Sz are the initial positions of the helicopter, and α is the azimuth range.

[0019] A further technical solution of the present invention is to use a Janus algorithm to calculate the intervisibility of each extended line segment.

[0020] A further technical solution of the present invention is: the pitch angle of the extended line segment corresponding to each extended node is calculated based on the elevation value of the extended node, using the following formula:

[0021] θ=asin(fabs(Ay-Sy) / D)

[0022] Wherein, θ represents the pitch angle, D represents the straight-line distance of the extended line segment, Ay represents the end point of the extended line segment, Sy represents the end point of the extended line segment, and fabs represents the absolute value of the floating-point number;

[0023] The pitch cost of the extended line segment corresponding to the extended node is calculated according to the pitch angle of each extended line segment, using the following formula:

[0024]

[0025] Where β is the pitch angle of the helicopter.

[0026] A further technical solution of the present invention: the calculation of the valley cost of each extended line segment from both sides includes:

[0027] Draw a perpendicular line from the center point of the extended line segment, and proceed northward and southward from the center point with a step length to obtain the coordinates of the points on the perpendicular bisector:

[0028] According to the north and east values ​​of each point, find its elevation value from the digital elevation data, expressed as Vdn(e) and Vun(e), and calculate the valley cost of each extended line segment using the following formula:

[0029]

[0030] Among them, Vdn(y) and Vun(y) are the coordinate values ​​of the points on the perpendicular bisector.

[0031] A further technical solution of the present invention is as follows: the distance cost of each extended node from the end point is calculated based on the planned end point position and multiple extended nodes, using the following formula:

[0032] Cost3=sqrt((Ax-Ex)×(Ax-Ex)+(Ay-Ey)×(Ay-Ey)+(Az-Ez)×(Az-Ez))

[0033] Among them, Ex, Ey, and Ez are the planned end points.

[0034] A further technical solution of the present invention is to use the A* algorithm to select the expansion node corresponding to the minimum comprehensive cost.

[0035] A computer system, characterized in that it comprises: one or more processors, and a computer-readable storage medium for storing one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors implement the above-mentioned method.

[0036] A computer-readable storage medium, characterized in that it stores computer-executable instructions, which are used to implement the above method when executed.

[0037] A computer program product, characterized by comprising computer executable instructions, wherein the instructions are used to implement the above method when executed.

[0038] The beneficial effects of the present invention are:

[0039] The present invention provides a low-altitude penetration rapid planning method based on real-time valley detection, which is aimed at helicopter mountain penetration and fire strike missions in complex geographical / confrontation environments, and provides helicopters with a safe and fast valley following route during the penetration phase, thereby improving the safety and success rate of mission execution.

[0040] The present invention is based on a digital elevation model, which is different from the route planning algorithm based on terrain feature extraction. It converts the valley following problem into a calculation problem of the distance between the two sides of the route and the obstructing mountains, thereby realizing real-time valley detection and judgment, omitting the processing time of terrain feature extraction and the on-board storage requirements of terrain feature data, and providing a feasible technical approach for on-board real-time planning. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The drawings are only for the purpose of illustrating particular embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like components throughout the drawings.

[0042] Figure 1 Flow chart of the method of the present invention.

[0043] Figure 2 Schematic diagram of the valleys on both sides of the extended line segment distance of the present invention. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0045] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0046] The present invention provides a low-altitude penetration rapid planning method based on real-time valley detection, comprising the following steps:

[0047] Step 1: Get the planned end point location;

[0048] Step 2: Get the initial position of the aircraft;

[0049] Step 3: Obtain the parameters of the planned platform's azimuth and pitch maneuvering range;

[0050] Step 4: Expand feasible nodes according to the extended azimuth range;

[0051] Step 5: Calculate the intervisibility of each extended line segment;

[0052] Step 6: Calculate the pitch cost of each extended line segment;

[0053] Step 7: Calculate the cost of each extended line segment from the valleys on both sides;

[0054] Step 8: Calculate the distance cost between each extended node and the end point;

[0055] Step 9: Calculate the comprehensive cost of each extended node;

[0056] Step 10: Use the A* algorithm to optimize the expansion nodes according to the comprehensive cost value;

[0057] Step 11: Set the judgment conditions for the end of planning.

[0058] In order to enable those skilled in the art to better understand the present invention, the present invention is described in detail below in conjunction with specific embodiments.

[0059] In the embodiment of the present invention, the following equipment and conditions on the helicopter need to be utilized:

[0060] 1) Mission loading card;

[0061] 2) Navigation system;

[0062] 3) Database system;

[0063] 4) Task integrated display.

