Rapid calculation method for collision between aircraft and terrain
By dividing the latitude and longitude grid and minimizing the area of the flight mission area, combined with the data query method of temporary storage areas, the problem of collision detection between aircraft and terrain in large-scale complex terrains is solved, fast and accurate collision detection is achieved, and the flight is improved The accuracy of the simulation.
Patent Information
- Application Number
- CN202411548389.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-01
- Publication Date
- 2025-02-18
AI Technical Summary
The prior art is difficult to quickly and accurately detect the collision between the aircraft and the terrain in large-scale complex terrain, resulting in the possibility of crossing mountains and drilling in the ground in flight simulation.
By dividing the flight mission area into small grids according to latitude and longitude, sorting it into digital data, and using the smallest area division and temporary storage area, we can quickly query the relationship between the aircraft's flight altitude and terrain height to determine whether a collision occurs.
It realizes the rapid and accurate detection of the collision between the aircraft and the terrain in a large-scale complex terrain, improves the accuracy of flight simulation, and is suitable for complex environments such as multi-space buildings.
Smart Images
Figure CN119474241A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of aircraft simulation, and in particular relates to a fast calculation method for collision between an aircraft and terrain. Background Art
[0002] In the field of aircraft simulation, aircraft collision and destruction is an important condition for the aircraft to end its flight mission. In the entire flight simulation mission, the aircraft has to perform a variety of flight operations, especially near-ground flight or complex regional flight in demand missions, which is often unavoidable. Due to the vast flight area, the amount of terrain data is particularly huge, and subject to the complexity and diversity of the terrain, the calculation of the collision between the aircraft and the terrain can only be performed in a small range (such as an airport). Using the terrain height function within a small range, collision calculation can be performed within the small range. Beyond this area, the aircraft will fly through the mountains and the ground during the simulated flight without detecting the collision, or simply require the simulator operator to fly a certain distance from the ground to avoid such a situation. However, when a small aircraft simulates flight in a complex geographical terrain, it is necessary to consider the problem of collision with the terrain, such as the flight simulator doing flight exploration between canyons and mountains. Therefore, a reasonable and fast method for calculating the collision between the aircraft and the terrain is needed to improve the flight mission. Summary of the invention
[0003] The purpose of the present invention is to provide a fast calculation method for collision between an aircraft and terrain, which can quickly detect whether a collision between an aircraft and terrain occurs in a large area of complex terrain.
[0004] The technical solution of the present invention is as follows: A fast calculation method for collision between an aircraft and terrain, comprising the following steps: Step 1: Arrange the geographical terrain height information of the area where the aircraft will fly into digital storage information that can be recognized by a computer; Step 2: Minimum area division; Step 3: Determine the geographical location of the aircraft based on the airport longitude and latitude coordinates and the aircraft's flight status transmitted by the flight control system and avionics system, and then write the data in the group into a temporary storage area.
[0005] In the step 1, the flight mission area is divided into a grid of longitude and latitude, and the minimum unit interval of the grid is (0.000001 second, 0.000001 second). Then, the terrain height order of longitude from small to large is stored at the minimum latitude interval, and then the terrain height order of longitude from small to large is stored after the latitude is increased according to the minimum interval, until the maximum latitude value of the flight area.
[0006] The mathematical expression included in step 1 is: Jmin is the minimum longitude, Jmax is the maximum longitude, Wmin is the minimum latitude, Wmax is the maximum latitude, and H(i) is the terrain height. The sorting method is (Jmin, Wmin, H(0)), (Jmin + 0.000001 seconds, Wmin, H(1)) … (Jmax, Wmin, H(i)), (Jmin, Wmin + 0.000001 seconds, H(i + 1)) ….
[0007] The geographical terrain height information in Step 1 is sourced from aerial survey or geographical database.
[0008] In Step 2, the minimum area division adopts the method of using the temporary storage area A. When the maximum flight speed of the aircraft is 120 Km / h, divide the maximum flight speed by 3.6, then multiply by 0.2 s to obtain the side length of the minimum area. Use the processing program to automatically process and divide into area blocks according to longitude and latitude, and then mark each block with the minimum longitude and latitude within the block. Group every 100 areas as a set, and mark the minimum longitude and latitude within each set separately. Divide them into three layers. The largest layer is the entire area where the aircraft flies, the middle layer is the group area composed of every 100 interconnected areas, and the smallest layer is the minimum area divided by the above method.
