DE102022003178B3 - Method for combating an enemy flying object - Google Patents

Abstract

In a method for combating an enemy flying object with rotors or propellers, it is intended to quickly and reliably calculate whether the flying object was successfully combated or not. The new method uses a combat arrangement with an effector and a radar (30) and a computer arrangement (40) connected to it, where the steps are: a) the effector fights the enemy flying object, b) the computer arrangement (40) evaluates the combat in such a way, c) that the computer arrangement consists at least of micro-Doppler echo signals received from the radar (30) and optionally additionally Values of evaluation parameters are calculated from macro-Doppler echo signals received from the radar (30) in such a way that d) in order to evaluate whether the flying object was successfully combated or not, the computer arrangement (40) • Values of the evaluation parameters that occurred before a Start of the fight were recorded, and • values of the evaluation parameters that were recorded after the start of the fight are evaluated.

Description

The invention relates to a method for combating an enemy flying object.

From the DE 10 2015 008 296 B4 a method for combating an enemy drone is known. The method first uses a control assembly with an effector, which is an HPEM device. Furthermore, the method uses a recognition device. What is described is that several detection devices for optical, thermal, acoustic and/or radar signals are expediently combined in order to increase the accuracy of target detection and the calculation of the trajectory and speed of an enemy small drone. The publication does not address whether and how an evaluation of the fight takes place.

From the EP 3 715 901 A1 An automated method for detecting and classifying a drone is known for monitoring the airspace of an airport. Instead of using specialized micro-Doppler radars, conventional radars such as continuous wave radar, phased array radar or pulse radar are used for drone detection and classification. This is because drones are detected and classified based on a radar plot layer of digital radar images by sending a section of such a digital radar image to a deep learning model implemented in an electronic processing unit.

From the US 2020/0182967 A1 a method for monitoring a machine is known. A radar aimed at the machine records and analyzes micro-Doppler signals and derives monitoring parameters from them. Alarm is given when values of a monitoring parameter are exceeded. Monitoring parameters can be a rotation frequency or a translation frequency of moving parts of the machine.

From an essay (Klaer, P., Huang, A., Sevigny, P., Rajan, S., Pant, S., Patnaik, P., & Balaji, B. (2020). An Investigation of Rotary Drone HERM Line Spectrum under Maneuvering Conditions. Sensors (Basel, Switzerland), 20(20), 5940) it is known that micro-Doppler analysis offers a way to distinguish drones from one another. In this article, HERM stands for an abbreviation of “Helicopter Rotor Modulation”. Modulation of the Doppler frequency is caused by movements of blades or rotating propellers. Micro-Doppler radar signatures are detected using a short-time Fourier transform. Depending on a STFT (Short Time Fourier Transform) window length, two different types of spectrograms are obtained. If the window length is shorter than the rotation, the period of the propeller and the pulse repetition frequency (PRF) of the radar are sufficiently high. It is then possible to record the periodic behavior of the individual rotating blades as blade flashes. The spectrogram can provide information about the number of rotating rotor blades and their relative direction of movement. If a long window length is used for the STFT (integration over several cycles of rotor blade rotation), the time resolution decreases and the frequency resolution increases. The spectrogram shows the HERM lines. HERM lines are spectral lines that are periodic in Doppler frequency rather than time. HERM lines make it possible to classify a drone, for example whether it is a single-propeller or multi-propeller drone.

From the DE 10 2017 108 733 B4 Methods for determining the parameters of drones are known in which a laser Doppler vibrometer is used. The parameters can be the rotation speeds of the individual rotors.

From the US 2020 / 0 158 822 A1 a method for combating an enemy drone with rotors or propellers is known. The method uses its own drone with a combat system with a safety net and a radar and a computer system connected to it. The computer arrangement classifies the enemy flying object from micro-Doppler echo signals received from the radar and additionally from macro-Doppler echo signals received from the radar.

From the CN 1 10 133 573 A 1 a method for combating an enemy drone with rotors or propellers is known. The method is used to protect an infrastructure facility and uses a stationary jammer and a stationary radar and a computer arrangement connected thereto. The jammer fights the enemy flying object. The computer arrangement evaluates the combat by evaluating the radar signals.

From an essay ( P. Wellig et al.: “Radar Systems and Challenges for C-UAV” 2018. 19th International Radar Symposium (IRS). Bonn. Germany. 2018. Pages 1-8 . IEEE https://ieeexplore.ieee.org/abstract/document/8448071 [accessed on June 12, 2023]) is a method for classifying an enemy drone with rotors or propellers. The method uses a radar and a computer arrangement connected to it. The classification is carried out by evaluating micro-Doppler echo signals and macro-Doppler echo signals.

