EP2159531B1 - Hit detection method - Google Patents

Description

The present invention relates to a method for generating a directed energy selection for the detection of hits according to the preamble of claim 1. Furthermore, it relates to uses and devices for carrying out the method.

For combat exercises, it is known to use weapons in which shots are simulated by laser light beams. The participants in the exercises, but also possible target objects, are equipped with sensors which, when a laser beam strikes, i.e. of a simulated shot, give a signal. The occurrence of such a signal is used to display a hit. The evaluation can be done in different ways, e.g. by central registration, the signal e.g. is transmitted by radio, local signatures (signs of fire, etc.), acoustic signals etc.

Data is modulated onto the laser light. The modulation is carried out by changing the intensity, in the simplest case by switching the light on and off. The transmitted data thus appear as light pulses.

Another aspect of using laser light is the safety of the participants. In general, the laser sources must comply with the highest safety class, so that a direct look into the laser source with the naked eye or even through binoculars cannot cause any damage to the eye.

It has been shown that the detection of hits only has a significant lack of realism. It is therefore desirable to recognize short misses. Such a close miss can are indicated by optical or acoustic signals and, for example, draw attention to the fact that a bombardment is taking place.

According to DE-A1-42 13 209 the energy distribution of the laser beam is used for this. The laser light sources usually used have a bell-shaped distribution of the intensity over the cross section with the maximum in the center of the light beam. The sensors measure the intensity of the light beam that hits them. A close mistake (missed shot) or a "hit" outside the range of the weapon is characterized by an intensity below a predetermined threshold. Hits with a light intensity above this threshold are recognized as hits. A disadvantage of this method is that the sensors used must have an increased sensitivity in order to be able to detect with certainty the lower intensity of a short error up to a minimum intensity. As mentioned above, the intensity of the laser transmitter cannot be increased arbitrarily because the safety requirements set an upper limit.

In the US-A-4,373,916 the amplitude or intensity of the laser beam is also evaluated. Here, however, it is proposed to use sensors with different sensitivities. Obviously, this has the disadvantage that an increased number or more expensive sensors are necessary.

According to the US-A-3,588,108 the laser beam is swung from the weapon, with other data being modulated depending on the angle to the firing direction. The recipient can use the data to derive the angle at which the firing path is located and to determine whether there is a hit or a close mistake. The disadvantage of this solution is that increased effort in the laser source for the swiveling of the laser light and the dependent coding of different data, the higher evaluation effort on the part of the receiver and also the high expenditure of time, since in particular a complete swivel cycle has to be waited over all positions until it is certain that no hit at all is present.

In the GB-A-2 259 559 It is proposed to use two laser transmitters in the weapon, the two laser light sources having intensity distributions of different widths. In particular, the light from one laser light source can thus be recognized as a hit at a greater distance from the center of the beam than that from the other. It can thus be concluded from the detection of the first-mentioned laser light source at the hit location and the non-detection of the second laser light source that there is a scarce error. A disadvantage of this solution is the need to provide two laser light sources in the weapon. In addition, the temporal transmission of the data from the two laser light sources must be coordinated with one another in order to be able to reliably detect the impingement of both beams for a direct hit.

The GB-A-2 290 483 provides for additional data components to identify scarce errors. These additional data components are sent with a lower intensity. If these weaker parts are also recognized in addition to the data sent with "normal" intensity, the result is a hit. If, on the other hand, only the data without the weaker parts is detected, it is a short error. The disadvantage of this solution is the considerably increased amount of data, which leads to a higher expenditure of time for the distinction between a short error and a hit.

Starting in particular from the last-mentioned document, it is an object of the present invention to provide a method for generating an energy beam which allows a quicker detection of a short error or a hit.

Another object of the present invention is the simplified detection of a short fault.

Another object of the invention is to reduce the total energy of an energy beam used for the shot simulation.

A method that solves at least the first-mentioned object is specified in claim 1. The further claims specify preferred embodiments as well as uses and devices for carrying out the method.

Accordingly, as usual, data for identifying the weapon are transmitted by pulses or intensity modulation of the laser. In addition, part of the data is sent with a significantly increased intensity or increased modulation stroke. For example, this is simply done by increasing the power of the laser while sending these data parts.

By increasing the intensity of these data parts, they can be detected even at a greater distance from the center of the laser beam, ie a sensor with a predetermined detection threshold can recognize them at a greater distance from the center. This particular piece of data is also an integral part of the data that is normally transmitted, so that no additional time is required to transmit it. The data parts transmitted with higher intensity preferably comprise only a subordinate portion of the total data sent, so that the upper limit of the total intensity given for security reasons, eg laser class I, can be achieved by only slightly reducing the intensity of the other data.

Fig. 1

Schematische Darstellung eines Datenpakets in einem Zeit-Intensitäts-Diagramm;

Fig. 2

Schematische Darstellung eines Ziels mit Sensoren;

Fig. 3

Prinzipdarstellung einer Treffererkennungssituation;

Fig. 4

Schematische Darstellung einer Situation eines knappen Vorbeischusses;

Fig. 5

Blockschema eines Laserstrahlsenders; und

Fig. 6

Blockschema eines Detektors.

