JP3186838B2 - Proximity fuse device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a proximity fuse device,
In particular, it is mounted on a moving body equipped with a warhead (for example, a flying object such as a cannonball, a missile, an underwater vehicle such as a torpedo), and when the moving body comes close to a target object (for example, an aircraft, a ship, etc.), The present invention relates to a magnetically actuated device for instructing ignition of an ammunition.

[0002]

2. Description of the Related Art A conventionally known magnetically-operated proximity fuse device uses a phenomenon in which the magnetic field of the earth is distorted around a metal surface, and includes a system for detecting a change in the magnetic field using a coil. I have. In such a proximity fuze device, when a moving body on which the device is mounted passes near a target object including a metal component, the magnetic field passing through the coil in the above system changes, thereby generating an electromotive force in the coil. ,
Since an electric current is generated in accordance with the magnitude, an ignition timing signal is transmitted to the ignition circuit of the warhead using the electric current.

[0003] As another known form, there is a proximity fuze device which reacts when a target object is a metallic object without using the magnetic field of the earth. One example is disclosed in, for example, JP-A-63-55034. In this device, a transmission coil and a reception coil are separately arranged, and canceling or nullification (nullization) is performed by an induced output signal from a high-level electromagnetic field directly induced from the transmission coil and a drive signal to the transmission coil. The target object is detected separately from the interference guidance signal for detecting the target object.

[0004]

In the above-described magnetically-operated proximity fuse device, the change in the magnetic field of the earth is extremely small, so that the electromotive force (ie, current) induced in the coil.
However, there is a problem in that it is difficult to transmit an ignition timing signal at an optimal timing using the current. That is, it has been difficult to realize a device for instructing the firing operation of the ammunition of the warhead at a precisely defined distance from the target object.

[0005] Further, in the proximity fuze device which does not depend on the magnetic field of the earth, there are restrictions on the location of the coil by the casing when mounting on a flying object or underwater vehicle, and the influence of the surroundings of the device. Therefore, there is a problem that fluctuation of nullification (nulling) occurs in response to this. Further, in the underwater vehicle, the magnetic and electric noise components during the cruising become larger than the magnetic and electric noise components at the time of adjustment on land. For this reason, there is a problem that the detection level of the target object has a small margin with respect to the noise during traveling, which leads to an unstable state, which may cause an accidental explosion.

[0006] In the conventional system, it is possible to secure safety by adjusting the magnetic balance on land, but the magnetic unbalance and the electric noise component increase during sailing. As a result, the margin of the detection level is reduced, and accordingly, the security is also reduced. Therefore, there is a problem that the reliability of the target detection of the proximity fuse device is reduced. The present invention
It was created in view of the problems in the prior art,
Eliminates the need for a high-level electromagnetic field between the transmitting coil and the receiving coil, reduces the influence of the casing on mounting, prevents malfunctions, and accurately detects the target object near the moving object and detonates It is an object of the present invention to provide a proximity fuze device capable of transmitting a timing signal at an optimal timing.

[0007]

According to the present invention, in order to solve the above-mentioned problems, the present invention is mounted on a moving body having a warhead mounted thereon, and when the moving body comes close to a target object, an ignition operation of the ammunition of the warhead is performed. A code generator for generating a coded two-phase random signal, a delay circuit for delaying the generated coded two-phase random signal by a predetermined bit, A modulator that performs direct spread modulation on a two-phase random signal with a signal of a predetermined frequency and outputs an encoded modulation signal, a transmission coil that distributes and emits a high-frequency magnetic field in the air by the encoded modulation signal from the modulator, A receiving coil for generating induced power by an interference induction magnetic field generated by an eddy current flowing on the surface of the metal part of the target object by a high-frequency magnetic field from the transmitting coil; Means for distributing the coded modulation signal according to the power into two signals, and a coded two-phase random signal from the delay circuit and a code from the code generator for the two coded modulation signals, respectively. And a demodulation circuit for outputting a first demodulated signal and a second demodulated signal, respectively, and adding a fixed bias to the output second demodulated signal. A circuit for setting a threshold level adapted to the electromagnetic environment inside and outside the device; and a circuit for comparing the set threshold level with the output first demodulated signal, and based on a result of the comparison, The proximity fuze device is provided, wherein the ignition operation is commanded when the level of the first demodulated signal is high.

