AU754674B2

AU754674B2 - Shooting simulation method

Info

Publication number: AU754674B2
Application number: AU34252/00A
Authority: AU
Inventors: Hermann Juttner
Original assignee: STN Atlas Elektronik GmbH
Current assignee: Atlas Elektronik GmbH
Priority date: 1999-03-18
Filing date: 2000-02-26
Publication date: 2002-11-21
Anticipated expiration: 2020-02-26
Also published as: CA2366526A1; CA2366526C; EP1159578A1; EP1159578B1; DE19912093A1; WO2000057123A1; AU3425200A; DE50001795D1

Description

1 Title Shooting simulation method Technical Field The invention concerns a method to simulate the shooting of ballistic projectiles using barrelled weapons, of the type defined in the generic part of claim 1.

Backqround to the Invention A known method for shooting simulation (DE 37 20 595 Al) is based on a so called two-way simulation, wherein first the distance to the target is :measured with the gun sight aimed at the target, following this the target, provided with a retro-reflector, is illuminated with a laser and the light reflected *by the retro-reflector is imaged on a position-analysing, electro-optical device -15 on the barrelled weapon. The position of the retro-reflector determined from the image is compared with the position of the hit of the simulated shot, that is calculated based on the measured distance, the type of weapon and ammunition and gun sight used, that forms the hypothetical trajectory with the line of sight. If the position of the retro-reflector concurs with the position of the hit, a hit report is released by the barrelled weapon, if the two do not concur, a failure report is generated.

In the case of an also known method, based on a two-way simulation for shooting simulation of ballistic ammunition and moving targets (DE 31 14 000 Al) before triggering the simulated shot the target is continually measured by laser pulses emitted from the weapon.

For this purpose within a spatial angle sector relative to the axis of the barrel of the barrelled weapon, the spatial angle sector having a certain divergence in the vertical and lateral directions, a pulse-coded, tightly concentrated laser beam is so emitted and swivelled successively horizontally and vertically, that the laser beam sweeps over the spatial angle sector in the form of a scanning pattern, in vertically superposed lines, line by line. At the same time the reference line for the scanning pattern is the axis of the barrel of the barrelled weapon. If the laser being generating the scanning pattern at the correct alignment of the barrelled weapon strikes the retro-reflector of a target situated in the spatial angle sector, then the laser beam is reflected in itself, and the returning laser beam reaches an optical receiver at the weapon. This 2 measures the transit time of the reflected laser beam and determines the distance to the target as well as the angular position laterally and vertically from its relationship to the scanning pattern. A computer assigned to the receiver calculates, using the stored data like type of ammunition, from the distance of the target and the vertical angle deviation the trajectory of the projectile resulting at this distance of the target and the nominal elevation angle of the barrelled weapon. This measuring of the target is continuously repeated and the obtained data of target measuring, distance to target and the data of flying time of the projectile and nominal elevation angle derived from them are stored in a memory. A trigger button for shooting is connected to the computer. Its actuation will cause the termination of the measuring of the target and the last stored data is read out from the memory and modulated on a laser beam emitted to the target. At the target a virtual hit of the projectile is calculated from the transferred and demodulated data and the movement of the target itself is measured by measuring the direction of reception of the laser beam and the speed of travel during the flying time of the projectile and based on the position of the target at the end of the flying time of the projectile and the virtual hit of the projectile a hit or otherwise is determined.

The technical expense, however, for such two-way simulation method is very high and it increases out of proportion with the increasing distance of the target. For the measuring of the target a highly sensitive measuring electronics has to be used. That is an additional cost for the shooting simulator. At the same time the optical level of the laser light increases with the increasing distance r by 1/r 4 so that the measured results are becoming increasingly more unreliable. At the same time an increase of the laser capacity is hardly possible, since to protect the participant of a target practice the capacity class of the laser is specified and limited so that to be tolerated by the eyes.

