US20070074625A1

US20070074625A1 - Method and device for setting the fuse and/or correcting the ignition time of a projectile

Info

Publication number: US20070074625A1
Application number: US11/436,327
Authority: US
Inventors: Jens Seidensticker; Dietrich Stauffacher
Original assignee: Oerlikon Contraves AG
Current assignee: Rheinmetall Air Defence AG
Priority date: 2005-05-23
Filing date: 2006-05-18
Publication date: 2007-04-05
Also published as: ES2365039T3; EP1726911A1; CA2545300A1; DK1726911T3; ATE506594T1; DE502006009327D1; DE102005024179A1; EP1726911B1; ZA200604101B; JP5005954B2; JP2006329616A

Abstract

To avoid mechanical and thermodynamic wear of a programming system, a microwave transmitter, preferably operating in the GHz range, is integrated in the system, while at the same time the advantages of measurement of the muzzle velocity and of a current compensated fuse setting are preserved. The microwave transmitter transmits the current fuse setting, for example, as determined by a fire control computer, to the ammunition, e.g., a projectile. A direct measurement of the actual muzzle velocity itself can be dispensed with, since the real muzzle velocity is determined by the current flight velocity information of the projectile, i.e., it is extrapolated back from this. On the basis of this current projectile velocity, the ignition time, which was preset with the ignition time of the projectile using a standard muzzle velocity, is corrected and used as the current fuse set time.

Description

BACKGROUND OF THE INVENTION

The invention concerns a method and a device for programming a time-fuse projectile or for correcting an ignition time of a projectile fired from a weapon.
Various time programmings for ammunition are known. The fuses are set either manually outside the loading chamber before the projectile is fired or electrically in the loading chamber by ignition electronics. The latter type of fuse setting is described, for example, in DE 101 52 862 A1.
A method and a device for transmitting information to programmable projectiles are described in EP 0 992 762 B1.
A method for correcting the preprogrammed triggering of a process in a spin-stabilized projectile and a device for carrying out this method are described in EP 0 992 761 B1.
EP 0 918 209 B1 discloses a projectile with programmable time fuses.
A method and a device for programming time fuses of projectiles are also described in EP 0 769 673 B1. To compute a disintegration time, a predetermined muzzle velocity of the projectile and a predetermined distance to a target are used.
DE 38 35 656 A1 discloses a method for correcting the ignition point and a circuit configuration for carrying out this method. The device measures the actual projectile velocity profile with respect to time only for a specific period of time after firing. The further velocity profile of the projectile is then extrapolated. When the distance of flight determined in this way reaches a desired value, the detonation is triggered.
CH 691 143 A5 discloses a device for measuring projectile velocity at the muzzle of the barrel of a high-cadence cannon. The device has two sensors that are spaced a certain distance apart on a support tube. The sensors respond to changes in magnetic flux and are connected to evaluation electronics. In this regard, each sensor has a pair of coils and a closed magnetic circuit. The measured projectile velocity or the fuse set time updated with it is then also supplied as information to the projectile, generally before the projectile leaves the muzzle area.
Although the above device is distinguished by a high degree of accuracy, it is subject to mechanical and thermodynamic stresses, since the measuring and programming units are exposed, among other things, to the muzzle gases.

SUMMARY OF THE INVENTION

The object of the invention is to provide a device or an improved programming system that is no longer exposed to mechanical and thermodynamic wear.
Pursuant to this object, and others which will become apparent hereafter, one aspect of the present invention resides in a method for setting a fuse and/or correcting ignition time of a projectile fired from a weapon. The method includes the steps of measuring current projectile velocity, computing true muzzle velocity of the projectile during passage through a cannon tube based on the current projectile velocity, and adjusting and/or correcting a fuse set time of the fuse based on the computed muzzle velocity.
Another aspect of the invention resides in a device for setting the fuse and/or correcting the ignition of the projectile, which device includes as transmitter/receiver and a fire control system arranged at the weapon and a chip and a timer arranged at the projectile. The chip is connected to the timer and an output of the timer is connect with a fuse or an ignition device of the projectile. It is further possible to provide the projectile with a computing and/or correction unit. In this case the chip would be connected to the computing and connecting unit and the timer, while the output of the computing and/or correction unit is also connected to the timer.
The invention is based on the idea of integrating a microwave transmitter, preferably operating in the GHz range, in the system while at the same time preserving the advantages of measurement of the muzzle velocity and of a current compensated fuse setting. This microwave transmitter transmits the current fuse setting, for example, as determined by a fire control computer, to the ammunition, e.g., a projectile. A direct measurement of the actual muzzle velocity can be dispensed with, since the real muzzle velocity is determined by information of the current flight velocity of the projectile, i.e., it is extrapolated back from this. On the basis of this current projectile velocity, the ignition time, which was preset with the ignition time of the projectile using a standard muzzle velocity, is corrected and used as the current fuse set time.
The flight velocity is measured, for example, by means of the Doppler shift of the transmitting frequencies, preferably at the projectile end. To this end, the transmitting frequency is fixed, and the deviation is measured. Since the time that the projectile has been traveling is known, the current flight velocity can be determined, and, in addition, the real muzzle velocity of the projectile, which the projectile had at the time it was fired through the muzzle area, can be computed. The current fuse set time is then determined from this data and made available to the projectile.
If there is a deviation from a preprogrammed standard fuse setting, a correction is then made in the ammunition or by the fire control system, which then reflects the current fuse set time.
The ammunition or the projectile contains a chip for the programming, for example, an RFID (radio frequency identification) chip (see http://de.wikipedia.org/wiki/RFID). This chip has the preferred property that it can be supplied with energy by microwave energy.
In addition, an advantage is obtained from the fact that the chip can be programmed by the fire control unit with, among other things, the current standard fuse setting and with a correction value or a value that is not determined until during the flight of the projectile.
The timer present on the ammunition (or in the ammunition) can then be counted down to zero over the (remaining) flight distance and can then bring about the desired disintegration before a target.
In addition, the computed muzzle velocity can also be transmitted back if this computation is made in the projectile to allow any deviations that may arise to be taken into account in the fire control system.
This system eliminates the previously known expensive measuring and programming unit in the cannon or cannon tube. The microwave transmitter that is used can be locally mounted on the cannon where it is not exposed to either muzzle gases or mechanical stresses. The transmitter/receiver is electrically supplied by the electrical system of the cannon and is supplied with data of the fire control system. Any data transmitted back from the ammunition can be retransmitted to the fire control system, which can then take it into account.
The invention is explained in greater detail below with reference to the specific embodiment illustrated in the drawing.