[0008] In a preferred embodiment of the present invention, the modulator has means for performing Manchester encoding when performing coded modulation, and the demodulation circuit includes first and second demodulated signals. Means for decoding the Manchester-encoded signal when generating

[0009]

According to the above-mentioned structure, a nullification (nullization) is not performed by a signal directly induced by a high-level electromagnetic field between a transmission coil and a reception coil and a drive signal to the transmission coil. Threshold levels that are adapted to the magnetic and electrical noise environment inside and outside the device without causing a decrease in detection margin and safety due to an increase in magnetic unbalance and electrical noise components during navigation Therefore, it is possible to accurately detect a nearby target object using the encoded two-phase random modulation signal.

Therefore, it is possible to transmit the detonation timing signal to the ignition circuit of the warhead at an optimum timing, and it is possible to effectively concentrate the munitions of the warhead on the target object. Further, when the modulator and the demodulation circuit have means for performing Manchester encoding or decoding thereof, it is necessary to prevent the binary signal "1" or "0" from being transmitted continuously. Therefore, it is possible to reduce the energy loss of the signal. This also contributes to improving the distortion of the received signal waveform caused by passing through the transmission coil and the reception coil.

The details of the other structural features and operations of the present invention will be described with reference to the accompanying drawings using embodiments described below.

[0012]

FIG. 1 schematically shows a configuration of a magnetically operated proximity fuse device according to an embodiment of the present invention. The proximity fuze device of the present embodiment is mounted on a moving body equipped with a warhead (for example, a flying object such as a shell, a missile, or an underwater vehicle such as a torpedo). This is a device for transmitting an explosion timing signal to an ignition circuit of a warhead when approaching a predetermined distance from a moving body.

In FIG. 1, reference numeral 1 denotes a code generator for generating a modulation code (coded two-phase random signal C1) by driving, for example, a shift register by an output clock signal of a built-in clock oscillator (not shown). Reference numeral 2 denotes a delay circuit that delays the encoded two-phase random signal C1 output from the code generator 1 by 1 bit, 3 denotes an oscillator that oscillates a constant high-frequency signal F, and 4 denotes a 1-bit delayed code from the delay circuit 2. 2 shows a modulator that performs direct spread modulation on a generalized two-phase random signal C2 using a high-frequency signal F from an oscillator 3 using, for example, a balanced modulator, and outputs the result as an encoded modulation signal M1.

Reference numeral 5 denotes a transmitting coil for emitting a high-frequency magnetic field in the air in accordance with the coded modulation signal M1 from the modulator 4, and 6 denotes an eddy current flowing on the surface S of the metal part of the target object 30 by the high-frequency magnetic field from the transmitting coil 5. A receiving coil for generating an induced power by an interference induction magnetic field generated by Ir and inducing an encoded modulation signal M2 according to the induced power, an amplifier 7 for amplifying the induced encoded modulation signal, and an amplifier 8 for amplifying the induced encoded signal. A divider 9 that distributes the divided signal into two, and a demodulator 9 that responds to the one-bit delayed coded two-phase random signal C2 from the delay circuit 2 and one of the signals (the coded modulation signal M2) distributed by the distributor 8 Similarly, reference numeral 10 denotes a demodulator which responds to the coded two-phase random signal C1 from the code generator 1 and the other signal (coded modulated signal M2) distributed by the distributor 8.

The demodulator 9 obtains a correlation between the received signal (ie, the coded modulation signal induced by the receiving coil 6) and the 1-bit delayed coded two-phase random signal C2 from the delay circuit 2 (correlation). Demodulation), a strong correlation output is generated only when the target object 30 approaches and the induced power is generated in the receiving coil 6 by the interference induction magnetic field. After only a predetermined frequency band component is filtered through the band-pass filter 11, the correlation output signal is amplified and detected by the amplification detector 13 and input to the detector 16.

The signal directly spread by the coded two-phase random modulation signal generates a high-level correlation output with respect to a signal having the same phase as the own code, and outputs another code or 1 code.
Only a very low level correlation output is generated for a code signal whose phase is shifted by more than a bit. This principle is described in, for example, the document "SPREAD SPECTRUM SYSTEMS, RCDIXON
The present invention utilizes this principle.

Similarly, the demodulator 10 receives the received signal (the coded modulation signal induced by the receiving coil 6) and the code generator 1
Performs correlation demodulation with the encoded two-phase random signal C1. In this case, the code output from the code generator 1 has a phase one bit ahead of the coded two-phase random modulation signal actually used for transmission.
Can generate only a signal in which an uncorrelated transmission signal that is not correlated with noise in the apparatus or an external interference signal is despread by the modulation code C1. This demodulator 10
After only a predetermined frequency band component is filtered through the band-pass filter 12, the output signal is amplified and detected by the amplification detector 14 and input to the bias generator 15.

