RU2797820C1 - Artillery shell with remote explosion control system - Google Patents

Abstract

FIELD: measurements.

SUBSTANCE: remote measurements in military equipment. Artillery projectile with a remote detonation control system contains a body, an explosive, a fuse with a transducer, safety mechanism (14) and actuator (15) mechanism, an angular velocity sensor (7) and a detonation distance code receiver (9) installed in the projectile and connected to fuse remote control module. The angular velocity sensor (7) installed in the bottom part of the projectile contains an analyzer of the radiation polarization plane (18) coming from the laser to the photodetector (19). The output of the photodetector (19) is connected in series with the pulse shaper (20) and the pulse frequency multiplier (21). The output of the pulse frequency multiplier (21) is connected to the counting input of the microcontroller (22), which measures the pulse frequency and the initial velocity of the projectile by the number of pulses for a given period of time. The control output of the microcontroller (22) is connected to the input of the electric igniter circuit (13).

EFFECT: increased accuracy of remote initiation of detonation of small-caliber rotating artillery shells in range.

1 cl, 4 dwg

Description

FIELD OF TECHNOLOGY

The present invention relates to autonomous devices for determining the initial speed with controlled initiation of the detonation of rifled artillery shells.

BACKGROUND OF THE INVENTION

In artillery, programmable air-blast projectiles are widely used. The computer complex of the artillery system determines and enters into the projectile the specified distance of its detonation after the shot. Actual detonation time may differ from the specified one due to different properties of the charge and wear of the gun barrel. Measuring and entering into the projectile the value of its initial velocity significantly increases the effectiveness of the artillery system.

An analogue of this device is (patent RU No. 194159 for the invention application: 2019131329 IPC F42C (2006.01) published: 29.11. 2019. Bull. No. 34). In this device for remote detonation of an artillery projectile, a controlled initiation of the detonation of a fragmentation or high-explosive projectile in the air is carried out without its direct contact with the target being struck, with significant savings in ammunition. In a device for remote detonation of an artillery projectile in the form of a remote fuse with an element for actuating it at a given distance from the point of the shot, the diameter of the rear part of the fuse body exceeds the outer diameter of the head part of the projectile body with the formation of an annular surface with a laser sensor placed on it, which receives a signal for initiation of the explosion. Several control signal receivers are located on the annular surface of the fuse body. In FIG. 1 shows the head of an artillery projectile with a fuse and several photodetectors.

The fuse of an artillery projectile contains a body 1 of a conical shape, the diameter of its rear part (larger base of the cone) exceeds the smallest diameter of the head part of the projectile 2 with the formation of an annular surface 3, in which a hole is drilled and a signal photodetector 4 is installed to detonate the projectile, which receives a laser signal to detonate the projectile . The photodetector 4 is oriented in the direction opposite to the direction of the shot. The size of the hole and the installation depth of the photodetector 4 is determined empirically in order to maximally cut off "foreign" laser radiation signals.

To increase the reliability of signal reception on the annular surface 3, evenly installed photodetectors 4 can be mounted. There are no computer systems on board the projectile, only the signal receiver 4 (with or without an encoder) and the detonation initiator. These signal receivers 4 can be retrofitted to existing designs of fuses.

The device works as follows.

The device is used in relation to the target being hit, located behind some obstacle out of line of sight. Pre-calculate the optimal time to detonate the projectile by means of a tank ballistic computer (TBV). At the same time, the distance to the target is taken into account, corrections are made for the target speed, wind speed and direction, charge temperature, etc., as well as the nature of the target being hit (armored object, infantry, drone).

The device is used against a visible target at ranges up to 10 km. So, in relation to an armored object, undermining should be carried out at a distance of 3-5 Ohm, for infantry and a drone 20-500 m. The signal to detonate the projectile by means of laser radiation is given after the calculation of the TBV. The laser signal to initiate the detonator is supplied from a direct (directional) source placed on a tank or artillery piece.

The laser radiation signal can be either encrypted or conventional. The disadvantage of this device is that it is used in relation to the visible target being hit, and the signal to initiate the detonator is supplied from the source (laser), which does not always give the desired result.