The invention is based on the object of developing a method for combating an enemy drone with rotors or propellers in such a way that it can be calculated quickly and reliably whether the enemy drone was successfully combated or not. Successfully fought means eliminated, repelled or switched off in the sense that the enemy flying object has been rendered harmless, has been deprived of its function or has been so damaged that it can no longer carry out its mission.

This object is achieved according to the invention by the features of claim 1.

The advantages of the invention result from the fact that when fighting an enemy drone with rotors or propellers, it is calculated without delay whether the drone was successfully fought or not. There is no waiting until an enemy drone visibly falls to the ground. Rather, it is possible to evaluate whether a drone is switched off even in real time because radar data from a radar is used.

The radar detects micro-Doppler echo signals from the rotors or propeller of the enemy flying object and macro-Doppler echo signals from the enemy drone's flight path.

The computer arrangement calculates values of evaluation parameters at least from the micro-Doppler echo signals and additionally from the macro-Doppler echo signals. Values of the evaluation parameters that were recorded before a combat start are compared with values of the evaluation parameters that were recorded after a combat start in order to evaluate whether the drone was successfully combated or not.

An early evaluation of whether the enemy drone was successfully combated or not offers a variety of advantages. The immediate, real-time evaluation reduces the effector's energy requirements because the effector only needs to be used for as long as necessary to combat. As soon as it is clear that successful combat against an enemy drone has been calculated, the combat arrangement can devote itself to new combat tasks.

The radar is the sensor that detects whether the flying object has been successfully combated. The sensor therefore works regardless of the weather and time of day with high reliability. Because of its small size, the sensor can also be used in small control systems.

Furthermore, many combat arrangements already have a radar for target tracking. Surprisingly, this radar is now also used for the additional function of evaluating combat success using micro-Doppler echo signals.

• • eine Anzahl der Rotoren oder der Propeller, und
• • eine Drehgeschwindigkeit jedes Rotors oder Propellers,

weil diese Evaluierungsparameter aussagekräftig sind.The evaluation parameters of the rotors or propellers calculated from micro-Doppler echo signals are at least

• • a number of rotors or propellers, and
• • a rotation speed of each rotor or propeller,

because these evaluation parameters are meaningful.

• • eine Vertikalgeschwindigkeit oder eine Horizontalgeschwindigkeit.

An evaluation parameter of the enemy drone's trajectory calculated from macro-Doppler echo signals is at least

• • a vertical speed or a horizontal speed.

This is useful for refining the evaluation.

The enemy drone can be, for example, a quadrocopter. The drone can also be a fixed-wing UAV.

Enemy drones often operate in a swarm. If the evaluation shows that the fight was not successful, the fight against the enemy drone will continue, and if the evaluation shows that the fight was successful, the fight against the drone will be discontinued, and if there are further drones to be fought, the Effector fought one of the other drones.

The effector is a proven HPEM device.

The combat arrangement is integrated into its own drone.

• • zum einen Werte von Evaluierungsparametern aufweist, die vor einer Testbekämpfung erfasst wurden,
• • zum anderen Werte von Evaluierungsparametern aufweist, die nach einer Testbekämpfung erfasst wurden, und
• • zusätzlich Bekämpfungserfolgswerte aufweist, die den Evaluierungsparametern zugeordnet sind, die nach einer jeweiligen Testbekämpfung ermittelt wurden.

According to an advantageous embodiment of the invention according to claim 2, the computer arrangement uses an algorithm for evaluation. Alternatively or additionally, the computer arrangement accesses a database with data from previously tested drones, the database

• • on the one hand has values of evaluation parameters that were recorded before a test fight,
• • On the other hand, has values of evaluation parameters that were recorded after a test fight, and
• • additionally has control success values that are assigned to the evaluation parameters that were determined after each test control.

• 1a eine Bekämpfungsanordnung, eine gegnerische Drohne und ermittelte Vordaten aus Mikro-Doppler-Echo-Signalen;
• 1b eine Bekämpfungsanordnung und eine gegnerische Drohne im Moment einer HPEM-Bekämpfung;
• 1c eine Bekämpfungsanordnung, eine gegnerische Drohne und ermittelte Nachdaten aus Mikro-Doppler-Echo-Signalen;
• 1d-i eine Evaluierung mittels Algorithmus;
• 1d-ii eine Evaluierung mittels einer Datenbank mit Vergleichsdaten zuvor getesteter Drohnen.