An advantage of at least one embodiment of the invention is to specify a method of the type mentioned in the introduction to simulate shooting, that makes it possible to considerably reduce the manufacturing costs for the shooting simulator that makes feasible to realise this method and at the same time ensures an adequate accuracy when used in training ground manoeuvres.

Summary of the Invention The present invention provides a method to simulate the shooting of ballistic projectiles using barrelled weapons with the following steps of the method occurring after triggering the shot: a) a target is illuminated only in one plane by the successive swivelling of an optically tightly concentrated emitted light that is radiated by an optical transmitter assigned to the barrelled weapon, b) modulated, exclusively weapon-specific information, namely information regarding the momentary position and the vertical direction (elevation) of the barrelled weapon as well as regarding the type of the weapon and of the projectile, are transferred with the emitted light to the target, c) in which with an optical receiving device for the emitted light and with a position determining system to detect the target fitted with a target position, cl) a virtual hit of the projectile is determined from the received and demodulated weapon-specific information, dtmec2) the distance between the target and the barrelled weapon is determined from the received and demodulated weapon-specific information "position of the barrelled weapon" and from the position of the target obtained from the position determining system, and c3) a hit is determined by comparing the distances between the target and the barrelled weapon on the one hand and the virtual hit of the projectile and the barrelled weapon on the other.

20 The method according to the invention has the advantage that only a single optical transfer path is required from the shooter to the target and, consequently, the simulator requires a lower laser capacity at higher sensitivity.

The checking, whether the shooter has so aimed his barrelled weapon that a 0 0: target situated at the estimated distance is hit or not, is carried out at the target on the basis of the data of the aimed barrelled weapon, what is possible without any problem, since the position of the weapon and of the target are continuously measured and the position of the weapon is transmitted to the target when the shot is triggered. The method allows a realistic handling of the weapon, while the tilting of the weapon, the type of ammunition, the type of weapon, the azimuth and elevation angles (lead and elevation) set are considered when determining the hypothetical or virtual point of impact.

By using the method according to the invention height differences between the target and the weapon are also corrected. An indication of hitting several targets situated on the same line of fire will be avoided, since each target itself determines based on its distance from the shooting weapon, whether the hypothetical or virtual point of impact does or does not concur with i"ts position.

The method according to the invention can be used for barrelled weapons, like tank guns, where the aiming of the gun sight of the weapon is to be practised and for barrelled weapons like bazookas, where it is used for the estimation of the aiming allowance. For this purpose merely the direction of swivelling of the transmitted light has to be transferred from the vertical into a horizontal plane and made to suit the swivelling angle.

Useful embodiments of the method according to the invention with advantageous developments and constructions of the invention become apparent from the further claims.

According to a preferred embodiment of the invention the transmitted light is produced as a succession of laser pulses and the weapon information is modulated upon each laser pulse. Laser pulses have the advantage that they have only a small energy density despite the high pulse level and consequently transmit a capacity to the target that is adequate for the shooting simulation while having the safety necessary for the eyes. In addition, the laser pulses can be modulated relatively free of interference, so that the information regarding the weapon can be reliably transmitted to the target.

The invention is explained below in detail based on embodiments illustrated in the drawing. They show schematically illustrated in: AMENDED PAGE Figs.1 and 2 a tank carrying a barrelled weapon on a training ground when firing at a target in side view (Fig.1) and top view (Fig.2), Fig.3 a block circuit diagram of the components of a shooting simulator, situated on the weapon, Fig.4 a block circuit diagram of the components of the shooting simulator, situated on the target, Fig.5 a perspective illustration of a bazooka in firing position aimed at a target tank travelling on the exercise ground.

Figs.1 and 2 show a scenario of an exercise on a manoeuvre ground in side view and top view, wherein the tank 10, equipped with a barrelled weapon (tank gun) 11, is in combat against several targets 13, 14, 15 on the ground 12. The target 13 chosen by the tank 10 is schematically illustrated and can be, for example, an enemy tank, the direction of its movement being indicated in Fig.2 by arrow 16.

