Process for controlling the detonation of a mine and mine with triggering device operating in accordance with the process

A process for controlling the detonation of a mine for the combating of vehicles, in particular armored vehicles such as tanks, with an electronically-triggered detonating arrangement and, a mine including a triggering device which is actuated pursuant to the inventive process. The detonating arrangement is only triggered when a receiver which is connected ahead thereof has determined requisite, preset aggregate vehicular criteria in a vehicle approaching the mine. The receiver is provided with a pattern comparator which is supplied from a pattern storage in accordance with a pregiven vehicular type criterium and with a detector receiving signal from the currently detected vehicle.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a process for controlling the detonation 
of a mine for the combating of vehicles, in particular armored vehicles 
such as tanks, with an electronically-triggered detonating arrangement 
and, moreover, relates to a mine including a triggering device which is 
actuated pursuant to the inventive process. 
2. Discussion of the Prior Art 
In order to combat naval vessels, land vehicles or aircraft it is known to 
employ mines whose detonating arrangements are activated through the 
intermediary of electronically-controlled triggering devices; for example, 
upon contact or, in the case of remote-effect mines, upon the reaching of 
a predetermined degree of proximity. 
The present invention is predicated on the recognition that the tactical 
effectiveness of mines can be improved when they respond only selectively 
to objects, the combating of which is particularly rewarding or, 
respectively, particularly essential, so that the effect of laid down 
distributed or ejected mines will not become purposeless when they are 
brought to detonation by objects which are not rewarding from a military 
standpoint. 
Based on the foregoing recognition, the present invention has as its object 
the provision of a process and of a mine of that constructional type which 
leads to an enhanced degree of mine effectiveness. 
SUMMARY OF THE INVENTION 
Accordingly, it is an object of the present invention to provide a process 
of the type described in which the detonating device is only triggered 
when a receiver which is connected ahead thereof has determined requisite, 
preset aggregate vehicular criteria from a vehicle approaching the mine. 
Another object of the present invention is to provide a mine which is 
detonated pursuant to the foregoing process, wherein the receiver is 
provided with a pattern comparator which is supplied from a pattern 
storage in accordance with a pregiven vehicular type criterium and with a 
detector receiving signal from the currently detected vehicle. 
For such vehicular type criteria, pursuant to which there is to be 
initiated the triggering of the mine detonating arrangement, there is 
especially adapted the noise which is generated during the traveling 
motion of the vehicle, such as the frequency spectrum of the sound waves 
projected from the moving vehicle into the surrounding medium. This 
frequency spectrum will evidence characteristic distinctions in accordance 
with the vehicle type, such as for a truck in comparison with a tank. 
These signals are detected by a receiver which is designed for this 
purpose, analyzed and compared with a pregiven pattern as the criterium 
for the type of vehicle construction, at the approach of which they should 
trigger. At all times, the analysis of such a frequency spectrum; for 
example, in the manner of the digitally-calculated Fourier analysis, is 
quite complex in regard to its circuitry. The requirement for an 
inexpensive receiver for the function of such an "intelligent mine" is, 
however, not optional; a simplified process based on this signal 
processing can always be of use as a socalled waking function in order to 
activate further evaluating criteria, particularly such as those described 
hereinbelow. 
Pursuant to a modification of the invention, provision is made that the 
prerequisite pattern and for the receipt of the vehicle type criteria be 
based on the heat radiation distribution of the operatively warm vehicle. 
Within the context of the invention there can, as a result, be made 
provision that by means of a receiver arrangement of infrared detector 
elements there can be obtained a radiation scanning pattern of the 
vehicle, approaching the mine or its receiver, to extrapolate image with 
respect to typical radiation distributions, and to classify it through 
predetermined patterns. 
