Practice mine, programming device therefor, and simulation device using said mine

IS 2 155 183 T3

DESCRIPTION

Exercise mine, programming device and simulation device used by said mine.

The scope of the present invention is that of exercise mines and devices that allow the simulation of the action of a mine.

Simulation devices are known that implement complex means to materialize the action of a mine on a vehicle or an individual.

Thus, the mine was almost never on the ground, but was assigned a theoretical position by a control post that was coupled by radio link to receivers carried by vehicles and / or individuals.

The position of the latter is known by means such as satellite positioning systems (commonly referred to as GPS) or inertial navigation plates. The checkpoint compares the actual position of vehicles and individuals with that of the mines and sends a signal to them when one of them starts a mine.

Such devices are complex in practice. They require the use of positioning means, the precision of which may be insufficient, and involve heavy calculating means. In practice, they can only be used on land specifically prepared and equipped with appropriate infrastructures.

These devices are also incomplete, since they do not allow to simulate the real placement of a minefield.

On the other hand, exercise mines are known which comprise harmless pyrotechnic charges (smoke, noise generators) which are put into operation by the approach of the vehicle or the individual. The advantage of mines of this type is that they allow the operation of a real mine to be realistically simulated. However, these are costly because they implement a pyrotechnic charge and the means of detection of a real mine.

Furthermore, although its effect, in principle, has no danger, uninitiated mines of this type may remain on the ground. Its use therefore requires a long and costly decontamination of the ground after the exercise.

US patent US5027709, which serves as the basis for the preamble of claims 1 and 8, describes a mine programming or simulation system that implements a passive circuit carried by a mine. This circuit is powered by inductive coupling with a system linked to the vehicle and is capable of transmitting signals to it. Such a device is complex and expensive.

Also known from document GB 2105952 is an anti-theft device for commerce comprising a label intended to be arranged on an article intended for sale. This tag comprises a passive oscillating circuit and a fuse. This device is not intended for the simulation of mines, nor for the lifting of a minefield.

The object of the invention is to solve the foregoing problems, proposing, on the one hand, an inert and inexpensive exercise mine, but which allows realistically simulating the effect of a real mine and, on the other, a device simulation of the action of a mine, which puts into practice an exercise mine of this type.

The invention also proposes a device for programming an exercise lead of this type, which makes it possible to confer on a given exercise lead different detection characteristics.

Finally, the invention proposes a device for simulating a minefield lifting operation, a device that also implements an exercise mine according to the invention.

Thus, the invention has as its object an exercise mine comprising at least one passive oscillating circuit tuned to a certain frequency, a circuit intended to be detected by at least one active oscillating circuit carried by an individual or a vehicle, mine characterized in that the passive oscillating circuit comprises at least one fusible or destructible part.

The passive oscillating circuit could comprise, at least, one inductance on the terminals of which at least two circuit branches are mounted, each branch being formed by a capacitance and a fusible or destructible part mounted in series.

The passive oscillating circuit could be made in the form of a rigid printed circuit fixed to amine.

It could also be made in the form of a flexible printed circuit attached to the lead.

Advantageously, the passive oscillating circuit was formed by a screen printing of a conductive paint.

This silkscreen could be carried by a label attached to the lead.

The invention also has as its object a device for programming a mine of this type, a device characterized in that it comprises an active oscillating circuit that generates a signal of adjustable frequency and intensity, an active circuit that allows determining the oscillation frequency of the passive circuit carried by the mine, and comprising a switch that allows the generation of a power signal to be controlled at this frequency of oscillation, Signal intended to blow a fuse attached to the mine's passive oscillating circuit.

The invention also has as its object a device for simulating the action of a mine, comprising means for detecting at least one passive oscillating circuit carried by a working mine, means comprising at least one oscillating circuit active, device characterized in that it comprises a variation detector that commands the emission of a power signal through the active oscillating circuit, a signal that commands the emission of a signal intended to melt, at least, a fusible or destructible part attached to the passive oscillating circuit carried by the mine.