Another analogue is (patent RU No. 2535313 for invention application: 2012137290/03 IPC F42C (2006.01) published: 10.03.2014. Bull. No. 7), in which a programmable projectile contains an energy storage device, an electronic unit, a fuse and a sensor for receiving signals and energy . Programming, as well as energy transfer, is carried out when the projectile passes through the gun barrel, muzzle brake, or similar element that acts as a waveguide. Actual detonation time may differ from the specified one due to different properties of the charge and wear of the gun barrel. Measuring and entering into the projectile the value of its initial velocity significantly increases the effectiveness of the artillery system. Another analogue is (patent RU No. 2406959 for invention application: 2009126134/02 IPC F41A (2006.01) published: 20.12. 2010. Bull. No. 35), it is proposed to use the barrel or muzzle brake as a waveguide to measure the muzzle velocity of a projectile. In this case, the effect of the Doppler change in the frequency of the received signal is used. The description of the patent also considers a device for measuring the speed of a projectile using a pair of inductors located behind the muzzle brake at a certain distance between them. In this case, the speed is determined by measuring the time interval for the projectile to pass the distance between the coils. Known systems with guided munitions, such as AHEAD, the distance between the coils is 10 cm. The small distance between the coils, the shape of their electromagnetic field, ambient temperature and propellant gases limit the accuracy of measuring projectile velocity.

The measured value of the exit velocity of the projectile from the gun barrel enters the computer system and determines the required delay time of the projectile detonation. This value must be entered into the projectile through the communication devices before the projectile is completely out of the barrel. A short period of time of the order of 10 ^-4 seconds to perform these procedures imposes stringent requirements on the communication channel and computing devices of the complex. At the same time, the accuracy of solving the problem is also limited. The disadvantage of the considered devices for measuring the initial velocity of projectiles is also the complication of the design of artillery pieces.

The next analogue is (patent RU No. 2703835 for the invention application: 2018135544 IPC F41F (2006.01) published: 10/22/2019. Bull. No. 30). In this analog, a projectile angular velocity meter is installed inside the projectile, which uses an inertial method for determining the initial velocity of a guided projectile of a rifled gun.

When fired from a rifled gun, the projectile, together with the projectile angular velocity meter, begins to rotate, and the meter flywheel, due to its inertial properties, tries to maintain its initial angular orientation. The speed of rotation of the projectile at the outlet of the gun barrel is determined by the time interval between a given number of voltage pulses on the inductor. The use of a ferrite core in the inductor ensures the measurement of signals over a wide frequency band. In this case, it becomes possible to tie the voltage pulses on the inductor to the time scale with high accuracy. It became possible to measure the speed of rotation of the projectile by the time interval between a given number of pulses on the inductor, associated with the number of revolutions of the projectile. A measurement procedure is provided with an error of no more than 0.1% over a time interval of less than 0.1 second.

The flight speed of the projectile is determined at the initial stage of its flight by the speed of its rotation, taking into account the rifling pitch at the muzzle section of the gun barrel. To enable placement of the device in projectiles of small and medium caliber, the diameter of the device must be sufficiently small.

The closest invention, the prototype, is artillery ammunition (patent RU No. 2310154 for invention application: 2006114810/02, IPC F42B (2006.01) published: 10.11.2007. Bull. No. 31).

The purpose of the prototype is to improve the accuracy of remote initiation of detonation of small-caliber rotating artillery shells in range.

This is achieved by the fact that in artillery ammunition with controlled initiation, including a body, filling, a fuse containing a converter, a safety and actuator, as well as a fuse remote control unit as part of a serial time code receiver with a decoder and a delay device. In the body of the projectile there is a sensor for the speed of rotation of a small-caliber projectile, made mainly in the form of a magnetometer connected to the Earth's magnetic field. The speed sensor is connected to the delay device through the counter of the specified number of pulses connected to the decoder of the receiving device. The delay device contains two clock-controlled switches connected to the decoder in the signal processing lines, closed through the counter by the firing time, one - through the divider, and the other - through two serial "AND" circuits, closed by the counter of the measured interval, both lines are connected by a register through a common a comparison circuit, wherein the small-caliber projectile rotation speed sensor is connected to the first of the serially connected "AND" circuits of the delay device. Using a direct relationship between the angular and linear velocities of a rotating product in the initial flight segment, the initial velocity of each projectile is determined, according to which it is adequate to adjust the fuse initiation distance (time) in automatic mode. The speed of rotation of the projectile around its longitudinal axis is measured by counting the number of revolutions per unit time, using the Earth's magnetic field. When the ammunition rotates around its axis and the lines of force of the Earth's magnetic field intersect, an EMF variable in magnitude and polarity arises in the form of a periodic pulse signal that unambiguously characterizes the linear velocity received by the projectile when fired. Depending on the actual muzzle velocity compared to the set baseline, the delay circuit generates an appropriate delay in the initiation of the projectile detonation, with a smaller error in range and, therefore, with a smaller distance from the target, which significantly increases the effectiveness of the damaging effect of the projectile. At the same time, the ammunition load required to complete a combat mission is significantly reduced.

