System, method, computer program and computer readable medium

Abstract

The invention relates to a system for ascertaining the position, orientation and / or movement of a beacon, comprising at least one receiver and a beacon, the beacon comprising a transmitter, the transmitter of the beacon being designed to emit electromagnetic waves in the frequency band, and the receiver comprising means for determining the position, orientation and / or movement of the beacon, the device is designed to receive waves and to ascertain the position, orientation and / or movement of the beacon therefrom, the system having at least one further beacon, one frequency band of the transmitter of the further beacon or a plurality of frequency bands of the transmitter of the further beacon being different from the frequency band of the transmitter of the beacon.

Description

Technical Field

[0001] The invention relates to a system for determining the position, orientation and / or movement of a beacon, the system comprising at least one receiver and a beacon, wherein the beacon comprises a transmitter, wherein the transmitter of the beacon is designed to emit electromagnetic waves in a frequency band, and the receiver comprises means which are designed to receive the waves and thereby determine the position, orientation and / or movement of the beacon. Background Art

[0002] It is known in the prior art to locate a transmitter by emitting a short-duration pulse of an ultra-wideband (UWB) signal having a signal power over a broad frequency spectrum, whereby the distance to the transmitter can be determined.

[0003] This method has the disadvantage that when locating a plurality of transmitters, the signals of the transmitters are superimposed in the frequency domain so that each correlation of the signals is associated with considerable effort.

[0004] Likewise, in the method described, the signal is used only for distance measurement and no further use of the signal, for example for transmitting data, is possible.

[0005] The separation of the signals of multiple transmitters, for example by time interleaving, also has many disadvantages. Simultaneous transmission is not possible, which makes it impossible to simultaneously obtain information about the transmitters, such as information about the position, orientation, speed or acceleration, and thus also makes it difficult to evaluate, for example, the relative transmitter positions to each other. Complex coordination of the signals is also required to prevent overlap in time. Temporal synchronization is only possible with great effort. This applies to all established positioning methods, such as time of arrival (TOA), round trip time offlight (RTOF) and time difference of arrival (TDOA). Likewise, continuous tracking of small shifts in phase is not possible, which reduces accuracy. Other sensor devices, such as inertial measurement units (IMUs), can only be synchronized with great effort, because for this purpose, another separate and synchronized communication system is required.

[0006] Likewise, the method is only feasible with high hardware expenditure, because the wide frequency band requires expensive transmitters. In particular, many transmitters have high energy consumption. Therefore, it is difficult to realize an energy-self-sufficient transmitter. In order to coordinate the transmitters, the transmitters mostly also have receivers. In the case of an additional, possibly broadband receiver, the hardware expenditure and energy consumption are increased again. Without a receiver, a UWB solution in which many transmitters are coordinated, simultaneously and time-stamped is feasible only under high expenditure and low efficiency.

[0007] As an alternative to time interleaving, the Code Division Multiple Access (CDMA) method is considered. However, there are difficulties here also with many moving transmitters, because the long codes limit the sampling rate, and the non-ideal signal shape makes implementation for UWB difficult. In this method as well, very complex transmitters are required.

[0008] Also known is a positioning method disclosed in DE 10 2019 110 512 A1 for determining the position of at least one object using a wave-based signal. In this case, a narrowband signal is evaluated by a spatially distributed phase measurement, thereby obtaining direction information instead of distance information. The signal can be modulated, for example, to transmit data. Synchronization of the transmitter is also not required.

[0009] The following method is known, which is disclosed in "S. Brückner et al., "Phase Difference Based Precise Indoor Tracking of Common Mobile Devices Using an Iterative Holographic Extended Kalman Filter", IEEE Vehicular Technology Open Journal, Vol. 3, pp. 55-67, January 2022".

[0010] A method for positioning using a quasi-coherent holographic extended Kalman filter (Quasi Coherent Holographic Extended Kalman Filter, QCHEKF) is also known from "E. Sippel et al., "Quasi-Coherent Phase-Based Localization and Tracking of Incoherently Transmitting Radio Beacons", IEEE Access, Vol. 9, pp. 133229-133239, 2021, doi: 10.1109 / ACCESS.2021.3115563".