The bias generator 15 adds a constant bias to the input signal (ie, a signal of a predetermined frequency band component of the output of the demodulator 10), and applies a magnetic and electrical noise environment inside and outside the apparatus. Set the adaptive threshold level accordingly. The signal having the set threshold level is input to the detector 16.

The detector 16 compares the output signal of the demodulator 9 input via the band-pass filter 11 and the amplification detector 13 with the output signal of the bias generator 15 (the signal having the above threshold level). When the signal level of the former exceeds the signal level of the latter based on the comparison, a signal corresponding to the level difference is output. The output signal based on this comparison is a signal in which the noise in the device, the external interference signal component, and the uncorrelated transmission signal component have been canceled out.
Only the received signal component from the target object 30 is truly indicated (detection signal). This detection signal is sent to the warhead and used as an ignition timing signal for controlling the firing operation of the ammunition of the warhead.

In the modulator 4 and the demodulators 9 and 10 used in the present embodiment, the modulation codes C1 and C2 are used to improve the distortion of the received signal waveform caused by passing through the transmitting and receiving coils 5 and 6. Is subjected to Manchester encoding for transmission and reception. The Manchester encoding is, as shown in FIG. 2, two bits represented by “1” and “0”.
Each of the time slots T is divided into two for the value signal, and the code form is represented by a pulse on the left or right side of the time slot according to the level of the binary signal.
In the example of FIG. 2, the Manchester encoded signal is represented by a pulse on the left side of each time slot when the binary signal is “1”, and a pulse on the right side of each time slot when the binary signal is “0”. It is represented by

By performing the Manchester encoding of the modulation code in this manner, it is possible to prevent the binary signal "1" or "0" from being transmitted continuously, and to reduce the energy loss of the signal. It becomes possible. FIG. 3 shows a circuit configuration of the modulator 4 relating to Manchester encoding. The circuit shown is an exclusive OR gate 21 which responds to NRZ (Non Return to Zero) data (high-frequency signal F from oscillator 3) and NRZ clock (1-bit delayed coded two-phase random signal C2 from delay circuit 2). And NR
A frequency doubler 22 that doubles the frequency of the Z clock (C2) to generate a Manchester encoding clock
And a delay flip-flop 23 that generates Manchester encoded data (encoded modulation signal M1) in response to the generated Manchester encoding clock and the output of the exclusive OR gate 21.

FIG. 4 shows a circuit configuration of the demodulator 9 (or 10) for decoding the Manchester coded signal. The illustrated circuit includes a low-pass filter (LPF) 25 that passes a low-frequency component of a reception signal (the coded modulation signal M2 induced by the reception coil 6), and an output of the LPF for a predetermined time T / 2 (FIG. 2). And a comparator 27 that compares the output of the delay circuit with the output of the LPF 25.
And a sampler / threshold detector 28 for sampling the output signal of the comparator 27 and detecting the threshold level in response to the NRZ clocks (modulation codes C1 and C2) to generate NRZ data.

As for the technology related to the Manchester encoding and its decoding, for example, the document “IEEE, TRANS”
ON COMM., Vol.COM-31, No. 5, MAY 1983, pp. 608-619 "
It is described in. In the configuration of the present embodiment, the encoded two-phase random signal C1 from the code generator 1 is larger than the modulated signal of the transmission high-frequency magnetic field (corresponding to the one-bit delayed encoded two-phase random signal C2 from the delay circuit 2). Topologically 1
This is a bit advanced signal. Therefore, the demodulator 10 demodulates only the uncorrelated signal which is not correlated with the internal noise in the apparatus, the external interference signal or the interference signal with respect to the coded modulation signal M2 induced by the receiving coil 6. The bias generator 15 adds a constant bias based on the output of the demodulator 10, sets a threshold level suitable for the electromagnetic environment, and sends it to the detector 16. The output of the bias generator 15 is such that the internal noise in the apparatus, the interference from the outside, or the interference signal component has been canceled out, so that the detector 16 outputs a signal component from the target object 30 (ie, Only the received signal) is output as the detection signal.

