EP0802392A1 - Method and device for the disintegrating time setting of a programmable projectile - Google Patents

Abstract

The disaggregation time determination involves performing a calculation based on an impact distance, RT, to a target determined from sensor data, a projectile velocity, Vm, at a muzzle and a given disaggregation distance, Dz. The disaggregation distance is kept constant by a correction of a disaggregation time using the equation: Tz(Vm) = Tz + K*(Vm-Vov) Tz(Vm) is the corrected disaggregation time. K is a correction factor. Vov is a lead velocity of a projectile. The correction factor is calculated based upon flying time of the projectile, air resistance and a value relating to a position of the gun barrel.

Description

The invention relates to a method and a device for calculating the disassembly time of a programmable projectile, wherein the calculation includes at least one target distance to a target object determined from sensor data, a projectile speed measured at the muzzle of a gun barrel and a predetermined optimal disassembly distance between a meeting point and a disassembly point of the projectile is the basis.

With the European patent application 0 300 255 a device has become known which has a measuring device for the projectile velocity arranged at the mouth of a gun barrel. The measuring device consists of two ring coils arranged at a certain distance from one another. When a projectile passes through the two toroidal coils, the change occurs of the magnetic flux generates a pulse in short succession in each ring coil. The pulses are fed to evaluation electronics, in which the projectile speed is calculated from the time interval between the pulses and the distance between the ring coils. In the direction of movement of the projectile, a transmitting coil is arranged behind the measuring device for the speed, which co-operates with a receiving coil provided in the projectile. The receiving coil is connected to a counter via a high-pass filter, which is connected on the output side to a timer. A disassembly time is formed from the calculated bullet speed and a hit distance to a target object determined from sensor data, which is inductively transmitted to the bullet immediately after the measuring device has flown through. With this disassembly time, the time fuse is set so that the projectile can be disassembled in the area of the target object.

If projectiles with sub-projectiles are used (ammunition with primary and secondary ballistics), an attacking target can be destroyed by multiple hits, as is known, for example, from a publication OC 2052 d 94 from the company Oerlikon-Contraves, Zurich, if, after the sub-projectiles have been ejected, Time of disassembly the expected area of the target is occupied by a cloud formed by the subprojectiles. When dismantling such a projectile, the part carrying the sub-projectiles is separated and torn open at predetermined breaking points. The ejected sub-projectiles describe a swirl-stabilized trajectory caused by the rotation of the projectile and lie evenly distributed on approximately semicircular curves of circular areas of a cone, so that a good chance of hitting can be achieved.

In the device described above, scattering in the disassembly distance, which is caused, for example, by scattering in the bullet speed and / or the use of non-updated values, cannot always achieve a good probability of being hit or fired. With larger disassembly distances, the circular area would be larger, but the density of the subprojectiles would be smaller. The reverse occurs with smaller disassembly distances: the density of the subprojectiles would be greater, but the circular area would be smaller.

The invention is based on the object of a method and an apparatus To propose a generic term by means of which an optimal hit or kill probability can be achieved while avoiding the disadvantages mentioned above.

This object is achieved by the invention specified in claims 1 and 10. Here, a given optimal disassembly distance between a disassembly point of the projectile and a meeting point of the target is kept constant by correcting the disassembly time of the projectile. The correction is made by adding a correction factor multiplied by a speed difference to the disassembly time. The projectile speed difference is formed from the difference between the current measured projectile speed and a lead speed of the projectile, the lead speed being calculated from the mean of a number of previous, successive projectile speeds.

The advantages achieved with the invention can be seen in the fact that a given disassembly distance is independent of the current measured bullet speed, so that a permanent optimal hit or shot probability can be achieved. The proposed correction factor for the correction of the dismantling time is based only on the shooting elements of the meeting point for the control of the weapon, namely the gun angles α, λ, the time Tf and the lead speed V0v of the projectile. This enables simple integration into existing weapon control systems, which requires minimal effort.

Fig.1

eine schematische Darstellung eines Waffensteuerungs-Systems mit der er findungsgemässen Vorrichtung,

Fig.2

einen Längsschnitt durch eine Mess- und Programmiervorrichtung,

Fig.3

ein Diagramm der Verteilung von Subprojektilen in Abhängigkeit von der Zerlegungsdistanz, und

Fig.4

eine andere Darstellung des Waffensteuerungs-Systems gemäss Fig.1.

The invention is explained in more detail below using an exemplary embodiment in conjunction with the drawing. Show it.

