JPH06281400A - Land mine - Google Patents

Abstract

(57) [Summary] [Purpose] For the purpose of moving at high speed, to provide a land mine that consumes less power for searching. [Structure] A sensor that detects the sound generated by the target and ground vibration that propagates on the ground due to the movement of the target, a means that detects the level of the received signal of this sensor, and the detection value of this level detection means When the level exceeds a predetermined level, a means for calculating the direction angle formed by the target and the reference coordinate axis based on the signal from the detection sensor, and the target direction, distance and speed are measured based on the calculated values of the calculating means. A radio wave transmission / reception sensor, a means for predicting the future meeting position of the warhead and the target based on the measurement value of this radio wave transmission / reception sensor, and a calculation result of this prediction calculation means aiming at the warhead in that direction and firing. And means.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention detects the approach direction of a target such as a helicopter or a tank, by detecting the approach direction of the target by means of aerial sound waves and vibration waves propagating on the ground surface and predicting the future meeting position of the target. However, it is concerned with land mines that fire by aiming the built-in warhead in that direction.

[0002]

2. Description of the Related Art Generally, a land mine is designed to ignite by detecting its weight and magnetism when a target approaches directly above. However, in recent years, as a land mine equipped with advanced technology, it detects the approach of the target with an acoustic sensor etc. and activates a radio wave transmission / reception sensor, performs signal processing of the target position based on the reflected radio waves, indexes the target position and fires it. Some have been proposed. For targets such as helicopters approaching at high speed, the wide-angle beam switching radar performs wide-angle beam search in the hemisphere to detect the approximate direction and distance of the target. After measuring the target position and determining the exact position,
Techniques for firing warheads are also known.

[0003]

In an example of a landmine with a radar, horizontal search is performed by selectively switching the director array of horizontal antenna elements, and is provided on a vertical plane that horizontally rotates in the elevation angle direction. The target is searched for in an arbitrary direction within the hemisphere by selectively switching the array of directors of the antenna element for the elevation angle direction. The signal processing time for target extraction from the transmission / reception signal that sequentially switches each direction in the hemisphere is the time required for horizontal rotation of the antenna for detecting the elevation angle, so in the case of a target such as a helicopter flying at high speed, the target must be searched from a sufficiently long distance. For example, there was a drawback that the target could not be captured and the transmission power consumption was large. At this time, even if the number of search points is reduced by using a wide-angle beam, the transmission power must be increased according to the beam width to obtain the same echo signal strength, and the search power consumption cannot be greatly reduced. Absent. Since the transmission power required to search for a target is generally proportional to the fourth power of the distance, there was a problem with the high-speed target that the power for land mines was exhausted early together with the increase in the search transmission time from a long distance. .

[0004]

The present invention adopts the following means in order to solve the above problems. That is, first, a sensor that detects the sound generated by a target such as a helicopter or a tank and a surface vibration that propagates on the ground surface when the target moves, and a means for detecting the level (magnitude) of the signal received by the sensor. is there. Next, when the signal level increases above the predetermined level by the level detecting means, means for calculating the direction angle formed by the target and the reference coordinate axis based on the signal from the sensor, and the calculated value of the calculating means. And a sensor for transmitting and receiving radio waves for determining the target tracking direction, distance and speed based on the above.
Also, based on the measured value of this radio wave transmission and reception sensor,
A means for predicting and calculating the future meeting position of the warhead and the target, and a means for aiming and firing the warhead in the azimuth direction based on the calculation result of the predicting and calculating means.