Exemplary embodiments of the invention are explained in more detail below using the drawings. Principle sketches show:

• 1a a combat arrangement, an enemy drone and determined preliminary data from micro-Doppler echo signals;
• 1b a combat assembly and an enemy drone at the moment of an HPEM engagement;
• 1c a countermeasure array, an enemy drone, and acquired follow-up data from micro-Doppler echo signals;
• 1d-i an evaluation using an algorithm;
• 1d - ii an evaluation using a database with comparative data from previously tested drones.

• Das vorliegende Verfahren zur Bekämpfung eines gegnerischen Flugobjektes mit Rotoren oder Propellern verwendet eine Bekämpfungsanordnung mit einem Effektor und einem Radar und eine hieran angeschlossene Rechneranordnung. Die Schritte sind:
  1. a) der Effektor bekämpft das gegnerische Flugobjekt,
  2. b) die Rechneranordnung evaluiert die Bekämpfung, derart,
  3. c) dass die Rechneranordnung mindestens aus vom Radar erhaltenen Mikro-Doppler-Echo-Signalen und fakultativ zusätzlich aus vom Radar erhaltenen Makro-Doppler-Echo-Signalen Werte von Evaluierungsparametern berechnet, derart,
  4. d) dass zur Evaluierung, ob das Flugobjekt erfolgreich bekämpft wurde oder nicht, die Rechneranordnung
     • • Werte der Evaluierungsparameter, die zeitlich vor einem Start der Bekämpfung erfasst wurden, und
     • • Werte der Evaluierungsparameter, die zeitlich nach einem Start der Bekämpfung erfasst wurden,

auswertet.Before the drawings are discussed, a method for combating an enemy flying object with rotors or propellers is presented in its entirety:

• The present method for combating an enemy flying object with rotors or propellers uses a combat arrangement with an effector and a radar and a computer arrangement connected to it. The steps are:
  1. a) the effector fights the enemy flying object,
  2. b) the computer arrangement evaluates the fight in such a way,
  3. c) that the computer arrangement calculates values of evaluation parameters at least from micro-Doppler echo signals received from the radar and optionally additionally from macro-Doppler echo signals received from the radar, such that
  4. d) that the computer arrangement is used to evaluate whether the flying object was successfully combated or not
     • • Values of the evaluation parameters that were recorded before the start of the fight, and
     • • Values of the evaluation parameters that were recorded after the start of the fight,

evaluated.

The enemy flying object has rotors. Deviating from this, the flying object could also have propellers.

The enemy flying object is an enemy drone.

The effector is an HPEM device.

The combat device is integrated into its own drone.

On the 1a , 1b and 1c In detail, these each show a combat arrangement with an HPEM device 20 and a radar 30 and a computer arrangement 40 connected to it. The combat drone 60 is also shown.

• • eine Anzahl der Rotoren,
• • eine Drehgeschwindigkeit jedes Rotors.

The evaluation parameters from the micro-Doppler echo signals of the enemy drone 60, which uses the computer arrangement 40, are:

• • a number of rotors,
• • a rotation speed of each rotor.

In addition, a vertical speed is used as a further evaluation parameter by the computer arrangement. The vertical speed results from macro Doppler echo signals of the trajectory of the enemy drone 60.

Turning to the evaluation parameter of the number of rotors, the enemy drone has four rotors.

The evaluation parameters of the rotational speed of a respective rotor are discussed in 1a the reference numbers N1, N2, N3 and N4 are shown: N1 is the rotational speed of a first rotor, N2 that of a second rotor, N3 that of a third rotor, and N4 that of a fourth rotor.

In the 1a values shown in the previous data and those in 1c The values shown for the subsequent data only represent exemplary, highly simplified, standardized, dimensionless quantities.

• 1a illustriert, dass zur Evaluierung, ob die Drohne 60 erfolgreich bekämpft wurde oder nicht, die Rechneranordnung 40 Werte der Evaluierungsparameter zeitlich vor einem Start der Bekämpfung erfasst.
• 1b illustriert, dass die HPEM-Einrichtung 20 die gegnerische Drohne 60 bekämpft.
• 1c illustriert, dass zur Evaluierung, ob die Drohne 60 erfolgreich bekämpft wurde oder nicht, die Rechneranordnung 40 Werte der Evaluierungsparameter zeitlich nach einem Start der Bekämpfung erfasst.
• 1d-i illustriert, dass zur Evaluierung, ob die gegnerische Drohne 60 erfolgreich bekämpft wurde oder nicht, die Rechneranordnung 40
  • • Werte der Evaluierungsparameter, die zeitlich vor einem Start der Bekämpfung erfasst wurden, und
  • • Werte der Evaluierungsparameter, die zeitlich nach einem Start der Bekämpfung erfasst wurden,

auswertet.Details of the procedure are described below.

