EP0144890B1 - Device and method for impact point determination - Google Patents

Description

The present invention relates to a method for determining meeting points according to the preamble of claim 1 and an apparatus for performing the method.

From DE-A-1 951 622, an arrangement for simulated representation of firing trajectories in training devices for the operating personnel of ballistic weapons or missiles is known, in which the firing trajectory is based on directional signals set by the operator as well as on stored signals which take account of the terrain coordinates and the type of ammunition continuously determined automatically and visually superimposed on the environment observed by the operator through the directional optics with the target located therein. The target is arranged there in a natural environment or in a three-dimensional model environment, and a computer is provided which continuously determines the individual points of the projection of the shooting path onto the view of the directional optics of the operator. A cathode ray tube is connected to the computer, on whose screen, which is immovable relative to the directional optics, the projection of the shot path determined by the computer can be represented. The directional optics are provided with a device by means of which the on-screen representation of the firing path is optically superimposed on the image of the environment seen by the operator. In order to determine the point of penetration of the firing trajectory and terrain, the computer continuously compares the firing trajectory coordinates with the coordinates of the railing sector under the firing trajectory. Likewise, the coordinates of the targets can be stored in the terrain, and these can also be compared with the firing trajectory coordinates synchronously in order to determine a hit or a shot placement.

On the other hand, it is already known from DE-A-3 133 866 to digitally save a visor, targets and terrain and to present them on a screen. Here, when the target is displayed on the terrain, a mutual concealment of the target and the terrain is taken into account.

Usually the target silhouette that can be hit is approximated by a rectangle. A hit may only be displayed if the bullet trajectory passes through the visible area of the target silhouette. To date, this fact has not been taken into account in the prior art, so that hits that are not at all were also displayed.

It is therefore the object of the present invention to specify a method which allows realistic meeting point determination. This object is achieved according to the characterizing features of patent claim 1. Further advantageous refinements of the method according to the invention and an apparatus for carrying out the method can be found in the subclaims.

• Fig. 1 ein Blockschaltbild zur Erläuterung der Bilderzeugung nach dem bekannten CSI-Verfahren (CSI = Computer Synthesized Imageryj;
• Fig. 2 die Darstellung eines Zieles;
• Fig. 3 die Darstellung eines teilweise verdeckten Zieles; und
• Fig. 4 einen Bildmultiplexer gemäss der Erfindung in näheren Einzelheiten.

An exemplary embodiment of the invention will be described in more detail below with reference to the figures of the accompanying drawing. Show it:

• 1 is a block diagram for explaining the image generation according to the known CSI method (CSI = Computer Synthesized Imageryj;
• 2 shows the representation of a target;
• 3 shows a partially hidden target; and
• Fig. 4 shows an image multiplexer according to the invention in more detail.

1 shows a block diagram for realizing the known CSI method. The impressions of a terrain, a target, a bullet tracer and a sighting mark, which are normally visible in a visor or a directional optics, are loaded in quick access memories 10, 12, 14 and 16 and are assembled pixel by pixel in the television clock via an image multiplexer 20 controlled by a computer 18 . The composite digital image information is fed via a digital / video converter 22 to a TV monitor 24, on which a composite image is displayed, in particular partial concealment of the targets by terrain parts such as ridges, bushes, houses etc. is possible.

Usually, the target area of a target Z is approximated by a rectangle R, which is optimally fitted into the target silhouette, as shown in FIG.

According to FIG. 3, the target Z approximated by the rectangle R can be covered, for example, by a hill in the background H. In this case, only real hits of the target result if the projectile trajectory and thus the tracer trajectory passes through the part of the target Z which lies above the target concealment line ZV predetermined by the background H. Below this line of concealment, target Z is protected by terrain H, and therefore no hit may be displayed.