[0005]

When a target such as a helicopter, a tank or an armored vehicle approaches a land mine, a sensor detects the sound generated by the target and the surface vibration propagating on the ground surface. Next, when the value detected by this sensor becomes equal to or higher than a predetermined first level, the direction angle measurement calculation means and the radio wave transmission / reception sensor are turned on for the subsequent detection of sound or vibration of land mines. When the level becomes equal to or higher than the predetermined level of 2, the target direction angle is calculated based on this detected value, then the pointing direction of the antenna of the radio wave transmission / reception sensor is determined based on this calculated value, and the target direction angle is determined by the radio wave transmission / reception sensor. Measure horizontal angle, elevation angle, distance and speed. Next, the future meeting position between the built-in warhead and the target is predicted and calculated based on the measured value of the radio wave transmission / reception sensor. Then, depending on the calculation result, the warhead is aimed in that direction and fired.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of a land mine embodying the present invention will be specifically described with reference to the drawings. In FIG. 1, reference numeral 1 is an acoustic sensor for detecting a sound generated by a target such as a helicopter or a tank. , An acoustic array consisting of four microphones is configured to convert sound waves arriving at three pairs of microphones having a common apex microphone into electric signals, and the mutual time relationship between the electric signals of each pair changes according to the arrival time difference of sound waves. By utilizing this, the signal processing unit 6 can calculate the horizontal angle and the elevation angle from the origin of the acoustic array to the target. Reference numeral 2 is a vibration sensor that detects ground vibrations that propagate on the ground surface when the target moves. Reference numeral 3 denotes a radio wave transmission / reception sensor for tracking a target, which includes an antenna, a tracking calculation device, and the like. Reference numeral 4 is a warhead, and 5 is a drive unit, which includes an antenna of the radio wave transmission / reception sensor 3 and a tracking mechanism and an aiming mechanism of the warhead 4. Reference numeral 6 denotes a signal processing unit. The signal processing unit receives direction signals from the acoustic sensor 1 and the vibration sensor 2 to calculate a current position of a target, and a warhead and a target built in the warhead 4. It includes means for calculating the future meeting position with. Reference numeral 7 denotes a power supply unit, which has a built-in battery serving as a drive source for an antenna such as the radio wave transmission / reception sensor 3, the drive unit 5, and an aiming mechanism.

FIG. 2 is a schematic explanatory view showing the mutual relationship of the main constituent means with respect to the signal processing unit 6 built in the battery. The acoustic sensor 1 and the vibration sensor 2 are connected to a target direction angle measurement unit 8, and the target direction angle measurement unit 8 includes level detection means 11 (not shown). It is connected to the drive unit 5 and further connected in parallel to the target future position calculation means 9. On the other hand, the drive unit 5 is connected to the radio wave transmission / reception sensor 3 and further connected in parallel to the warhead firing means 10. The target future position calculation means 9 is connected to the drive unit 5. The signal processing unit 6 includes the target direction angle measuring unit 8 and the target future position calculating means 9.