• 1a illustrates that to evaluate whether the drone 60 was successfully combated or not, the computer arrangement 40 values of the Eva luation parameters recorded before the start of the fight.
• 1b illustrates that the HPEM device 20 fights the enemy drone 60.
• 1c illustrates that in order to evaluate whether the drone 60 was successfully combated or not, the computer arrangement 40 records values of the evaluation parameters after the combat has started.
• 1d-i illustrates that the computer arrangement 40 is used to evaluate whether the enemy drone 60 was successfully combated or not
  • • Values of the evaluation parameters that were recorded before the start of the fight, and
  • • Values of the evaluation parameters that were recorded after the start of the fight,

evaluated.

To evaluate whether the drone 60 was fought successfully or not, the computer arrangement 40 uses an algorithm. The values for N1, N2, N3 and N4 of the pre-data and the post-data are obtained by subjecting the respectively received micro-Doppler echo signals to a Fourier transform. The values for N1, N2, N3 and N4 of the pre-data and the post-data are obtained from the respective frequency signals obtained. If the values of the preliminary data and the subsequent data for N1, N2, N3 and N4 are available, a computer program is used to compare these data. Put into words, the algorithm states that the fight has been successful if at least 2 of the 4 rotors have a speed reduction of more than 25%. This is the case in the example presented. The algorithm determined that drone 60 was successfully combated.

An alternative to evaluation using an algorithm or a supplement to evaluation using an algorithm is an evaluation using a database with comparative data from previously tested drones.

• • die Datenbank Werte von Evaluierungsparametern aufweist, die vor einer Testbekämpfung erfasst wurden,
• • die Datenbank Werte von Evaluierungsparametern aufweist, die nach einer Testbekämpfung erfasst wurden,
• • die Datenbank Bekämpfungserfolgswerte aufweist, die den Evaluierungsparametern zugeordnet sind, die nach einer jeweiligen Testbekämpfung ermittelt wurden.

This illustrates 1d - ii . To evaluate whether the drone 60 was successfully combated or not, the computer arrangement 40 accesses a database with data from previously tested drones, whereby

• • the database contains values of evaluation parameters that were recorded before a test fight,
• • the database contains values of evaluation parameters that were recorded after a test fight,
• • the database has control success values that are assigned to the evaluation parameters that were determined after a respective test control.

If the evaluation shows that the fight was not successful, the HPEM fight against the enemy drone 60 continues. If the evaluation shows that the combat was successful, then the HPEM combat of the drone 60 is stopped. If there are further drones to be combated because there is a swarm of drones to be combated, the HPEM device combats one of the additional drones.

Reference symbol list

20

HPEM facility

30

radar

40

Computer arrangement

60

enemy drone

N1

Rotation speed of the first rotor

N2

Speed of rotation of the second rotor

N3

Rotation speed of the third rotor

N4

Rotation speed of the fourth rotor

Claims (2)

Method for combating an enemy drone (60) with rotors or propellers, the method using its own drone with a combat arrangement with an HPEM device (20) and a radar (30) and a computer arrangement (40) connected thereto, the steps are: a) the HPEM device (20) fights the enemy drone (60), b) the computer arrangement (40) evaluates the combat in such a way that the computer arrangement (40) at least consists of micro-Doppler signals obtained from the radar (30). Echo signals and additionally values of evaluation parameters calculated from macro-Doppler echo signals obtained from the radar (30), such that the evaluation parameters from the micro-Doppler echo signals at least a number of the rotors or propellers and a rotational speed of each Rotors or propellers, and that an evaluation parameter from the macro-Doppler echo signals is at least a vertical speed or a horizontal speed, c) to evaluate whether the flying object is successful was fought or not, the computer arrangement (40) evaluates values of the evaluation parameters that were recorded before the start of the fight and values of the evaluation parameters that were recorded after the start of the fight, d) if the evaluation shows that If the fight was not successful, the fight against the enemy drone (60) is continued, and if the evaluation shows that the fight was successful, the fight against the enemy drone (60) is stopped if there are further drones to be fought the HPEM facility (20) is one of the other drones. Procedure according to Claim 1 , in which to evaluate whether the enemy drone (60) was successfully combated or not, the computer arrangement (40) uses an algorithm, and / or the computer arrangement (40) accesses a database with data from previously tested drones, the database for one has values of evaluation parameters that were recorded before a test fight, on the other hand has values of evaluation parameters that were recorded after a test fight, and additionally has control success values that are assigned to the evaluation parameters that were determined after a respective test fight.

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