BRIEF DESCRIPTION OF THE DRAWINGS

The single FIGURE is a schematic representation of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The sole drawing shows a programming system 1 or a generalized device for a time-fuse projectile 2 or a time-fuse piece of ammunition (etc.).
A programmable chip 3, for example, an RFID chip, is located on board the projectile 2 and preferably also contains the receiving and transmitting circuit and memory. A timer 4 present in the projectile 2 is also supplied by this chip 3 with the necessary time information on the spot. Parallel to this, the chip 3 is connected with a computing and/or correction unit 5 if such a unit is provided in the projectile 2. This unit 5 is then also connected with the timer 4. A fuse 6 is functionally connected with the output of the timer 4.
The power supply to these units of the projectile 2 can be provided by microwave radiation X. Another, preferred possibility is a conventional power supply, for example, a battery that can be activated (not shown).
On the cannon or weapon end 10, the programming system 1, which is preferably mounted on the cannon tube 11, has a transmitter/receiver 12 for data transmission to the projectile 2. This transmitter/receiver 12 is electrically connected with a fire control system or fire control computer 13 present in the weapon control system.
The programming system operates in the following way:
The current disintegration time, which is computed on the basis of the standard velocity of the projectile 2, is transmitted to the projectile. The deviation from the standard velocity is determined in the projectile by the Doppler method. On the basis of the deviation, the current disintegration time is computed in the projectile 2 or from the cannon end.
If this operation is carried out in the projectile 2 by the computing and/or correction unit 5, then a correction of the fuse set time for the fuse 6 can be performed at the projectile end, in which case the timer 4 is supplied with this information. The correction that has been made and the back-computed muzzle velocity that has been determined can be transmitted via microwave radiation X to the transmitter/receiver 12 on the cannon 10 and made available to a fire control system (not shown).
On the other hand, if the current projectile velocity is transmitted to the transmitter/receiver 12 of the cannon 10, and if the correction is carried out at the cannon end in the fire control system 13, then the desired value of the fuse time (flight time) based on the true muzzle velocity of the projectile 2 upon firing is transmitted to the projectile via the microwave radiation X. This fuse set time is corrected and used as the new fuse set time in the projectile 2.
Although the present invention ahs been described in relation to particular embodiments thereof, many other variations and modifications and other uses will become more apparent to those skilled in the art. It is preferred, therefore, that the present invention be limited not by the specific disclosure herein, but only by the appended claims.

Claims

1. A method for setting a fuse and/or correcting ignition time of a projectile fired from a weapon, comprising the steps of:

measuring of the current velocity of the projectile;

computing true muzzle velocity of the projectile during passage through a cannon tube based on the current projectile velocity; and

adjusting and/or correcting a fuse set time of the fuse based on the computed muzzle velocity.

2. A method in accordance with claim 1, including measuring the current velocity by the Doppler effect.

3. A method in accordance with claim 1, wherein computing true muzzle velocity includes considering current flight time.

4. A method in accordance with claim 1, including computing the correction of the fuse set time in a computing and/or correction unit in the projectile.

5. A method in accordance with claim 1, including computing the correction of the fuse set time at the weapon end in a fire control system, and transmitting data between the projectile and the weapon via microwaves.

6. A device for setting a fuse and/or correcting ignition time of a projectile fired from a weapon, comprising:

a transmitter/receiver and a fire control system arranged at the weapon; and

a chip, a computing and/or correction unit and a timer arranged at the projectile, the chip being connected with the computing and/or correction unit and the timer, wherein an output of the computing and/or correction unit is also connected with the timer, an output of the timer being connected with a fuse or an ignition device of the projectile.

7. A device for setting a fuse and/or correcting ignition time of a projectile fired from a weapon, comprising:

a transmitter/receiver and a fire control system arranged at the weapon; and

a chip and a timer arranged at the projectile, the chip being connected with a timer, and an output of the timer being connected with a fuse or an ignition device of the projectile.

8. A device in accordance with claim 6, wherein the transmitter/receiver is a microwave transmitter/receiver that operates in the GHz range.

9. A device in accordance with claim 7, wherein the transmitter/receiver is a microwave transmitter/receiver that operates in the GHz range.

10. A device in accordance with claim 6, wherein the chip in the projectile is an RFID chip.

11. A device in accordance with claim 7, where the chip in the projectile is an RFID chip.