DE3101928C2 - Device for the discrimination of overflying aircraft - Google Patents

Description

TPx V <HP or HP. TP> V determined whether the quotient Q, defined by Q = HP: TP
the condition

Q> Qkn, = V

Fulfills. If this is the case, the firing of the weapon generated by a movement sensor 7 can then be prevented if the moving object is an aircraft flying overhead.
As already mentioned, from the signals generated by the sound pickup, the bandpass filters 2, 3 determine spectral ranges. To simplify division with the following threshold, mean or rms values of the signal components are formed. On the basis of the threshold 6 it can be determined whether it contains more high or low frequency components. If high frequencies dominate, an overflight is concluded.

The invention relates to a device for discriminating overflying aircraft from taxiing or aircraft and other ground vehicles taking off to prevent accidental ignition Weapons, with sound pickups and band passes, which are tuned to characteristic frequency ranges are.

For various reasons it may be desirable between vehicles on the ground and overflying To be able to distinguish between aircraft. DE-AS 28 16 332 discloses a device for identification a moving sound source known, which is used to carry out noise abatement programs and serves to identify moving sound sources in the air on a fully automatic basis Way wants to achieve.

For this purpose, a number of sound catchers are required, which are arranged separately from one another on an axis, with a device for forming a Correlation function signal coupled with respect to the plurality of sound signals. The arrangement exists for example, two microphones that are vertically mounted on the floor one above the other. The recorded Sound signals are fed to spectral filters, with each microphone having a spectral filter assigned. In the spectral filters, whose frequency characteristics match the spectrum of the targeted sound source outgoing sound coincides, z. B. a low-flying aircraft or a The vehicle traveling on the ground becomes the frequency components presenting the type of targeted sound source taken. The frequency components are applied to a cross-correlation function calculator

1 sheet of drawings

Claims (1)

Claim: Device for the discrimination of overflying aircraft from taxiing or taking off aircraft and other ground vehicles to prevent unwanted ignition of weapons, with sound pick-up and bandpasses which are matched to characteristic frequency ranges, characterized in that only one sound pickup (1) has its input signals two bandpasses (2, 3), the bandpass filters (2, 3) forming mean or effective values (TP, HP) of the signal components _: that these values (TP, HP ) are first divided by one another in a device (6) calculation unit applied, which has a cross-correlation function calculated for a short interval The known device is too complex and with too many details for use in weapons technology Mistake. For the purposes of the invention, the main weapons that come into consideration are mines, soft should be triggered at airfields by aircraft rolling by. With such weapons it is important that the It cannot be triggered by the sound of aircraft flying overhead, as the weapon is in this case would be ineffective. The object of the invention is therefore to provide a device of the type mentioned at the outset, which is characterized by great simplicity compared to the prior art resulting quotient (Ö · "- the condition Q> Qkrii fulfilled, and that the device (6), when the condition is fulfilled, delivers a signal that prevents the weapon from being triggered. at the and secondly, it is determined whether the 15 excels and with the reliable misfires of the mentioned type can be avoided. This object is achieved in that only one sound sensor has two bandpass filters for its input signals feeds, the bandpasses central or The rms values of the signal components mean that these values are first divided by one another in a device and, secondly, it is determined whether the resulting quotient fulfills the condition (?> <? * ", and that the facility will enter if the condition is met Signa 'that prevents the weapon from being triggered The invention is explained in more detail with reference to the single figure. The figure shows a sound sensor with a preamplifier (1). The signal from this sound sensor 1 is fed to two bandpass filters 2, 3 which are clearly separated from one another in the frequency ranges and which allow certain characteristic frequency ranges to pass through. Each bandpass filter 2, 3 is followed by a rectification and smoothing device 4, behind which the output signals TP and HP are present. To simplify checking of the condition Q> Q _kri , the signal TP is amplified in an amplifier 5 and via the query