RU2334945C1 - Method of detection of helicopter translation movement at landing and device for its implementation - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: invention is related to the field of instrument making and may be used for systems of helicopter automatic control at the stage of landing (hovering). In order to achieve this result bearing angles of three identical points are determined on two serial bearing angles on two serial images of earth surface. These measurements are carried out from two serial positions of helicopter with the help of matrix photo-receiver, which is installed in focal plane of lens. At that device for method implementation consists unit of earth surface images receiver 1, which includes lens 3 and photomatrix 4, calculator 2, which includes module of earth surface images processing (5). In module (7) of helicopter forward translation components calculation system of linear equations (8) is solved and three components of helicopter spatial movement are calculated.

EFFECT: expansion of functional resources of helicopter automatic control system.

2 cl, 2 dwg

Description

The invention relates to aviation and is intended to determine the spatial movement of the helicopter relative to the ground at the landing stage, is used for automatic helicopter landing control systems.

A known method for determining the orientation of a moving object by the coordinates of reference sources (RI), including determining signals corresponding to the position of the image of the RI in the plane of the photodetector, determining the angles of bearings of each RI from the received signals taking into account the focal length of the lens and determining the coordinates of the RI according to the angles-bearings taking into account distance between points [1].

This method is implemented in a device containing reference sources on a moving object, and on a stationary one - two photodetector optical-location units and a unit for determining the coordinates of the radiation sources and the orientation of the moving object [2].

The disadvantage of the described analogue is the use of precision mechanical scanning, the presence of two optical-location blocks and reference sources with a known location on a moving object.

Known closest to the claimed invention, the method and device described in the patent of the Russian Federation No. 2275652 and related to remote sensing systems for the orientation of moving objects. The method is based on determining angles-bearings, coordinates of reference sources using two optical-location blocks, each of which contains a scanning mirror, a lens and a photodetector, and from the obtained values - determining the orientation of a moving object. Improving the accuracy of measuring the coordinates of radiation sources is achieved by taking into account changes in the distance between the optical-location blocks.

A device that implements this method is equipped with two optical location blocks connected to a block for determining angles of bearings of radiation sources connected to a block for determining coordinates of radiation sources and a block for determining the offset of reference points of angles of bearings, which are computing devices, an input unit, and data storage distance between the optical-location blocks and the adder.

The disadvantage of this device is the significant weight and cost due to the use of precision mechanical scanning, the presence of two optical location sides and reference sources with a known location on a moving object.

The objective of the invention is to expand the capabilities in determining the translational spatial movement of the helicopter on landing along the bearing angles of three identical points with an unknown location on the earth's surface (not available for the corresponding measurements), using one optical unit.

The technical result of the invention is achieved by the fact that in a method for determining the spatial movement of a helicopter in a landing based on determining angles of bearings of radiation sources using an optical unit and computing devices, angles of bearings of identical points are determined by software processing images of the earth's surface from two successive positions of the helicopter, for why they use the block of the receiver of images of the earth’s surface, calculate the matrix of guide cosines and the coefficients of the system of equations th, they solve a system of linear equations, whereby three components of the translational movement of the helicopter are determined, while the relative positions of identical points are unknown.

Software processing of the image of the earth's surface in order to find identical points can be carried out by the methods described in [1], for example, using contouring of the image and further selection of breakpoints in it. The use of a color image allows us to solve this problem with even simpler methods, for example, the selection of pixels (or groups of pixels) with a certain ratio of intensities of color components.

The method is implemented in a device for determining the translational movement of a helicopter, comprising an optical unit and computing devices, the optical unit being a block of a ground surface image receiver comprising a matrix photodetector located in the focal plane of the lens connected to a computer containing a ground surface image processing module, where software image processing is performed to determine the bearing angles of three identical points, the matrix calculation module s of directional cosines and coefficients of the system of equations where the mentioned coefficients are calculated based on the values of the angles measured by the inertial navigation system, a module for calculating the components of the translational movement of the helicopter, where the system of linear equations is solved and three components of the translational spatial movement of the helicopter are solved, while the image processing module the earth’s surface is connected by its input to the photomatrix, and the output - with the first input of the computational module Nia matrix of direction cosines and the coefficients of the system of equations, the second input of which is connected with an inertial navigation system, and an output connected to an input computing module translational movement components of the helicopter.

Figure 1 shows the layout of the two positions of the photomatrix in the process of determining the spatial movement of the helicopter and one of the three identical points P, figure 2 is a structural diagram of a device for determining the spatial movement of the aircraft.

The method is implemented as follows. The rectangular coordinate system OXYZ (Fig. 1) is associated with the first position of the helicopter, the photomatrix is located in the OYZ plane, and the optical axis of the lens coincides with the axis OX. The coordinate system O ₁ X ₁ Y ₁ Z ₁ is associated with the second position of the helicopter. An identical point on the earth's surface is located at point P. The center of the photomatrix is located at the origin of coordinates O (O ₁ is its second position). At the point F (F ₁ ) is the geometric center of the lens forming the optical image S (S ₁ ) of an identical point on the earth’s surface P.

Photoexposure of images of the earth's surface is performed on a photomatrix from two positions of the helicopter. The coordinates of the images of the identical point P on the photomatrix from these positions are determined. The position of the coordinate system O ₁ X ₁ Y ₁ Z ₁ relative to the OXYZ system is determined by the displacement vector of the coordinate origin r ₀ due to the movement of the helicopter, and the change in the angular position of the system O ₁ X ₁ Y ₁ Z ₁ is determined by the matrix of guiding cosines A.