The invention will be further explained in a preferred embodiment with reference to figures.

Fig. 1

Schematic representation of a data packet in a time-intensity diagram;

Fig. 2

Schematic representation of a target with sensors;

Fig. 3

Principle representation of a hit detection situation;

Fig. 4

Schematic representation of a situation of a short shot past;

Fig. 5

Block diagram of a laser beam transmitter; and

Fig. 6

Block diagram of a detector.

Diagram 1 of the Fig. 1 is a plot of time 3 (t) against intensity 5 (I). The total time 7 (T = t ₁ - t ₀ ) of a date 9 is, for example, a few ms. More precisely, it comprises a number 11 of data locations (for example 8-128), each of which can be occupied by a pulse 14.

A pulse 14 consists of a light pulse of a certain duration. The pulses 17, 18 are transmitted with a much higher intensity I ₂ than the intensity I _{1 of} the "normal" pulses 14. Experience has shown that the intensity I ₂ must be at least twice the intensity I ₁ , preferred Values of at least three to four times I ₁ with I ₀ as the zero point, in the simplest case corresponding to the intensity 0. The pulses 17, 18 can also serve to secure the transmission, since they detect with greater certainty because of their significantly higher intensity will.

Obviously, no additional time is required for the additional detection of a short error, since the pulses 17, 18 are an integral part of the data 9. In addition, only detectors of a certain sensitivity and an evaluation with exactly one detection threshold are required, since the larger radius for the detection of a short error results from the connection between the higher intensity I ₂ and the bell-shaped intensity distribution in the light beam 29. This situation is shown in Figs. 2 and 3 shown graphically. A target 25 (for example a simulation participant or an object such as a vehicle) is equipped with sensors 27. The target 25 is struck by the laser beam of a weapon. The laser beam has a core zone 31 in which the intensity of the normal data pulses 14 lies above the detection threshold. In the surrounding zone 33, on the other hand, the intensity of the data pulses is below the detection threshold, but the intensity I _{2 of} the missile pulses 17, 18 is above.

Fig. 2 represents a target 25, which is provided with sensors 27. The sensors 27 are set to emit a signal when they are struck by a simulated shot, ie the laser pulse emitted by the training device.

Fig. 3 represents the situation of a hit: One of the sensors 27, the sensor 35, is in the area of the core zone 31 and can therefore receive the date 9. A number of others Detectors 37 lie in the area of the edge zone 33, but not the core zone 31. The detection of the complete date by the sensor 35 has priority over the signal from the sensors 37 and leads to the detection of a hit. The situation is different in that Fig. 4 : Here none of the sensors 27 are hit by the core zone 31, only two sensors 37 are located in the area of the shooting zone 33 of the laser beam 29. The sensors 37 thus detect the presence of a weapon laser beam, but none of the detectors can completely decode a data item 9. However, the data components can be decoded with higher intensity (pulses 17, 18). As a result, 25 missed the target.

From the previous illustration, especially Fig. 1 , it can also be seen that in the event of a close-by shot, where only a small number of pulses 17, 18 are detected by the sensors 37, the complete information of the date 9 is not available to identify the sending weapon. Nevertheless, a rough identification of the weapon, for example the assignment to a group of simulation participants or to a weapon type, is possible by evaluating the time period between the pulses. Pulse 17 is sent at time t ₀ , here at the beginning of date 9, while pulse 18 is sent at time t ₁ . A pulse 42 is sent out from another transmitter (different weapon type; weapon of another exercise participant) instead of pulse 18 at time t ₂ (in Fig. 1 shown in dashed lines). The different time intervals t ₁ - t ₀ or. t ₂ - t ₀ can be used to obtain an indication of the transmitters of the respective data 9. It is also conceivable to send the pulse 17 at other times within the date 9. Since this is preferably used for the purpose of transmission synchronization or the like, it is preferably sent at the beginning of the date 9.

Fig. 5 shows the block diagram of a light beam transmitter. The controller 45 receives a signal 47, for example when a shot is triggered, and then generates the control signals 49 which control the light transmitter 51. Under control of the control signals 49, the light transmitter 51 emits the light beam 29 onto which the date 9 is modulated. Diagram 53 schematically shows the distribution of intensity I over the radius r of light beam 29. Curve 55 is the intensity of data pulses 14, curve 57 is that of pulses 17, 18 and 42 for a close pass. The line 59 is the intensity detection threshold I _{c of} the detectors 27. The intersections of the detection threshold 59 with the curves 55 and 57 result in the zones 31 (hit area) and 33 (close shot).