FIG. 4 shows the block diagram according to FIG. 1 in more detail. The computer 18 loads the quick access terrain or background memory 10 with one corresponding to the current viewing direction depending on addresses that are generated via address transmitters (not shown) coupled with a directional handle 26 Image section. This image section can be taken from a mass storage device 42, for example. The target memory 12 is also loaded with a specific target from a target program library 28. For this purpose, the computer can calculate the respective view of the target as a function of the target movement. Furthermore, different types of ammunition can be specified via an ammunition selector switch 30, and accordingly different light traces to be stored in the tracer memory 14 can be calculated by the computer 18.

The contents of all memories 10-16 are read out synchronously with the clock of the TV clock generator 40, and the respective information is combined in an OR gate 32 and, after digital / analog conversion, arrives in the digital / analog converter 22 on the TV -Monitor 24 for display.

A controller 34 determines for each pixel whether this pixel should be a target or terrain pixel. When deciding on a target pixel, its gray value must first deviate from zero (G _z > 0). If this is the case, then further checked by the controller 34 whether the target distance is less than the background distance (Ez <E _H ). If both conditions are met, the controller 34 switches a switch 36 so that a pixel from the target memory 12 is displayed. From this it can be seen that information can be derived from the controller 34 as to whether the pixel currently going through the switch 36 is a target pixel. If this information is combined in an AND gate 38 with the pixels of the tracer from the tracer memory 16, a signal is provided at the output of the AND gate 38 if and only if bullet tracer pixels and visible target pixels occur simultaneously, which is only the case is when the projectile trajectory and thus the tracer overlap on the screen. If the signal at the output of the AND gate 38 is only evaluated at the point in time in the process computer 18 at which the projectile trajectory has reached the target, it can be ensured that hits are only recognized when the projectile has first reached the target level and secondly, the bullet has touched the visible target area. For all other cases, the signal at the output of the AND gate is missing, so there is no hit display.

The method according to the invention and the arrangement for carrying out the method can not only be used with a realistic meeting point display for a tracer. The same problem arises when simulating a laser rangefinder, in which a target distance is only to be displayed if the laser beam hits the target and not the terrain. In this case it can be assumed that the laser beam coincides with the cross with a certain divergence. It is then checked to what extent the visible target parts and the divergence figure of the simulated laser beam overlap, for which purpose the divergence points of the laser beam from a memory 44 are coincident with the target picture elements in an AND gate 46.

The position of the coincidence in relation to the target can also be used to determine whether secondary echoes occur and whether these secondary echoes are at a smaller or greater distance than the target echo.

Claims (3)

1. A method for evaluating the impact point of a simulated projectile trajectory or of a simulated laser beam, respectively, on a simulated target movable within a simulated terrain, whereat the terrain, the target, a sight and a tracer trajectory of the projectile or the trajectory of the laser beam, respectively, are digitally stored image point-by-image point, and a composed image is generated on a TV-monitor in the field of view of the optics of a person to be trained and whereat at conformity of the simulated projectile trajectory or laser beam, respectively, with image points of the target a hit or a laser echo, respectively, is indicated, characterized in that a hit with a target is only indicated in the event where at range conformity between the projectile and the target the image points of the tracer trajectory coincide with image points of the visible target silhouette or a laser echo is only indicated where the image points correlated to the simulated laser beam coincide with the image points of the visible target, respectively.

2. Apparatus for implementing the method according to Claim 1 comprising digital memories (10, 12, 14, 16) for storing the terrain, the target, the tracer trajectory and the sight and comprising an image multiplexer (20) for superposing the contents of the memories, characterized in that the image multiplexer (20) comprises a switch (36) which in scanning of the memories randomly selects the image of the terrain (H) orthetarget (Z), respectively, whereat the switch (36) is actuated by a control unit (34) which compares the range of the target to the range of the terrain if a target is present.

3. Apparatus according to Claim 2, characterized by an AND-gate (38) enabling the hit indication to which the contents of the memory for the tracer trajectory is applied and which is enabled by the control unit (34) in the event where at the same time an image point of the target is to be displayed.

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