System and method for weapon effect simulation

Abstract

A weapon effect simulation system including a fire simulation system and at least one hit simulation system. The fire simulation system includes a transmitter for transmitting electromagnetic waves to simulate real ammunition from a weapon and elements for including information in the electromagnetic waves. The hit simulation system includes both a receiver for receiving the transmitted electromagnetic waves and a processor for determining, based on received electromagnetic waves, whether a target has been hit. The fire simulation system further includes a calculator for calculating the imagined trajectory of the simulated ammunition and a processor for determining the geographical position of the weapon, and wherein the elements for including information in the electromagnetic waves are arranged so as to include information related to coordinates in the three-dimensional space for the calculated ammunition trajectory.

Claims

1. A weapon effect simulation system, comprising: a weapon comprising a fire simulation system comprising a transmitter configured to transmit electromagnetic waves from a weapon to simulate real ammunition from the weapon, and the transmitter including information in the electromagnetic waves, the fire simulation system further comprising a calculating unit configured to calculate an entire imagined trajectory of the simulated ammunition and a processor configured to determine a geographical position of the weapon, wherein the transmitter is operative to include in the electromagnetic waves information related to the entire imagined calculated trajectory of the simulated ammunition given as coordinates in the three-dimensional space; and at least one target comprising a hit simulation system comprising a receiver configured to receive the transmitted electromagnetic waves from the weapon and a processor configured to determine whether a target has been hit based on the information related to the entire imagined calculated trajectory of the simulated ammunition given as coordinates in the three-dimensional space in the received electromagnetic waves.

2. The weapon effect simulation system according to claim 1, wherein the transmitter comprises a laser transmitter operative to transmit laser radiation with at least one beam lobe.

3. The weapon effect simulation system according to claim 2, wherein the transmitter further comprises a radio transmitter operative to transmit radio waves.

4. The weapon effect simulation system according to claim 3, wherein the processor is operative to determine target hits based primarily on the information in the laser radiation and secondarily on the information in the radio waves.

5. The weapon effect simulation system according to claim 1, wherein the transmitter comprises a radio transmitter operative to transmit radio waves.

6. The weapon effect simulation system according to claim 1, wherein the transmitter is operative to continuously include, based on the calculated trajectory, information concerning the current trajectory position of the simulated ammunition.

7. The weapon effect simulation system according to claim 1, wherein the processor is operative to include, during a period of time that is shorter than the flight time of the real ammunition and based on the calculated trajectory, information concerning the trajectory positions of the simulated ammunition.

8. The weapon effect simulation system according to claim 1, wherein the calculating unit is operative to determine an impact point or burst point of the ammunition, and wherein the information related to the calculated ammunition trajectory contains the impact point or burst point.

9. The weapon effect simulation system according to claim 1, wherein the fire simulation system comprises a transmitter operative to transmit information regarding the geographical position of the weapon, and wherein at least one target comprises a hit simulation comprising a receiver operative to receive said position data.

10. The weapon effect simulation system according to claim 9, wherein the information related to the calculated ammunition trajectory is determined relative to the geographical position of the weapon.

11. The weapon effect simulation system according to claim 1, wherein said hit simulation system comprises a processor configured to determine the geographical position of the target.

12. The weapon effect simulation system according to claim 11, wherein at least one of the targets comprises a hit simulation system comprising a transmitter, and wherein the fire simulation system comprises a receiver operative to receive information from the transmitter of the hit simulation system.

13. The weapon effect simulation system according to claim 12, wherein the transmitter of the hit simulation system is operative to transmit information regarding the geographical position of the target.

14. The weapon effect simulation system according to claim 13, wherein the calculating unit is operative to determine which target has been hit, and wherein the information related to the calculated ammunition trajectory includes information that identifies the determined target.

15. The weapon effect simulation system according to claim 12, wherein the transmitter of the hit simulation system is operative to transmit a hit message upon determination of a hit.

16. The weapon effect simulation system according to claim 15, wherein a receiver for a hit simulation system that has not determined a hit acts as a secondary object and is operative to receive the transmitted hit message.

