A method of measuring a navigation signal pattern

Abstract

The application discloses a kind of methods for measuring navigation signal field pattern, it is related to aviation navigation and flight verification technical field, by calculating the deviation between the actual position of unmanned aerial vehicle and corresponding position in preset route, the navigation signal measurement value at corresponding position in preset route is calculated by combining the navigation signal measurement value of unmanned aerial vehicle at actual position, the navigation signal that can be calculated includes azimuth signal, distance signal and elevation signal, when unmanned aerial vehicle is used for flight verification, the problem that the navigation signal collected is not complete when unmanned aerial vehicle cannot fly according to preset route, does not satisfy the problem of flight verification standard.

Description

Technical Field

[0001] This invention belongs to the field of aviation navigation and flight calibration technology, and specifically relates to a method for measuring navigation signal field patterns. Background Technology

[0002] With the development of oil exploration technology, the use of small aircraft or helicopters for oil exploration has entered a stage of rapid development. Aircraft performing exploration missions must rely on guidance signals transmitted by ground navigation equipment during missions and landings. To ensure the quality of these navigation signals, flight calibration is typically performed to measure and evaluate them. Flight calibration using unmanned aerial vehicles (UAVs) involves installing onboard calibration equipment on the UAV. Ground personnel then operate this ground calibration equipment according to flight calibration specifications to check and evaluate the spatial signal quality of various navigation devices.

[0003] Different types of navigation equipment emit different navigation signals. Navigation signals are mainly divided into different types such as azimuth signals, distance signals, and elevation signals. Azimuth signals provide the aircraft with azimuth information relative to ground navigation equipment, distance signals provide the aircraft with distance information to ground navigation equipment, and elevation signals provide the aircraft with elevation information relative to ground navigation equipment. Elevation signals are generally used to assist aircraft in approaching and landing.

[0004] Compared to traditional flight calibration, UAV flight calibration offers advantages such as better maneuverability and lower maintenance costs. However, due to the influence of its own performance and weather conditions, UAVs often struggle to follow pre-set flight paths during certain flight maneuvers. For example, when performing circular flight missions, the UAV's flight path is not a complete arc but rather an irregular curve that approximates an arc. Similarly, during approach flight missions, the UAV's flight path is not a smooth straight line but an irregular curve that fluctuates above and below the pre-set path. Because UAVs cannot fly exactly along the pre-set path, it is difficult to measure navigation signals that meet flight calibration standards, thus reducing the accuracy of flight calibration and hindering the proper inspection and evaluation of navigation equipment. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a method for measuring navigation signal field patterns. When the UAV is not flying on a preset route, this method calculates the measured value of the navigation signal on the preset route based on the relative positional relationship between the UAV and the preset route, thereby ensuring the integrity of the navigation signals collected during flight verification.

[0006] To achieve the above objectives, the principle of this invention is as follows: The airborne calibration equipment includes various navigation signal receivers and GNSS receivers. The UAV equipped with this airborne calibration equipment can not only measure navigation signals but also obtain its own precise positioning. Furthermore, the airborne calibration equipment acquires positioning information from ground navigation equipment before performing the flight calibration mission. When the UAV is not flying on the preset route, the deviation between the UAV's actual position and the corresponding position on the preset route is calculated. Combined with the navigation signal measurement value at the UAV's actual position, the measurement value of the navigation signal at the corresponding position on the preset route is then deduced.

[0007] The present invention provides a method for measuring the field pattern of navigation signals, comprising the following steps:

[0008] Step 1: Convert both the UAV coordinates and the ground navigation equipment coordinates into a spatial rectangular coordinate system.

[0009] Step 2: In the spatial rectangular coordinate system, draw the orthographic projection of the UAV onto the horizontal plane where the ground navigation equipment is located, and calculate the intersection point of the plane where the UAV, the UAV projection, and the ground navigation equipment are located with the preset flight path. This intersection point is the corresponding position of the UAV in the preset flight path, and is denoted as the ideal point.

[0010] Step 3: With the ground navigation device as the center and the distance from the UAV to the ground navigation device as the radius, draw an arc and calculate the coordinates of the intersection point of the straight line connecting the ground navigation device and the ideal point with the arc;

[0011] Step 4: Calculate the distance between each point according to the distance calculation formula in the spatial rectangular coordinate system; calculate the angle between the UAV, the ideal point and the horizontal plane at the ground navigation device according to the cosine theorem, as well as the angle between the UAV and the ideal point;

[0012] Step 5: Calculate the measured value of the navigation signal at the ideal point based on the positional relationship between the UAV and the ideal point.

[0013] Furthermore, the navigation signal includes an azimuth signal, a distance signal, and an elevation signal. The azimuth signal refers to the azimuth angle information of a point in space relative to the ground navigation device. The distance signal refers to the distance information between a point in space and the ground navigation device. The elevation signal refers to the elevation angle information of a point in space relative to the ground navigation device.