According to a particular mode of realization, the detection means comprise at least one

ES 2 receiver coil coupled to amplification means and to a band-pass filter.

According to another embodiment, the detection means comprise at least two active oscillating circuits, each circuit being tuned, or being able to tune, to a different natural frequency, thus making it possible to detect and distinguish at least two passive circuits carried by two different exercise mines.

According to another embodiment, the active oscillating circuit is designed in such a way that it can supply a signal at a modulated frequency within a given frequency band, in such a way as to allow the detection of at least two passive circuits carried by two different exercise mines.

According to another embodiment, the active oscillating circuit or the filter is linked to a variation detector whose sensitivity threshold is determined in such a way as to detect a positioning of this active oscillating circuit at a given distance from a passive oscillating circuit attached to a mine.

Advantageously, the variation detector commands a signaling means.

The signaling means can comprise cut-off means placed in a vehicle power supply circuit, these means being actuated by the variation detector in such a way as to command the stop of the vehicle.

According to another mode of realization of the invention, the simulation device comprises a control device of at least one duration of activity of an exercise mine, a device that comprises a clock and, at least, a memory or register intended to receive at least one number representative of a duration of activity, this control device commanding means of switches in such a way as to prevent the control of the signaling means by the variation detector when the duration of activity associated with this detected mine has elapsed.

According to a variant, the simulation device comprises a control device for at least two durations of activity of an exercise mine, a device that comprises means that make it possible to determine the tuning frequency of the detected passive circuit and associate to this frequency one of the activity durations stored in memory, in such a way that the control of the signaling means by the variation detector is prevented when the duration of activity associated with the detected mine has elapsed.

Advantageously, when the simulation device is adapted to a vehicle, the active oscillating circuit comprises a coil fixed to a front part of the vehicle and isolated from the west by a screen of material with high magnetic permeability and high resistivity.

The invention also has as its object a device for simulating a minefield lifting operation, which was characterized in that it comprises a generator of a signal at a determined frequency, this signal having an intensity chosen to blow the fuse or the integral fuses of a circuit

183 T3 4 oscillating passive carried by an exercise mine according to the invention.

The invention was better understood by reading the description of particular modes of realization, a description that is made in relation to the attached drawings and in which:

- figure 1 shows a mine according to a particular embodiment of the invention,

Figures 2a and 2b are views of the front and back of the label carried by the lead of Figure 1,

- Figures 3a and 3b show the implementation by a vehicle of the simulation device according to the invention,

Figure 4 is a simplified electrical diagram of the simulation device according to a first embodiment of the invention,

figure 5 represents a variant of the passive oscillating circuit,

Figure 6 is a simplified electrical diagram of the simulation device according to a second embodiment of the invention,

Figure 7 is a simplified electrical diagram of the simulation device according to a third embodiment of the invention,

Figure 8 is a simplified electrical diagram of the simulation device according to a fourth embodiment of the invention,

Figure 9 is a simplified electrical diagram of the simulation device according to a fifth embodiment of the invention,

FIG. 10 is a simplified electrical diagram of the device for simulating a minefield lifting operation.

Referring to figure 1, an inert exercise lead 1 according to the invention has a substantially cylindrical body 2. This lead has a shape that is similar to that of a war mine, this in order to allow its placement in a realistic way.

The placement could be manual or carried out by means of a disperser or a gravedigger. It could be used, for example, a disperser constituted by a projectile or a rocket that transports them or, also, by a disperser comprising launch tubes mounted on a vehicle.

In order to limit contamination of the exercise grounds, the mine will preferably be made up of a block of a biodegradable material, for example, compressed and dried peat or, also, a cement that disintegrates with moisture.

One face3 of the terminal carries a label4 affixed by pasting.