FIG. 3 is a detailed block diagram of the target direction angle measuring unit 8. The microphones S1 to S4 are arranged at equal distances on three orthogonal axes as shown in FIG. 5, and the microphone S1 at the origin position is provided inside the acoustic sensor 1 at the top of the head of FIG. Place the ke on the leg. An amplifier (not shown) that increases the microphone output is connected to these acoustic detectors, and the output is connected to the target direction angle measuring unit 8. The vibration sensor 2 is also connected to the target direction angle measuring unit 8 via an amplifier (not shown).
The outputs of the microphone S1 and the vibration sensor 2 are connected to the level detecting means 11 and also to the filter 12 in parallel. The filter 12 is connected to the delay time detecting means 13, while the delay time detecting means 13 is connected to the direction angle calculating means 14. Also, microphones S2, S3 and S4
The amplifier output of is directly connected to the filter 12. The power-on / off signal line from the level detecting means 11 is the filter 1
2. It is connected to the delay time detecting means 13 and the direction angle calculating means 14. The microphone array shown in FIG. 5 is suitable for aerial and ground targets. Further, the one in which three microphones are arranged at the origin at the two orthogonal axes and at the origin shown in FIG. 6 is suitable for the ground target. For a pair of signals of each output of the microphones, for example, a cross-correlation function is used, and the sound source direction is calculated from the delay time at the peak. The filter 12 shown in FIG. 3 removes the disturbing line spectrum from all the sensor amplified signals, and the delay time detecting means 13 causes the amplified signals S1 to S for each pair of sensor axes.
2, the sound wave arrival time differences (referred to as delay times) such as S1, S1 to S3, and S1 to S4 are detected. A cross-correlation function is calculated from a large number of digitized sound pressure signals that have been time-series sampled with the delay time as a parameter. At this time, the fast Fourier transform (FF
Use T). If the peak value of the cross-correlation function is then selected, the delay time corresponding to that value is related to the angle of arrival of the sound wave between the pair of microphones with respect to that axis. From the delay time of each axis, the direction of sound source is calculated by the direction angle calculating means 14. In the case of the microphone array in FIG. 5,
The direction angle calculating means 14 converts the target direction from the microphone coordinate system to the reference coordinate system of the radio wave transmission / reception sensor 3, and further decomposes and calculates the target direction into the target horizontal direction angle and elevation angle. When the input of the microphone S1 or the vibration sensor 2 is equal to or higher than the first level set by the level detecting means 11, the level detecting means 11 turns on the power source of each means after the filter 12 according to the instruction of the power on / off signal line from the level detecting means 11. , And put it in a standby state. At this time, calculation is not performed. When the input from the microphone S1 or the vibration sensor 2 exceeds a preset second level (exceeds the first level), the input side relay of the filter 12 is in contact, and each of the following means including the filter is in an operating state. , The calculation is started according to the input signal. The vibration sensor 2 instead of the acoustic sensor 1 is insulated from the ground and can be used instead of the microphone when detecting sound waves. Also,
It is also possible to dispose the vibration sensor 2 on the ground surface as shown in FIG. 6, detect the propagation wave of vibration propagating on the ground surface, and calculate the direction angle of the vibration source similarly to the sound wave.

One example of a land mine embodying the present invention is constructed as described above. In FIG. 7, when a target H such as a helicopter flies over the land where the land mine is laid, first, At the position A, the acoustic sensor 1 built into the land mine causes the sound wave emitted by the target to cause the microphone output signal to reach a predetermined first level or higher,
Detects the approach of a target. Here, for the first time, the target direction angle measuring unit 8 and the radio wave transmission / reception sensor 3 are turned on to be in a standby state. Next, when the target H further advances and reaches the position B, when it is detected that the microphone output signal of the acoustic sensor 1 becomes equal to or higher than a predetermined second level, the target direction angle calculation unit incorporated in the signal processing unit 6 is detected. The filter 12 and subsequent elements in 8 operate to calculate the target H and the directional angle between the three axes of the microphone coordinate axes and the target. This direction angle is converted into the reference coordinate system of the radio wave transmission / reception sensor, further divided into the horizontal direction angle and the elevation angle, and the initial value is given to the radio wave transmission / reception sensor 3. After that, radio wave transmission / reception sensor 3
Autonomously calculates the target position and the Doppler speed, and passes them to the signal processing unit 6. The signal processing unit 6 obtains a target course direction from the speed and past time-series position data, and calculates a target speed component. From the above, the target approach detection section A to
During B, only the level detection of the output signal by the microphone array is performed, and at the target position B, the directional angle calculating means in the directional angle measuring unit first calculates the target directional angle. Therefore, the detection sections A and B do not require radio wave transmission / reception as compared with the conventional land mine radio wave transmission / reception sensor, so that power consumption in this section can be significantly reduced. If you try to start the search at the target position B, you will search each direction in the hemisphere with a wide beam,
The extension time required for the calculation process of extracting the target from the interference noise and the horizontal rotation time of the antenna for the elevation direction are required, and the target will pass the attack range of the land mine before the direction of the target is determined. If the accuracy of the direction angle detected by the sound is necessary and sufficient in place of the transmission / reception sensor 3 of the radio wave for detecting the direction angle and position of the target, a wide radio wave pulse, an infrared laser pulse or an ultra-wave pulse capable of switching the transmission direction to the indicated direction. The target position can also be calculated by emitting a sound wave pulse and measuring the distance according to the arrival time of the received echo. The target position B to C is a tracking section by the radio wave transmission / reception sensor 3, and the drive unit 5 aims the warhead at the target at a position close to the land mine so that the hit rate is high in this section. At this time, the future meeting position should be a position that takes into account the required landing time. That is, the target predicted position at the next predicted time calculated by the radio wave transmission / reception sensor 3 with respect to the target position at the current time by the drive unit 5 is set as a corrected predicted position at which the target has moved by the required landing time, and this is set as the aiming direction. The bullet head 5 rotates in the horizontal direction and in the vertical vertical direction in conjunction with the radio wave transmission / reception sensor 3, and at the time of ignition, it rotates at the corrected predicted angular velocity at the prediction time. However, adjust the firing timing so that the angular velocity at the predicted meeting time is below the allowable value. This future meeting position and firing timing determination is calculated by the target future position calculation means 9.
Then, based on this calculated value, the warhead 4 aimed by the drive unit 5 is ignited by the firing means 10. In addition, in order to classify whether the target is a helicopter or a tank upon an attack, the sound and vibration spectrum classification and vibration level are used to classify the target characteristics. FIG. 8 shows a flowchart of landmine operation.

