System, method, computer programme, and computer-readable medium

Abstract

The present invention relates to a system for determining the position, the orientation and / or the movement of a beacon, said system comprising at least one receiver and one beacon, the beacon comprising a transmitter, the transmitter of the beacon being designed to emit electromagnetic waves in a frequency band and the receiver having means which are designed to receive the waves and to determine a position, orientation and / or movement of the beacon therefrom, the system having at least one further beacon, the frequency band of the transmitter of the further beacon or the frequency bands of the transmitters of the further beacons differing from the frequency band of the transmitter of the beacon.

Description

[0001] System, method, computer program and computer-readable medium

[0002] The present invention relates to a system for determining the position, orientation and / or movement of a beacon, 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 has means designed to receive the waves and to determine therefrom a position, orientation and / or movement of the beacon.

[0003] It is known from the state of the art to locate transmitters by emitting a short pulse of an Ultra Wide Band (UWB) signal with a signal power across a broad spectrum, which allows a distance to the transmitter to be determined.

[0004] This method has the disadvantage that when locating multiple transmitters, their signals overlap in the frequency range, making any assignment of the signals a considerable effort. Furthermore, the signals in this method are only used for distance measurement, and no other use, such as data transmission, is possible.

[0005] Separating the signals from multiple transmitters, for example through time interleaving, also has many disadvantages. Simultaneous transmission is not possible, which makes simultaneous acquisition of information about the transmitters, such as position, attitude, speed, or acceleration, impossible and thus also complicates the evaluation of the relative positions of the transmitters. Complex signal coordination is also necessary to prevent temporal overlap. Temporal synchronization is only possible with considerable effort. This applies to all established positioning methods such as time of arrival (TOA), round trip time of flight (RTOF), or time difference of arrival (TDOA). Likewise, continuous tracking of small shifts via the phase is not possible, which reduces accuracy.Additional sensors, such as inertial measurement units (IMU), can only be synchronized with great effort, as this requires another separate and synchronized communication system.

[0006] Likewise, this method requires significant hardware complexity, as a wide frequency band requires an expensive transmitter. Large numbers of transmitters, in particular, result in high energy consumption. Therefore, the implementation of energy-autonomous transmitters is fraught with challenges. Transmitters typically also have a receiver to coordinate the transmitters. Additional, possibly broadband, receivers further increase the hardware complexity and energy consumption. Without a receiver, a UWB approach in which many transmitters are located in a coordinated, simultaneous, and time-stamped manner is highly complex and inefficient.

[0007] A Code Division Multiple Access (CDMA) approach is a possible alternative to time interleaving. However, this approach also presents difficulties with many moving transmitters, as long codes limit the sampling rate and non-ideal signal shapes significantly complicate implementation for UWB. This approach also requires very complex transmitters. Also known is the positioning method disclosed in DE 10 2019 110 512 A1 for locating at least one object using wave-based signals. Narrowband signals are evaluated using spatially distributed phase measurements, which determines directional information instead of distance information. These signals can be modulated, for example, to transmit data. Synchronization of the transmitter is also not necessary.

[0008] A method is known which is disclosed in “S. Brückner, et al., "Phase Difference Based Precise Indoor Tracking of Common Mobile Devices Using an Iterative Holographie Extended Kalman Filter", IEEE Open Journal of Vehicular Technology, vol. 3, pp. 55- 67, January, 2022“.

[0009] Likewise, a method for localization using a Quasi Coherent Holographic Extended Kalman Filter (QCHEKF) is known from “E. Sippel et al., "Quasi-Coherent Phase-Based Localization and Tracking of Incoherently Transmitting Radio Beacons," in IEEE Access, vol. 9, pp. 133229-133239, 2021 , doi: 10.1109 / ACCESS.2021 .3115563”.

[0010] To detect the movements of a body or individual body parts, optical tracking systems are often used. These systems are based on optical markers that must be worn over clothing to ensure a line of sight to multiple infrared cameras. Alternatively, inertial sensors can be used, which evaluate the orientation of individual body parts in a skeleton model. The inherent disadvantage of this measurement principle is its limited accuracy and the lack of absolute position measurement in space.

[0011] Against this background, the present invention is based on the object of improving the determination of the position, orientation, and / or movement of one and, in particular, multiple beacons using one of the aforementioned systems. 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.

[0012] Accordingly, the invention provides 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 transmitters of the further beacons differ or differ from the frequency band of the transmitter of the beacon.

[0013] A Holographic Extended Kalman Filter (HEKF) is preferably used for multiple transmitters with frequency interleaving or frequency division multiplexing (FDM). Each transmitter has its own frequency band. For example, the carrier frequencies used in the frequency bands are spaced 4 MHz apart, with an overall band of 61 to 61.5 GHz.

[0014] Preferably, it is provided that the beacon can be arranged on an object or a living being or on a shell of an object or a living being and the system has means which are designed such that the position of the beacon can be determined with respect to the living being or the body shell.

[0015] It is conceivable that the system further comprises a preferably radio- and / or wave-based sensor system and / or an imaging measuring arrangement, wherein the system has means designed to control the sensor system and / or the imaging measuring arrangement such that the sensor system and / or the imaging measuring arrangement can detect a position and / or movement of the beacon and / or the system has means designed to display the position of the beacon with spatial accuracy in an image of the object or the living being or the shell of an object or a living being. In an advantageous embodiment, it is provided that the beacon further comprises a sensor, wherein the transmitter and the receiver are further designed to transmit data from the sensor to the receiver by means of the waves.

