FI3604131T3

FI3604131T3 - System and method for detecting flight movements

Info

Publication number: FI3604131T3
Application number: FIEP18186540.3T
Authority: FI
Inventors: Axel Brokmeier; Guy Kouemou
Original assignee: Hensoldt Sensors Gmbh
Priority date: 2018-07-31
Filing date: 2018-07-31
Publication date: 2024-06-13
Also published as: EP3604131B1; EP3604131A1; DK3604131T3

Description

1 EP3 604 131

SYSTEM AND METHOD FOR DETECTING FLIGHT MOVEMENTS

Description

The present invention relates to a toll system and to a method for detecting flight movements of an unmanned aerial vehicle (aircraft) and in particular to a toll system for drones using RF backscatter technology.

Background

In the future, there will be a massive increase in logistics traffic in urban areas. This development is a key challenge for future transport services. To address the problem of traffic congestion, other means of transport are used, such as bicycle couriers, delivery robots, or unmanned drones. A mix of measures and modes of transport will be used to relieve congestion on the roads and at the same time reduce harmful environmental impacts such as exhaust fumes and noise.

From a certain distance in the range of 5 to 50 kilometers, it may make sense to use drones for delivery. It is conceivable to create logistics platforms at container stations, airports or ports in order to distribute goods from there to households via various routes. The use of drones can also noticeably reduce road traffic.

Given that the number of unmanned aerial vehicles (UAVs) is expected to increase significantly, there is a need for stricter regulation of these UAVs. For the aviation industry, the existing regulations were and are no longer adequate, especially with the growth of professional applications using large, heavy aircraft.

For this purpose, it is important to reliably detect the flight movements of such aerial vehicles. In particular, it must be ensured that only authorized aerial vehicles can move in an airspace. Their flight movements are to be increasingly controlled and monitored along specific flight paths. There is also a need for motion detection systems that can be specifically used in toll systems for drones and other unmanned aerial vehicles.

EP3330732A1 discloses a method for air traffic control and/or flight management of aerial vehicles. Said method involves sending a query message

2 EP3 604 131 from a base station of an air traffic control and/or flight management arrangement that is received by a transponder in an aerial vehicle. Response messages are sent back from the transponder and received by base stations. The position of the aerial vehicle is determined in the receiving base stations or in a processing unit of the air traffic control and/or flight management arrangement to which the transmitting base station and the receiving base stations are connected.

EP3352298 A1 discloses a backscatter transponder that can support a variety of tasks, particularly in aviation.

EP1210615 B1 discloses a system for determining the position of a transponder moving along a course.

Abstract

At least some of the above problems are solved by a toll system according to claim 1 and a method according to claim 6. The dependent claims relate to further advantageous embodiments of the toll system according to claim.

Optionally, the at least two detection modules are designed to query at least one of the following items of information pertaining to the unmanned aerial vehicle and to transmit said information to the control module: - identification information, - a flight altitude, - a position, - a speed, - a destination point, - a starting point, - a cargo, - a flight direction.

3 EP3 604 131

Therefore, identification can be achieved by transmitting information (e.g., a number or a key or similar data) in a targeted manner. However, it is also possible that the absence of identification information may be used to conclude that this is an unauthorized flight movement or an unauthorized aerial vehicle.

The at least two detection modules may be a plurality of detection modules, wherein the number may be arbitrary. The toll system can then optionally have a data connection between the at least one control module and the plurality of detection modules, wherein the at least one control module is designed to determine the flight movement of the unmanned aerial vehicle based on the transmissions of data from the plurality of detection modules. In this embodiment, no handover is required because the control module receives the data on the various detections from the various detection modules and can use this to determine the flight path.

Optionally, the transponder has an RF back scatter transponder, and the at least two detection modules each comprise an FMCW radar unit (interrogator), wherein the FMCW radar units carry out a query by means of a frequency modulated continuous wave signal (FMCW).

Optionally, the FMCW radar units are designed to query the unmanned aerial vehicle's transponder at a distance of at least 100 m.

The present invention also relates to a method for detecting a flight movement of an unmanned aerial vehicle as disclosed in claim 6.

Brief description of the figures

The exemplary embodiments of the present invention will be more fully understood from the following detailed description and the accompanying drawings, which, however, should not be construed as limiting the disclosure to the specific embodiments, but are for illustration and understanding only.

Fig. 1 shows a system for detecting flight movements of unmanned aerial vehicle in an example not according to the invention.

Fig. 2 shows an exemplary embodiment of a transponder on the unmanned aerial vehicle.

4 EP3 604 131

Fig. 3 illustrates further details of the backscatter method used when querying aerial vehicles according to exemplary embodiments.

Fig. 4 shows a flow chart for a method for detecting a flight movement according to an example not according to the invention.