Fig. 1

1 shows a schematic illustration of a weapon control system with the device according to the invention,

Fig. 2

a longitudinal section through a measuring and programming device,

Fig. 3

a diagram of the distribution of subprojectiles as a function of the disassembly distance, and

Fig. 4

another representation of the weapon control system according to Fig.1 .

In Figure 1, 1 denotes a fire control and 2 a gun. The fire control system 1 consists of a search sensor 3 for the detection of a target 4 , a follow-up sensor 5 connected to the search radar 3 for target detection, 3-D target tracking and 3-D target measurement, and a fire control computer 6 . The fire control computer 6 has at least one main filter 7 and a lead computing unit 9 . The main filter 7 is connected on the input side to the follow sensor 5 and on the output side to the lead computing unit 9 , the main filter 7 receiving the 3-D target data received from the follow radar 5 in the form of estimated target data Z such as position, speed, acceleration, etc. Computing unit 9 forwards. Meteorological data can be supplied to the lead computing unit 9 via a further input Me. The meaning of the designations on the individual connections or connections is explained in more detail below on the basis of the functional description.

A computer of the gun 2 has an evaluation circuit 10 , an update computing unit 11 and a correction computing unit 12 . The evaluation circuit 10 is connected on the input side to a measuring device 14 for the projectile velocity, which is arranged at the mouth of a gun barrel 13 and is described in more detail below with reference to FIG . 2 , and is connected on the output side to the lead computing unit 9 and the update computing unit 11 . The update computing unit 11 is connected on the input side to the reserve and correction computing unit 9, 12 and is connected on the output side to a programming part integrated in the measuring device 14 . The correction computing unit 12 is connected on the input side to the lead computing unit 9 and on the output side to the updating computing unit 11 . A gun servo 15 and a triggering device 16 responding to a fire command are also connected to the lead computing unit 9 . The connections between the fire control 1 and the gun 2 are combined to form a data transmission, which is designated by 17 . The meaning of the designations on the individual connections between the computing units 10 , 11 , 12 and between the fire control system 1 and the gun 2 is explained in more detail below on the basis of the functional description. 18 and 18 ' designate a floor which is shown during a programming phase ( 18 ) and at the time of disassembly ( 18' ). The projectile 18 is a programmable projectile with primary and secondary ballistics, which is equipped with an ejection charge and a time fuse and is filled with sub-projectiles 19 .

According to FIG. 2 , a support tube 20 attached to the muzzle of the gun barrel 13 consists of three parts 21 , 22 , 23 . Between the first part 21 and the second or third part 22 , 23 , ring coils 24 , 25 are arranged for measuring the projectile speed. On the third part 23 — also called the programming part — a transmission coil 27 held in a coil body 26 is fastened. The type of attachment of the support tube 20 and the three parts 21 , 22 , 23 to each other is not shown and described. Lines 28 , 29 are provided for supplying the ring coils. Soft iron bars 30 are arranged on the circumference of the support tube 20 for the purpose of shielding against magnetic fields which interfere with the measurement. The projectile 18 has a receiving coil 31 which is connected to a timer 34 via a filter 32 and a counter 33 . When the projectile 18 passes through the two ring coils 24 , 25 , a pulse is generated in short succession in each ring coil. These pulses are fed to the evaluation circuit 10 ( FIG. 1 ), in which the projectile speed is calculated from the time interval between the pulses and a distance a between the ring coils 24 , 25 . Taking the projectile speed into account, a disassembly time is calculated, as described in more detail below, which is transmitted inductively to the receiver coil 31 in digital form when the projectile 18 passes through the transmitter coil 27 for the purpose of setting the counter 32 .

In Figure 3 , Pz denotes a point of disassembly of the projectile 18 . The ejected subprojectiles are, depending on the distance from the point of decomposition Pz, evenly distributed on approximately semicircular curves of (in perspective) circular areas F1, F2, F3, F4 of a cone C. On a first abscissa I, the distance from the point of decomposition Pz is plotted in meters m, while on a second abscissa II, the area sizes of the areas F1, F2, F3, F4 are plotted in square meters m ² and their diameter in meters m. In the case of a characteristic projectile with, for example, 152 subprojectiles and an apex angle of the cone C of initially 10 °, the values plotted on the abscissa II are obtained as a function of the distance. The density of the subprojectiles on the circular areas F1, F2, F3, F4 decreases with increasing distance and is 64, 16, 7 and 4 subprojectiles per square meter with the selected ratios. Given a given disassembly distance Dz, which is based on the calculation of the disassembly time described below, for example 20 m, a target area of 3.5 m diameter would be occupied with 16 subprojectiles per square meter in the assumed example.