[0009] Step 3 includes defining the temporary storage area as Area A. During flight, query whether the flight height H of the aircraft is greater than the terrain height h plus half of the fuselage 0.5L and greater than the terrain height h plus half of the wingspan 0.5R at the same longitude and latitude coordinates, that is, H > h + 0.5L and H > h + 0.5R, then it is judged that there will be no collision; if H < h, then it is judged that there is a collision; if h < H < h + 0.5L, combined with the flight attitude of the aircraft, the flight elevation angle a, and the roll angle b, then if H - h > 0.5L × sina and H - h > 0.5R × sinb, it is judged that there will be no collision. If any of these two conditions is not satisfied, it is judged that there is a collision; L is the length of the fuselage.
[0010] In Step 3, the maximum longitude coordinate in Area A is Jmax, and the minimum longitude coordinate is Jmin. J is the longitude where the aircraft is currently located. If the aircraft longitude coordinate Jmin + 0.05(Jmax - Jmin) < J < Jmin + 0.95(Jmax - Jmin), then Area A does not need to read new area data. If it is outside this area, the data in Area A is updated. The newly updated data needs to satisfy Jmin + 0.48(Jmax - Jmin) < J < Jmin + 0.52(Jmax - Jmin) under the new maximum longitude coordinate Jmax and the new minimum longitude coordinate Jmin. At the same time, the value of the pointer is refreshed to the new position.
[0011] In step 3, the maximum latitude coordinate in area A is Wmax, and the minimum latitude coordinate is Wmin. If the latitude of the aircraft is Wmin + 0.05 (Wmax - Wmin) < W < Wmin + 0.95 (Wmax - Wmin), then area A does not need to read new area data. If it is outside this area, the data in area A is updated. The newly updated data needs to satisfy Wmin + 0.48 (Wmax - Wmin) < W < Wmin + 0.52 (Wmax - Wmin) under the new maximum latitude coordinate Wmax and the new minimum latitude coordinate Wmin. At the same time, the value of the pointer is refreshed to a new position.
[0012] The beneficial effects of the present invention are as follows: After adopting this method, collision detection will be more accurate, and it can be applied to large-scale maps for fine collision detection, and can be applied to multi-space buildings such as bridges and canyons. Figure 4 It is the effect diagram after adopting this technical method. Figure 4 It is the effect diagram of the collision detection of the aircraft corresponding to the terrain and grid after using the fast calculation method of collision. In the figure, the moving position of the aircraft corresponds to the position of the terrain height data. During the flight of the aircraft, the height data will be continuously compared to feedback the collision detection signal. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Figure 1 It is the terrain grid division diagram; Figure 2 It is the data area grid division diagram; Figure 3 It is the geographical terrain height grid drawing; Figure 4 It is the effect diagram after using the present invention; Figure 5 It is the fast collision calculation logic diagram, which shows the relationship between the aircraft collision calculation and the flight simulator and its scheduling loop logic. DETAILED DESCRIPTION OF THE INVENTION
[0014] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.
[0015] A fast calculation method for the collision between an aircraft and the terrain. First, extract the radio altitudes of all geographical terrains in the flight mission area, divide the flight mission area into grids according to longitude and latitude, and the minimum unit interval of the grid is (0.000001 second, 0.000001 second). Under such division, the interval relative to the geographical terrain is approximately (1m, 1m). Under such precision conditions, the terrain height can be accurately restored to the terrain view, that is, the seen mountains or high-rise buildings can be accurately bound to their appearance contours with height and longitude and latitude data.
[0016] Under the above-mentioned geographical terrain grid unit division, the amount of altitude and longitude and latitude data obtained is extremely large. If the data is 100 km*100 km, it will be more than 4G. The data amount is extremely large. Under the condition of meeting the flight trajectory of high-speed aircraft, people's resolution time for visual effects is about 0.1 seconds. Within 0.1 seconds, the flight trajectory of the aircraft is related to the flight speed and flight control of the aircraft. In the flight simulator, the flight control solution frequency of the aircraft is generally within 10 milliseconds. There are at least ten longitude and latitude coordinate points of the track in one judgment cycle. After solving, they can be searched ten times in the altitude and longitude and latitude data, and it is required to be completed within 0.1 seconds. For a large amount of altitude and longitude and latitude data, the amount of data to be calculated and searched is too large. Therefore, the data in the database is divided into small areas according to longitude and latitude. The area size is generally divided according to the maximum flight distance of the aircraft in 0.2s. After the aircraft is selected, the program will automatically call the corresponding module library. When the aircraft selects the take-off position or loads the initial flight status, the initial position of the aircraft is quickly located by searching the area, and the initial longitude and latitude position pointer is determined. Then, the increase or decrease of the pointer is used to call the minimum data to achieve the purpose of rapid detection and judgment.