In two ways they express the vector OP and equate the right parts of these expressions

The following vectors are expressed.

where M _x and M _x1 are the projections of the vectors M and M ₁ on the axis OX and O ₁ X ₁ ,

ijk and i ₁ j ₁ k ₁ are unit vectors in the coordinate systems OXYZ and O ₁ X ₁ Y ₁ Z ₁ ,

F = OF = O ₁ F ₁ is the focal length of the lens.

The first two relations follow from the similarity of the pairs of triangles OSF SPD and O ₁ S ₁ F ₁ , S ₁ PD ₁ .

Rewrite the last vector equality (1) taking into account the obtained expressions

The unit vectors i ₁ , j ₁ , k ₁ and i, j, k are interconnected by a known relation

where a _ij are the elements of the matrix of guiding cosines A.

where a, b, c are the angles of rotation of the helicopter along the axes OX, OY, OZ, respectively. Substituting the expressions for the unit vectors (3) into the vector relation (2) and projecting onto OX, OY, and OZ, we obtain

The values of M _x , M _x1 are intermediate, their definition is not necessary, therefore, the system of equations is simplified as follows. Express M _x from the first equation and substitute this expression in the second and third equations. In the process of simplifying equations (4), the following notation is also used:

An analysis of the obtained equation shows that it includes three unknown quantities β _x , β _y , β _z (x ₀₁ , y ₀₁ , z ₀₁ ) and three angular values a, b, c, measured by an inertial navigation system (ANN), which are uniquely determine the coefficients of the matrix of guide cosines. The determination of the three quantities β _x , β _y , β _z is the goal of the task. In addition to unknown quantities, the well-known constant F and the quantities α _y , α _z and α _y1 , α _z1 measured by photomatrixes also entered into equation (5).

Thus, for the solvability of the problem, it is necessary to compose at least three equations. To prevent the linear dependence of these equations and subsequent problems with their numerical solution, three points on the earth’s surface, not lying on one straight line, are used. For each of the three points write an equation similar to equation (5).

where i = 1 ... 3.

Simplify the resulting system of equations. To do this, enter the following notation:

The values of the coefficients В ⁱ _x , В ⁱ _y , В ⁱ _z (i = 1 ... 3) are calculated using relations (7), then the system of equations (6) takes the form:

The equations are solved for β _x , β _y , β _z using the following relations

The components of the translational movement of the aircraft are calculated by the formulas:

x ₀₁ = Fβ _x ; y ₀₁ = Fβ _y ; z ₀₁ = Fβ _z .

Thus, the solution to the problem of determining the movement of a helicopter relative to the ground is based on measuring the coordinates of images of three identical points of the earth’s surface that are not lying on one straight line, obtained from two points of the helicopter’s trajectory, and calculating its spatial movement based on these measurements.

A device for determining the spatial movement of the helicopter on landing (Fig. 2) contains a block for receiving images of the earth's surface 1, including a lens 3 and a photomatrix 4, a computer 2, which includes a module for analyzing images of the earth's surface 5, module 6 for calculating the matrix of guide cosines and system coefficients equations, module 7 calculating the components of the translational movement of the helicopter.

The device operates as follows.

The images of the earth's surface are projected by the lens 3 on the photomatrix 4. In the module 5 for processing the images of the earth's surface, the coordinates of the identical image points are determined, which enter the module 6 for calculating the matrix of guiding cosines and coefficients of the system of equations, which also receives signals from the ANN, where numerical values of the coefficients are generated system of equations, and then in the module 7 for calculating the components of the translational movement of the helicopter, the system of linear equations (8) is solved and calculated three components of the translational movement of the helicopter.

To increase the accuracy of determining the spatial movement of the helicopter, precision information sensors and a computer with the required bit depth are used.

Information sources

1. Technical vision of robots. Under the total. ed. Yu.G. Yakushenkova. - M.: Mechanical Engineering, 1990. - p.168.

2. Patent for invention GB No. 2002986 A, publ. 02/28/1979.

3. RF patent for the invention RU No. 2275652 C2, G01S 5/16, publ. 04/27/2006, bull. No. 12 (prototype).

Claims (2)

1. A method for determining the spatial movement of a helicopter in landing, including determining angles of bearings of radiation sources that are used to determine the orientation of a moving object, characterized in that the determination of angles of bearings of identical points is carried out using a single optical location unit, processing images of the earth’s surface, namely, the angles-bearings of images of its three identical points on photomatrixes are determined during photo exposure from two successive positions of the helicopter, computes the coefficients of the matrix of the direction cosines and systems of linear equations using the values of the rotation angles coming from the inertial navigation system (INS), solve the system of linear equations, and calculating the three components of the translational movement of the helicopter, the mutual arrangement of identical points is unknown. 2. A device for determining the spatial movement of the helicopter on landing, containing a photodetector and a computing device, characterized in that the photodetector device is a single lens with a photomatrix in its focal plane, which is part of the receiver unit for the earth’s surface image, and the computer contains a terrestrial image processing module surfaces, a module for calculating the matrix of guide cosines and coefficients of the system of equations, a module for calculating the components of the translational the helicopter, and the module for processing images of the earth’s surface, where the angles of bearings of three identical points of the earth’s surface, not lying on one straight line, are determined by software processing of the output, connected with the first input of the module for computing the matrix of guiding cosines and coefficients of the system of equations, and its the second input is connected to the ANN, where the coefficients of the matrix of guide cosines and a system of linear equations are calculated using the values of the rotation angles from the ANN, the calculation module components of the translational movement of the helicopter, where they solve a system of linear equations and calculate the components of the translational spatial movement of the helicopter between its two positions, the input is connected to the output of the module for calculating the matrix of guiding cosines and coefficients of the system of equations, in addition, the input of the computer is connected to the output of the photomatrix of the block of the receiver of images of the earth's surface .

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