Targets 14 and 15 are stationary and are, for example, buildings or natural obstacles.

For shooting exercise a so called shooting simulator is used, that has a component 17 allocated to the barrelled weapon 11 and a component 18 allocated to the target 13. The component 17 allocated to the weapon, illustrated in the block circuit diagram of Fig.3, is situated in a housing 19 that is fixed on the barrelled weapon 11 and thus takes part in the swivelling motion of the tank's gun in the azimuth and elevation, as well as in any tilting of the tank's body and consequently of the barrelled weapon 11 while travelling overland. In the housing 19 an optical transmitter 20 is pivotably provided in the vertical direction, that radiates a tightly concentrated laser light as a sequence of laser pulses emitted at constant cycles. A swivelling movement of the optical transmitter 20 is affected by means of a stepping motor 21, that is controlled, just like the optical transmitter by a central control unit 22. To the input side of the central control unit 22 a tilting sensor 22 measuring the tilting of the body of the tank 10 and consequently that of the barrelled weapon 11, an inclination sensor 24 measuring the elevation angle E of the barrelled weapon 11, i.e. the elevation of the barrelled weapon 11 relative to the horizontal, as well as an interface 25 are connected, via which information about the type of ammunition, the type of weapon, the momentary position of the tank 10 on the ground and the triggering of the simulated shot are conveyed to the central control unit 22. For this purpose the interface 25 is connected via an input 27 with a position determining system 26, e.g. a GPS (global position system) or a DGPS (differential global position system), provided on the tank 10, and receives via other inputs 28, 29 and 30 corresponding information about the type of weapon and ammunition as well as a trigger pulse when triggering the simulated shot. Additionally, there is an optical modulator included in the optical transmitter 22 controlled by the central control unit 22, the modulator modulating upon each laser pulse emitted by the optical sensor information entering via the interface 25 about the type of weapon and ammunition as well as the values measured by the tilting sensor 23 and the inclination sensor 24.

The component 18 of the shooting simulator, installed on the target, shown in the block circuit diagram of Fig.4, has an optical receiving device 31 with a plurality of optical sensors 32, e.g. laser diodes, which convert the incoming laser pulses into electric signals. If the target 13, as assumed, is also a tank, then (as this is illustrated in Fig.1 for the shooting tank 10) the plurality of light detectors or optical sensors 32 form a girdle horizontally surrounding the body of the tank. All optical sensors 32 are connected to a signal processor 33, that contains a demodulator and eliminates from the received laser pulses the weapon information (position of the weapon, type of the weapon, type of firing, elevation of the barrelled weapon) transmitted with it and conveys them to a microprocessor 34. From a position determining system 35 (GPS or GDPS), fastened on the target 13, the microprocessor 34 additionally receives the momentary position of the target 13. Based on the weapon information and the position of the target the microprocessor 34 determines a virtual hit of the projectile by calculating a hypothetical trajectory resulting from the alignment of the weapon and the distance between the barrelled weapon 11 and the target 13.

The microprocessor 34 carries out a comparison of the impact of the projectile and the distance to the target and, if they concur, it triggers a hit recorder 36, that emits an optical, acoustic or electro-magnetic hit signal. For the determination of the virtual impact of the projectile, a plurality of trajectories of projectiles with the parameters of the elevations of the barrelled weapon (elevation angle E) as well as weapon and projectile types are stored in the microprocessor 34. By using the received and demodulated weapon information the relevant trajectory is sought out and the virtual impact of the projectile is read out.

A simulation of shooting with barrelled weapons firing ballistic projectiles is carried out as follows by using such a shooting simulator: The gunner aligns the barrelled weapon 11 with the target 13 by means of a gun sight that is usually connected with the barrelled weapon 11 and sets a certain elevation (elevation angle E) for the barrelled weapon 11 based on the distance estimated by him. If the target 13 is a moving target, the gunner, as this is indicated in Fig.2, will consider an additional lead for the barrelled weapon and the barrelled weapon 11 is set at an azimuth angle (p relative to the direct line of sight to the target 13.