[0017] The height of the geographical terrain is generated based on the highest altitude of the object within (0.000001 seconds, 0.000001 seconds). If there is space below the highest altitude (such as the position of the bridge under the water), there is a mark to determine whether there is space below the highest point. The data format is (longitude, latitude, number of cavities, height 1, height 2 bottom, height 2 top...) For specific spatial effects, see Figure 3 : If the altitude of the terrain under the latitude and longitude coordinates of the flight trajectory of the aircraft is not higher than the altitude of the aircraft within the flight trajectory of 0.1 seconds, and if the altitude of the aircraft is lower than the altitude of the terrain under the latitude and longitude coordinates of the flight trajectory, it is determined that the aircraft has collided. The aircraft is destroyed.
[0018] A fast calculation method for collision between an aircraft and terrain includes the following steps: Step 1: Arrange the geographical terrain height information of the area where the aircraft will fly into digital storage information that can be recognized by a computer; According to the method described above, the flight mission area is divided into longitude and latitude grids. The minimum unit interval of the grid is (0.000001 seconds, 0.000001 seconds). Then, the terrain height order from small to large longitude is stored at the minimum latitude interval. Then, after increasing the latitude at the minimum interval, the terrain height order from small to large longitude is stored until the maximum latitude value of the flight area. The mathematical expression is: Assuming Jmin: minimum longitude, Jmax maximum longitude, Wmin: minimum latitude, Wmax: maximum latitude, H(i) is the terrain height, the sorting method is (Jmin, Wmin, H(0)), (Jmin+0.000001 seconds, Wmin, H(1))...(Jmax, Wmin, H(i)), (Jmin, Wmin+0.000001 seconds, H(i+1))...) The geographical terrain height information can be derived from aerial photography or geographic databases. The visual content of the flight simulator visual system must be highly consistent with the geographical terrain height information. The grid division must be able to fully reflect the location characteristics of the protrusions, that is, the mountains or tall buildings seen can be accurately bound to their appearance contours using height and longitude and latitude data.
[0019] The specific grid division only needs to meet the contour conditions of the terrain visual development. If the contour of the terrain visual development is rough, it means that the development terrain data is sparse, and the grid division does not need to be detailed, and it can roughly match the interval degree of the terrain data.
[0020] Step 2: Minimum area division; The minimum area division adopts the temporary storage area A. For example, the maximum flight speed of Cessna aircraft is 120Km / h. The maximum flight speed is divided by 3.6, and then multiplied by 0.2s to get the side length of the minimum area. The processing program is used to automatically process it into blocks according to the longitude and latitude. Then each block is marked according to the minimum longitude and latitude in the block, and each 100 blocks are grouped. The minimum longitude and latitude in each group are marked separately. It is divided into three layers. The three layers are the largest layer, which is the entire area where the aircraft flies, the middle layer is composed of groups of 100 blocks connected to each other, and the smallest layer is the smallest area divided by the above method. If the geographic data is still large, you can make several more levels as needed. Ensure that the computer can find the data area faster when calling data.
[0021] Step 3: Determine the geographical location of the aircraft based on the airport longitude and latitude coordinates and the aircraft's flight status transmitted by the flight control system and avionics system, and then write the data in the group into a temporary storage area.
[0022] Define this temporary storage area as Area A. In fact, only the geographical terrain data of the flight area of the aircraft for about 2 seconds is stored in Area A, and the data volume is already very small. At the current stage, on the mainstream computers with a machine configuration above i5, the current data volume can meet the real-time query and scheduling of 10 milliseconds for the aircraft. During the flight, it is only necessary to query whether the flight altitude H of the aircraft is greater than the terrain altitude h plus half of the fuselage 0.5L and greater than the terrain altitude h plus half of the wingspan 0.5R, that is, H>h + 0.5L and H>h + 0.5R, then it is judged that there will be no collision; if H<h, it is judged that there is a collision; if h<H<h + 0.5L, combined with the flight attitude of the aircraft, the flight elevation angle a and the roll angle b, then if H - h>0.5L×sina and H - h>0.5R×sinb, it is judged that there will be no collision. If any of these two conditions is not met, it is judged that there is a collision; L is the fuselage length.
[0023] The maximum longitude coordinate in Area A is Jmax, and the minimum longitude coordinate is Jmin. J is the longitude where the aircraft is currently located. If the longitude coordinate of the aircraft Jmin + 0.05(Jmax - Jmin)<J<Jmin + 0.95(Jmax - Jmin), then Area A does not need to read new area data. If it is outside this area, the data in Area A is updated. The newly updated data needs to meet Jmin + 0.48(Jmax - Jmin)<J<Jmin + 0.52(Jmax - Jmin) under the new maximum longitude coordinate Jmax and the new minimum longitude coordinate Jmin. At the same time, the value of the pointer is refreshed to the new position.