Therefore, the target object 3 is located near the proximity fuse device.
When the 0 metal part S approaches, the above detection signal is output,
Based on this, a detonation timing signal is sent to the ignition circuit of the warhead. As described above, according to the proximity fuze device of the present embodiment, the transmission coil 5 distributes and emits the coded and modulated high-frequency magnetic field, and the reception coil 6 detects the interference induction magnetic field to induce the corresponding coded modulation signal M2. , Further divided into two signals via an amplifier 7 and a divider 8,
At 10, correlation demodulation is performed between the modulation codes C 2 and C 1, respectively, and a bias generator 15 and a detector 1
In step 6, the signal is compared with a threshold level set in accordance with an external interference signal component due to another high-frequency magnetic field, an internal noise component in the apparatus, and the like. Therefore, it is possible to accurately detect only the metal part S of the adjacent target object 30. This is the target object 30
This contributes to effectively and accurately concentrating the munitions of the warhead.

Since the modulator 4 and the demodulators 9 and 10 are configured to perform Manchester encoding or decoding thereof, it is possible to prevent the same code of a binary signal from being transmitted continuously. Can be. As a result, energy loss of the signal can be reduced, and the distortion of the received signal waveform caused by passing through the transmission and reception coils can be improved.

Further, there are disadvantages as seen in the conventional type (that is, when mounted on a moving body, there is a problem in mounting for performing balancing (nulling) using a direct induction magnetic field between the transmitting coil and the receiving coil). It is possible to eliminate restrictions, adjustment of casing equilibrium from a nearby stationary metal object due to trimming, and the like.

[0027]

As described above, according to the present invention, it is possible to eliminate the inconveniences of the conventional type and to accurately detect a target object in the vicinity. As a result, the firing timing signal can be transmitted to the ignition circuit of the warhead at an optimal timing, and the warhead can be effectively concentrated on the target object.

Also, by using the Manchester encoding method, it is possible to reduce energy loss due to continuous transmission of the same code of a binary signal.

[Brief description of the drawings]

FIG. 1 is a block diagram schematically illustrating a configuration of a magnetically actuated proximity fuse device as one embodiment of the present invention.

FIG. 2 is a signal waveform diagram for explaining Manchester encoding used in the apparatus of FIG. 1;

FIG. 3 is a circuit configuration diagram relating to Manchester encoding of the modulator in FIG. 1;

FIG. 4 is a circuit configuration diagram relating to decoding of a Manchester encoded signal of the demodulator in FIG. 1;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Code generator 2 ... Delay circuit 4 ... Modulator 5 ... Transmission coil 6 ... Reception coil 8 ... Distributor 9,10 ... Demodulator 15 ... Bias generator 16 ... Detector 30 ... Target object C1 ... Coding 2 phase Random signal C2: Delayed coded two-phase random signal F: Signal of predetermined frequency (output of oscillator) Ir: Eddy current M1: Coded modulation signal (for generating high-frequency magnetic field) M2 (by interference induced magnetic field) (Induced) coded modulation signal S: metal part (surface) of target object

Claims (2)

(57) [Claims] 1. A device mounted on a moving body having a warhead mounted thereon, the device instructing the firing operation of the ammunition of the warhead when the moving body approaches a target object (30). A code generator (1) for generating a signal (C1), a delay circuit (2) for delaying the generated coded two-phase random signal by a predetermined bit, and a delayed coded two-phase random signal (C2) ) Is directly spread-spectrum-modulated with a signal (F) having a predetermined frequency and outputs a coded modulation signal (M1). A high-frequency magnetic field is distributed in the air by the coded modulation signal from the modulator. A transmitting coil (5) for emitting, and a receiving coil (5) for generating an induced power by an interference induction magnetic field generated by an eddy current (Ir) flowing on a surface (S) of a metal portion of the target object by a high-frequency magnetic field from the transmitting coil. A) coded modulation signal corresponding to the induced power of the receiving coil (M
Means (8) for distributing 2) into two signals, and for each of the distributed two coded modulation signals, a coded two-phase random signal from the delay circuit and a coded two-phase signal from the code generator. A demodulation circuit (9, 10) for performing correlation demodulation with a random signal and outputting a first demodulated signal and a second demodulated signal, respectively, and adding a constant bias to the output second demodulated signal. And a circuit (15) for setting a threshold level adapted to the electromagnetic environment inside and outside the apparatus, and a circuit (16) for comparing the set threshold level with the output first demodulated signal. A proximity fuse device wherein the ignition operation is commanded when the level of the first demodulated signal is high based on the result of the comparison. 2. The modulator according to claim 1, further comprising: means for performing Manchester encoding when performing the coded modulation, wherein the demodulation circuit performs the Manchester encoding when generating the first and second demodulated signals. 2. The proximity fuze device according to claim 1, further comprising means for decoding the coded signal.