17. The weapon effect simulation system according to claim 16, wherein the processor is operative to decide upon receiving hit messages whether the secondary object has been hit.

18. The weapon effect simulation system according to claim 15, wherein the transmitter is operatively connected with the receiver of the fire simulation system and is operative to break off the simulation upon receiving the hit message.

19. The weapon effect simulation system according to claim 15, wherein the fire simulation system comprises a display configured to display hit locations and effects based on received hit messages.

20. The weapon effect simulation system according to claim 19, wherein the display is operative to display hit locations and effects visually.

21. The weapon effect simulation system according to claim 1, wherein the fire simulation system is disposed at a weapon.

22. The weapon effect simulation system according to claim 1, wherein the processor has a geographical position that is separate from the geographical position of the transmitter.

23. The weapon effect simulation system according to claim 1, wherein said at least one hit simulation system is disposed in connection with a respective target.

24. The weapon effect simulation system according to claim 1, wherein the processor is operative to determine a hit location on the target.

25. The weapon effect simulation system according to claim 1, wherein the processor is operatively connected with the transmitter of the fire simulation system and operative to break off the simulation if a hit is determined corresponding to damage or injury that renders continued firing impossible.

Description

BRIEF DESCRIPTION OF FIGURES

(1) FIG. 1 shows an example of an application of the invention for firing practice.

(2) FIG. 2 shows a block diagram of the simulation equipment contained in the tank depicted in FIG. 1 according to a first embodiment.

(3) FIG. 3. shows the application in FIG. 2 with the imagined trajectory of a simulated round of ammunition marked.

(4) FIG. 4 shows a block diagram of equipment contained in a target depicted in FIG. 1 according to a first embodiment.

(5) FIG. 5 shows a block diagram of the simulation equipment contained in the tank depicted in FIG. 1 according to a second embodiment.

(6) FIG. 6 shows a block diagram of equipment contained in a target depicted in FIG. 1 according to a second embodiment.

PREFERRED EMBODIMENTS

(7) A conventional weapon, which consists in the example according to FIG. 1 of a gun on a tank 1, can be used in simulated firing practice. In FIG. 2, a weapon system comprises the gun and a simulation system disposed at the gun. The simulation system in turn comprises a transmitter device 2 disposed in connection with the gun, suitably in the barrel 4 of the gun, and a simulator unit 3. The simulator unit 3 is connected with a firing system 5 for the gun, an ammunition selector 18 for selecting the ammunition type, a measuring position sensor 19 to determine the motion status of the weapon, and a GPS receiver 20 that receives the geographical position of the simulator unit 3. According to one embodiment, the GPS receiver is supplemented with a radio receiver for receiving a correcting signal, so-called DGPS.

(8) The weapon is aimed and fired as though a real round were being fired, and each time the gunner fires the weapon, the transmitter equipment 2 is initiated in that a control unit 6 actuated by the firing system 5 of the tank causes a laser transmitter 12 in the equipment 2 to emit radiation in the direction of the barrel, which radiation is preferably pulsed. The laser radiation is shaped upon emission in a known manner into lobes 7′ and 7″ with long and narrow cross-sections 8′ and 8″, which extend along separate planes, forming an angle to one another. From the weapon, the radiation propagates in a fan-shaped beam toward a target area 9, which the gunner in the tank can monitor. In the target area there is a target group, which consists in the example shown of three vehicles 10, 10′ and 10″. The laser lobes 7′ and 7″ are caused to rapidly and periodically scan the target area 9 or a part thereof. This is achieved in a known way via deflecting elements 11 that are arranged in the beam path of the laser transmitter 12. In the unrestricted example illustrated in FIG. 1, the number of beam lobes used is two, but three or more beam lobes could optionally be used.

(9) The deflecting elements 11, realized in the form of e.g. mutually movable optical wedges, are controlled by means of signals from the control unit 6 so that each lobe executes a forward- and backward-moving linear sweep movement with a predetermined speed and direction of movement within a predetermined solid angle area whose cross-section in FIG. 1, is designated 9′, and which is suitably centered relative to the barrel.

