Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F42—AMMUNITION; BLASTING
  • F42C—AMMUNITION FUZES; ARMING OR SAFETY MEANS THEREFOR
  • F42C13/00—Proximity fuzes; Fuzes for remote detonation
  • F42C13/04—Proximity fuzes; Fuzes for remote detonation operated by radio waves

Definitions

• the present invention relates to a proximity fuse for initiating a detonation of the effective part of a robot, comprising a passive unit having a first antenna means for receiving electromagnetic radiation within the microwave range, with a relatively narrow first antenna lobe, and a second antenna means for receiving electromagnetic radiation within the microwave range, with a second, relatively broad antenna lobe, enclosing, as to the directions thereof, the first antenna lobe, the first and second antenna lobes preferably being rotationally symmetric in the roll direction of the robot, the proximity fuse comprising electronic components and circuits for detecting a first signal from the first antenna lobe and a second signal from the second antenna lobe, and a first means for issuing a third signal for initiating a detonation of said effective part.
• the object of the present invention is therefore to provide a proximity fuse of the kind mentioned in the beginning, providing a secure operation also in the case where the target or escorting airplanes issue more or less strong interfering signals.
• such a proximity fuse is primarily characterized in that the proximity fuse is arranged to issue the third signal in the case where the following conditions are simultaneously fulfilled, i.e. that both the quotient of the amplitude of the first signal and the amplitude of the second signal exceeds a first value determined in advance and that the time derivative of said quotient exceeds a second value determined in advance.
• this proximity fuse is arranged to emit the third signal in the case where in addition the amplitude of the first signal exceeds a third value determined in advance.
• a proximity fuse including only a passive unit but often a proximity fuse is preferred that also comprises an active unit having a first transmitter for issuing modulated electromagnetic radiation within the microwave range and a first receiver for receiving the portion of this radiation that is reflected from a target, the radiation being issued and received by a third antenna means within a relatively narrow, third antenna lobe which is a preferably rotationally symmetric in the roll direction of the robot, and further comprises a second means for generating a fourth signal in the case where the target detecting conditions in the active unit, that are based on parameters such as distance value, signal amplitude, doppler frequency, are satisfied.
• a proximity fuse according to the invention is primarily characterized in that the proximity fuse is arranged to issue the third signal in the case where at least one of the following conditions is satisfied: either the fourth signal is generated, or that both the quotient of the amplitude of d e first signal and the amplitude of the second signal exceeds a first value determined in advance and that the time derivative of said quotient exceeds a second value determined in advance, or that in addition the amplitude of the first signal exceeds a third value determined in advance.
• Fig. 1 shows a first embodiment of the proximity fuse according to the invention, only including a passive unit, having a directly detecting receiver
• Fig. 2 shows a second embodiment of the proximity fuse, also only including a passive unit, but having a heterodyne receiver (local oscillator and mixer)
• Fig. 3 shows a third embodiment of the proximity fuse, having an active unit combined with a passive unit according to Fig. 1
• Fig. 4 shows a fourth embodiment of the proximity fuse, having an active unit combined with a passive unit according to Fig. 2
• Fig. 5 shows a fifth embodiment of the proximity fuse, having an active unit comprising a band pass filter and an envelope detector, combined with a passive unit according to
• Fig. 1 shows a sixth embodiment of the proximity fuse, having an active unit comprising a band pass filter and an envelope detector, combined with a passive unit according to
• Fig. 2 and Fig. 7 shows a longitudinal sectional view through the point of a robot including rotationally symmetric first and second antenna lobes.
• a first antenna means having a relatively narrow, first antenna lobe is denoted by 1 and a second antenna means having a second, relatively broad antenna lobe, by 2.
• the second antenna lobe encloses tiie first one but tfiat is true.
• the antenna lobes are preferably rotationally symmetric in the roll direction of a robot and directed somewhat forwards. This is an advantageous embodiment, though other ones are conceivable.
• the signal from the first antenna means 1 passes through a unit including a bandpass filter 3, an envelope detector 4 and an amplifier 5 and thus proceeds, in the shape of a first signal S 1 both to a first signal processing unit 9 and to a quotient forming unit 10.
• the signal from the second antenna means 2 passes through another unit, including a bandpass filter 6, an envelope detector 7 and an amplifier 8 and thus proceeds, in the shape of a second signal S2, to said quotient forming unit 10.
• the signal Z from the quotient forming unit is supplied both to said first signal processing unit 9 and to a derivative unit 11, from which the signal dZ/dt is also provided to the signal processing unit 9.
• a third signal S3 can be fed to an effective part, not shown, of the robot and initiate a detonation thereof in the case where the conditions set out in claim 1 are satisfied, i.e. that the quotient Z of the amplitude Al of the signal SI and the amplitude of the signal S2 exceeds a first value Zl determined in advance and in addition that the time derivative dZ/dt exceeds a second value Z2 determined in advance.
• some security is obtained that only jamming transmitters in the target which are located near by, can initiate a detonation of the effective part, interfering signals from escorting or more remote airplanes not being able to achieve this effect.