In Figures 2a and 2b the label 4 is seen in detail.^orThis is made of a flexible plastic material, for example, Nylon (or also of paper) and carries a conductive ink tank (for example, based on graphite) on each of its faces. The deposit will be made, preferably, by screen printing. The set of conductive ink reservoirs constitutes an oscillating electrical circuit 5 comprising an inductor 6 on whose terminals a capacitor 7 is mounted.

A 7th capacity armor is carried

ES 2 155 183 T3 on one side of label 4, and the other armor

7b is carried by the other side of the label. The label material constitutes the dielectric of this capacity.

The inductance is carried by a single face of the label and is formed by a conductive track in the shape of a spiral. The capacitance armature 7b is connected to the inductance by a connection 8 that passes through the label.

The connection could be made, for example, by providing a hole that passes through the label and which is filled, after screen printing, by a conductive material. The hole may also metallize.

The oscillating circuit 5 is totally passive. No power source is foreseen, which makes the mine extremely rugged and cheap. The capacitance and inductance values ​​will be chosen such that this circuit is tuned to a given frequency that depends on the characteristics of an active oscillating circuit carried by an individual or a vehicle.

It is easy to vary the capacity by playing with the surface of the armatures 7a, 7b and to vary the inductance by playing with the length and maximum diameter of the spiral.

It is thus possible to choose different characteristics for a mine intended to simulate a counter-tank mine or for a mine that simulates a counter-personnel mine.

Figures 3a and 3b show a vehicle 9 (here a battle tank) that carries in its front part a box 10 that constitutes a part of a simulation device according to the invention.

The box is placed in a substantially middle position between the vehicle chains (see figure 3b).

This box contains an active oscillating circuit that is positioned in such a way that it emits an electromagnetic field towards the front of the vehicle 9.

The active oscillating circuit is intended to act as a detector for the passive oscillating circuit 5 carried by the exercise mine.

1.

Figure 4 shows a simplified electrical diagram of the simulation device according to the invention.

The box contains detection means, comprising: an active oscillating circuit comprising an inductance 11, a capacitance 12 and a generator 13, a circuit connected to a variation detector 14. The active circuit is tuned to a frequency that is the same as that of the passive oscillating circuit 5 carried by mine 1.

During the passage of the detector box near the mine 1, the active oscillating circuit 11, 12, 13 becomes unbalanced due to the coupling that acts between the active oscillating circuit 11, 12, 13 and the passive circuit 5. This is it translates, for example, into a variation in its frequency, its amplitude or its consumption depending on the assembly under consideration (assemblies of this type are classic and well known to those skilled in the art).

The variation detector 14, of known type (for example, a synchronous detector), has a sensitivity threshold determined in such a way that it detects the approach of the active oscillating circuit 11, 12, 13 at a given distance from the passive oscillating circuit 5. This distance will be chosen as the one corresponding to the commissioning of a real mine by the vehicle.

The variation detector is linked to a control means 15 that will then automatically start up one or more signaling means depending on the user's wishes, for example:

- the operation of a siren

16,

-Send it by radio (antenna 17) to an exercise management center, with the information that the vehicle is out of combat.

- the cut of circuits 18 (electrical and / or hydraulic) placed in a vehicle power supply circuit, cut that leads to the stop of its engine 39 and / or its immobilization on the ground.

The control means will comprise, for example, a microprocessor that manages the start-up of the signaling means (by means of static relays) according to the programming given by the user. It will also be able to include a GPS receiver that can calculate the coordinates of the carrier during the encounter of the mine, and radio transmission means that send these coordinates and that can, likewise, send information relative to the nature of the mine found (for For example, the value of the passive circuit frequency or a code stored in memory and associated with this frequency). Naturally, the control means could be realized with conventional means, for example, electromechanical relays controlled by a wired logic circuit.

It is possible to precisely regulate the activation distance, playing, on the one hand, with the sensitivity of the variation detector 14 and, on the other, with the power of the generator 13.