When the shot is triggered by the gunner, a trigger pulse is sent to the interface 25 via the input 30, that causes control unit 22 to activate the optical transmitter The optical transmitter 20 emits a succession of laser pulses, while it is successively swivelled downward in the vertical plane. On this occasion the first laser pulses are emitted in a direction that runs parallel to the axis of the barrel.

Every laser pulse will have information regarding the momentary position and alignment of the barrelled weapon, in the present case regarding the elevation angle E supplied by the inclination sensor 24 and the tilting angle supplied by the tilting sensor 23, as well as the type of weapon and type of ammunition, modulated upon. At some time during the vertical swivelling movement of the laser transmitter 20 at least one laser pulse hits one of the light detectors or optical sensors 32 on the target 13. This laser pulse is received by the optical receiving device 31 and processed by signal technology in the components described. The virtual hit of the projectile is determined now at the target 13 from the weaponry information (elevation angle E, tilting angle, type of weapon, munition) transmitted by the laser pulse as well the distance between target 13 AMENDED PAGE and the barrelled weapon 11 is determined from the position of the weapon 11 transmitted by the laser pulse and the known position of the target. If the impact of the projectile and the distance of the target concur, a hit will be indicated.

In the scenario illustrated in Figs.1 and 2 at the triggering of the simulated shot the target 14 will also be hit at some time by laser pulses. Provided it is included in the object of the training, according to Fig.3 the target 14 is also equipped with component 18 of the shooting simulator allocated to the target. In the target 14 the same calculation is carried out as in target 13. However, in this case the distance of the target 14 to the barrelled weapon 11 is considerably shorter than the distance of the virtual impact of the projectile from the barrelled weapon 11, so that no hit will be indicated.

For the purpose of reducing the number of optical sensors 32 to be provided on the receiver, the laser light of the optical transmitter 20 could be expanded in the horizontal direction, so that the optical sensors 32 on the target 13 could be positioned at a greater distance from one another. To ensure the same sensitivity for all optical sensors 32, the laser capacity has to be increased to enable to illuminate a larger area on the target 13 using the same energy density.

On a larger training ground, in certain sections of the ground, due to the structure of the ground or due to buildings and plants, the satellite reception may be interfered with or prevented, so that the position of the weapon and/or of target is not available as a determinable information to determine the hit. In these cases the laser pulses emitted by the optical transmitter 20 have an additional information regarding the time of transmission of each laser pulse modulated on them. The information stating the time of transmission is the time between the triggering of the simulated shot and the emission of the respective laser pulse.

This information is received by a counter integrated in the central control unit 22, the counter starting at the triggering of the shot and clocked with a constant frequency. From the information transmitted with the received laser pulse regarding its time of emission and the weapon information the distance between the target and the barrelled weapon can be determined in the target 13. Thus Jeven in the case of interrupted GPS reception the positions of hit can be AMENDED PAGE determined and the shooting exercises can be continued. In the case of an intact GPS reception the distance to the target, determined on the basis of the known positions of the barrelled weapon 11 and of the target 13, can be controlled.

Fig.5 shows a training scenario, in which the firing of a bazooka 37 at a travelling tank 38 is to be practiced. The bazooka 37 represents the barrelled weapon 11 and the target tank 38 the target 13, that moves in the direction of arrow 16 in The essence of this exercise is the correct setting of a lead of the barrelled weapon 11, i.e. of a correct azimuth angle so that the moving target 13 (target tank 38) will be hit at the correct moment after firing the bazooka 37; the armourpiercing ammunition fired by the bazooka 37 requires a certain flight time to bridge over the distance to the target 13, during which the target 13 will have moved on over a path corresponding to its speed from the position occupied when triggering the shot.

