Patent GB-1386830-A (GB)
Title: System for simulating the firing of a weapon at a target
IPC: F41G3/26
Filed: 1972-12-20
Abstract: 1386830 Teaching warfare SAAB-SCANIA AB 20 Dec 1972 [31 Dec 1971] 58948/72 Heading F3C [Also in Division H4]  A system for simulating the firing of a weapon at a target comprises a transmitter fixed to the barrel of the weapon for transmitting a diverging beam of optical radiation towards the target at which the weapon is aimed, a first device fitted to the weapon which causes the transmitter to send out a pulse train in response to simulated firing of the weapon, reflector means fitted on the target so as to reflect towards the weapon, at least a part of the radiation from the transmitter falling upon the target when the weapon is aimed at the target, a second device fitted on the weapon for receiving a pulse train reflected via the reflector means; the second device calculating from the pulse train the distance between the weapon and the target and calculating and indicating the position of an expected point of impact of a projectile from the weapon in relation to the target, a third device which can be programmed for the type of weapon and the type of ammunition and can cause the transmitter to transmit, as simulated fire towards the target, a coded pulse signal giving the type of weapon, the type of ammunition, the calculated distance between the weapon and the target and the calculated position of the point of impact in relation to the target, and a fourth device fitted to the target for receiving the coded pulse signal and for computing from said signal and indicating the effect of simulated fire. The second device may comprise a distance meter, a position-sensitive detector and a computer circuit which is connected to the distance meter and to the detector, and may indicate the expected point of detonation as a luminous spot reflected into the sight of the weapon which in case of a hit appears to lie on the target. The fourth device may comprise a computer device and a counter which can be pre-set to a number which corresponds to the total effect of the firing which is required for knocking out the target and which is counted down by the hit effect number and indicates, when it has been counted down to zero, that the target has been knocked out. A fifth device may be fitted to the weapon and can be pre-set to a number corresponding to the number of projectiles which the weapon carries. The fifth device can be counted down for each simulated firing and at countdown to zero from the pre-set number stops the firing. A recording device may be connected to the fourth device and records the time of and the effect of the simulated firing against the target. In an embodiment a tank 1, Fig. 1, fires at a tank 2, the simulated fire consisting of laser radiation beam which diverges from a laser pulse transmitter 4 attached to a barrel 5 of the tank 1 so that its axis is in line with the centre line of the barrel. The tank 2 has a reflector 6 which reflects the laser radiation back to the tank 1. A position-sensitive detector is connected to the transmitter 4 and the radiation from the latter comprises a laser pulse train with fixed frequency for measuring the position of the tank 2 and a laser pulse signal which constitutes the simulated fire itself and which in coded form contains the pre-calculated detonation point in relation to the target with regard to the position of the target, the movement of the tank 2 during the firing time, the type of ammunition, the firing distance, the kind of arms and the type of ammunition. The tank 2 is provided with laser radiation detectors 7, Fig. 3, which have sensitivity sectors covering the perimeter of the tank 1. A reflector 6 and a detector 7 can be formed into one unit as shown  in Fig. 2. The field of vision of the sight of the tank 1 is indicated at 8 in Fig. 4, the field of vision of the position-sensitive detector is 9 and the surface illuminated by the radiation beam of the transmitter 4 is 10. A point 13 of intersection between lines 11, 12 represents coordinates of the field of vision of the positionsensitive detector and relates to the position of the tank 2. The deviation of the target in elevation is a h  and in the azimuth direction is a s  and should coincide when firing is effected. Firing is by a trigger 15, Fig. 5, the laser transmitter is controlled by a control element 16, the frequency of the laser pulse train is controlled by an oscillator 17, which is connected via a measuring pulse generator 18 to the control element 16. The generator 18 converts the output signal of the oscillator 17 to distinguish it from previous laser pulse signals. If the aiming is accurate, the laser pulses will be reflected from the reflector 6 to the detector 14. The time taken by the pulses to leave the transmitter 4, to be reflected by a reflector 6 and by a mirror 19, and to be detected by the detector 14 which is connected to a computer device 20 allows the latter to calculate the distance between the tanks 1 and 2. The angular deflection at the instant of firing between the centre line of the barrel 5 and the centre of gravity of the reflected laser radiation is calculated by an angular position computer 21. Allowance for the distance to the tank 2 and the type of ammunition is made by an ammunition selector 22 and the firing time is calculated by a computer device 23. At the end of the firing time another laser pulse train is emitted and the angular relation to the centre-line of the barrel is calculated anew in the angular position computer 21. A gyro 24 is provided to determine the magnitude of the azimuth as well as the elevation of the barrel 5. The ammunition selector 22 is connected to a computer device 25 and the latter is connected to the computer device 20 to obtain the setting for the firing distance. The position in elevation of the detonation point is now calculated by a detonation point computer 26 which is connected to a detonation position indicator 27 and a luminous spot is generated which is reflected into the sight of the tank 1, this representing the detonation point of a discharged projectile. The detonation point computer 26 is connected to a coding device 28 which is connected to the ammunition selector 22 and to the distance computer device 20 and which is programmed with the type of weapon and of ammunition so as to cause the laser pulse transmitter to emit a laser pulse signal. This signal interrupts the laser pulse train which contains in coded form the calculated distance, the detonation point in relation to the tank 2 and is achieved by the coding device 28 receiving an output signal of the oscillator 17 and generating a coded signal which, via the control element 16, acts upon the transmitter 4. The laser pulse signal is converted by a detector 7 to an electrical pulse signal which passes to a hit data computer 31, via a hit receiver 29 and a decoder 30. The hit receiver 29 amplifies the detector signal and the decoder 30 is connected to an oscillator 32 having the same frequency as the oscillator 17 and produces the original information from the coded signal. The hit computer 31 determines if the correct type of ammunition is used and calculates the effect of the detonation. The detectors 7 are allocated different values according to the simulated damage received allowing for the type of ammunition used &c. The hit data computer 31 passes a signal to a hit effect counter 33 which is pre-set to a number which represents the amount of hits required to knock out the tank 2 and informs a hit indicator 34 when the tank 2 has been knocked out. An ammunition counter 35 is provided, is coupled to the trigger 15 and to the ammunition selector 22, and is pre-set to the number of projectiles carried by the tank 1.