Naturally, the box 10 may not contain more than a part of the oscillating circuit 11, 12, 13 and will almost always contain the inductance 11.

Specifically, this inductance will be made in the form of a coil and it will be isolated from the magnetic mass of the vehicle by a screen of material with high magnetic permeability (greater than or equal to 1,000) and high resistivity (greater than 10^-6 ÍLm) This screen will be placed, for example, at the bottom of box 10 and can be made from Mumetal.

Such an arrangement makes it possible to limit the influence of the carrier on the oscillating circuit.

At this example, a passive circuit 5 can be tuned to a frequency between 100 kHz and 10 MHz. The active circuit carried by the vehicle will work at the same frequency and will have a power lower than 5 W (for example), which allows a detection of the passive circuit at a distance between the coil and the lead of the order of 500 mm. The sensitivity threshold can then be adjusted in such a way that the mine is only detected when it is

ES 2 155 183 T3 find under the vehicle and this whatever the position of the mine with respect to the ground.

It is seen, therefore, that the invention allows a very realistic simulation of the operation of a mine. This simulation is both more realistic when the command means can cause the vehicle to stop and put it out of combat.

The radio transmission of the vehicle status allows remote monitoring of the conduct of the exercise. None of the means put into practice needs complex calculation means. The vehicle could be equipped with navigation means coupled to the radio transmission means, this in order to retransmit the coordinates of the immobilized vehicle to the exercise management center.

The invention has been previously described in its application to the simulation of contravehicle mines. It is also possible to define a counterpersonal exercise mine that is equipped with a passive oscillating circuit according to the invention. A different frequency of use was then chosen from the frequency or frequencies associated with contravehicle mines.

Each individual participating in the exercise will be provided with an appropriate individual detector, analogous to the one described above, and whose frequency and range are chosen in such a way that the counter-personnel mine is detected and its commissioning is simulated (for example, by means of an alarm carried by the individual, coupled, eventually, to a dye cartridge that marks his suit).

It was observed that, thanks to the invention, to conduct the exercise in a realistic way, it is not necessary to know precisely the location of the different mines. It is therefore possible to disperse these mines by all known conventional operational means (projectiles, rockets, launchers).

It was observed that, by an appropriate choice of operating frequencies, a contravehicle mine will not be detected by an individual, which makes the exercise more realistic.

The mines used are totally inert and their abandonment on the ground does not generate any risk for the civilian population or animals. In addition, they can be made of biodegradable materials, which facilitates their automatic elimination. The passive oscillating circuit is non-toxic and small, and does not pollute the ground. On the other hand, it is possible to carry out the circuit on a biodegradable label (paper, for example).

Figure 5 represents a variant embodiment of the passive oscillating circuit 5, represented, in this case, in the form of a serigraph carried by a label 4.

The circuit according to this variant comprises a fuse 19 made by thinning the screen-printed conductive track.

Following this variant, during the detection of the passive circuit by the variation detector 14, means are provided (for example, a power switch) that control the generator 13 in such a way that the latter sends a signal of sufficient intensity so that the current induced in passive circuit 5 blows fuse 19.

The interest of a variant of this type is to render the passive circuit 5 ineffective afterwards. Thus, the most realistic exercise is carried out, not being able to detect an exercise mine more than once.

Without departing from the framework of the invention, several variants are possible.

Thus, the passive oscillating circuit carried by the mine can be realized in the form of a rigid printed circuit fixed to the mine, or placed inside it.

This circuit can carry classic electronic components (capacities, resistances, inductances, fuse) soldered to the tracks of the printed circuit.

The passive oscillating circuit can also be realized in the form of a flexible or relatively flexible printed circuit, fixed to the lead, for example, a glass / epoxide circuit or a circuit that carries solid metal tracks of a plastic material.

Figure 6 shows a simplified electrical diagram of a simulation device according to a second embodiment of the invention.