The above described method for shooting simulation is now varied inasmuch, that the optically tightly concentrated emitted light, therefore the pulse sequence of laser pulses, is now swivelled in a horizontal plane (azimuth) with a constant velocity and in each swivelled position an additional information is modulated upon each laser pulse regarding the momentary swivelling angle ai relative to the axis of the barrelled weapon. At the same time the laser pulses are emitted at a constant clock rate (transmission frequency). Apart from the above described information regarding the weapon 11, an information regarding the momentary azimuth swivelling angle ai relative to the axis 39 of the barrelled weapon is modulated upon each laser pulse in every swivelled position of the optical transmitter 20. For a better explanation the swivelling angles a, to a4 are schematically shown in Fig.5. The transmitter 20 is once again integrated in the component 17 of the shooting simulator installed on the weapon, the component firmly connected with the barrelled weapon 11, in this case combined into an assembly with the gun sight of the bazooka 37. Because by virtue of the fastening of the component 17 on the barrelled weapon 11, the optical axis of the transmitter 20 is vertically slightly offset relative to the axis 39 of the barrelled weapon, the reference line 39' indicating the swivelling angle is offset by the same amount above the axis 39 of the barrelled weapon. Thus the reference line 39' indicating the swivelling angle runs in the centre of the barrelled weapon always parallel to the axis 39 of the barrelled weapon. The range of the swivelling angle of the optical transmitter 20 is limited to an azimuth range to the right and to the left of the centre of the barrelled weapon, i.e. of the axis 39 of the barrelled weapon, the range being at least as large as the lead angle qP required to combat a target 13 moving transversely to the axis 39 of the barrelled weapon, that angle taking into consideration the flight time of the projectile of the barrelled weapon 11 fired at the moving target 13. The swivelling movement of the optical sensor takes place with the triggering of the simulated shot always starting from one of the limiting edges of the swivelling range, in the example shown in Fig.5 from the left outside limiting edge of the swivelling angle range.

The moving target 13, formed by a target tank 38 and travelling, as shown in the direction of arrow 16, is fitted on the target with the same component 18 of the shooting simulator as is illustrated in the block circuit diagram in Fig.4, while the number of the optical sensors 32 of the optical receiving device 31 is limited to two to three on each longitudinal side of the target 13, and the optical sensors 32 are provided in the turret region of the target tank 38. To ensure a reliable reception of the light pulse by the optical sensors 32, the laser pulses can be expanded in the vertical direction, so that each laser pulse will illuminate the maximal height of the target tank 38 up to the top edge of the turret. In the component 18 of the shooting simulator fitted to the target the same evaluation of the information, transmitted in the laser pulses, is carried out as described above, with the only difference being that the distance to the target involved is first corrected by means of information regarding the swivelling angle and the known movement of the target 13. This correction is carried out in such a manner that the distance to the target is calculated for a target position that would be occupied by the target 13 moving at the target's speed after travelling a path that is determined from the information regarding the swivelling angle and the momentary distance of the target within the flight time of the projectile, the time flight in turn being calculated from the weapon information. This information regarding the swivelling angle corresponds to the lead (p set with the barrelled weapon 11 in the azimuth and if the lead qp is correctly set, the projectile's hit calculated from the weapon information concurs with the corrected distance to the target and a hit will be indicated.

If, as described above, additional information regarding their moment of emission is modulated upon the laser pulses emitted by the optical transmitter 20, then in the case of the shooting simulator described in Fig.5 the transfer of an additional angle information ai regarding the direction of transmission to the target 13 can be omitted, since the angle information regarding the direction of transmission can be derived from this information from the moment of emission of the laser pulse.