Detailed description

Fig. 1 shows an example of a system suitable for detecting a flight movement B of an unmanned aerial vehicle 10 (e.g., a drone) with a transponder 12. The system comprises at least two detection modules 111, 112 for detecting the unmanned aerial vehicle 10 by querying the transponder 12. The system also comprises at least one control module 120 for triggering the query of the transponder 12 and for evaluating transmitted data from the transponder 12.

The evaluation comprises determining a flight movement B and identifying the unmanned aerial vehicle 10. The flight movement B can be detected, for example, by the unmanned aerial vehicle 10 passing multiple detection modules 110 (111, 112, 113, ...) in succession. A third detection module is shown only by way of example. The number and placement thereof can also be arbitrary. Since the unmanned aerial vehicle identifies itself, it is possible to reconstruct its flight path solely from the fact that the aerial vehicle 10 has passed through multiple different detection modules 110 or was detected there. For example, if a plurality of detection modules 110 are present at different locations in an area, the flight path B in the area can be reconstructed by detection alone.

Using suitable transponder technology, the detection modules 110 can be queried at a range of up to several 100 m. The individual detection modules 110 can of course be spaced apart from each other by a greater distance than this range. For example, they can be distributed within the area or arranged in a targeted manner along predetermined flight routes (that are to be monitored) in order to be able to reconstruct the flight movement B by detecting the aerial vehicle 10. It is understood that the aerial vehicle 10 does not have to pass through all of the detection modules 110, but that at least two detected points are sufficient to determine the flight movement B, at least as long as the flight is in a straight line.

EP3 604 131

In this way, exemplary embodiments make it possible to monitor prescribed flight routes for the unmanned aerial vehicle 10. This also makes a toll system possible that can be used to collect fees based on the flight route or the length thereof. It is also possible to detect unauthorized flight movements in the 5 area. For example, simple reflections of the query signals (e.g., radar signals) from flying objects can be used for this purpose (e.g., if they do not identify themselves or do not identify themselves correctly).

According to a further example that is not claimed, it is possible to form only one control unit 120 that is in contact with the individual detection modules 110. When an aerial vehicle 10 has been detected by one of the detection modules 110, corresponding information about the identification of the aerial vehicle 10 can be passed on to the control module 120. If the aerial vehicle 10 continues to move and is detected by the next detection module 110, said detection module can also pass this information on to the control module 120. The control module 120 thus receives corresponding items of information in succession from the individual detection modules 110 that have detected the aerial vehicle 10.

In addition, you receive the identification information of the aerial vehicle 10 so that the flight path B of the aerial vehicle 10 can be reconstructed.

Each detection module 110 comprises an associated control unit 120, which is housed, for example, in an interrogator. According to this exemplary embodiment, the detection module 110 detects the aerial vehicle 10 with the respective identification and passes this information on to the associated control module 120. The control modules 120 of the individual interrogators can be in contact with each other so that they pass on information about a detected aerial vehicle 10. In this way, it is possible for the aerial vehicle 10 to be transferred from one interrogator to the next interrogator. For example, if the aerial vehicle 10 leaves the detection area of a respective interrogator, neighboring interrogators can be informed. Optionally, it is also possible to provide a server module that ultimately receives all information about flight movements B of aerial vehicles 10. In this way, it can be determined whether the aerial vehicle 10 has moved along authorized flight paths and whether it has the necessary authorization for the flight movement.

6 EP3 604 131

According to further exemplary embodiments, not only the identification information is transmitted by the aerial vehicle 10. A range of additional information provided by the transponder 12 of the aerial vehicle 10 can be queried.

This includes in particular one or more of the following items of information: - identification information, - an altitude of the unmanned aerial vehicle, - a position of the unnamed aerial vehicle, - a speed, - a destination point, - a cargo, - territoriality information (e.g., in relation to a country, district, city, etc.), - a starting point, - a flight direction.

In order to be able to transmit this information, according to exemplary embodiments, for example, RF backscatter technology is used in the transponder 12, wherein the transponder 12 can be integrated, for example, into a sticker for identification. For example, the sticker can simultaneously allow for visual identification (e.g., by means of a valid identification number printed thereon). The RF backscatter transponders operate on the principle of information transmission by modulated reflection. The detection modules 110 comprise an interrogator system on the ground that has a transmitting unit and a receiving unit that radiate a transmission signal with a low transmission power to a backscatter transponder 12 on the aerial vehicle. There, the signal is modulated and reflected to the receiver or the modulated signal is sent back in order to identify the example drone via a remote query. This is possible via an air interface up to a distance of 100 meters from a ground unit.

7 EP3 604 131

It is understood that backscatter technology is only one example that can be used within the scope of the present invention. However, the invention should not be limited thereto.