This mode differs from the previous one in that the control means 15 comprises an activity duration control device 20.

This device comprises a memory 22, into which a duration of activity of the exercise mines is entered (for example, with a keyboard 23).

It also includes a clock 21, a comparator 25 and a solid state relay 24.

The operation of this variant embodiment is as follows:

Before the exercise, the duration of activity of the exercise mines used is entered in memory 22. The clock is adjusted at the beginning of the exercise in such a way that time 0 corresponds to the assumed placement of the mines.

Static relay 24 was in the normally closed position. Thus, when a mine is detected by the variation detector 14, the signaling means are commanded as before.

When the time indicated by the clock 21 becomes equal to that entered in the memory 22, the comparator 25 causes the opening of the solid state relay 24.

After this opening, the signaling means are no longer actuated when the vehicle (or the individual) encounters an exercise mine.

A variant of this type also makes the exercise more realistic.

Specifically, the activity duration control device 20 is carried out with the aid of a microprocessor that manages the operation of the control means 15.

Figure 7 shows a simplified electrical diagram of a simulation device according to a third embodiment of the invention.

The detection means contained in this device comprise two generators 13a and 13b, each feeding a different active oscillating circuit formed by an inductor (11a, 11b) and a capacitor (12a, 12b). Each active circuit was tuned to a frequency

IS 2 155 183 T3 different.

This simulation device is put into practice with exercise mines that comprise a passive oscillating circuit 5 of the type that was schematized in figure 7. This oscillating circuit comprises an inductor 6 on whose terminals two circuit branches are mounted, each of which is formed branch by a capacitance (7a, 7b) and a fuse (19a, 19b) mounted in series.

This passive oscillating circuit was represented, in this case, in a first state in which no fuse was blown. There is, then, a resonant natural frequency Fr equal to Fr1 = (2 π y / L (Ca + Cb))^-1.

The active oscillating circuit (11a, 12a, 13a) was chosen such that it is tuned to the resonance frequency Fr1.

With a passive oscillating circuit 5 of this type, the flux variations to which the self-induction coil was subjected induce a current I that is distributed in each branch as a function of the value of the Ca or Cb capacity of said branch. The higher value capacity (for example Ca) will be traversed by the highest current. If the circuit is subjected to an intense field of frequency Fr1, a current I1 could be caused, causing the fuse 19a located in this branch to blow.

The passive oscillating circuit 5 is then modified and there is a new resonance frequency Fr2 = (2 k (LCB ')^-1.

The active oscillating circuit (11b, 12b, 13b) was chosen such that it is tuned to this resonance frequency Fr2.

There is thus a means of recognizing two different types of mines. The active oscillating circuits (11a, 12a, 13a) and (11b, 12b, 13b) both emit permanently. When one of them is unbalanced due to its coupling with a passive circuit 5, this unbalance is detected by the associated variation detector 14a or 14b.

In the case of figure 7, it is the circuit 11a, 12a, 13a tuned to the frequency Fr1 that detected the proximity of the passive circuit 5 that carries its two fuses.

Once the fuse 19a has been destroyed, it is the circuit 11b, 12b, 13b tuned to the frequency Fr2 that will detect the proximity of the passive circuit 5.

The variation detectors 14a and 14b are connected to the control means 15, which, in this embodiment, comprises an activity duration control device 20.

This device comprises a clock 21 and two memories or registers 22a, 22b.

Each memory is destined to receive a representative number of a theoretical activity duration of the exercise mine used.

Memory 22a will receive an activity duration that will be associated with an exercise mine whose passive circuit has the resonance frequency Fr1, and memory 22b receives an activity duration that is associated with a mine whose passive circuit has the resonance frequency Fr2. .

The memories are programmed by means of the keyboard 23 or a serial link.

