RU2825560C1 - Method of determining rectangular coordinates from slant range to target taking into account true value of its height - Google Patents

Abstract

FIELD: measuring.

SUBSTANCE: invention relates to determination of rectangular coordinates by slant range to target with allowance for true value of its height using unmanned aerial vehicles (UAV). Essence of the disclosed method consists in the fact that a UAV of a quadcopter type is used, a control pad with a loaded matrix of heights, the altitude of the quadcopter is measured, angle of inclination of the quadcopter camera to the target, calculating the horizontal range to the target, calculating rectangular coordinates of the target from the rectangular coordinates of the operator, determining the quadcopter operator's elevation above the target and calculating the slant range to the target, specifying the target rectangular coordinates, specifying the target height, and continuing calculations until the difference in the target rectangular coordinates does not exceed ten metres.

EFFECT: high accuracy of determining rectangular coordinates of a target from a slant range taking into account the true height of the target.

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Description

Currently, there are several methods for determining target coordinates using quadcopter-type unmanned aerial vehicles (QUAVs).

The simplest way is to compare the image from the UAV KVT camera with the AlpinQuest program and then take the coordinates from this program. The error in determining the coordinates can reach up to 200 meters or more, depending on the contours of the terrain.

Another method uses the program "ZeVs UAV". This is a background application running on top of the piloting program, allowing you to determine the coordinates of the target due to the calculation algorithm using the following data: the coordinates of the takeoff point and the flight altitude of the UAV KVT, the angle of the camera and the directional angle to the target. The error in determining the coordinates of this method will depend on the flight altitude and the correctness of the input of the angle of the camera and can reach 150 meters.

A method for determining coordinates using the Glaz/Groza program is known. This method is a calculation algorithm using the following data: coordinates of the takeoff point and the flight altitude of the KVT UAV, the camera tilt angle and the directional angle to the target, but unlike the ZeVs UAV, these data are determined automatically. And the flight and line of sight are displayed on the tablet, which allows for more accurate target coordinates. The error can reach from 10 to 100 meters.

The range to the target is determined using formula (1).

where D _r is the horizontal range to the target;

H _quadr - UAV flight altitude KvT;

γ is the angle of inclination of the camera directed at the target.

Knowing the rectangular coordinates of the operator, the directional angle and the horizontal range to the target, the rectangular coordinates of the target are found using formulas (2 and 3).

where X _c , Y _c are the rectangular coordinates of the target;

X _op , Y _op - rectangular coordinates of the operator;

α - direction angle to the target.

The main disadvantage of this method is that it does not take into account the target's excess over the height (position) of the UAV KVT operator. With a height difference of 200 meters, the error in determining the horizontal range, and therefore the error in determining the rectangular coordinates, can be 250...300 meters.

To eliminate this error, it is proposed to use a method for determining rectangular coordinates based on the slant range to the target by successively approaching the target height to the true value.

The claimed invention “Method for determining rectangular coordinates based on the slant range to a target while taking into account the true value of its height” solves the above-mentioned problems.

The essence of the claimed invention is explained by the drawings (see Fig. 2-4) and consists in the fact that knowing the rectangular coordinates of the operator (X _op , Y _op ), the directional angle (α) and the horizontal range to the target (D _g ), the rectangular coordinates of the target are determined, and from them, using the height matrix with the expansion .htg, determine the target height (H _c ). Then determine the slant range to the target (D _n ), using for this the flight altitude of the UAV KvT (H _quadr ), the angle of inclination of the camera to the target and the excess of the UAV KvT operator over the target (ΔH map), specify the rectangular coordinates of the target, then, using the height matrix with the extension .htg, specify the target height (H _{ts i} ). Calculations continue until the difference in the rectangular coordinates of the target ΔХ=ΔХ ^ts _i+1 -ΔХ ^ts _i and ΔY=ΔY ^ts _i+1 -ΔY ^ts _i does not exceed 10 meters.

Brief description of the drawings.

Fig. 1: shows the initial data for determining rectangular coordinates by horizontal range (D _r ), the flight altitude of the quadcopter (H _op ), the angle of inclination of the camera directed at the target - γ.

Fig. 2: shows the initial data for determining the slant range (D _n ), and from them - the rectangular coordinates of the target.

Fig. 3: shows the procedure for determining the rectangular coordinates of a target by slant range when determining the absolute altitude through a height matrix with expansion .htg.

Fig. 4: shows the procedure for determining the difference in height between the operator and point F when determining the rectangular coordinates of the target through the slant range, taking into account the true value of its height.

Implementation of the invention

To implement the invention it is necessary:

1. Using the height matrix *.htg, which supports all mobile applications, determine the absolute height of the point corresponding to the calculated rectangular coordinates X ^ц and Y ^ц . Next, as shown in Fig. 4, we find the difference between the absolute height of the point and the absolute height of the UAV operator KVT using formula (4).

where _Δ H _i ^map is the difference in heights of the i-th point;

H ₁ - absolute height of the point corresponding to the calculated rectangular coordinates X and Y;

H _o - absolute altitude of the UAV operator;

2. Solving triangle ADC (Fig. 3), angle ψ according to formula (5).

3. Knowing that angle BAC is right, we find angle β using formula (6).

4. Based on the theorem, the sum of the angles in a triangle is 180°, we find the angle ξ (Figure 6) using formula (7).

5. Solving triangle ABE (Fig. 2) using the law of sines, we find the slant range to the target using formula (8).

where D _n is the slant range to the target;

6. Find the rectangular coordinates of point E using formulas (9 and 10).

Next, again through the height matrix *.htg, the absolute height of the point corresponding to the calculated rectangular coordinates is determined (Fig. 4).

Then we find the difference between the absolute altitude of the point and the absolute altitude of the UAV operator using formula (11).

where _Δ H _i ^map is the difference in heights of the i-th point,

H ₂ - absolute height of the point corresponding to the calculated rectangular coordinates ,

H _o - absolute altitude of the UAV operator KvT.

Next, we solve triangle AFG in the same way as in point 2. We find the slant range from triangle ABF in the same way as in points 3, 4 and 5. We determine the rectangular coordinates of point F in the same way as in point 6.

This algorithm continues until the difference between will not exceed 10 meters.

The implementation of this method into the algorithms of the Glaz/Groza software of the KVT UAV allows for a significant increase in the accuracy of determining target coordinates.

The technical result achieved by the claimed invention consists in increasing the accuracy of determining the rectangular coordinates of a target by slant range, taking into account the true value of the target's height.

Claims (1)

A method for determining rectangular coordinates based on the slant range to a target taking into account the true value of its altitude, which consists in using a quadcopter-type unmanned aerial vehicle, a control tablet with a loaded height matrix with the *.htg extension, measuring the altitude of the quadcopter (H _quadr ), the angle of inclination of the quadcopter camera to the target (γ), calculating the horizontal range (D _g ) to the target, calculating the rectangular coordinates of the target (X _{ts i} , Y _{ts i )} based on the rectangular coordinates of the operator (X ^op , Y ^op ), determining the excess of the quadcopter operator over the target (ΔH ^map _i ) and calculating the slant range to the target (D _n ), specifying the rectangular coordinates of the target (X ^ts _i+1 , Y ^ts _i+1 ), specifying the height of the target (H ^ts _i+1 ), continuing the calculations until the difference in the rectangular coordinates of the target ΔX=ΔX ^ц _i+1 - ΔХ ^ц _i and ΔY=ΔY ^ц _i+1 -ΔY ^ц _i will not exceed ten meters.