The essence of the prototype is illustrated by drawings, which show:

in fig. 2 - general view of the projectile in section;

in fig. 3 - functional diagram of the control of the initiation of undermining.

The high-explosive fragmentation body 2 (Fig. 2) of a small-caliber artillery projectile contains an explosive filling 5, a remote control unit 6 and a sensor 7 for the speed of rotation of the projectile around the longitudinal axis. In the bottom part of the housing 2, an optical window 8 is made through which the laser radiation located in the artillery system enters the time code receiver 9, consisting of a photodetector 10 and a decoder 11 connected in series. The remote control unit 12 is connected to the electric igniter 13 (Fig. 3) , which is equipped with a standard safety mechanism 14 and an actuator 15. The projectile rotation speed sensor 7 is connected to the remote control unit 12 through the pulse register 16 and the pulse counter 17.

The described device operates as follows.

After the shot, after a delay time, an external transmitter connected to the gun emits a laser code burst in the direction of the projectile in the form of two pairs of pulses. The interval between two pairs of pulses is proportional to the delay time of the projectile detonation, and the time interval between pulses in pairs is determined by the maximum possible initial velocity of the projectile of this type and at the same time serves as an identification feature to exclude the reception of random interference signals as control signals.

Upon receipt of the receiver 10 through the optical window 8 of the housing 2 two pairs of coded control pulses in the decoder counts the time interval between these pairs of pulses. The remote control unit 12 generates a signal that is fed to the electric igniter 13. The trigger signal of the electric igniter 13 through the standard safety device 14 causes the beam detonator 15 to trigger the detonation of the explosive filling 5 and detonate the projectile at a given point in the flight path. When calculating the root-mean-square error in determining the initial velocity of the projectile ±0.15%, the deviation of the initial velocity of a small-caliber projectile at the level of 3σ will be ±4.5 m/s. Automatic control of the time (distance) of the detonation significantly reduces the error in range, so the air detonation of these small-caliber projectiles at the 3σ level is characterized by errors:

- at a distance of 1 km ± 7.8 m;

- at a distance of 2 km ± 13.4 m.

When the magnetometer 7 rotates as part of the projectile on the flight path with speeds inherent in small-caliber projectiles (100 thousand revolutions per minute), an EMF of 10 mV appears in the Earth's magnetic field.

As a magnetometer 7, magnetoresistive sensors of the KMZ51 or HMS1001 type are used, made in an integrated design. They are sensitive to the magnitude and direction of the magnetic field vector. The disadvantage of this device for measuring the speed of rotation of the projectile is the measurement error that occurs during the precessional and nutation movements of the projectile.

Thus, there is a need in the field of technology for a more accurate small-sized device placed in the projectile and measuring its initial velocity.

The technical objective of the invention is to improve the accuracy of remote initiation of detonation of small-caliber rotating artillery shells in range.

The claimed technical result is achieved due to the fact that, in a known device containing a housing, an explosive, a fuse with a converter, safety and actuators, an angular velocity sensor and a detonation distance code receiver installed in the projectile and connected to the fuse remote control module, according to the invention the angular velocity sensor is installed at the bottom of the projectile and contains an analyzer of the plane of polarization of the radiation coming from the laser to the photodetector, the output of the photodetector is connected in series with the pulse shaper and the pulse frequency multiplier, while the output of the pulse frequency multiplier is connected to the counting input of the microcontroller, which determines by the number of pulses for a given time interval, pulse frequency and initial velocity of the projectile, while the control output of the microcontroller is connected to the input of the electric igniter circuit. New features that have significant differences in the proposed device is the following set of elements and relationships between them:

1. The bottom part of the projectile contains an analyzer of the plane of polarization of the radiation coming from the laser;

2. The radiation passing through the rotating polarization plane analyzer hits the photodetector. The circular frequency of the variable component of the signal from the photodetector is twice the angular velocity of the projectile;

3. The output of the photodetector is connected through the pulse shaper to the input of the pulse frequency multiplier, which makes it possible to increase the pulse frequency by N times;

4. The output of the pulse frequency multiplier is connected to the counting input of the microcontroller, which determines the signal frequency by the number of pulses for a fixed period of time. In this case, the relative frequency measurement error for the set counting time decreases by N times.

5. At the initial velocity of the projectile V ₀ =1000 m/s, the measurement error of the initial velocity will be: ΔV ₀ =0.255 m/s, and the systematic error of the air explosion at a distance L=1000 m will be 0.255 m.

The claimed device is the result of scientific research and experimental work.