[0014] Compared with the prior art, the beneficial effects of the present invention are: the present invention solves the problem that when using a drone for flight calibration, if the drone cannot fly according to the preset route, the collected navigation signal is incomplete. Through the present invention, the measurement values ​​of the navigation signal at all positions on the preset route can be calculated, thereby meeting the flight calibration standards, improving the accuracy of flight calibration, and making correct checks and evaluations of the navigation equipment. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the position in a spatial rectangular coordinate system;

[0016] Figure 2 for At that time, a diagram showing the positional relationship of each point;

[0017] Figure 3 for At that time, a diagram showing the positional relationship of each point;

[0018] Figure 4 for At that time, a diagram showing the positional relationship of each point;

[0019] Figure 5 for At that time, the diagram shows the positional relationship of each point. Detailed Implementation

[0020] To make the objectives, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] Airborne calibration equipment includes various navigation signal receivers and GNSS receivers. UAVs equipped with this equipment can not only measure navigation signals but also obtain their own precise positioning. Furthermore, the airborne calibration equipment acquires positioning information from ground-based navigation equipment before performing flight calibration missions. When a UAV cannot fly along a preset route, the measured value of the navigation signal at the corresponding location within the preset route is calculated. The main steps are as follows:

[0022] Step 1: Convert both the UAV coordinates and the ground navigation equipment coordinates into a spatial rectangular coordinate system, such as... Figure 1 As shown, in the spatial rectangular coordinate system o-xyz, the ground navigation equipment is located at T Point, drone at P Point P. The navigation signal values ​​measured by the UAV at point P are marked as follows: This represents the azimuth signal, specifically the azimuth angle measurement of point P relative to the ground navigation equipment. This represents the distance signal, specifically the measured distance between point P and the ground navigation equipment. This indicates the elevation angle signal, which is the measured elevation angle of point P relative to the ground navigation equipment.

[0023] Step 2: Draw the orthographic projection of point P onto the horizontal plane containing point T. This projection is denoted as A. Point B is the intersection of the plane containing points P, T, and A with the preset route. Based on the known coordinates of the preset route and the coordinates of points P, T, and A, the coordinates of point B are calculated and denoted as B. Point B is the position of the drone on the preset flight path corresponding to point P;

[0024] Step 3: Based on the coordinates of points P and T, calculate the distance between points P and T, and denot it as . In the plane containing P, T, and A, with T as the center, Draw an arc with radius TB, intersecting the line TB at point C. Calculate the following system of equations.

[0025]

[0026] The coordinates of point C can be calculated and denoted as C. ;

[0027] Step 4: Calculate the distance between points B and C using the distance calculation formula in a rectangular coordinate system, and denote it as... Calculate the distance between points T and B, denoted as . Calculate the distance between points P and B, denoted as . Calculate the distance between points T and A, denoted as . Calculate the distance between points P and A, denoted as . Calculate the distance between points A and B, denoted as . ;Calculate the value of ∠PTB using the Law of Cosines. Calculate the value of ∠PTA. Calculate the value of ∠BTA. ;

[0028] Step 5: Calculate the measured values ​​of the navigation signals at point B. The measured values ​​of various navigation signals at point B are marked as follows: This represents the azimuth angle measurement of point B relative to the ground navigation equipment. This represents the measured distance between point B and the ground navigation equipment. This represents the elevation angle measurement of point B relative to the ground navigation equipment. Based on the positional relationship between P and B, it can be divided into the following four cases:

[0029] when At times, such as Figure 2 As shown, the measured values ​​at point B are as follows: , , ;

[0030] when At times, such as Figure 3 As shown, the measured values ​​at point B are as follows: , , ;

[0031] when At times, such as Figure 4 As shown, the measured values ​​at point B are as follows: , , ;

[0032] when At times, such as Figure 5 As shown, the measured values ​​at point B are as follows: , , .

[0033] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for measuring the field pattern of navigation signals, characterized in that, By calculating the deviation between the actual position of the UAV and the corresponding position in the preset flight path, and combining the navigation signal measurement value of the UAV at the actual position, the measurement value of the navigation signal at the corresponding position in the preset flight path is calculated. This specifically includes the following steps: Step 1: Convert both the UAV coordinates and the ground navigation device coordinates into a spatial rectangular coordinate system. In the spatial rectangular coordinate system, the location of the UAV is denoted as point P, and the location of the ground navigation device is denoted as point T. The navigation signal value measured by the UAV at point P is marked as follows: This represents the azimuth signal, specifically the azimuth angle measurement of point P relative to the ground navigation equipment. This represents the distance signal, specifically the measured distance between point P and the ground navigation equipment. This indicates the elevation angle signal, which is the measured elevation angle of point P relative to the ground navigation equipment. Step 2: Draw the orthographic projection of point P onto the horizontal plane where point T is located. This projection is denoted as point A. The plane containing P, T, and A intersects the preset flight path at point B. Point B is the position of the UAV on the preset flight path corresponding to point P. Calculate the coordinates of point B based on the known coordinates of the preset flight path and the coordinates of points P, T, and A. Step 3: Based on the coordinates of points P and T, calculate the distance between points P and T, and denot it as . In the plane containing P, T, and A, with point T as the center, Draw an arc with radius TB, intersecting the line TB at point C, and calculate the coordinates of point C; Step 4: Calculate the distance between points B and C using the distance calculation formula in a rectangular coordinate system, and denote it as... Calculate the distance between points T and B, denoted as . Calculate the distance between points P and B, denoted as . Calculate the distance between points T and A, denoted as . Calculate the distance between points P and A, denoted as . ; Calculate the distance between points A and B, denoted as . According to the Law of Cosines, calculate the values ​​of ∠PTB, ∠PTA, and ∠BTA respectively, where the value of ∠PTB is denoted as . ; Step 5: Calculate the measured values ​​of the navigation signals at point B. The measured values ​​of various navigation signals at point B are marked as follows: This represents the azimuth angle measurement of point B relative to the ground navigation equipment. This represents the measured distance between point B and the ground navigation equipment. This represents the elevation angle measurement of point B relative to the ground navigation equipment. Based on the relative positional relationship between point P and point B, it can be divided into the following four cases: when At that time, the measured value at point B was as follows: , , ; when At that time, the measured value at point B was as follows: , , ; when At that time, the measured value at point B was as follows: , , ; when At that time, the measured value at point B was as follows: , , .

2. The method for measuring the field pattern of navigation signals according to claim 1, characterized in that, The measured navigation signals include azimuth, distance, and elevation signals.

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