[0010]

According to the present invention, when approaching a tank or a helicopter during high-speed flight, it is possible to indicate the initial pointing direction of the radio wave transmission / reception sensor toward the target direction calculated from the acoustic and vibration sensor signals. The search function of the radio wave transmission / reception sensor becomes unnecessary. As a result, the transmission power for the search function when searching the radio wave transmission and reception sensor becomes unnecessary,
Compared with the conventional sensor system for transmitting and receiving radio waves for land mines, it has the effect of consuming less power. The vibration and acoustic signal processing time is a time-series minute interval of sensor output with several processings compared to the calculation processing time of each point in the hemisphere of the radio wave transmission / reception sensor. Therefore, there is an effect that the time is set within a predetermined repetitive calculation time interval and is significantly shortened. Furthermore, when compared with the phased array radar method, it is possible to detect the target direction with several sensors and a simple direction angle measurement system, and it is possible to make a landmine that is inexpensive, small, lightweight and consumes less power. is there.

[Brief description of drawings]

FIG. 1 is a schematic perspective view of an essential part of an example of a land mine embodying the present invention.

FIG. 2 is a block diagram showing an example of the connection relationship of each technical means with respect to the signal processing unit built into the land mine of the present invention.

FIG. 3 is a block diagram illustrating a direction measuring system for a sound source and a vibration source.

FIG. 4 is a block diagram illustrating a generally used tracking radar system.

5 is an explanatory diagram showing an arrangement of microphones showing an example of the acoustic sensor in the case of FIG. 3. FIG.

FIG. 6 is an explanatory diagram showing a planar arrangement of acoustic sensors.

FIG. 7 is an explanatory diagram showing a relationship with a target when the land mine of the present invention is laid.

FIG. 8 is a flowchart showing an operating state of the land mine of the present invention.

[Explanation of symbols]

 1 acoustic sensor 2 vibration sensor 3 radio wave transmission / reception sensor 4 warhead 5 drive unit 6 signal processing unit 7 power supply unit 8 target direction angle measurement unit 9 target future position calculation unit 10 warhead firing unit 11 level detection unit 12 filter 13 delay time detection Means 14 Direction angle calculation means 15 Signal transmission / reception unit 16 Tracking device 17 Interference noise removal unit 18 Detection signal output unit

Claims (1)

[Claims] 1. A sensor for detecting a surface vibration propagating on the ground surface when a sound such as a helicopter or a tank is generated and the target moves, and a strength level of a signal received by the sensor is detected. And a signal level increased by the level detection means above a predetermined level, based on the signal from the detection sensor,
A means for calculating the direction angle formed by the target and the reference coordinate axis, a radio wave transmission / reception sensor for measuring the direction, distance and speed of the target based on the calculation value of this calculation means, and a measurement value for this radio wave transmission / reception sensor. Based on the above, a land mine characterized by comprising a warhead, a means for predicting and calculating a future meeting position of a target, and means for firing the warhead by aiming the warhead in that direction according to the calculation result of the predictive calculating means.