Fig. 5 shows schematically a hit detection device 63. A number of detectors 27, which are located at a target 25, are connected to an evaluation unit 65. If one of the detectors 27 delivers a hit signal, ie a complete data item 9, the evaluation unit 65 recognizes a direct hit and triggers the corresponding actions. On the other hand, if the evaluation unit 65 receives a signal from at least one of the detectors 27 for the detection of shot pulses 17, 18 or 42, but from none of the detectors 27 a signal that represents a complete date 9, it detects a close shot.

• Es sind mehr als zwei Pulse 17, 18 mit erhöhter Intensität vorhanden, z.B. drei oder vier. Entsprechend steigen damit auch die Möglichkeiten bzw. die Genauigkeit, mit der der Sender selbst bei einem nahen Vorbeischuss identifiziert werden kann, und/oder die Sicherheit der Treffererkennung. Denkbar ist auch nur ein derartiger Puls 17, wodurch eine Identifikation des Senders ausscheidet.
• Es sind Pulse 17, 18 für die Erkennung eines nahen Fehlschusses mit verschiedener, jedoch deutlich unterschiedlicher Intensität vorhanden. Damit ergibt sich mehr als ein Vorbeischussbereich 33 um die Kernzone 31, wodurch in Stufen die Entfernung eines Vorbeischusses bestimmbar ist.
• Die Modulation muss nicht 100 % sein, d.h. zwischen den Pulsen, innerhalb der Pulse und/oder zwischen den Datenpaketen kann der Lichtsender einen schwachen Lichtstrahl aussenden. Entscheidend ist die Differenz zwischen dieser Grundhelligkeit I₀ und der Spitzenintensität I₁ der Pulse 14 bzw. I₂ der Pulse 17, 18 bzw. 42.

Starting from the preceding description of the invention and a preferred exemplary embodiment, numerous modifications are accessible to the person skilled in the art without departing from the scope of protection of the invention, which is given by the patent claims. The following are conceivable:

• There are more than two pulses 17, 18 with increased intensity, for example three or four. Accordingly, the possibilities or the accuracy with which the transmitter can be identified even in the event of a close pass and / or the security of the hit detection also increase. Only such a pulse 17 is also conceivable, as a result of which the transmitter cannot be identified.
• There are pulses 17, 18 for the detection of a close miss with different but clearly different intensities. This results in more than one shot-in area 33 around the core zone 31, whereby the distance of a shot-in can be determined in stages.
• The modulation does not have to be 100%, ie between the pulses, within the pulses and / or between the data packets, the light transmitter can emit a weak light beam. The difference between this basic brightness I ₀ and the peak intensity I _{1 of} the pulses 14 and I _{2 of} the pulses 17, 18 and 42 is decisive.

Claims (7)

1. Method for generating a directed energy beam (29) for the detection of a hit in a simulation environment, the energy beam being modulated during its transmission with at least one datum (9) and having an intensity distribution (55, 57) according to which the intensity decreases from the centre of the energy beam outwards, and a high intensity portion (17, 18; 42) of the datum (9) being imprinted on the energy beam with a substantially higher intensity (I₂) than the remainder (14) of the datum so that the impact of the high intensity portion of the datum on a target area with at least a predetermined minimum intensity and the fact that the remainder of the datum is below the minimum intensity (59) on the target area is recognizable as a near hit of the target area, characterised in that the proportion of time of the high intensity portion (17, 18; 42) in a datum (9) is at most one fifth, preferably at most one tenth, and/or the high intensity portion (17, 18; 42) of the datum (9) comprises at least two temporally separated periods, the time lag between those periods being utilisable as an indication regarding the emitter of the energy beam.
2. Method according to claim 1, characterised in that the energy beam (29) is laser light, preferably infrared laser light.
3. Method according to one of claims 1 to 2, characterised in that imprinting is achieved by amplitude modulation of the intensity, specifically by switching the beam on and off, the beam intensity being increased during the transmission of the high intensity portion (17, 18; 42) of the datum (9).
4. Method according to one of claims 1 to 3, characterised in that the beam intensity during the transmission of the high intensity portion (17, 18; 42) of the datum (9) is at least twice, preferably three times, and particularly preferably four times as high as it is during the transmission of the remainder (14) of the datum.
5. Method according to one of claims 1 to 4, characterised in that the high intensity portion (17, 18; 42) of the data (9) includes elements of the data that serve for the control of the data transmission, preferably for synchronisation purposes.
6. Hit detection method in which a directed energy beam according to one of claims 1 to 5 is used, wherein the impact of the high intensity portion of the datum on a target area with at least a predetermined minimum intensity and the fact that the remainder of the datum is below the minimum intensity on the target area (59) is classified as a near hit of the target area.
7. Device for carrying out the method according to one of claims 1 to 6, characterised in that it includes a transmitter (51) for generating the energy beam (29) that is operatively connected to a control unit (45) so that the beam intensity (I) is controllable by the control unit, and the control unit is configured to cause the transmission of a modulated energy beam by the transmitter as a function of a datum (9) to be transmitted, a high intensity portion (17, 18; 42) of the datum (9) being modulated with increased intensity (I₂).

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