RU2661269C2 - Method for trajectory control of unmanned aerial vehicle to fly around urban territories in vertical plane - Google Patents

Abstract

FIELD: aircraft engineering.

SUBSTANCE: invention relates to a method for trajectory control of an unmanned aerial vehicle (UAV). Above method consists in placing the UAV from the control center to a trajectory with a given inclination angle, correcting the angle of the trajectory when the UAV is approaching a group of obstacles, each of which is approximated in a certain way.

EFFECT: durability of the UAV is improved due to the automation of the process of flying over groups of obstacles in the vertical plane during a low altitude flight.

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Description

The invention relates to methods for trajectory control of unmanned aerial vehicles (UAVs) and can be used to increase their safety when performing low-altitude flights.

Increasing the survivability of aircraft in the process of controlling an aircraft [1] is one of the main trends in the development of systems with UAVs. One of the ways to increase the survivability of UAVs during low-altitude flights (MVP) in an area with typical urban development is to fly around obstacle groups in a vertical plane. In manned aircraft (LA), a special radar system — a low-altitude flight electronic control system (RESU MVP) —is used to create a profile flight of an aircraft in which the flight path of the aircraft repeats the profile, is used to carry out the MEP over rough terrain and urban areas; terrain. It is important to note that RESU MVP should ensure the solution of tasks at any time of the year, days and any weather conditions. These requirements predetermine the multichannel principle of constructing a computing system for a radar system using radar to determine the distance to obstacles and radio altimeters to control the current altitude [2]. Thus, the composition of the specified system includes equipment that is characterized by sufficiently large weight and size and cost characteristics. Obviously, the use of a similar complex as part of the onboard equipment of the UAV seems inappropriate according to the criterion of "cost-effectiveness". In addition, when solving some special tasks, the use of an active radar is not recommended, since this can serve as a strong unmasking factor.

In existing systems with UAVs [2] (prototype) (see Fig. 1), including a control point 1 and an unmanned aerial vehicle 2, for flying around urban buildings 3 during low-altitude flight, as a rule, the route method is used, which is carried out in two stage. At the first (preparatory) stage, the dispatcher (operator, combat control officer) outlines a number of control points 4, which the UAV must pass with a given angle of inclination of the trajectory. Further, to ensure consistent UAV passage of the designated points in the navigational calculation, guidance algorithms for stationary targets (alternately for each corresponding control point) are implemented. At the second stage, the aircraft 2 is directly controlled to bypass the obstacle group in the vertical plane 3 along the calculated trajectories 5 using control commands from the control room (command) point 1. The procedure for the existing method of flying around an obstacle group by the aircraft is illustrated in FIG. one.

It should be noted that this method of flying around obstacle groups associated with the application of control points involves the direct participation of a person and is a rather laborious task, since such actions must be performed for each UAV. Moreover, the application of such points requires extensive experience with the operator, and, in the general case, this is a non-trivial task.

The technical result of the invention is to increase the survivability of the UAV through the use of command control and automation of the process of flying around groups of obstacles in a vertical plane at low altitude flight of the UAV along the planned route.

The claimed technical result is achieved due to the fact that when planning a UAV flight route, each obstacle of the group in the vertical plane is approximated by a rectangle located in the upper part of the OXY coordinate plane, one of whose sides lies on the OX axis (coinciding with the zero offset). The operator for describing the selected obstacle indicates only the center of such a rectangle and the length of its sides. Next, the aircraft is directly controlled by bypassing obstacle groups by correcting the calculated guidance trajectory.

The possibility of achieving a technical result is due to the following reasons:

- a significant reduction in the time the operator describes the obstacles, which reduces the load on the operator [3];

- a universal (of the same type) way of describing obstacles, which makes it possible to apply traditional methods of controlling aircraft [2].

A variant of the mutual arrangement of the steered aircraft and the group of obstacles is illustrated in FIG. 2, on which the aircraft moves uniformly with a speed of V _LA , rectilinearly and parallel to the earth's surface at a given height N. Obstacles look like typical urban buildings.

For such conditions, one of the possible control methods that increases the survivability of an unmanned aerial vehicle is a new method, obtained on the basis of the mathematical apparatus of the dynamic inverse problem method [4] using the results of [7], in which the trajectory of the controlled UAV is corrected when it approaches a group of obstacles by combining its velocity vector with a tangent constructed to the desired trajectory. The calculation of the required increment of the angle of inclination of the trajectory (mismatch parameter) of the controlled UAV is carried out according to the rule:

where the variables w ₁ and w ₂ are calculated by differentiating the function ψ (x, y) from the coordinates of the UAV. The OXY coordinate system is chosen so that the coordinate y corresponds to the flight altitude, and the direction of the x coordinate axis corresponds to the flight direction of the UAV. The expression for the variables w ₁ and w ₂ has the form:

The function ψ (x, y) is the stream function of the ideal fluid flow around several rectangular parallelepipeds, which can be obtained on the basis of the provisions of the theory of functions of a complex variable and the expression for the complex potential of the circulationless flow around several rectangular parallelepipeds, highlighted as its imaginary part.

The expression for the complex potential and the dependence for the stream function and the velocity potential of the resulting ideal fluid flow, in turn, using the conformal mapping of the exterior of the rectangular parallelepiped section to the exterior of the circular cylinder [5, 6, 7], in the case under consideration are written as follows:

where z = x + iy is the complex variable on the complex plane OXY, N is the number of rectangles approximating the objects,

- угол, зависящий от соотношения сторон j-ого прямоугольника (X_j - длина, Y_j - высота прямоугольника), V и

- скорость БЛА (до и после облета рельефа) и его сопряженная скорость, соответственно;

, z_0j=x_0j+iy_0j (х_0j, y_0j - смещение центра j-ого прямоугольника относительно начала выбранной системы координат OXY),

.

is the angle depending on the aspect ratio of the j-th rectangle (X _j is the length, Y _j is the height of the rectangle), V and

- UAV speed (before and after overflown terrain) and its conjugate speed, respectively;

, z _0j = x _0j + iy _0j (x _0j , y _0j is the offset of the center of the j-th rectangle relative to the origin of the selected coordinate system OXY),

.