An artillery projectile with controlled detonation initiation (Fig. 4) contains: an analyzer of the plane of polarization of radiation 18, a photodetector 19, a pulse shaper 20. The output of the pulse shaper 20 is connected to a pulse frequency multiplier 21, and its output is connected to the counting input of the microcontroller 22, which determines by the number pulses for a given period of time, the frequency of pulses and the initial velocity of the projectile. The detonation distance code receiver includes a photodetector 19, the output of which is connected through a pulse shaper 20 to the microcontroller input 22 decoding the detonation distance. The electric igniter input 13 is equipped with a regular safety mechanism 14 and an actuator 15. The device for controlled initiation of an artillery projectile detonation operates as follows. A laser mounted on an artillery piece emits plane polarized radiation in the direction of the projectile. The laser radiation, having passed the polarization plane analyzer 18, falls on the photodetector 19. When the projectile 2 rotates with an angular velocity Q, the polarization plane analyzer 18 of the plane polarized laser radiation incident on the projectile rotates with it. The intensity of the radiation passed through the analyzer 18 and incident on the photodetector 19, in accordance with the Malus law, corresponds to the formula:

where I ₀ is the intensity of the radiation falling on the polarizer of the polarization plane; ϕ is the angle between the planes of polarization of the plane polarized radiation of the laser and the analyzer.

Since the projectile 2 rotates with an angular velocity Ω, the angle between the plane of polarization of the laser radiation and the analyzer 18 will change according to the law:

Substituting (2) into (1), we get:

As follows from formula (3), the intensity of the radiation reflected from the projectile 2 contains constant and variable components. The variable component of the signal changes with twice the frequency with respect to the angular velocity of the projectile ƒ _np =2Ω/2π=Ω/π.

The linear velocity of the projectile V ₀ is related to the angular velocity of its rotation Ω, the angle of inclination of the barrel rifling α on the muzzle section of the gun barrel, and the barrel caliber d, and is determined by the formula:

So, for example, at projectile speed V ₀ =1000 m/s, barrel caliber d=20 mm., angle of rifling at the muzzle section of the gun barrel α=7°, the angular velocity of the projectile will be:

Ω=12278.5 rad/s, or 1955 rpm=117310 rpm. In this case, ƒ _np =3910 Hz., and after the frequency multiplier 21, the frequency will be ƒ _uch =N*ƒ _np =N*3910 Hz., where N is the multiplication factor of the multiplier.

The relative frequency measurement error is [1]:

where T _cf is the counting time.

As follows from relation (5), the relative frequency measurement error is the smaller the greater the pulse frequency and counting time. The counting frequency is increased due to the frequency multiplier. The counting time is limited by the time spent by the projectile at the stage of intermediate ballistics and is taken equal to T _cf =0.1 seconds.

The microcontroller 22, for a certain period of time, counts the number of pulses coming from the pulse frequency multiplier 21, determines the pulse frequency ƒ _f and calculates the initial velocity of the projectile according to the formula (4).

The initial velocity of the projectile is entered into the system for calculating the time of detonation of the projectile after the shot, taking into account the entered detonation distance. At the frequency of counting pulses ƒ _pr =3910 Hz., counting time T _cf =0.1 sec. and N=10, the relative frequency measurement error is [1]:

This will ensure the measurement of the frequency with an absolute error of Δƒ=3910*0.000256=1 Hz., and the initial speed:

In this case, the systematic error of an air explosion at a distance of L = 1000 m will be:

ΔL=ΔV*t=0.255* 1000/1000=0.25 5 m.,

and at a distance of L=2000 m ΔL=0.51 m. Here it is assumed that the distance of detonation L is set exactly.

Thus, the use of the proposed invention makes it possible to increase the accuracy of remote detonation of an artillery projectile, significantly simplify, reduce weight and increase the reliability of the measuring system, as well as improve its energy characteristics. The total volume of the analyzer, together with the microcontroller, placed in the projectile is less than 1 ^cm3 , and the weight is not more than ten grams.

Claims (1)

An artillery projectile with a remote detonation control system, containing a body, an explosive, a fuse with a converter, safety and actuator mechanisms, an angular velocity sensor and a detonation distance code receiver installed in the projectile and connected to a fuse remote control module, characterized in that the angular velocity sensor speed, installed at the bottom of the projectile, contains an analyzer of the polarization plane of the radiation coming from the laser to the photodetector, the output of the photodetector is connected in series with the pulse shaper and the pulse frequency multiplier, while the output of the pulse frequency multiplier is connected to the counting input of the microcontroller, which determines by the number of pulses for a given a period of time, the pulse frequency and the initial velocity of the projectile, and the control output of the microcontroller is connected to the input of the electric igniter circuit.

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