Claims

1. A method to simulate the shooting of ballistic projectiles using barrelled weapons with the following steps of the method occurring after triggering the shot: a) a target is illuminated only in one plane by the successive swivelling of an optically tightly concentrated emitted light that is radiated by an optical transmitter assigned to the barrelled weapon, b) modulated, exclusively weapon-specific information, namely information regarding the momentary position and the vertical direction (elevation) of the barrelled weapon as well as regarding the type of the weapon and of the projectile, are transferred with the emitted light to the target, S. c) in which with an optical receiving device for the emitted light and with a position determining system to detect the target fitted with a target position, cl) a virtual hit of the projectile is determined from the received and 15 demodulated weapon-specific information, S-c2) the distance between the target and the barrelled weapon is determined from the received and demodulated weapon-specific information "position of the barrelled weapon" and from the position of the target obtained from the position determining system, and 20 c3) a hit is determined by comparing the distances between the target and the barrelled weapon on the one hand and the virtual hit of the projectile and the barrelled weapon on the other.

2. A method according to claim 1, characterised in that a tilting of the barrelled weapon is measured relative to a vertical and/or horizontal reference line and the measured value is modulated upon the emitted light and that the information regarding the tilting of the weapon is referred to in the target when determining the virtual impact of the projectile.

3. A method according to claim 1 or 2, characterised in that trajectories of projectiles with the parameters of leads as well as of types of weapons and projectiles are stored in the target, and that with the received and demodulated weapon-specific information the relevant trajectory is sought out and the virtual hit of the projectile is read out.

4. A method according to any one of claims 1 to 3, characterised in that the emitted light is swivelled upward in a vertical plane in a direction that is parallel to the barrelled weapon.

A method according to claim 4, characterised in that the optical receiving device of the preferably moving target is provided with a girdle horizontally surrounding it and comprising a plurality of light detectors at a distance from one another and fastened on the target.

6. A method according to claim 4 or 5, characterised in that the emitted light is optically expanded in the horizontal direction.

7. A method according to any one of claims 1 to 3, characterised in that the emitted light is swivelled with a constant velocity in a horizontal plane and in every swivelled position information regarding the momentary swivelled angle relative to the barrelled weapon is modulated upon the emitted light and that the distance to the target referenced for the establishment of the hit at the target is first corrected by means of the information regarding the swivelling angle and the known movement of the target itself.

8. A method according to claim 7, characterised in that the correction is carried out in such a manner that the distance to the target is calculated for a target position that the target moving at the target's speed occupies after travelling a path that is determined from the information regarding the swivelling angle and the momentary distance of the target during the flight time of the projectile obtained from the information regarding the weapon.

9. A method according to claim 7 or 8, characterised in that the swivelling range of the emitted light is limited to the same azimuth angle to the right and left of the centre of the barrelled weapon, that corresponds at least to a maximum lead angle of the barrelled weapon in the azimuth that takes the maximum flight duration of the fired projectile into consideration when combating a target moving at maximum speed transversely to the direction of firing, and that when triggering the simulated shot the swivelling of the transmission direction takes place starting from one of the limiting edges of the swivelling range.

A method according to any one of claims 1 to 9, characterised in that the emitted light is produced as a succession of laser pulses and the weapon- specific information are modulated upon each laser pulse.

11. A method according to claim 10, characterised in that the laser pulses are transmitted with constant clock rate.

12. A method according to any one of claims 7 to 11, characterised in that an additional information regarding the time of emission is modulated upon each ,e-A aser pulse and by omitting the transfer of the swivelling angle information the swivelling angle information is derived at the target from the information about the time of emission.

13. A method according to claim 12, characterised in that the time between the triggering of the simulated shot and the emission of the respective laser pulse is given as information regarding the time of emission.

14. A method according to claim 13, characterised in that the information regarding the time of emission is obtained on the output of a counter clocked with a constant frequency. A method according to any one of claims 1 to 14, characterised in that the positions of the barrelled weapon and of the target are determined by S.means of a satellite-supported position determining system, e.g.

GPS or .':DGPS, provided on them.

16. A method to simulate the shooting of ballistic projectiles using barrelled .o°weapons substantially as described herein with reference to the drawings. Dated this thirteenth day of September 2002 STN Atlas Elektronik GmbH e °Patent Attorneys for the Applicant: B RICE CO F B RICE CO