[0011] In order to detect the movement of the body or individual body parts, optical positioning systems are usually used, which are based on optical markers that must be carried on clothing in order to ensure a line of sight connection with a plurality of infrared cameras. Alternatively, inertial sensor devices can be used, which evaluate the orientation of the individual body parts in a skeleton model. The inherent disadvantages of this measuring principle are the limited accuracy and the lack of absolute position measurement in space. Summary of the invention

[0012] Against this background, the invention is based on the object of improving the determination of the position, orientation and / or movement of one and in particular a plurality of beacons by means of one of the above-mentioned systems.

[0013] This object is achieved by the subject matter having the features of independent claim 1. Advantageous developments of the invention are the subject matter of the dependent claims.

[0014] Accordingly, it is proposed according to the invention that the system has at least one further beacon, wherein the frequency band of the transmitter of the further beacon or the frequency bands of the transmitter of the further beacon differ from the frequency band of the transmitter of the beacon.

[0015] Preferably, a holographic extended Kalman filter (HEKF) is used for a plurality of transmitters with frequency interleaving or frequency division multiplexing (FDM). Each transmitter has its own frequency band. For example, the carrier frequencies used in the used frequency band have a frequency spacing of 4 MHz in the entire band of 61 GHz to 61.5 GHz.

[0016] It is preferably provided that the beacon can be arranged on an object or living being or on the skin of an object or living being and that the system has means which are designed to determine the position of the beacon relative to the skin of the living being or body.

[0017] It is conceivable that the system also includes a preferably radio-based and / or wave-based sensor device and / or imaging measuring device, wherein the system has a mechanism configured to control the sensor device and / or imaging measuring device so that the sensor device and / or imaging measuring device can detect the position and / or movement of the beacon, and / or the system has a mechanism configured to display the position of the beacon in a location-correct image of an object or an organism or the skin of an object or an organism.

[0018] In an advantageous embodiment, the beacon also comprises a sensor, wherein the transmitter and the receiver are also designed to transmit data of the sensor to the receiver by means of waves.

[0019] In other words, preferably only the phase of the wave is used to determine the position and / or movement of the beacon. Data can thus be transmitted via the amplitude of the wave using conventional amplitude modulation methods. It is also conceivable to modulate the phase of the wave, in particular when only the phase difference is evaluated to determine the position and / or movement of the beacon.

[0020] It is conceivable that the frequency band lies in the range between 61 GHz and 61.5 GHz and / or that the carrier frequencies of the used frequency band have a frequency spacing of 4 MHz.

[0021] Furthermore, it is conceivable that the frequency bands are located in any frequency range and / or that the carrier frequencies of the used frequency bands have any frequency spacing. In this case, the frequency spacing is preferably such that the frequency bands do not overlap and / or do not interfere.

[0022] It may be provided that the transmitter has an antenna, wherein the system has means which are designed to use the position of the antenna to ascertain the position and / or the movement of the beacon and to image the beacon.

[0023] It can also be provided that the system does not have means which are designed to synchronize beacons and / or transmitters of beacons with other beacons and / or transmitters of beacons.

[0024] The determination of the position and / or the movement can also be referred to as positioning.

[0025] Preferably, there is no need for the transmitters to be synchronized with each other, since all transmitters are always able to transmit at any time without interfering.

[0026] For example, synchronization for relative evaluation between multiple transmitters in gait analysis is preferably implicitly performed by simultaneous transmission and reception by the same receiving hardware. This achieves precise simultaneous position information without additional effort. This is particularly advantageous for relative evaluation of body posture, for example.

[0027] If additional sensors are provided at the beacons, the data transmission of the measurement signals of the sensors preferably takes place in a deterministic manner and the positioning of the beacons is preferably implicitly synchronized in time, since the same wave or the same signal is used for positioning and data transmission.

[0028] It may be provided that the beacon has an inertial sensor system which is designed to determine the orientation of the beacon in space.

[0029] It is conceivable that the receiver has means which are designed to receive waves with a sampling rate of more than 10 kHz.