(10) The simulator unit 3 contains a memory 22 arranged so as to store an identity that is unique for the tank 1. The targets 10, 10′ and 10″ also each have a unique identity stored in a memory 31 (FIG. 4) belonging to each respective target. The tank 1 constantly receives geographical position information via the GPS receiver 20. The targets 10, 10′ and 10″ also possess knowledge regarding their current positions via a GPS receiver 32 disposed at each respective target.

(11) In FIG. 2, the imagined trajectory 16′ (FIG. 3) of an ammunition 15 is generated in that, upon firing of the weapon, an ammunition trajectory calculating unit 17 that works together with the control unit 6 is initiated to generate a signal that reproduces the trajectory 16′ of the ammunition 15, taking into account such factors as will affect the trajectory before, after and at the instant of firing. Factors that are of interest before firing include the type of ammunition, which is selected in view of the target to be attacked. In the illustrative example, the gunner indicates the selected ammunition type by setting the ammunition selector 18, which is operatively connected with the ammunition trajectory calculating unit 17. Other factors that affect the ammunition trajectory are the alignment of the weapon and its motion status at the instant of firing. These parameters are supplied from the measuring position sensor, 19, which is operatively connected with the ammunition trajectory calculating unit. For example, the measuring position sensor 19 is equipped with a gyro by means of which the motion status of the weapon is detected. The influence of the atmosphere can affect the imagined ammunition trajectory both stochastically and as calculated based on known conditions from actual cases; such examples can include wind and air temperature. If the imagined ammunition is of a type that is guided after firing, then the guidance signals associated therewith are also included among the factors that can affect the imagined ammunition trajectory. The ammunition calculating unit 17 generates a signal that is determined relative to the direction of the gun and represents the imagined ammunition trajectory 16. The geographical position of the firing system from the GPS receiver 20 of the tank at the instant of firing is added to this signal to supply ammunition positions for the trajectory as an output signal. Ammunition position data representing the instantaneous ammunition trajectory position of the simulated ammunition can then contain, e.g. both the current range from the firing system, and azimuth and elevation relative to the direction of the firing system at the instant of firing, plus the geographical position of the firing system at the instant of firing. The more densely the points are calculated, the more accurate the simulation.

(12) The information stored in the memory 22 regarding the identify of the weapon, the information from the selector 18 regarding the ammunition type, and the information regarding the current ammunition position from the ammunition trajectory calculating unit 18 is fed via the control unit 6 to a code unit 21 in the transmitter [Deleted: laser] equipment 2. In the code unit 21, the identity, ammunition type and current ammunition position data (e.g. range, azimuth, elevation and the geographical position of the firing system) relative to coordinates in the three-dimensional space for the calculated ammunition trajectory are converted into series of pulses and pauses by means of which the lobes 7′ and 7″ of the laser transmitter are modulated in a manner that is known per se. The control unit 6 is arranged so as to control the laser transmitter 12 and the deflecting element 11 so that the laser lobes 7′ and 7″ illuminate the target area 9 in sweeps transmitted throughout the entire simulation process, whereupon the data concerning the ammunition position are updated for each sweep based on the calculated ammunition trajectory.