Since the scanning pattern in the direction of movement of the vehicle will 
produce itself through a time-serialized signal processing during the 
course of the approach, or upon the moving past of the vehicle, it merely 
requires a one-dimensional arrangement of infrared receiver elements, 
essentially grouped for a spatial receiving segment which is not located 
in the plane of the direction of movement of the vehicle and, preferably, 
stands perpendicular relative to this plane of movement. Scanned hereby is 
the radiation distribution in vertical elevation across the vehicle 
profile; namely, strip-shaped transverse to the direction of the continual 
vehicle movement. Obtained through these scanning strips is an infrared 
line image with respect to the contours of the vehicle; in effect, a 
contour profile representation with consideration given in the scanning 
pattern to the varying intensity distribution of the heat irradiation of 
the vehicle. Since the contour of a tank will clearly distinguish from the 
contour of, for example, a jeep or a truck, from a comparison with the 
typical pattern of a tank signature there is obtained the criterium for 
triggering of the detonating arrangement and, consequently, for the 
detonation of the mine for combating of only the type of object which is 
of interest. Disadvantageous for this solution is always the high cost for 
a receiver arrangement of that type which must be combined from a line 
grouping of selective infrared elements completely correlated with each 
other in their response characteristic. Also this component can be too 
expensive for the sought for, economical mass product, which as a rule is 
not reusable, in the form of the receiver for an "intelligent mine", of 
the herein contemplated type. 
Pursuant to a further modification leading to a preferred embodiment of the 
invention, there is considered the elimination of this raster-like 
scanning for obtention of the contour of the detected vehicle and, in lieu 
thereof, to determine the heat radiation of the detected vehicle through 
parallel-offset scanning strips relative to the vehicle moving through a 
strip-shaped action receiving characteristic at the present signal 
processing timepoint. Obtained therefrom is then (in lieu of the edge 
profile with the radiation intensity appearing in the represented geometry 
as brightness modulation) a distribution of the radiation intensity, 
determined transverse to the direction of vehicle movement, across the 
length of the vehicle in its direction of locomotion. Again, this is also 
typical for different types of vehicles. Thus, for a tank, following its 
profile from forwardly to the rear, the radiation intensity rises 
initially ramp-like so as to then remain somewhat constant; it makes a 
jump in the region of the turret, and within a short time drops off to a 
constant value, and then again rises extremely steeply high up and then 
drops down to zero; namely, in the region behind the engine which is 
located in the rear end portion. In contrast therewith, the lengthwise 
distribution of the radiation intensity determined transverse of a truck 
moving in the same direction past the receiver typically differs 
therefrom; namely in the region of the engine block and the driver cab it 
increases steeply and is relatively high, drops down to a lower constant 
value in the region of the load section, rises somewhat once again for a 
short period in the region of the rear axle differential, and then drops 
down to zero. Only when the typical intensity jumps occur in a typical 
sequence can there be determined any correlation with the stored pattern, 
and the mine is then selectively detonated since it has been approached by 
a vehicle which it is intended to combat. 
Such an infrared receiver for that type of obtained radiation intensity 
detection in a strip-shaped receiving area can consist of a single 
detector element which, preferably, has an optic connected ahead thereof 
for the blending of the spatial sector transverse to the plane of movement 
of the vehicle and for enhancing of the received radiation energy. 
Preferably employed is a single detector element which, in contrast with 
the usual geometry, is not edged so as possibly be limited to point-shape, 
but is formed as an elongated strip so as to directly provide the median 
value formation through the instantaneous scanning strip. The utilization 
of such a detector element no longer represents a significant cost factor 
since it need no longer be correlated with respect to coacting further 
elements which cooperate therewith. 
There is thus obtained an inexpensive capability for the selective 
triggering of the detonating mechanism of a mine in accordance with the 
appearance of predetermined vehicles within its destructive range, whose 
vehicle type criteria are easily determined and wherein, with a 
comparatively low requirement, they can be compared with stored criteria 
having the same signal characteristics.