Between each memory 22a, 22b and the signaling means (16, 18), there are positioned switch means (for example, static relays 26a, 26b). Each medium is in a normally open state. AND^orThis is commanded by the associated variation detector 14a, 14b. The detection of an exercise mine of a certain type also causes the tipping of the relay 26a, 26b associated with this type of mine.

An OR logic gate 27 regroups the outputs of the memories 22a, 22b downstream of the static relays 26a, 26b. The output of this gate gives the content of memory 22a or 22b corresponding to the mine detected by the active oscillating circuits. This content is compared (comparator 25) with the time value supplied by clock 21.

The static relay 24 will, in this case, be in a normally open state. When the useful life of the detected lead (T1 or T2) has not been exceeded, the static relay 24 is closed and triggers the signaling means 16, 18.

When the useful life has been exceeded, the relay 24 is normally open and the signaling means are not actuated.

As a variant, it is of course possible to provide a static relay 24 which is in a normally closed state. In this case, the comparator 25 was mounted in such a way that, when the duration of the detected useful life has been exceeded, the relay is open and the signaling means are not actuated.

Therefore, a closing timer for the static relay 24 was envisaged, to allow the vehicle to move away from the mine in question so as to allow the vehicle to take into account another type of mine whose duration of activity has not yet elapsed. A timing of this type could be replaced by the detection of the movement away from the oscillating circuit previously detected (return to the initial state of the active oscillating circuit).

Specifically, the activity duration control device 20 was also realized with the help of the microprocessor that manages the operation of the control means 15.

The command means could transmit, as before, through the antenna 17, parameters relative to the detected mine, for example, the coordinates of the carrier during the encounter of the mine, and the nature of the mine found (passive circuit frequency or code associated with this frequency). This transmission could be sent, whether or not the duration of the mine's activity has elapsed. Information regarding the nature of the mine could be taken, for example, at the exit of gate O 27.

This embodiment of the invention has been described with a passive circuit comprising two capacity / fuse branches connected to the inductance terminals and with a simulation device composed of two active oscillating circuits. It is, of course, possible to define a passive circuit, carried by a label attached to the lead, and equipped with several capacity / fuse branches. A passive circuit of this type could have as many different resonance frequencies as there are branches carrying a capacitance. It was chosen

IS 2 one of these frequencies by blowing a certain number of fuses.

In practice, to carry out an operation of this type, a programming device is used that comprises an active oscillating circuit (analogous to that used in the vehicle) but in which it is possible to vary the frequency and amplitude of the emitted signal. This active circuit allows, first of all, to determine the oscillation frequency of the passive circuit. Once the circuit is tuned to this frequency, the operator activates a switch that allows the generation of a power signal to be controlled at this oscillation frequency. As previously described, this signal blows the fuse found in the branch that has the maximum value capacity, thus modifying the natural frequency of the passive circuit.

The resonance frequency search operations after the generation of a power signal are repeated as many times as necessary to blow different fuses of the passive circuit and give it the desired natural frequency.

As a variant, the programming of the passive circuit could be done by mechanically cutting the branches that must be excluded from the passive resonant circuit.

As an example, it is possible to make a passive circuit that includes an inductance L = 5μΗ and three capacities Ca = 10nF, Cb = 5nF and Cc = 1nF. A circuit of this type can have three resonance frequencies: Fr1 = 563 kHz (if all three capacities are active), Fr2 = 919 kHz (if only Cb and Cc are active) and Fr3 = 2,250 kHz (if only Cc is active) . These three frequencies are far enough apart from each other to ensure easy discrimination of three different types of mines.

The simulation device carried by the vehicle (or by an individual) then comprised three active circuits tuned to these three possible frequencies.

Figure 7 described the embodiment in which the mines could have different durations of activity, each duration of activity being associated with a different frequency of the passive circuit.

It is possible to define another mode of realization in which, to each possible frequency for the passive circuit, not a different duration of activity is associated, but a different nature of the mine.