• the amplitude Al of the first signal is in addition to exceed a tirird value Z3 determined in advance.
• the signal from the first antenna means 1 also in this case proceeds to a bandpass filter 3 but then to a mixer 13 where it is mixed with a local oscillator signal from a HF-oscillator 12, after which the resulting signal continues to a bandpass filter/amplifier 15 and then passes to an envelope detector 4, and then it proceeds, as in the first embodiment, in the shape of a first signal SI both to the first signal processing unit 9 and to the quotient forming unit 10, etc.
• the signal from the second antenna means 2 passes to the bandpass filter 6, after that to a mixer 14, where it is mixed with a local oscillator signal from the HF-oscillator 12, after which the resulting signal continues to a bandpass filter/amplifier 16 and an envelope detector 7 and therefrom, in the shape of a signal S2, proceeds to the quotient forming unit 10.
• the passive unit of the proximity fuse is combined with an active unit as is illustrated in a tiiird embodiment of the proximity fuse according to the invention in Fig. 3, the performance thereof can be improved.
• the passive unit is here identical to tiiat in the first embodiment in Fig. 1.
• the first antenna means is here referenced la and the bandpass filter has here been denoted by 3a.
• the active unit has a third antenna means 17 for issuing modulated electromagnetic radiation for an active search of targets. This radiation is provided by an HF-oscillator 18 that is modulated by a modulator 19.
• the signal from the HF-oscillator proceeds together with a signal from the low pass filter 3a to a mixer 20, from which the resulting signal is fed to a second signal processing unit 21.
• a tiiird signal S4 that passes to the first signal processing unit 9, together with said first signal SI, the signal Z and the signal dZ/dt.
• the third signal S3 is issued for initiating a detonation either in the case where the signal S4 is generated or the conditions according to claim 1 are satisfied, or in the case where the conditions according to claim 2 are satisfied.
• the operation of the active unit can be assigned a priority by arranging a threshold of the amplitude Al of the first signal, i.e. determining that it is to exceed a certain value AL, in order that the passive unit is to generate a detonation. It is defined in claim 4.
• Proximity fuses having an active unit can also, in a third embodiment that appears from Fig. 4, be designed including a passive unit according to Fig. 2.
• the signal from the bandpass filter 3 only passes through the mixer 20, the signal therefrom also being supplied to the passive unit.
• the mixer 14 of the passive unit receives, in addition to the signal from the second antenna means 2 through the bandpass filter 6, also a local oscillator signal from the HF-oscillator 18 of the active unit.
• the active unit is provided with a bandpass filter 22 arranged in series with an envelope detector 23, through which a signal passes from the first antenna means, through the mixer 20, in addition to its travel to the second signal processing means 21.
• a fifth signal S5 the amplitude of which is related to the amplitude of an occurring jamming or disturbing signal, i.e. the disturbance amplitude of the pass band.
• This signal S5 passes to the first signal processing unit 9.
• a detonation is initiated either in the case where the signal S4 is generated, or that the conditions of claim are satisfied combined with the condition that the amplitude A5 of the signal SS exceeds a value AM determined in advance, that is determined considering die probability that the target detecting conditions are satisfied.
• the pass band of the bandpass filter 22 preferably covers a frequency band that at least includes the frequency range of d e issued, modulated electromagnetic radiation, the bandpass filters 15, 16, 3a and 6 preferably covering a broader frequency band.
• the passive unit is the kind illustrated in Fig. 1, and in the sixth embodiment the passive unit corresponds to that of Fig. 2, i.e. including a heterodyne receiver.
• the passive and active unit can, actually, have separate antennas but they can also be combined, being arranged to perform d e required operations. It is suitable to construct the antenna means as array antennas.
• Fig. 7 a longitudinal sectional view is illustrated of die point of a robot 24comprising first and second antenna lobes 26, 27, that are rotationally symmetric about an axial symmetry axis 25.
• Parts of the signal processing can also be made digitally, the signals being A/D-converted and d e analogue circuit functions being performed using equivalent program algorithms.
• the embodiment described above presupposes that bandpass filters of a relatively broad band type are used.
• An alternative is to replace diem with a filter bank of narrow band filters, which is each one followed by an envelope detector comprising me following signal processing 10, 11, 9.
• the signals SI, S2, ... , S5 and Z, dZ/dt are then replaced with vectors of die same dimensions as die filter bank.
• the filter bands and d e operations thereof can be substituted by for example FIR-filters or FFT-algorithms.

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Radar Systems Or Details Thereof (AREA)
• Manipulator (AREA)
• Variable-Direction Aerials And Aerial Arrays (AREA)
• Numerical Control (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=20396223

Family Applications (1)

Country Status (5)

Families Citing this family (1)

Family Cites Families (5)

• 1994
  • 1994-12-06 SE SE9404216A patent/SE506114C2/sv not_active IP Right Cessation
• 1995
  • 1995-12-04 DE DE69520800T patent/DE69520800T2/de not_active Expired - Lifetime
  • 1995-12-04 EP EP95941288A patent/EP0809784B1/de not_active Expired - Lifetime
  • 1995-12-04 WO PCT/SE1995/001454 patent/WO1996018079A1/en active IP Right Grant
• 1997
  • 1997-06-05 NO NO19972561A patent/NO313649B1/no not_active IP Right Cessation

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events