[0064] Input data corresponding to the device:

[0065] 1) The combat mission target data loaded on the mission card, including the longitude, altitude and latitude data of the planned end point;

[0066] 2) The real-time position of the combat helicopter obtained from the navigation system, including real-time longitude, altitude, and latitude data;

[0067] 3) Obtain digital elevation data of the mission area, helicopter position, and pitch maneuvering position data from the database system.

[0068] Calculate the output data:

[0069] 1) The helicopter's flight path is output to the mission integrated display.

[0070] The specific steps of the embodiment of the present invention are as follows:

[0071] Step 1: Get the planned end point location;

[0072] The end position is expressed as: (Ex, Ey, Ez)

[0073] Step 2: Get the initial position of the helicopter;

[0074] The starting position is represented by: (Sx, Sy, Sz)

[0075] Step 3: Obtain the azimuth and pitch maneuvering range parameters of the helicopter;

[0076] The azimuth range is expressed as: α

[0077] The pitch angle range is expressed as: β

[0078] Step 4: Expand feasible nodes according to the azimuth range;

[0079] A total of 5 nodes are expanded to the left and right of the azimuth range as nodes to be evaluated.

[0080] The coordinate values ​​of A to E are as follows:

[0081] Ax=Sx+200×cos(α)

[0082] Az=Sz+200×sin(α)

[0083] Bx=Sx+200×cos(α×0.5)

[0084] Bz=Sz+200×sin(α×0.5)

[0085] Cx=Sx+200

[0086] Cz=Sz

[0087] Dx=Sx+200×cos(α×0.5)

[0088] Dz=Sz-200×sin(α×0.5)

[0089] Ex=Sx+200×cos(α)

[0090] Ez=Sz-200×sin(α)

[0091] Step 5: Calculate the intervisibility of each extended line segment;

[0092] The Janus algorithm is used to calculate the intervisibility of each extended line segment and discard the extended line segments that are not intervisible.

[0093] Step 6: Calculate the pitch cost of each extended line segment;

[0094] According to the north (x) and east (z) values ​​of the five extended nodes calculated in step 5, find their elevation values ​​from the digital elevation data and use the elevation values ​​as the y-axis coordinate values ​​of the five nodes: Ay, By, Cy, Dy, Ey. Use the following formula to calculate the pitch angle of each extended line segment, taking point A as an example:

[0095] θ = asin(fabs(Ay-Sy) / D), where D is the straight-line distance from point A to point S, and fabs is the absolute value of a floating-point number;

[0096] The pitch cost of each extended line segment is calculated based on θ, and the formula is as follows:

[0097]

[0098] Step 7: Calculate the cost of each extended line segment from the valleys on both sides;

[0099] like Figure 2 As shown, take point A as an example, and take the extended line segment SA as the due east direction (in other cases, first perform the coordinate rotation transformation method and rotate to the due east). Draw a vertical line from the center point of the extended line segment, and calculate the point coordinates from the center point to the north and south with a step length:

[0100] Vdn(x)=Sx+(Ax-Sx) / 2

[0101] Vdn(y)=Sy+(Ay-Sy) / 2

[0102] Vdn(z)=Sz-step×n

[0103] Vun(x)=Sx+(Ax-Sx) / 2

[0104] Vun(y)=Sy+(Ay-Sy) / 2

[0105] Vun(z)=Sz+step×n

[0106] Where n is 1, 2, 3, etc. Usually, the step is 50, and the maximum detection distance on both sides of the vertical line is 1000, that is, the maximum value of n is 20;

[0107] According to the north (x) and east (z) values ​​of each point, find its elevation value from the digital elevation data, expressed as Vdn (e) and Vun (e), where n is 1, 2, 3, etc., and calculate the valley cost of each extended line segment. The formula is as follows:

[0108]

[0109] Step 8: Calculate the distance cost between each extended node and the end point;

[0110] Take point A as an example:

[0111] Cost3 = sqrt((Ax-Ex)×(Ax-Ex)+(Ay-Ey)×(Ay-Ey)+(Az-Ez)×(Az-Ez)) When calculating other nodes, replace the values ​​of Ax, Ay, and Az with the coordinate values ​​of the nodes themselves.