[0030] Preferably, significantly higher sampling rates, for example sampling rates >10 kHz, are possible, which can be advantageous for fast movements and complex evaluations by means of, for example, machine learning.

[0031] It is preferably provided that the system is part of a sports, training or fitness measurement or fitness information system or is used for diagnostic or therapeutic purposes in the field of medicine, psychology or health.

[0032] It is conceivable that the system may include more than two beacons and / or more than one receiver.

[0033] By simultaneously and continuously measuring the phase of the wave, preferably even small position changes of the beacon, for example during biological movements, can be detected very well. This is possible in particular in a quasi-coherent holographic extended Kalman filter (QCHEKF).

[0034] Advantageously, the system has more than one receiver, wherein the receivers preferably have a common frequency reference. Thus, the high requirements for the phase stability of the oscillators used, which are necessary in the transmitter for evaluating the absolute phase in the QCHEKF, are replaced by a constant phase between the receivers. Thus, the relative phase relationship between at least two receivers can then be utilized by quasi-coherent evaluation. This enables precise positioning similar to that of the QCHEKF with a very stable oscillator, but with clear advantages in terms of cost and energy requirements due to a very simple transmitter.

[0035] In particular, very simple transmitters are possible with regard to cost and energy requirements.

[0036] Additional measurements are conceivable, for example imaging the body skin at a receiver with largely identical hardware. The measurements are therefore implicitly synchronized with the localization by simultaneous data recording. The radio-based and / or wave-based sensor and / or imaging measuring device is therefore preferably identical to the hardware, in particular the receiver, for localization or is integrated therein.

[0037] That is to say, it is conceivable to use exactly the same antenna for positioning and imaging, since this allows the beacon to be imaged / marked with the correct position in the image of the body skin. This is preferably done without geometric calibration of the position of the beacon. Therefore, the position of the beacon relative to the body is preferably determined without calibration. This is advantageous in terms of simple applicability.

[0038] Imaging and positioning can also be performed simultaneously, for example via simple frequency multiplexing.

[0039] The invention also relates to a method carried out by the system according to the invention, said method comprising the following steps:

[0040] a) provide beacons;

[0041] b) detecting the position and / or movement of the beacon,

[0042] Therein a further beacon is provided, wherein the frequency band of the transmitter of the further beacon is different from the frequency band of the transmitter of the beacon.

[0043] Preferably, the method further comprises the following steps:

[0044] c) generating an image of an object or organism or the skin of an object or organism;

[0045] d) Preferentially correctly displaying the location of the beacon in the image of the organism or body skin.

[0046] It is conceivable that the method further comprises the following steps:

[0047] e) Transmit data from the sender to the receiver.

[0048] It can also be provided that the method further comprises the following steps:

[0049] f) Determine the orientation of the beacon in space.

[0050] It may be provided that the method is used in sports, training or fitness measurement or fitness information systems or in the field of medicine, psychology or health for diagnostic or therapeutic purposes.

[0051] The invention also relates to a computer program comprising instructions which cause a system according to the invention to perform the method steps of the method according to the invention.

[0052] The invention also relates to a computer-readable medium on which a computer program is stored.

[0053] The term "integument or body integument" is preferably understood to mean the boundary surface which, in the body of an organism, creates a boundary between the inside and the outside. The outside is usually the air or the atmosphere surrounding the organism, while the inside is the body or the material structure of the body. In many animals and in humans, the body integument can be defined by the skin surface.

[0054] A beacon preferably refers to a unit consisting of a sensor, a processing unit and a transmitting device with an integrated energy source. The energy source can be, for example, a battery or a capacitor or can be formed or supplied by taking energy from the environment, for example by energy harvesting. The task of the beacon is preferably to detect data locally and to process the data accordingly so that the data can be forwarded to a base station via the transmitting device.

[0055] Radio technology is preferably understood to be a system that can send and receive signals using transmitting and receiving devices, in particular antennas. The signal can be transmitted optically, acoustically or in particular electromagnetically. The purpose of the signal transmission can be to convey information in the form of data that should be transmitted from the transmitter to the receiver and / or to collect positioning information.

