RU2282127C2 - Method for guidance of guided missile and guidance system for its realization - Google Patents

Abstract

FIELD: development of missile control systems, applicable in antitank missile complexes.

SUBSTANCE: the method for guidance of a guided missile includes the launch of the guided missile, reception and focusing on the photodetector of the luminous flux of the background-target situation containing the luminous flux of the background and the luminous flux of the useful signal source, discrimination of the co-ordinates of the useful signal source, the co-ordinates of the guided missile are determined and the control commands for transmission to the missile are formed. Before the launch of the guided missile the useful signal margin K_MIN factor is assigned, after focusing of the luminous flux of the background-target situation the video frame of the image of the background-target situation is formed, the output signal is taken off each cell of the matrix type photodetector, the signal corresponding to the mean value of all the output signals from the photodetector cells is determined, the root mean square deviation of output signals from the photodetector cells is determined, threshold value U_thr of the useful signal is determined from the mathematical expression, and the co-ordinates of the image that is formed at the cells with the level of the output signal satisfying the condition U_out ≥ U_thr are discriminated. The guidance system has also an objective lens, radiation photodetector, series-connected co-ordinates discrimination unit, command formation unit, in addition it has series-connected useful signal margin factors unit, analyzing device and a selection unit. The output of the objective lens is connected to the input of the radiation photodetector, whose first output is connected to the second input of the selection unit, whose output is connected to the input of the co-ordinates discrimination unit. The second output of the radiation photodetector is connected to the second input of the analyzing device, the radiation photodetector is based on a matrix-type photodetector.

EFFECT: enhanced quality of missile guidance without any change of the missile construction, enhanced reliability and accuracy of discrimination of the useful signal source at various background-target situations during the whole flight time of the guided missile and improved interference protection of the whole control system without its essential complication.

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Description

The proposed guided missile guidance method and guidance system for its implementation relate to the development of missile control systems and can be used in anti-tank missile systems (ATGMs).

Closest to the proposed is a method of pointing an anti-tank missile, implemented in ATGM 9K111 "Bassoon" and taken as a prototype [1. Launcher 9P135. Technical description. Order of the Red Banner of Labor Military Publishing House of the Ministry of Defense of the USSR, Moscow, 1975, pp. 11-13], including the launch of an anti-tank missile with an onboard radiation source, passage of the light flux from the radiation source through the lens and optical raster, modulation of the light flux with optical raster, receiving a modulated light flux from a radiation source by a photodetector with a continuous photosensitive surface, identifying the coordinates of the onboard radiation source, determining the coordinates of the anti-tank acts and formation of anti-tank missile command teams.

Closest to the proposed is an anti-tank missile guidance system that implements the known method of anti-tank missile guidance and used in the 9K111 Fagot portable ATGM [1. Launcher 9P135. Technical description. Order of the Red Banner of Labor Military Publishing House of the Ministry of Defense of the USSR, Moscow, - 1975, p.11-13]. This guidance system contains a series-connected lens that receives a signal from an onboard radiation source, an optical raster, a radiation photodetector, a photocurrent amplifier, a coordinate extraction unit and a command generation unit, as well as a reference voltage generator connected between the optical raster and the coordinate allocation unit.

A functional diagram of an anti-tank missile guidance system that implements the known method of anti-tank missile guidance is shown in FIG.

The guidance system of an anti-tank missile works as follows. The input for it is the angular deviation of the onboard radiation source of the anti-tank missile from the line of sight. The lens (1) focuses the radiation of the phono-target environment (FCO) with the on-board radiation source on the optical raster (2), which has transparent and opaque sectors located radially and performs plane-parallel movement (scanning), which provides frequency modulation and spatial selection of the light flux onboard radiation source. The frequency-modulated luminous flux is perceived by the photodetector of radiation (3) and converted into the corresponding electrical signals. The frequency-modulated signal from the photodetector enters the photocurrent amplifier (4), where it is amplified to the required value. The output signal from the photocurrent amplifier contains information on the angular deviations of the radiation source of the rocket from the aiming line, which enters the coordinate allocation unit (5). After converting the signal of the photocurrent amplifier, the coordinate extraction unit generates voltages corresponding to linear deviations of the rocket from the aiming line. The signals from the reference voltage generator (7) are used as reference voltages during phase detection. Stresses proportional to the deviation of the missile from the aiming line along the course and pitch, from the output of the coordinate allocation unit are sent to the command generation unit (6), where they are converted into control signals intended for transmission via PLC to the missile.