[0112] Step 9: Calculate the comprehensive cost of each extended node;

[0113] The calculation formula is: Cost = Cost1 + Cost2 + Cost3

[0114] Step 10: Use the A* algorithm to optimize the expansion nodes according to the comprehensive cost;

[0115] Select the expansion node with the smallest comprehensive cost value and repeat steps 5-10;

[0116] Step 11: Set the judgment conditions for the end of planning;

[0117] When the distance between the selected expansion node with the smallest comprehensive point and the end point is less than 200, the planning is judged to be completed, that is, the valley line following route calculation from the start point to the end point is completed.

[0118] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should be included in the protection scope of the present invention.

Claims

1. A low-altitude penetration rapid planning method based on real-time valley detection, characterized in that: include: Obtain the initial position and azimuth range of the helicopter, and expand feasible nodes according to the initial position and azimuth range of the helicopter to obtain multiple expansion nodes; Based on the multiple extended nodes, multiple extended line segments are obtained, the intervisibility of each extended line segment is calculated, and the extended line segments without intervisibility are discarded based on the intervisibility; Acquire elevation values ​​of multiple extended nodes, and calculate the pitch angle of the extended line segment corresponding to the extended node based on the elevation value of each extended node; calculate the pitch cost of the extended line segment corresponding to the extended node according to the pitch angle of each extended line segment; Calculate the cost of the valleys on both sides of the extended line segment corresponding to each extended node; Get the planned end point location, and calculate the distance cost between the extended node and the end point based on the planned end point location and the extended node; Calculate the comprehensive cost of each extended node based on the pitch cost, valley cost and distance cost of each extended node; Select the expansion node corresponding to the minimum comprehensive cost and use it as the next expansion starting point to continue expanding nodes until the expansion node and the planned end point position meet the requirements; Connect the initial position of the helicopter, the expansion node with the minimum comprehensive cost, and the planned end point to determine the valley line following route.

2. According to claim 1, a low-altitude penetration rapid planning method based on real-time valley detection is characterized in that: The feasible node expansion is performed according to the initial position and azimuth range of the helicopter, using the following formula: Ax=Sx+200×cos(α) Az=Sz+200×sin(α) Among them, Ax and Az are the coordinates of the extended nodes, Sx and Sz are the initial positions of the helicopter, and α is the azimuth range.

3. According to claim 1, a low-altitude penetration rapid planning method based on real-time valley detection is characterized in that: The Janus algorithm is used to calculate the intervisibility of each extended line segment.

4. According to claim 1, a low-altitude penetration rapid planning method based on real-time valley detection is characterized in that: The pitch angle of the extended line segment corresponding to each extended node is calculated based on the elevation value of the extended node, using the following formula: θ=asin(fabs(Ay-Sy) / D) Wherein, θ represents the pitch angle, D represents the straight-line distance of the extended line segment, Ay represents the end point of the extended line segment, Sy represents the end point of the extended line segment, and fabs represents the absolute value of the floating-point number; The pitch cost of the extended line segment corresponding to the extended node is calculated according to the pitch angle of each extended line segment, using the following formula: Where β is the pitch angle of the helicopter.

5. According to claim 1, a low-altitude penetration rapid planning method based on real-time valley detection is characterized in that: The calculation of the cost of the valleys on both sides of each extended line segment includes: Draw a perpendicular line from the center point of the extended line segment, and proceed northward and southward from the center point with a step length to obtain the coordinates of the points on the perpendicular bisector: According to the north and east values ​​of each point, find its elevation value from the digital elevation data, expressed as Vdn(e) and Vun(e), and calculate the valley cost of each extended line segment using the following formula: Among them, Vdn(y) and Vun(y) are the coordinate values ​​of the points on the perpendicular bisector.

6. According to claim 1, a low-altitude penetration rapid planning method based on real-time valley detection is characterized in that: The distance cost between each extended node and the end point is calculated based on the planned end point position and multiple extended nodes, using the following formula: Cost3=sqrt((Ax-Ex)×(Ax-Ex)+(Ay-Ey)×(Ay-Ey)+(Az-Ez)×(Az-Ez))where, Ex, Ey, and Ez are the planned end points.

7. According to claim 1, a low-altitude penetration rapid planning method based on real-time valley detection is characterized in that: The A* algorithm is used to select the expansion node corresponding to the minimum comprehensive cost.

8. A computer system, characterized in that include: One or more processors, and a computer-readable storage medium for storing one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors are enabled to implement the method of claim 1.

9. A computer-readable storage medium, characterized in that Computer executable instructions are stored, and when the instructions are executed, they are used to implement the method of claim 1.

10. A computer program product, characterized in that The invention comprises computer executable instructions, which are used to implement the method of claim 1 when being executed.

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