DETAILED DESCRIPTION 
The scene represented in FIG. 1 illustrates a tank 2 as the type of vehicle 
approaching a mine 1 laid in the terrain. In the illustrated exemplary 
embodiment, a receiver 4 is positioned towards one side of the mine 1, and 
consequently also towards one side of the path of movement 3 of the tank 
2, preferably in an elevated region of the terrain, which is in an 
operative connection either wirelessly or through a wire with its mine 1 
through a control connection 5. However, in lieu thereof or additionally 
thereto, as is symbolically illustrated in FIG. 2, there can be employed a 
socalled remote-effect mine 1' which is built in directly together with 
the receiver 4, such as when the presumed path of movement 3 cannot be 
previously determined with sufficient probability. 
The receiver 4 operates with an infrared detector element 6 which in the 
distant range evidences a spherical receiving characteristic. The desired 
strip shaped characteristic 7 is obtained through the utilization of a 
geometrically conforming optic 8 which, in the illustrated principle 
representation, is indicated as consisting of a lens, which in actual 
practice, however, preferably can be constructed as a mirror with the 
location of the detector element 6 within its focal point. It is decisive 
that the interaction of a preferably strip-shaped detector element 6 and 
the optic 8 imparts the receiving characteristic with an opening pyramid 
of stretched cross-section so that there is detected a strip-shaped 
spatial segment perpendicular to the plane of movement of the tank 2. In 
the illustrated preferred exemplary embodiment, the receiving 
characteristic 7 is fixedly directed relative to the orientation of the 
receiver 4 in the terrain. Due to the locomotion of the tank 2 through the 
receiver characteristic 7, there is thus determined in the direction of 
the height of the vehicle, in effect transverse to the plane of movement, 
the heat radiation of the tank 2 in strip shapes which are offset relative 
to each other. 
The receiving amplifier 9 which is connected to the output of the detector 
element 6 with a scanning circuit 10 controlled in timed sequence, 
delivers a mutually time-sequenced series of intensity values which 
correspond with the intensity of the heat radiation determined through the 
strips of the detected vehicle profile. Thus, at a correspondingly large 
number of scanned values there is produced a received curve plot 11 which, 
as can be ascertained from the raster structure entered therein for the 
tank 2 in FIG. 1, includes the more details the more frequently is scanned 
the receiving signal of the detector elements 6 during the course of the 
passage through the receiving characteristic 7. 
Inasmuch as the length of the curve plot 11 over the time axis is dependent 
upon how rapidly the tank 2 (FIG. 1) traverses the receiving 
characteristic 7, there can be provided in the receiver 4, for instance 
behind the scanning circuit 10, a distortion circuit 12 which expands or 
compresses the curve plot 11 to a standard representative length; for 
example through uniform distribution of the sequence of the quantitized 
intensity median values among the storage positions of a storage of 
predetermined capacity. Thereafter the accordingly processed curve plot 
can be read out and directly compared in a pattern comparator 13 with a 
corresponding pregiven curve plot contained in a pattern storage 14 from 
the significant vehicle type criteria. 
In lieu of such a comparison with a pregiven curve plot, information can 
also be contained in the pattern storage 14 with respect to predetermined 
characteristics of the curve plot 11, such as over the mere qualitative 
sequential series of lower, median and higher integration results. 
Eliminated thereby is a distortion of the received curve plot 11 with 
respect to a stored curve plot. 
The output of the pattern comparator 13 can have an action counter 15 
connected thereto which prevents the triggering of a detonating signal at 
already the first appearance of the sought for vehicle type criterium in 
the received curve plot 11, in order not to frighten away any following 
vehicles (tank 2) of the same type of construction, in that already the 
first tank 2 upon approaching the first of the mines 1 or mine 1' would 
cause these to detonate. In lieu thereof, the significant vehicle type 
criterium must appear a predetermined number of times before the 
detonating arrangement 16 or 16' of, respectively, mine 1 or 1' will be 
triggered. When a plurality of mines 1 or 1' are to be controlled in the 
same manner through the receiver 4, but with differently set action 
counters 15, it is possible to ensure thereby that first, and only upon 
the entering of a corresponding number of vehicles, all of types which are 
of interest, into the controlled terrain region, will concurrently 
detonate all of mines 1 laid therein and provide for a correspondingly 
greater tactical effect.