In FIG. 4 , 4 and 4 ' denote the target to be defended, which is shown in a hit or shoot position ( 4 ) and in a position ( 4' ) preceding the hit or shoot position.

The device described above works as follows:

The lead computation unit 9 calculates a target distance RT from a lead speed VOv and the target data Z, taking meteorological data into account for storeys with primary and secondary ballistics.

worin Vg(Tf) durch ballistische Approximation bestimmt ist und Tz die Flugzeit des Geschosses bis zum Zerlegungszeitpunkt Pz, sowie ts die Flugzeit eines in der Geschossrichtung fliegenden Subprojektiles vom Zerlegungspunkt Pz bis zum Treffpunkt Pf bedeuten (Fig. 3,4)The lead speed VOv is formed, for example, from the mean value of a number of measured projectile speeds Vm supplied via the data transmission 17 , which immediately precede the current measured projectile speed Vm. On the basis of a predetermined disassembly distance Dz and taking into account the projectile velocity Vg (Tf) which is dependent on a hit time Tf, a disassembly time Tz of the projectile can be determined according to the following relationships: $$\text{Dz = Vg (Tf) ∗ ts and Tz = Tf - ts}$$

where Vg (Tf) is determined by ballistic approximation and Tz is the flight time of the projectile to the disassembly time Pz, and ts is the flight time of a subprojectile flying in the projectile direction from the disassembly point Pz to the meeting point Pf ( Fig. 3,4 )

übermittelt (Fig.1, Fig.4).The lead computing unit 9 also determines a gun angle α of the azimuth and a gun angle λ of the elevation. The quantities α, λ, Tz or Tf and VOv are referred to as shooting elements of the meeting point and are fed to the correction computing unit 12 via the data transmission 17 . The shooting elements α and λ are also fed to the gun servo 15 and the shooting elements VOv and Tz are also fed to the update computing unit 11 . If only primary ballistics is used, the hit time will be used instead of the decomposition time Tz $\text{Tf = Tz + ts}$

transmitted ( Fig.1, Fig.4 ).

The calculations described above are carried out repeatedly in cycles, so that in the current cycle i the latest data α, λ, Tz or Tf and VOv are available for a specific period of validity.

Between the clock values, the current (running) time (t) is interpolated or extrapolated.

The correction arithmetic unit 12 calculates a correction factor K according to the equation at the beginning of each cycle i using the latest set of shooting elements α, λ, Tz or Tf and VOv $$\text{K =}\frac{\hfill {\text{- (1 + δTG / δto) * TG * (1 + 0.25 * q * (VOv * Vn)}}^{\text{1/2}}\text{* TG)}}{\hfill {\text{(1+ (TG * (1 + 0.5 * q * (VOv * Vn)}}^{\text{1/2}}{\text{* TG) * ω}}^{\text{2nd}}\text{)) * VOv}}$$

errechnet wird, wobei i der aktuelle Takt, i-1 der vorhergehende Takt und to die Dauer eines Taktes ist, und wobei die Flugzeit TG eines Geschosses gleich der Treffzeit Tf ist. ω² ist eine die Stellung des Geschützrohres 13 betreffende Grösse, die sich nach der Beziehung $${\text{ω}}^{\text{2}}{\text{= (rate}}_{\text{α}}{\text{∗ cos λ)}}^{\text{2}}{\text{+ (rate}}_{\text{λ}}{\text{)}}^{\text{2}}$$

berechnet, wobei $$\begin{array}{c}\begin{array}{c}{\text{rate}}_{\text{α}}{\text{= (α}}_{\text{i}}{\text{- α}}_{\text{i-1}}\text{)/to und}\\ {\text{rate}}_{\text{λ}}{\text{= (λ}}_{\text{i}}{\text{- λ}}_{\text{i-1}}\text{)/to}\end{array}\end{array}$$

die Geschützrohr-Winkelgeschwindigkeiten in Richtung α bzw. in Richtung λ bedeuten.