Fig. 2 shows an exemplary embodiment of the backscatter transponder 12, which is attached to the unmanned aerial vehicle 10 and cooperates with the system from Fig. 1. The transponder 12 comprises an antenna arrangement 210, a switch 220 (SPDT), a modulator 230, a data memory 240 and a power supply 250.

The switch 220 couples to the antenna system 210 and changes the impedance of the antenna arrangement 210 in response to a switching signal by periodically switching between at least two impedances Z1 and Zo, which lead to different phase shifts pi, 92. The modulator 230 switches between two frequencies fi and f2 for modulation and the data memory can contain one or more items of information (data words). By means of the switch 220, which is attached, for example, to the base of the antenna arrangement 210, two different reflection states can be achieved by switching to the two different impedances (Z1 and Zz). By periodically switching the

SPDT 220 between the two impedances, a periodic spectrum is created.

Fig. 3 shows an example of the signal received by the receiver (i.e., the detection module 110). This frequency response is generated by RF backscatter technology using a frequency modulated continuous wave (FMCW) radar system in the detection module 110. The transmitter emits a continuous transmission signal, which, however, does not have a fixed frequency. For example, the frequency changes periodically over time (e.g., in the form of a sawtooth pattern with successive ramps). When such a transmission signal is transmitted and answered or reflected by the transponder 12, the received signal at the later time has a different frequency than the transmission signal transmitted at that time. The distance from the transponder 12 can be determined from the frequency shift of the two signals. If both signals are mixed, a low-pass filter can be used to specifically determine the difference frequency, and from this the distance to the transmitter can be determined. A possible delay between the reception of the transmission signal and the transmission of the reflection signals by the transponder 12 can be neglected or can be considered as known.

8 EP3 604 131

The additional information, such as identification or further information about the aerial vehicle 10, is transmitted by modulating the return signal. As mentioned, the antenna of the transponder 12 can be switched between different impedances. In the simplest case, the effective length of the antenna can be varied, wherein the change in length is in the order of magnitude of the wavelength of the transmitted signal. When the transponder 12 switches between the two switching states with a modulation frequency (e.g., f1 or f2), the two signal lines 311, 312 are generated around the modulation frequency and can be detected by the receiver 110. The distance from the target object (in this case the target is the backscatter transponder 12) is proportional to the frequency Af (due to the ramp in the frequency signal), which in turn corresponds to half the distance of the signal lines 311, 312 (due to the frequency mixing, the modulation provides signal lines with a frequency of fmod + Af). In addition, further signal pairs 321, 322 occur at multiples of the modulation frequency of the transponder 12. The amplitudes of these higher modes are attenuated (e.g., by 12 dB). It is important for the application that the frequency spacing of the spectral lines 311, 312, which are symmetrical about the modulation frequency fmod, is proportional to twice the target distance. The distance from the aircraft 10 can be determined from this.

Based on this frequency response from a backscatter transponder 12, information can be easily detected by the receiver (detection modules 110). Since the reflected signal has a very broad spectrum and individual signal lines 311, 312 clearly stand out from the background clutter, they can be easily separated by a filter. By changing the modulation frequencies (between f1 and 2), the lines 311, 312 and 321, 322 are shifted and no longer appear in a corresponding filter (e.g., a bandpass filter).

Therefore, by clocking between the modulation frequencies f1 and f2, information can be transmitted according to a data word in the data memory. The demodulation of the word is very simple because the clocking with the modulation frequency leads to shifts of the signal lines 311, 312. For example, a binary "1" of the bit sequence of the data word from the memory can be defined in such a way that the signal lines are in the filter (the signal lines 311, 312 are detected), while a binary "0" is outside the filter.

This clocking is effected by the modulator 230, which periodically switches the switch 220 between the two impedances at a clock frequency f1 or

9 EP3 604 131 f2. The data memory 240 is designed to store, for example, identification data of the unmanned aerial vehicle 10 and other data relating to the aerial vehicle 10.

This data can then be modulated onto the reflected signal by the detection modules 110 via the modulation of the modulator 230 onto a query signal in order to provide this information to the detection module.

An advantage of the described transponder 12 (RF backscatter ID) is that it does not need its own radiation source (passive system), but only modulates the signal of the interrogator system (detection module 110) and thus transmits the desired information. With the help of such an interrogator system, a toll system can be established and, at the same time, drone traffic can be intelligently controlled.

Fig. 4 shows a flow chart for a method for detecting a flight movement

B of an unmanned aerial vehicle 10 having a transponder 12, according to a further example that is not claimed. The method comprises: - detecting S111 the unmanned aerial vehicle 10 by querying the transponder 12 by means of a first detection module 111; - detecting S112 the unmanned aerial vehicle 10 by querying the transponder 12 by means of a second detection module 112; and - determining S120 a flight movement B of the unmanned aerial vehicle 10.