[0056] Localization may be understood as the determination of the position and / or orientation of an object, such as a beacon, in space, in particular in three-dimensional space.

[0057] A base station is preferably a unit which is usually fixed in place and whose main task is to receive the signals sent by the beacons. In addition, it can also send signals for controlling the beacons. A base station contains at least one receiving device and usually a processing unit for processing the data. It may be advantageous if a plurality of base stations are connected to one another, in particular when the base stations are used for positioning purposes.

[0058] Furthermore, it is conceivable that the radio-based and / or wave-based sensor system is designed in such a way that movements of the body are detected by means of beacons fastened to the body surface.

[0059] It is also conceivable that the beacon includes an inertial sensor system, by means of which the orientation of the beacon is determined.

[0060] It is also conceivable that the radio-based and / or wave-based sensor system is designed so that the position of the sensor on the human body skin is determined by it and the measurement data are used to be able to associate the measurement of each beacon precisely with a specific body position.

[0061] Preferably, an imaging measuring device is provided which is suitable both for generating an image of the body skin and for receiving radio signals of the beacons and for displaying the positions of the beacons in the image of the body skin with the correct location.

[0062] It is conceivable that the system, the method or the device is used for diagnostic or therapeutic purposes in the field of medicine, psychology or health.

[0063] At this point it should be noted that the terms "a" and "an" do not necessarily denote exactly one element, although this is a possible embodiment, but can also denote a plurality of elements. Likewise, the use of the plural also includes the presence of the elements involved in the singular, and conversely the singular also includes a plurality of the elements involved. Furthermore, all features of the invention described herein can be claimed in any combination with one another or in isolation from one another. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Further advantages, features and effects of the present invention are apparent from the following description of preferred exemplary embodiments with reference to the accompanying drawings, in which identical or similar components are denoted by the same reference numerals. In this case, it is shown:

[0065] Figure 1 One embodiment of the system according to the invention is shown.

[0066] Figure 2 A further embodiment of the system according to the invention is shown. DETAILED DESCRIPTION

[0067] Figure 1 The system in the embodiment has one or more beacons 200 placed at the body skin of a person 10. The beacons can have sensors. Typically, 12 beacons 200 distributed over the entire body are used. In order to increase the degree of detail, significantly more beacons 200 can also be placed. In the case of limiting the measurement range to specific areas of the body, the number of beacons 200 can also be significantly reduced.

[0068] The beacon 200 processes the data in such a way that the data can be transmitted via radio technology. One or more base stations 100 receive the signals and process them in such a way that not only the sensor signals can be extracted but also the position and / or orientation of the beacon 200 can be inferred. Advantageously, this makes it possible for the first time to simultaneously perform positioning and transmit sensor data via a common radio transmission channel.

[0069] The beacon 200 is placed on the body skin, for example, by means of an adhesive layer or an elastic band, and detects parameters such as acceleration data. Further parameters such as orientation can be detected by sensors contained in the beacon 200 .

[0070] The use of electromagnetic waves in the frequency range of 3MHz to 3THz has been shown to be advantageous. For example, it includes the frequency bands of modern communication systems such as WLAN or 5G or 6G mobile radio standards. In particular, the internationally standardized IMS frequency bands of, for example, 61GHz to 61.5GHz are also suitable. The frequency band provides sufficient bandwidth, which enables the use of multiple beacons 200, in that the beacons can be distinguished by a base station 100, for example, by separate transmission frequencies. The use of electromagnetic waves in the mentioned frequency bands has been shown to be advantageous, especially when a phase-based positioning method is used as in DE 10 2019 110 512. The disclosure of DE 10 2019 110 512 A1 is hereby fully included in this specification. In addition, electromagnetic waves in the frequency range can penetrate a variety of materials, such as clothing, with little loss.