Modern conditions for the development of anti-tank systems have set the task of overcoming a number of fundamental technical difficulties inherent in this method of guiding an anti-tank missile and guidance system for its implementation. First of all, this refers to the impossibility of ensuring a constant signal-to-noise ratio throughout the flight in the guidance system. This is due to the fact that the photodetector, when exposed to high temperature, generates a large number of noise electrons, the number of which remains constant over the entire flight time of the rocket, while the light flux from the onboard radiation source incident on the entrance pupil of the OS decreases inversely with the square of the distance to the rocket . Due to a decrease in the signal-to-noise ratio, the accuracy of rocket coordinates allocation is significantly reduced, while noise immunity is worsened and the sensitivity of the entire control system is reduced.

The objective of the invention is to develop such a guidance method for guided missiles and guidance systems for its implementation, which would improve the quality of guidance of the missile without changing the design of the missile itself, to increase the reliability and accuracy of the selection of the source of the useful signal in various phono-target environments throughout the flight time of the guided missile and good noise immunity of the entire control system without its significant complication.

The problem is solved in that in the guided missile guidance method, including guided missile launch, receiving and focusing on a photodetector a luminous flux of a phono-target environment containing a background luminous flux and a luminous flux of a useful signal source, identifying coordinates of a useful signal source, determining coordinates of a guided missile and forming control commands for transmission to the missile, guided missile launch to designate the safety factor for the desired signal K _MIN, after focusing a light stream target environment form the video frame image target environment, with each cell of the photodetector matrix type removed output signal U _OUT determine the signal corresponding to the mean value of all the output signals from the photodetector cells U _p, determine the standard deviation of the output signals of the photodetector σ _F cells, determine the desired signal threshold U _POR = U _Ф + К _MIN · σ _Ф , and the coordinates of the image that is formed on the cells with the output signal level satisfying the condition : U _OUT ≥U _ERP.

The problem is also solved by the fact that the guided missile guidance system containing a lens, a radiation photodetector, serially connected coordinate allocation unit and command generation unit, additionally introduced a series of coefficients, an analyzing device and a selection unit, the lens output being connected to the input of the radiation photodetector the first output of which is connected to the second input of the selection block, the output of which is connected to the input of the coordinate allocation block, and the second output is a photodetector ika radiation is connected to a second input of the analyzing device, the emission light detector is based on the photoreceiver matrix type.

Improving the reliability and accuracy of the selection of the source of the useful signal under various phono-target situations throughout the flight time of the guided missile is provided by calculating the threshold level of the useful signal for the current frame, which reflects the real phono-target situation.

A functional diagram of a guided missile guidance system that implements the proposed guided missile guidance method is shown in FIG. 2.

Guided missile guidance system operates as follows. The luminous flux of the PTF with an onboard radiation source, the lens of the optical system (1) focuses directly on the photodetector of matrix-type radiation (3), on the sensitive cells of which an image of the PTF is formed. The analyzing device (8) determines the signal corresponding to the average value of all signals from the cells of the photodetector U _Ф , on which the FCO images were formed, as well as the standard deviation (RMS) of the output signals of the cells of the photodetector σ _Ф. Based on the data embedded in the block of coefficients (10), the threshold value of the useful signal U _POR = U _Ф + К _MIN · σ _{Ф is} calculated. After that, the threshold value of the useful signal is transmitted to the selection block (9), which searches from the entire matrix space of cells whose output signal level exceeds U _POR , which will correspond to the image of the useful signal source. At the next stage, the coordinate allocation unit (5) converts data only from cells selected from the entire matrix space that carry information about the angular deviations of the onboard radiation source of the guided missile from the aiming line. Stresses proportional to deviations of the rocket from the aiming line along the course and pitch from the output of the coordinate allocation unit are sent to the command generation unit (6), where they are converted into control signals designed to change the spatial position of the guided missile.