(13) In one example, the ammunition calculating unit 17 is arranged so as to calculate the ammunition trajectory in real time, whereupon the most recently calculated value is fed continuously via the control unit to the code unit for transmission together with the laser radiation. Alternatively, the entire ammunition trajectory is calculated upon the firing of a simulated round, whereupon the values at the calculation points are output compressed over, e.g. 1-2 seconds, corresponding to a suitable period for “Fire-and-Forget” and “Hunter-Kill”. The interval between respective sweeps should be chosen so that it is sufficiently short to achieve successful transmission to mobile targets such as vehicles, while higher update rates will at the same time yield higher levels of simulation accuracy. In FIG. 4, a target system at each target 10, 10′ and 10″ comprises a receiver unit 34 comprising one or more laser radiation-sensitive detectors 29 and a decoder 30. The fields of view of the detectors should be such that radiation can be detected in all occurring directions of fire as long as the target on which the detectors are disposed is not concealed. The information-bearing modulated radiation that is received by the detectors 29 is converted thereby into an electrical signal, which is fed to the decoder 30 for conversion into a form that is suitable for continued signal processing in an effect assessment unit 33. The assessment unit 33 comprises an information assessment unit 27 arranged so as to extract from the received information the identity of the unit transmitting the laser radiation and so as to compare, for each identity, the decoded ammunition position data with the target coordinates obtained via the GPS receiver 32 of the target. The ammunition position data and the target coordinates are stored together with the identity of the transmitting unit in the memory 31, which is contained in the effect assessment unit 33. If the comparison yields the result that the ammunition has not passed the target, new decoded ammunition position data are awaited for said identity. Upon reception of the new ammunition position data, they are compared with the target coordinates, whereupon the compared coordinates are fed to the memory 31 for storage as described above. At least in the case where the target is mobile, the coordinates for the target position are also updated for each new comparison. In one embodiment, the information transmitted from the transmission [Deleted: laser] equipment concerning the ammunition does not indicate the ammunition type, but rather indicates an identity that is unique for the ammunition, which identity in turn indicates the ammunition type. When the current position of the ammunition satisfied the condition that the ammunition has passed the target, the identity of the ammunition is, in this embodiment, stored in the memory 31 together with identity of the transmitting unit. The information assessment unit 27 is subsequently arranged so as to no longer process data for the ongoing simulation for this ammunition identity.

(14) When the ammunition has passed the target, the information assessment unit 27 also feeds a signal to the hit assessment unit 28, which initiates a hit assessment. During the hit assessment, a hit location for the ammunition is first calculated. This calculation comprises, e.g. the following steps: 1. The ammunition positions stored in the memory 31 are retrieved. 2. An ammunition trajectory is calculated by interpolating the retrieved ammunition positions. 3. The GPS coordinates for the target stored in the memory 31 are retrieved. 4. A trajectory for the target is calculated by interpolating the retrieved target coordinates. 5. The orientation of the target is determined so that the hit point can be calculated with the correct angle of aspect on the target. The orientation can be determined based on, e.g. the direction obtained from the GPS receiver or knowledge as to which detectors have been illuminated. 6. The hit point is calculated as the point at which the above-generated curves intersect.

(15) The aforedescribed calculation can also be performed continuously during the time while new ammunition positions are being received.

(16) In the event that the simulation is terminated early, e.g. if the firing system goes into concealment, the hit assessment unit can instead, based on received information, extrapolate the continuation of the ammunition trajectory. To increase the reliability of the simulation in this case, the firing system can transmit supplemental information continuously by radio. The hit assessment unit can then use this information as a reference in its extrapolation as per the foregoing algorithm example. The information about the entire trajectory for the real ammunition can also be contained within a time interval that is shorter than the real interval. For example, if the weapon system is of the “Fire & Forget” type, the entire trajectory can be calculated and transmitted over the period of time in which the gunner sees the target, so that the transmission can be completed before the gunner then releases the target from the sight and throws himself down into concealment. This principle is also important in the “Hunter-Kill” case. The ammunition trajectory can then be calculated by interpolating the retrieved ammunition positions as per the above algorithm, but with the addition that the comparison with the geographical position path of the target can be shifted in time so that the correct geographical point for the target is awaited.

(17) A vulnerability calculation is then performed to calculate the effect that a real round of ammunition would have had on the target if it had followed the same trajectory as the imagined ammunition. The calculation is based on, e.g. a predefined division of the target into different vulnerability fields, and translation of the above-calculated hit point into a field number. A hit within a specified field yields a specific effect, e.g. if a hit to the tank track results in a break in the track, causing the tank to become immobile, the soldiers inside the tank can continue to be combat-capable. The ammunition type is also taken into account in assessing the effect of the ammunition, since ammunition type information is stored in the memory 31. Additional examples of vulnerability calculations include firing on a house, where the hit location on the outer wall is determined with such precision that not only the effect on the outer wall is simulated, but also the residual effect on rooms behind the wall, whereupon one or more rooms may be affected. The effects on secondary objects such as people and objects that are present in the affected rooms when fired upon can thus be simulated as well. The effects on secondary objects can also be of significance in other situations, e.g. soldiers who are located in the immediate proximity of a vehicle that is hit, but where the soldiers are not directly exposed to the effect of the weapon because they are, e.g. concealed behind the vehicle.