Vn

ist eine Normgeschwindigkeit der Ballistik.

q

ist eine den Luftwiderstand des Geschosses berücksichtigende Grösse, die sich nach der Beziehung $$\text{q = (CWn ∗ γ ∗ Gq) / (2 ∗ Gm),}$$

errechnet, wobei die Bedeutung der einzelnen einzusetzenden Werte im Patentanspruch 9 aufgeführt ist.Herein δTG / δto is the derivative of the flight time TG of the projectile after the time, according to the equation $${\text{δTG / δto = (TG}}_{\text{i}}{\text{- TG}}_{\text{i-1}}\text{) / to}$$

is calculated, where i is the current measure, i-1 the previous measure and to the duration of a measure, and wherein the flight time TG of a projectile is equal to the time Tf. ω ² is a quantity relating to the position of the gun barrel 13 , which depends on the relationship $${\text{ω}}^{\text{2nd}}{\text{= (rate}}_{\text{α}}{\text{∗ cos λ)}}^{\text{2nd}}{\text{+ (rate}}_{\text{λ}}{\text{)}}^{\text{2nd}}$$

calculated where $$\begin{array}{c}\begin{array}{c}{\text{rate}}_{\text{α}}{\text{= (α}}_{\text{i}}{\text{- α}}_{\text{i-1}}\text{) / to and}\\ {\text{rate}}_{\text{λ}}{\text{= (λ}}_{\text{i}}{\text{- λ}}_{\text{i-1}}\text{) / to}\end{array}\end{array}$$

the gun barrel angular velocities in the direction α or in the direction λ mean.

Vn

is a standard speed of ballistics.

q

is a quantity considering the air resistance of the projectile, which depends on the relationship $$\text{q = (CWn ∗ γ ∗ Gq) / (2 ∗ Gm),}$$

calculated, the meaning of the individual values to be used is listed in claim 9 .

Instead of choosing a numerical (or, if necessary, a filtered) solution as described above, the tachometer value ω can also be read directly from the gun and used for the calculation.

The update arithmetic unit 11 calculates a corrected disassembly time Tz (Vm) from the correction actuator K supplied by the correction arithmetic unit 12 , the current measured projectile speed Vm supplied by the evaluation circuit 10 and the lead speed Vov supplied by the lead computing unit 9 the relationship $$\text{Tz (Vm) = Tz + K ∗ (Vm-VOv).}$$

The corrected decomposition time Tz (Vm) is interpolated or extrapolated depending on the validity for the current running time t. The newly calculated disassembly time Tz (Vm, t) is fed to the transmitter coil 27 of the programming part 23 of the measuring device 14 and, as already described above with reference to FIG. 2 , is transmitted inductively to a projectile 18 flying by.

With the correction of the disassembly time Tz, the disassembly distance Dz ( Fig. 3,4 ) can be kept constant irrespective of the scatter of the projectile speed , so that an optimal meeting or Probability of shooting can be achieved.

Reference list

1

Fire control

2nd

gun

3rd

Search sensor

4th

target

5

Follow sensor

6

Fire control computer

7

Main filter

9

Lead computing unit

10th

Evaluation circuit

11

Update processing unit

12th

Correction computing unit

13

Gun barrel

14

Measuring device

15

Gun servo

16

Release device

17th

Data transmission

18th

bullet

18 '

bullet

19th

Subprojectile

20th

Support tube

21

First part

22

Second part

23

third part

24th

Ring coil

25th

Ring coil

26

Bobbin

27

Transmitter coil

28

management

29

management

30th

Soft iron bars

31

Receiving coil

32

filter

33

counter

34

Timer

a

distance

Pz

Position of the decomposition point

F1-F4

Circular areas

C.

cone

I.

First abscissa

II

Second abscissa

Dz

Disassembly distance

RT

Hit distance

VOv

Lead speed

Vm

Current measured bullet speed

Tz

Disassembly time

ts

Subprojectile flight time

Pf

meeting point

α

Gun angle

λ

Gun angle

Tf

Meeting time

TG

Flight time

Tz (Vm)

Corrected disassembly time

Me

Entrance (Meteo)

Z.

Target dates

Claims (10)