[0024] The maximum latitude coordinate in Area A is Wmax, and the minimum latitude coordinate is Wmin. W is the latitude where the aircraft is currently located. If the latitude coordinate of the aircraft Wmin + 0.05(Wmax - Wmin)
Claims
1. A fast calculation method for collision between an aircraft and terrain, characterized in that: It includes the following steps: Step 1: Organize the geographical terrain height information of the area where the aircraft will fly into digital storage information that can be recognized by a computer; Step 2: Minimum area division; Step 3: Determine the geographical terrain position of the aircraft according to the airport longitude and latitude coordinates and the flight state of the aircraft transmitted by the flight control system and the avionics system, and then write the data in this group into the temporary storage area.
2. A fast calculation method for collision between an aircraft and terrain as claimed in claim 1, characterized in that: In Step 1, the flight mission area is divided into longitude and latitude grids. The minimum unit interval of the grid is (0.000001 second, 0.000001 second). Then, first store in the order of terrain height with longitude increasing from small to large under the minimum latitude interval, and then store in the order of terrain height with longitude increasing from small to large after increasing the latitude by the minimum interval until the maximum latitude value of the flight area.
3. A fast calculation method for collision between an aircraft and terrain as claimed in claim 2, characterized in that: The mathematical expression included in Step 1 is: Jmin is the minimum longitude, Jmax is the maximum longitude, Wmin is the minimum latitude, Wmax is the maximum latitude, and H(i) is the terrain height. The organizing method is (Jmin, Wmin, H(0)), (Jmin + 0.000001 second, Wmin, H(1))…(Jmax, Wmin, H(i)), (Jmin, Wmin + 0.000001 second, H(i + 1))… 4. A fast calculation method for collision between an aircraft and terrain as claimed in claim 2, characterized in that: The geographical terrain height information in Step 1 is sourced from aerial survey or geographical database.
5. A fast calculation method for collision between an aircraft and terrain as claimed in claim 1, characterized in that: In Step 2, the minimum area division adopts the method of the A area of the temporary storage area. When the maximum flight speed of the aircraft is 120 Km / h, divide the maximum flight speed by 3.6, and then multiply by 0.2 s to obtain the side length of the minimum area. Use the processing program to automatically divide into area blocks according to longitude and latitude, and then mark each block with the minimum longitude and latitude within the block. Group every 100 areas as a group, and mark the minimum longitude and latitude within each group separately. Divide into three layers. The largest layer is the entire area where the aircraft flies, the middle layer is the group area composed of every 100 interconnected areas, and the smallest layer is the minimum area divided by the above method.
6. A fast calculation method for collision between an aircraft and terrain as claimed in claim 1, characterized in that: Step 3 includes defining this temporary storage area as the A area. During flight, query whether the flight height H of the aircraft is greater than the terrain height h plus half of the fuselage 0.5L and greater than the terrain height h plus half of the wingspan 0.5R at the same longitude and latitude coordinates, that is, H>h + 0.5L and H>h + 0.5R, then it is judged that there will be no collision; if H<h, it is judged that there is a collision; if h<H<h + 0.5L, combined with the flight attitude of the aircraft, the flight elevation angle a and the roll angle b, then if H - h>0.5L×sina and H - h>0.5R×sinb, it is judged that there will be no collision. If either of these two conditions is not satisfied, it is judged that there is a collision; L is the fuselage length.
7. A fast calculation method for collision between an aircraft and terrain as claimed in claim 6, characterized in that: In step 3, the maximum longitude coordinate in area A is Jmax, and the minimum longitude coordinate is Jmin, where J is the longitude at which the aircraft is currently located. If the aircraft's longitude coordinate satisfies Jmin + 0.05(Jmax - Jmin) < J < Jmin + 0.95(Jmax - Jmin), then area A does not need to read new section data. If it is outside this area, the data in area A is updated. The newly updated data needs to satisfy Jmin + 0.48(Jmax - Jmin) < J < Jmin + 0.52(Jmax - Jmin) under the new maximum longitude coordinate Jmax and the new minimum longitude coordinate Jmin. At the same time, the value of the pointer is refreshed to the new position.
8. A fast calculation method for collision between an aircraft and terrain as claimed in claim 6, characterized in that: In step 3, the maximum latitude coordinate in area A is Wmax, and the minimum latitude coordinate is Wmin, where W is the latitude at which the aircraft is currently located. If the aircraft's latitude coordinate satisfies Wmin + 0.05(Wmax - Wmin) < W < Wmin + 0.95(Wmax - Wmin), then area A does not need to read new section data. If it is outside this area, the data in area A is updated. The newly updated data needs to satisfy Wmin + 0.48(Wmax - Wmin) < W < Wmin + 0.52(Wmax - Wmin) under the new maximum latitude coordinate Wmax and the new minimum latitude coordinate Wmin. At the same time, the value of the pointer is refreshed to the new position.