[0071] When using the method in DE 10 2019 110 512 A1, it is advantageous that each beacon 200 sends its measurement signal in a separate frequency band, i.e. at an individual transmission frequency. It is thus possible in a simple manner for all beacons 200 to transmit simultaneously without interfering with each other. This is very advantageous for the positioning and tracking of highly dynamic movements, because the positions and vector velocities of all beacons 200 can also be detected simultaneously in the base station by the simultaneous transmission of all beacons 200, and thus the complex and error-prone time and motion correction calculation methods for equalizing different measurement time points can be discarded. That is to say, the proposed preferred design achieves the optimal accuracy of the detected body part positions, body part movements and overall body postures and body movements on the one hand and a relatively low computational effort on the other.

[0072] The radio transmission of the sensor data can be carried out, for example, by modulating the transmitted signal, for example by amplitude modulation, since the amplitude modulation does not impair the positioning capability. The transmitting device and the processing unit of one or more receivers can also be used to receive the signal sent to the beacon 200. This can be, for example, a control signal for configuring the beacon 200. The beacon 200 can be supplied with electrical energy, for example, by an energy source E integrated in the beacon 200, such as a battery, a capacitor, or by obtaining energy from the environment, for example by energy harvesting.

[0073] One or more base stations 100 are used to receive the signals emitted by the beacons 200. For three-dimensional positioning in space, a plurality of base stations are advantageous, each of which has at least one, preferably a plurality of, receiving antennas 100. This is particularly the case when the orientation of the beacons 200 changes due to movements of the body skin and a direct connection to all base stations 200 cannot be ensured at all times.

[0074] In principle, all known localization methods can be used to locate the position of beacon 200, such as evaluating the received power or signal propagation time. However, it is particularly advantageous to use phase-based methods that can evaluate the phase angle of the received signal and can therefore be used independently of the signal modulation used.

[0075] A robust method is in particular the evaluation of the reception phase differences between different receiving devices. A particularly advantageous evaluation method is the method using a Kalman filter proposed in patent document DE 10 2019 110 512 A1 or in US 2021 / 0389411 A1, since the method, in contrast to conventional methods, does not evaluate the angle of the received signal as an intermediate step. The aforementioned patent documents and all embodiments and methods contained therein are fully referenced herein.

[0076] It is particularly advantageous if the aforementioned device is combined with an imaging sensor system based on a camera, a depth camera, a laser scanner or ultrasound, but in particular with an imaging radar system. As an imaging radar system, it is possible to use, for example, radars used in security personnel scanners. In particular, multi-mode sensor devices are also considered. The advantages of the combination are as follows: The absolute position of the beacon 200 on the body skin is very important. Therefore, the imaging sensor system used should be able to image the body skin and the beacon 200 located on the body skin. Radar systems are particularly suitable for this because even when the beacon 200 is hidden by clothes, the beacon 200 can be located and imaged with the help of the radar sensor device.

[0077] A further particularly advantageous embodiment results if the antenna and / or the electronic signal receiving device of the imaging radar system is also used to receive the beacon signal. In this case, the imaging radar system and the beacon 200 should preferably operate in a common frequency band. The advantage resulting from this embodiment variant is that the image of the body skin and the position of the beacon 200 are detected in the same reference coordinate system. A further advantage can be that the common use of hardware for different purposes leads to a cost reduction for the entire system.

[0078] exist Figure 22 shows an exemplary system or device with a multi-mode sensor device for detecting beacons 200. An imaging MIMO FSK radar is shown as a main modality 20 together with a depth camera as an auxiliary modality 30, which are oriented one above the other and offset from each other. The MIMO-FSK radar or main modality 20 preferably has a receiving antenna 21 and a transmitting antenna 22.

[0079] Figure 2 The object 10 in the figure is, for example, a moving person or a body part and is provided with a beacon 200. The individual points of the person or the body part are Figure 2 In each case, the vehicle moves with a velocity vector V having the reference numeral 11 , which can be decomposed into Cartesian components V1 and V2 .

[0080] The depth camera or auxiliary modality 30 is connected to the computer 40 via a connection 35 , via which distance features of the object 10 detected by the depth camera or auxiliary modality 30 are transmitted.