(18) According to an expanded embodiment, the ammunition trajectory calculating unit 17 calculates the distance that the ammunition has covered and supplies this information continuously to the code unit 21 along with the position information for the ammunition. The hit assessment unit 28 then takes the distance covered by the ammunition into account in assessing the effect of the ammunition. If a fuse range is also included in the information in the laser radiation, it is possible to simulate, e.g. a timed air burst. In this embodiment, the information assessment unit 27 can be arranged so as to compare the fuse range with information about the distance covered by the ammunition, and to activate the hit assessment unit 28 when the distance covered by the ammunition exceeds the fuse range, which unit will then perform a vulnerability calculation as above. Alternatively, the simulation equipment 3 contains means for performing said comparison, and means for changing the ammunition type when the ammunition has traveled so far that the fuse range has been traversed. One type of ammunition can thus have different types of effects on the targets, depending on range. In the example involving a timed fuse, only a direct hit is possible in the first phase, while with a fuse range, e.g. via a timed air burst, an effect on the surface of the targets is achieved.

(19) Based on the hit assessment, the hit assessment unit 28 generates a message and supplies that message to a radio transmitter 26, which transmits the message. The message contains information regarding the damage that the ammunition 15 has inflicted on the target. The message can include, e.g. information about the identity of the target, the identity of the weapon that caused the damage, the ammunition type/ammunition identity, and the degree of damage inflicted on the target. During use in a military exercise, the message is received by a central unit that receives status messages from all the actors involved in the exercise that have a separate identity, such as people, weapons, vehicles, etc. In one example where the tank is equipped with a radio receiver 14 (FIG. 5) arranged so as to receive the status messages, the control unit 6 is arranged so as to break off the simulation of the ammunition 15 upon receiving a message that the ammunition 15 has hit. In the event that the tank is equipped with the radio receiver 14 arranged so as to receive the status messages, the gunner can also be re-supplied with the hit location and effect in that the information in the received status messages is converted into a graphical presentation and, e.g. reflected into the gunner sight. The firing system is then arranged so as to calculate, based on the received hit location, the coordinates in the sight and, based on received effect information, so as to select the type of symbol that represents said effect. The symbol is displayed at the calculated coordinates in the sight.

(20) In FIG. 5 and FIG. 6, all actors such as weapons, vehicles and people can be connected to radio communication equipment. The actors are in this case also equipped with a GPS receiver. The actors thus have equipment to transmit information concerning their geographical positions by radio to other actors, and they can also receive geographical position information from other actors. The weapon system as per FIG. 5 is accordingly equipped with the aforementioned radio receiver 14 and a radio transmitter 13, while the target system according to FIG. 6 is equipped with a radio receiver 25 in addition to the radio transmitter 26 already in place. By exchanging information by radio, the target simulation systems at each target come to know the position of the fire simulation system. As a result, a considerably smaller amount of information is included in the laser radiation, since the geographical position of the firing system does not need to be included.

(21) Furthermore, the transmitter equipment 2 in FIG. 5 contains a radio transmitter 23 connected to the code unit 21 and arranged so as to transmit identity, ammunition type and ammunition position information in the same way as the laser transmitter 12. The receiver unit 34 of the target systems is equipped with a radio receiver 24 that is arranged so as to receive information transmitted from the radio transmitter 23. The information assessment units 27 of the target systems are then arranged so as to assess the quality of the received laser radiation. If the quality of the laser radiation is satisfactory, further processing is carried out in the information assessment unit 27 and the hit assessment unit 28, based on the information coded in the laser radiation. If, on the other hand, the quality of the laser radiation is deemed unsatisfactory, then further processing is carried out based on the information coded in the radio waves.