It could be considered, for example, that such a passive circuit 5 that carries its two fuses 19a and 19b and that has a frequency Fr1 corresponds to a counter-tank mine and that the passive circuit in which the fuse 19a has blown and that has the frequency Fr2 corresponds to a counterpersonnel mine.

The simulation device used in this case is similar to that described in relation to figure 7. It differs from this in that the outputs of memories 22a, 22b after relays 26a and 26b are not compared with the clock signal (suppression of the comparator 25 and the OR gate 27). In fact, the information "type of mine" (supplied, for example, by memories 22a, 22b) is used to send the signaling means

183 T3 12

16, 18. These means may be different for each type of mine. A “counter-tank” mine causes, for example, the vehicle to stop and a counter-personnel mine simply a sound signal. As before, the command means could transmit the coordinates of the vehicle and the characteristics of the mine found.

Such an embodiment is particularly advantageous, since it makes it possible with a single passive circuit mode to simulate different types of mines.

In the embodiments described in relation to Figures 6 and 7, after the detection of a mine whose duration of activity has not elapsed, a power signal of a sufficient intensity was provided for the current to be generated by the generator 13. inducing in passive circuit 5 blow fuse 19. When circuit 5 comprises several fuses not yet destroyed, the duration of the signal will be chosen sufficient to ensure the destruction of all the fuses and the putting out of service of the passive circuit.

Figure 8 shows a simplified electrical diagram of the simulation device according to a fourth embodiment of the invention.

This device is also represented in association with a passive circuit 5 that comprises at least two capacity / fuse branches placed in parallel at the terminals of inductance 6.

The active circuit differs from the circuits described above in that the detection means comprise a frequency modulated generator 28 coupled to an emitter coil 29. Frequency modulated generators are well known to those skilled in the art. These provide a signal whose frequency varies periodically between two fixed limits.

Generators of this type are commonly used in electronics, for example, to regulate the tuned circuits of radio or television receivers.

The generator was coupled as before to a variation detector 14, linked in turn to the control means 15.

The latter comprise a computer 30 that receives the signal from the variation detector (link 32) as well as the signal supplied by the generator (link 31).

The calculator thus determines the frequency value F emitted by the generator 28 and for which a coupling with the passive circuit 5 has been detected.

This calculator is also linked to two memories or registers 22a, 22b, each containing a representative number of a theoretical activity duration of the exercise mine used. By programming the computer 30, a given frequency of the generator 28 has been associated with each memory. The computer is also programmed in such a way that it supplies at its output 33 the content of the memory corresponding to the detected frequency. This number is compared with the signal of the clock 21 (comparator 25), and when the "duration of activity" of the detected mine has elapsed, the switch means 24 are controlled in such a way that the control of the signaling means is prevented.

ES 2 155 183 T3 (16, 18).

The static relay 24 will be, for example, normally open and its closure will be commanded by the comparator 25 if the duration of mine activity has not elapsed.

With this embodiment it is, of course, possible to detect more than two types of passive circuits.

It is also possible not to consider different durations of activity, but rather to replace the comparator 25 and the relay 24 by means of controlling a signaling adapted to the type of mine detected (counter-tank or counter-personnel).

It is also advantageous to generate a power signal that makes it possible to put the detected passive circuit out of service.

The advantage of a variant of this type is that it makes it possible with a single generator 28 to adapt the simulation device to many different passive circuits.

However, when the simulation device must be implemented by a fast vehicle (speed greater than 30 km / h), the variant comprising several generators that emit their signals simultaneously will be preferred (figure 7).

Figure 9 shows a simulation device following a fifth embodiment of the invention.

This mode differs from the previous ones in that the detection means comprise, on the one hand, a generator 36 containing an active oscillating circuit coupled to an emitting coil 37 and, on the other hand, a receiving coil 41 connected to a receiving amplifier circuit 40 .