In the proposed guided missile guidance system, the optical system, the coordinate allocation unit and the command generation unit can be performed as in the prototype. The radiation photodetector can be made on the basis of a high-frequency CCD matrix [2]. The analyzing device, the coefficient block, and the selection block can be performed on the basis of signal microprocessors [3] and programmable logic integrated circuits [4].

The proposed guided missile guidance method and guidance system for its implementation in comparison with prototypes allow to achieve:

 - a constantly high level of signal-to-noise ratio throughout the flight range of a guided missile;

- ensuring high accuracy of missile guidance without significant complication of control equipment;

- increase the noise immunity of the control system as a whole.

Justify the operation of the guided missile guidance system as follows. The calculation of the threshold value of the useful signal U _{POR is} carried out according to:

where U _f - the magnitude of the signal corresponding to the average value of all output signals from the cells of the photodetector;

K _MIN - safety factor for the useful signal;

σ _F - standard deviation of the output signals of the cells of the photodetector.

The safety factor for the useful signal K _{MIN is} selected empirically depending on the conditions of the combat use of the anti-tank systems taking into account the flight range of the guided missile.

, определяется по зависимости:The signal value corresponding to the average value of all signals from the cells of the photodetector

is determined by the dependence:

where N _Y , N _Z - the number of sensitive cells of the photodetector vertically and horizontally, respectively;

- выходной сигнал с ячейки i-го столбца j-строки.

- the output signal from the cell of the i-th column of the j-row.

The standard deviation of the output signals of the cells of the photo receiver σ _f is determined by the dependence:

An analysis of dependencies (1) - (3) shows that the threshold value of the useful signal U _POR is determined by the actual current phono-target environment, allows you to select the source of the useful signal at different levels of the luminous flux of the phono-target environment and internal noise of the photodetector and, therefore, increase the reliability and accuracy of extraction source of a useful signal in various phono-target environments.

Information sources

1. Launcher 9P135. Technical description. Order of the Red Banner of Labor Military Publishing House of the USSR Ministry of Defense, Moscow, - 1975, pp. 11-13 - prototype.

2. V.Ya. Stenin. The use of charge-coupled microcircuits. "Radio and communications", Moscow, 1989.

3. User Guide for signal microprocessors ADSP-2100 / Per. from English O.V. Luneva; Ed. A.D. Viktorov; St. Petersburg State Electrotechnical University. - St. Petersburg, 1997 .-- 520 p.

4. V. B. Steshenko. FPGA company "ALTERA": Design of signal processing devices. / -M.: "Dodeka", 2000

Claims (2)

1. A guided missile guidance method, including launching a guided missile, receiving and focusing on a photodetector a luminous flux of a phono-target environment containing a luminous flux of a background and a luminous flux of a useful signal source, extracting coordinates of a useful signal source, determining coordinates of a guided missile and generating control commands for transmission to a missile, characterized in that the guided missile launch to designate the safety factor for the desired signal K _MIN, after focusing the light flux background target obs anovki form a video frame image target environment, with each cell of the photodetector matrix type removed output signal U _OUT determine the signal corresponding to the mean value of all the output signals from the photodetector cells U _F, determine the standard deviation of the cell output signals of the photodetector σ _F define the useful signal threshold U _POR = U _F + K _MIN · σ _F and secrete the coordinates of the image that is formed on the cells to the output level satisfying the condition: U _OUT ≥U _POR. 2. Guided missile guidance system comprising a lens, a radiation photodetector, a serially connected coordinate allocation unit and a command generation unit, characterized in that an additional useful signal safety factor block, an analyzing device and a selection unit are additionally introduced into it, the lens output being connected with the input of the radiation photodetector, the first output of which is connected to the second input of the selection block, the output of which is connected to the input of the coordinate allocation unit, and the second output radiation photodetector is connected to the second input of the analyzing device, the emission light detector is based on the photoreceiver matrix type.

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