The method can be at least partially computer-implemented, i.e., it can be implemented at least partially (e.g., the corresponding control functions) by instructions that are stored on a storage medium and capable of carrying out or causing the steps of the method when running on a processor. The instructions typically comprise one or more instructions, which may be stored in various ways on various media in or peripheral to a control unit (having a processor), which, when read and executed by the control unit, cause the control unit to perform functions, functionalities and operations necessary to carry out a method according to the present invention. The detection module and the control modules can be implemented in the form of software that communicates, for example, with corresponding antenna systems in order to implement the functions described.

10 EP3 604 131

Exemplary embodiments of the present invention offer in particular the following advantages: - The registration of drones in databases can be combined with the system and thus checked (to determine whether only authorized drones are being operated). - Regulations and techniques for drone flight management (e.g., compliance with prescribed flight altitudes, flight corridors, etc.) can be checked. - A labeling requirement for drones can be monitored. - A toll system can be implemented to cover the increased costs.

Such a toll system can also be used to regulate and control the volume of traffic (direct it to certain areas). - RF backscatter transponders are very cost-effective and can be attached to drones without major mechanical and technological effort. - The toll billing modalities (central billing, prepaid options, etc.) are independent of this and can be designed as required.

The features of the invention disclosed in the description, the claims and the figures may be essential, both individually and in any combination, to the realization of the invention if they fall within the scope of the appended claims.

11 EP3 604 131

List of reference symbols 10 unmanned aerial vehicle, 12 transponder (e.g., FMCW transponder) 110, 111, 112, ... detection modules 120 control module(s) 130 server module 210 antenna arrangement 220 switch (SPDT) 230 modulator 240 data memory 250 power supply

B flight movements of the unmanned aerial vehicle f1, f2 modulation frequencies

Z1, Z2 switchable impedances 311,312 first signal pair 321, 322 second signal pair

Claims

1 EP3 604 131 SYSTEM AND METHOD FOR OBSERVING FLIGHT MOVEMENTS PATENT CLAIMS

1. Toll system for unmanned aircraft (10), wherein the toll system comprises the following: a transponder (12) designed — for use in an unmanned aircraft (10), at least two detection modules (111, 112) for detecting the unmanned aircraft (10) along the flight path (B) by interrogating the transponder (12), in which case the toll system comprises a connected control module (120) for each observation module (111, 112), in which case each control module (120) is designed to trigger the transponder (12) inquiry and evaluate the data sent from the transponder (12) , where the evaluation comprises identifying the unmanned aircraft (10) and determining its flight movement (B), in which case the connected control modules (120) are — designed to move the unmanned aircraft (10) between the at least two observation modules (111, 112) in question, whereby the transfer comprises sending information that enables at least one identification of the unmanned aircraft (10); and a server that determines the flight movements (B) of the aircraft (10) from successive observations.

2. The toll system according to claim 1, in which the at least two observation modules (111, 112) are designed to query at least one of the data concerning the unmanned aircraft (10) and send said data to the control module (120): - identification data - flight altitude - location

2 EP3 604 131 - speed - destination point - departure point - cargo - direction of flight.

3. The toll system according to claim 1 or 2, where the at least two observation modules (111, 112) are several observation modules (110), and the system further comprises a data connection between the connected control modules (120) and each observation module (110), and each control module (120) is designed to determine the flight movement (B) of the unmanned aircraft (10) based on data transmissions received from a plurality of observation modules (110).

4. The toll system according to one of the preceding claims, wherein the transponder (12) has an RF backscatter transponder, and the said at least — two observation modules (110) each comprise an FMCW radar unit, which enables interrogation by means of a frequency-modulated continuous wave signal (FMCW).

5. The toll system according to claim 4, wherein the FMCW radar units are designed to interrogate the transponder (12) when attached to the unmanned aerial vehicle (10), at a distance of at least 100 m.

6. A method for detecting the flight movement (B) of an unmanned aircraft (10) equipped with a transponder (12) in a toll system, where the toll system has at least two observation modules (111, 112), where each observation module (111, 112) comprises a connected control module (120), where the method comprises the following steps: detecting (S111) the unmanned aircraft (10) by interrogating the transponder (12) with the help of the first detection module (111);

3 EP3 604 131 detecting (S112) the unmanned aircraft (10) by interrogating the transponder (12) with the help of the second detection module (112);

moving the unmanned aircraft (10) between at least two observation modules (111, 112) with the help of the connected control module (120),

wherein the transfer comprises the sending of information that enables at least one identification of the unmanned aircraft (10); and determining (S120) the flight movement of the unmanned aircraft (B) from the successive observations (10) by means of the server.