A bandpass filter 38 receives the signals emitted by the generator 36 and those received and amplified by the circuit 40. (This isolates in the signal received by the coil 41 the frequency lines that are due to the magnetic field emitted by the coil 37, this in order to avoid disturbances due to outside fields.

The filter could be, for example, a synchronous filter, the principle of which is well known to the person skilled in the art.

The filter is linked to a variation detector which is in turn linked to control means that can be made in any of the ways described above.

The operation of this device is as follows.

When the device passes by the proximity of an exercise mine following the invention that carries a passive circuit 5, the field emitted by the coil 37 generates a current in the passive circuit 5.

This current causes a modification of the magnetic field in the vicinity of the passive circuit. This modification causes a variation in the amplitude of the voltage at the terminals of the receiving coil 41. This variation is detected by the detector 14 and causes the control means 15 to take into account a mine and the eventual start-up of the means. signaling 16, 18.

The advantage of a variant of the invention of this type is that it allows to separate the function "generation of a magnetic field" and the function "detection of a disturbance of the field". It is therefore possible to choose different inductance values ​​for coils 37 and 41, values ​​well adapted to the function of each coil.

Magnetic field imbalances caused by passive circuits are thus more easily detected, resulting in increased detector sensitivity.

Another advantage of this variant is that it allows the emitting coil and the receiving coil to be placed in different places.

Thus, for putting the simulation device into practice in a vehicle, the two coils will advantageously be placed under the vehicle at the level of a front part of the vehicle, each coil being arranged in the vicinity of a different side of the vehicle.

Thus, it will be possible to place the emitter coil 37 in the vicinity of the right front wheel (or right chain) and the receiving coil 41 in the vicinity of the left front wheel (or left chain).

It will also be possible to place the transmitter coil at the front of the vehicle and the receiver coil at the rear of the vehicle.

In all cases, the coils will preferably be oriented such that the emitter coil 37 emits its magnetic field towards the ground below the vehicle, the receiver coil 41 being oriented so as to receive a maximum magnetic flux from the ground.

Such an arrangement favors the detection of exercise mines located under the vehicle, therefore mines which, from an operational point of view, are located in such a place that they are normally initiated by the vehicle.

With proper sensitivity regulation, it is then possible to detect only the mines that are actually under the vehicle and not to detect those that are on either side of it. The device according to the invention thus provides a simulation even more similar to operational reality.

It is, of course, possible to combine this embodiment with the modes described above.

In particular, several pairs of emitter (36) / receiver (40) may be provided, each associated with a different detection frequency, this in order to distinguish mines of different natures or durations of activity (combination of this mode of realization with that of figure 7).

A frequency modulated generator could also be provided for the generator 36 (this embodiment is combined with that of FIG. 8).

The invention also has for its object a device for simulating a machine for lifting a minefield. A device of this type is described in relation to figure 10.

This simulation device is put into practice with exercise mines according to the invention, that is, equipped with a passive oscillating circuit comprising one or more capacities (7a, 7b).

IS 2 155 183 T3

AND^to This comprises a generator 13 coupled to an emitting coil 29. The frequency of the generator can advantageously be regulated by the control means 15 (connection 34). The generator is also linked to a variation detector 14 whose output signal is applied to a computer 30 of the control means 15. The memories or registers 22a, 22b each receive a number representative of a duration of activity Theoaric of the exercise mine used.

The calculator verifies whether a detected mine is active or not, and eventually sends signaling means 16a, 16b when the mine is "active".

The intensity of the signal emitted by the generator will be chosen sufficient in such a way that it will blow the fuse or fuses carried by the passive circuit. In practice, although the intensity is permanently high enough to neutralize passive circuits, the approach of a circuit of this type will cause a disturbance of the emitted signal that is sufficient to ensure a detection and allow the emission of a signal (for example, sonora) reporting the destruction of a mine.

Analogously to the way described in relation to FIG. 7, several generators having different emission frequencies could be provided, this in order to allow the recognition of several mines of different types.