[0081] The MIMO FSK radar or master modality 20 is connected to a computer 40 via a connection 25, via which the speed and distance characteristics of the object 10 detected by the MIMO FSK radar or master modality 20 and the beacon signal are transmitted.

[0082] The computer 40 can be connected to a monitor 41 on which the results of algorithms executed on the computer 40 for imaging and motion determination of the object 10 and for determining the position of the beacon 200 on the body skin and the motion of the beacon 200 can be displayed.

Claims

1. A system for determining the position, orientation and / or movement of a beacon, the system comprising at least one receiver and a beacon, wherein the beacon comprises a transmitter, wherein the transmitter of the beacon is designed to emit electromagnetic waves in a frequency band, and the receiver comprises means for receiving the waves and thereby determining the position, orientation and / or movement of the beacon, characterized in that The system has at least one further beacon, wherein the frequency band of the transmitter of the further beacon or the frequency bands of the transmitter of the further beacon differ from the frequency band of the transmitter of the beacon.

2. The system according to claim 1, characterized in that The beacon can be arranged on an object or a living being or on the skin of an object or a living being, and the system has means which are designed to determine the position of the beacon relative to the skin of the living being or the body.

3. The system according to claim 1 or 2, characterized in that: The system also includes a preferably radio-based and / or wave-based sensor device and / or imaging measuring device, wherein the system has a mechanism configured to control the sensor device and / or the imaging measuring device so that the sensor device and / or the imaging measuring device can detect the position and / or movement of the beacon, and / or the system has a mechanism configured to correctly display the position of the beacon in an image of the object or the organism or in an image of the skin of the object or the organism.

4. A system according to any one of the preceding claims, characterized in that The beacon further comprises a sensor, wherein the transmitter and the receiver are also designed to transmit data of the sensor to the receiver by means of the waves.

5. A system according to any one of the preceding claims, characterized in that The frequency band lies in the range between 61 GHz and 61.5 GHz and / or the carrier frequencies used in the frequency band used have a frequency spacing of 4 MHz.

6. A system according to any one of the preceding claims, characterised in that The transmitter has an antenna, wherein the system has means which are designed to use the position of the antenna to ascertain the position and / or the movement of the beacon and to image the beacon.

7. A system according to any one of the preceding claims, characterised in that The system does not have any means which are designed to synchronize the beacons and / or transmitters of the beacons with other beacons and / or transmitters of beacons.

8. A system according to any one of the preceding claims, characterised in that The beacon has an inertial sensor system which is designed to determine the orientation of the beacon in space.

9. A system according to any one of the preceding claims, characterised in that The receiver has a mechanism which is designed to receive the waves at a sampling rate of greater than 10 kHz.

10. A system according to any one of the preceding claims, characterised in that The system is a component of a sports, training or fitness measurement or fitness information system, or is used for diagnostic or therapeutic purposes in the fields of medicine, psychology or health.

11. A system according to any one of the preceding claims, characterised in that The system comprises more than two beacons and / or more than one receiver.

12. A method with the aid of a system according to any one of the preceding claims, comprising the following steps: a) providing the beacon; b) detecting the position and / or movement of said beacon, It is characterized in that A further beacon is provided, wherein the frequency band of the transmitter of the further beacon is different from the frequency band of the transmitter of the beacon.

13. The method according to claim 12, characterized in that The method further comprises the following steps: c) generating an image of an object or organism or the skin of said object or organism; d) Preferentially correctly displaying the position of the beacon in the image of the living being or body skin.

14. The method according to claim 12 or 13, characterized in that The method further comprises the following steps: e) Transmitting data from the transmitter to the receiver.

15. The method according to any one of claims 12 to 14, characterized in that The method further comprises the following steps: f) Determining the orientation of the beacon in space.

16. The method according to any one of claims 12 to 15, characterized in that The method is used in sports, training or fitness measurement or fitness information systems or in the field of medicine, psychology or health for diagnostic or therapeutic purposes.

17. A computer program comprising instructions causing a system according to any one of claims 1 to 11 to perform the method steps according to any one of claims 12 to 16.

18. A computer readable medium having stored thereon a computer program according to claim 17.

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