The specified parameters are determined at the control room (DP).

Correction of the angle of inclination of the UAV trajectory begins when the distance from the controlled UAV to the center of the rectangle approximating the obstacle becomes less than a certain value:

where x _P and y _P are the coordinates of the center of the approximation rectangle; x and y - UAV coordinates; L is the given distance.

An exemplary view of the trajectory of flying around 7 of a group of obstacles that are approximated by rectangles 6 is shown in FIG. 3. It also shows the required increment Δϑ of the angle of inclination of the trajectory (mismatch parameter) of the controlled UAV formed according to rule (1).

Thus, to correct the angle of inclination of the trajectory when flying around obstacle groups in a vertical plane using the described method (1) - (4), it is necessary to take into account:

1) UAV motion parameters - x and y coordinates, value

2) the parameters of the obstacle groups are the coordinates of the centers of the approximation rectangles z _0j and the lengths of their sides X _j and Y _j .

The values necessary for the implementation of (1) - (4) and constituting the first group of parameters are measured by regular means at the control centers, and the quantities making up the second group are located in the memory of the KP VP computer, where they are entered directly by the dispatcher (operator, combat control officer) )

Correction of the angle of the trajectory of the controlled UAV stops when its height becomes equal to the initial (predetermined) height H of the flight of the unmanned aerial vehicle, determined by the planned flight route.

The specificity of the described method is that the dependencies (1) - (4) are based on the approximation of groups of obstacles in the vertical plane. This approach allows you to unify and automate the process of describing obstacles, thereby significantly reducing the load on the dispatcher.

The claimed technical result is provided by the proposed method (1) - (4) for controlling an unmanned aerial vehicle, as well as using a universal (of the same type) method for describing obstacle groups in a vertical plane, which makes it possible to significantly reduce the time for describing the relief of urban buildings by a dispatcher, thereby reducing the load on him.

Thus, the indicated technical result is achieved by the fact that, based on the measured values of the flight speed V of the _aircraft and the flight height H of the unmanned aircraft, as well as the coordinates of the centers of the approximation rectangles and their sides specified by the dispatcher (operator, combat control officer) using (3) , the stream function ψ (x, y) is calculated. Then, using (2), the values of the variables w ₁ and w _{2 are} determined, based on which the measured value of the current trajectory angle ϑ is formed, using (1) a signal is generated of the required increment of the trajectory angle Δ Б for the UAV, allowing flying around a group of urban buildings .

This allows you to use the described control method to correct the flight paths of aircraft when flying around them groups of urban buildings in a vertical plane at low altitude flight.

LITERATURE

[1] Verba V.S. Aviation complexes of radar patrol and guidance. Status and development trends. M .: Radio engineering. 2008.432 s.

[2] Aircraft radio control systems. T. 3. Command radio control systems. Autonomous and combined guidance systems / V.I. Merkulov, A.I. Kanashchenkov [et al.]. M .: Radio engineering, 2004.317 s.

[3] Air defense of Russia and scientific and technological progress. Combat complexes and systems yesterday, today, tomorrow / E.A. Fedosov [et al.]. M.: Bustard, 2001.

[4] Krutko P.D. Inverse problems of dynamics in the theory of automatic control. M .: Engineering, 2004.

[5] Loytsyansky L.G. Mechanics of fluid and gas. Fizmatgiz, 1959.

[6] Lavrentiev M.A., Shabat B.V. Methods of the theory of functions of a complex variable. M .: Nauka, 1965, 716 p.

[7] Suzansky D.N., Popov V.Yu. A method of constructing a reference motion path of a complex system // Proceedings of the XV International Conference "Problems of Control and Modeling in Complex Systems". Samara: Samara Scientific Center of the Russian Academy of Sciences, 2013.S. 543-547.

Claims (10)

The method of trajectory control of an unmanned aerial vehicle (UAV) with flying around groups of urban development objects in a vertical plane is that the UAV is brought to the planned rectilinear and parallel to the earth’s surface flight path from the control station along the path of flying around an obstacle group with a given angle of inclination trajectories, characterized in that the trajectory of the controlled UAV is adjusted when it approaches a group of obstacles, each of which is approximated by a rectangle, for which o the calculation of the required increment of the angle of inclination of the trajectory of the controlled UAV is performed according to the rule:

Where

here w ₁ and w ₂ are the components of the velocity vector of the controlled aircraft; ψ (x, y) is the function of the x and y coordinates of the controlled UAV in the fixed coordinate system OXY, defined as the imaginary part of the expression for the complex potential:

where z = x + iy is a complex variable on the complex plane OXY, N is the number of rectangles approximating the objects,

is the angle depending on the aspect ratio of the j-th rectangle (X _j is the length, Y _j is the height of the rectangle), V and

- UAV speed (before and after overflown terrain) and its conjugate speed, respectively;

, z _0j = x _0j + iy _0j (x _0j , y _0j is the offset of the center of the j-th rectangle relative to the origin of the selected coordinate system OXY),

, while the adjustment of the angle of inclination of the UAV trajectory begins when the distance from the controlled UAV to the center approximating the obstacle of the rectangle becomes less than a certain value L:

where x _P and y _P are the coordinates of the center of the approximation rectangle, x and y are the coordinates of the UAV, and they are carried out until the UAV’s flight height becomes equal to the initial height N.

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