Method for calculating the disassembly time of a programmable projectile, whereby the calculation calculates at least one target distance (RT) to a target object determined from sensor data, a projectile speed (Vm) measured at the muzzle of a gun barrel ( 13 ) and a given disassembly distance (Dz) between a meeting point ( Pf) and a decomposition point (Pz) of the floor ( 18 )
characterized in that the given disassembly distance (Dz) is kept constant by correcting the disassembly time (Tz), the correction by the relationship $$\text{Tz (Vm) = Tz + K ∗ (Vm-Vov)}$$

takes place, and being Tz (Vm) the corrected disassembly time, Tz the disassembly time, K a correction factor, Vm is the current measured bullet speed and Vov mean a lead rate of the projectile. Method according to claim 1 ,
characterized in that the correction factor ( K ) according to the equation $$\text{K =}\frac{\hfill {\text{- (1 + δTG / δto) * TG * (1 + 0.25 * q * (VOv * Vn)}}^{\text{1/2}}\text{* TG)}}{\hfill {\text{(1+ (TG * (1 + 0.5 * q * (VOv * Vn)}}^{\text{1/2}}{\text{* TG) * ω}}^{\text{2nd}}\text{)) * VOv}}$$

is calculated, whereby TG a flight time of the projectile, δTG / δto the derivation of the flight time according to the time, q a size that takes into account the air resistance of the projectile, VOv the rate of advance of the projectile, Vn a standard speed of ballistics and ω ² mean a size relating to the position of the gun barrel. Method according to claim 2 ,
characterized in that the calculations are repeated in cycles. Method according to claim 3,
characterized in that the derivation of the flight time (TG) after the time according to the equation $${\text{δTG / δto = (TG}}_{\text{i}}{\text{- TG}}_{\text{i-1}}\text{) / to}$$

is calculated, where i the current measure, i-1 the previous measure and to the duration of a bar. Method according to claim 3 ,
characterized in that the size (ω ² ) relating to the position of the gun barrel ( 13 ) according to the relationship $${\text{ω}}^{\text{2nd}}{\text{= (rate}}_{\text{α}}{\text{∗ cos λ)}}^{\text{2nd}}{\text{+ (rate}}_{\text{λ}}{\text{)}}^{\text{2nd}}$$

is calculated in which α a gun angle of azimuth, λ a gun angle of elevation, rate _{α is} a gun barrel angular velocity in the α direction and rate _λ mean a gun barrel angular velocity in the λ direction. Method according to claim 5 ,
characterized in that the gun barrel angular velocities in α or. in the λ direction according to the equations $$\begin{array}{c}\begin{array}{c}{\text{rate}}_{\text{α}}{\text{= (α}}_{\text{i}}{\text{- α}}_{\text{i-1}}\text{) / to}\\ {\text{rate}}_{\text{λ}}{\text{= (λ}}_{\text{i}}{\text{- λ}}_{\text{i-1}}\text{) / to}\end{array}\end{array}$$

are calculated, where i the current measure, i-1 the previous measure and to the duration of a bar. Method according to claim 3 ,
characterized in that the size (q) taking into account the air resistance of the projectile according to the relationship $$\text{q = (CWn ∗ γ ∗ Gq) / (2 ∗ Gm)}$$

is calculated, where CWn is a coefficient of drag, γ the air density, Gq a floor cross section and Gm mean the projectile mass. Method according to claim 2 ,
characterized in that the lead speed (VOv) is formed from the mean of a number of measured projectile speeds that immediately precede the current measured projectile speed (Vm). Method according to claim 2 ,
characterized in that the corrected disassembly time (Tz [Vm]) interpolates depending on the validity for the current running time (t). is extrapolated. Device for carrying out the method according to claim 1 , with a fire control computer ( 6) which is connected to a gun computer via a data transmission ( 17) , the fire control computer ( 6 ) at least has a lead computing unit ( 9 ), and the gun computer has at least one evaluation circuit ( 10 ) for determining the projectile speed (Vm) and an update computing unit ( 11 ), which on the input side for supplying the projectile speed (Vm) with the evaluation circuit ( 10 ) is connected and is connected on the output side to a programming part ( 23 ) of a measuring device ( 14 ) for the projectile speed (Vm),
characterized in that a correction computing unit ( 12 ) is provided for calculating the correction factor (K), the correction arithmetic unit ( 12 ) for the purpose of feeding the shooting elements on which the calculation is based gun angle (α, λ), lead speed (VOv) and disassembly or. Meeting time (Tz, Tf) is connected on the input side to the lead computing unit ( 9 ) via the data transmission ( 17 ), that the update computing unit ( 11 ) for the purpose of supplying the lead speed (VOv) and disassembling or. Meeting time (Tz, Tf) on the input side is connected to the lead computing unit ( 9 ) via the data transmission ( 17 ) and is connected to the correction computing unit ( 11 ) on the input side for the purpose of supplying the correction factor ( K ),
whereby the programmed person ( 23 ) is supplied with the corrected disassembly time (Tz (Vm)) determined in the update computing unit ( 11 ) via the output-side connection of the update computing unit ( 11 ).

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