[0016] 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 common amplitude modulation methods. It is also conceivable that the phase of the wave is modulated, especially if only phase differences are evaluated to determine the position and / or movement of the beacon.

[0017] It is conceivable that the frequency bands lie in a range between 61 and 61.5 GHz and / or that the carrier frequencies of the frequency bands used have a frequency spacing of 4 MHz.

[0018] It is also conceivable that the frequency bands lie within any frequency range and / or that the carrier frequencies of the frequency bands used have any frequency spacing. The frequency spacing is preferably such that the frequency bands do not overlap and / or do not interfere with each other.

[0019] It can be provided that the transmitter has an antenna, wherein the system has means designed to use the position of the antenna to determine the position and / or movement and to image the beacon.

[0020] It can also be provided that the system does not have any means designed to synchronize the beacon and / or the transmitter of the beacon with other beacons and / or transmitters of beacons.

[0021] Determining position and / or movement can also be referred to as tracking. Synchronization of the transmitters is preferably not necessary, as they can all transmit at the same time without interfering with each other.

[0022] Synchronization for relative analysis between multiple transmitters, such as in gait analysis, is preferably performed implicitly during reception by simultaneously transmitting the waves and using the same receiving hardware. This enables exactly simultaneous position information without additional effort. This is particularly advantageous for relative analysis, e.g., of body posture.

[0023] If an additional sensor is arranged on the beacon, the data transmission of the sensor's measurement signal is preferably carried out with deterministic measurement, and the location of the beacon is preferably implicitly synchronized in time, since the same wave or signal is used for location and data transmission.

[0024] It can be provided that the beacon has an inertial sensor system which is designed to determine the orientation of the beacon in space.

[0025] It is conceivable that the receiver has means designed to receive the waves with a sampling rate greater than 10 kHz.

[0026] Preferably, significantly higher sampling rates, such as > 10 kHz, are possible, which can be advantageous for fast movements and complex evaluations using, for example, machine learning.

[0027] Preferably, the system is intended to be part of a sports, training, fitness measurement or fitness information system or to be used for a diagnostic or therapeutic purpose in medicine, psychology or the health sector.

[0028] It is conceivable that the system may comprise more than two beacons and / or more than one receiver. By simultaneously and continuously measuring the phase of the wave, even small changes in the position of the beacon, such as those caused by the trembling of living beings, can be easily detected. This is particularly possible with Quasi Coherent Holographic Extended Kalman Filters (QCHEKF).

[0029] The system advantageously has more than one receiver, with the receivers preferably sharing a common frequency reference. Thus, the high phase stability requirement of the oscillators used, which is necessary in the QCHEKF transmitter for the evaluation of absolute phases, is replaced by the constant phase position between the receivers. Through a quasi-coherent evaluation, the relative phase relationships between the at least two receivers can subsequently be utilized. This enables positioning comparably accurate to that achieved with the QCHEKF with very stable oscillators, but with significant advantages in cost and power consumption due to the very simple transmitters.

[0030] This makes it possible to have very simple transmitters, especially in terms of cost and energy consumption.

[0031] An additional measurement, such as imaging a body shell at the receiver, is conceivable, using largely identical hardware. This is therefore implicitly synchronized with the positioning through simultaneous data acquisition. The radio- and / or wave-based sensor technology and / or the imaging measurement setup are thus preferably congruent with the hardware designed for positioning, in particular the receiver, or integrated into it(s).

[0032] It is therefore conceivable that exactly the same antennas could be used for positioning and imaging, as this would allow the beacons to be accurately depicted / drawn in the image of the body. This is preferably done without geometric calibration of the beacons' position. Thus, the position of the beacons relative to the body is preferably determined without calibration. This is advantageous in terms of ease of use. Imaging and positioning can also be performed simultaneously, e.g., via a simple frequency multiplex.

[0033] The invention also relates to a method with a system according to the invention comprising the following steps: a) providing the beacon; b) detecting the position and / or movement of the beacon, wherein a further beacon is provided, wherein the frequency band of the transmitter of the further beacon differs from the frequency band of the transmitter of the beacon.

[0034] Preferably, the method further comprises the steps of: c) generating an image of an object or living being or the shell of the object or living being; d) displaying the position of the beacon, preferably spatially correct, in the image of the living being or the body shell.

[0035] It is conceivable that the method further comprises the step: e) transmitting data from the transmitter to the receiver.

[0036] It may also be provided that the method further comprises the step: f) determining the orientation of the beacon in space.

[0037] It may be intended that the method is used in a sports, training, or fitness measurement or fitness information system or for a diagnostic or therapeutic purpose in medicine, psychology or the health sector.

[0038] The invention also relates to a computer program comprising instructions that cause the system according to the invention to execute the method steps of a method according to the invention. The invention also relates to a computer-readable medium on which the computer program is stored.

[0039] The term "body envelope" or "body covering" is primarily understood to mean the boundary surface that creates the boundary between the inside and outside of a living being's body. The outside is usually air or the atmosphere surrounding the living being, and the inside is the body or its physical structures. In many animals and humans, the body envelope can be defined by the surface of the skin.

[0040] A beacon preferably refers to a unit comprising a sensor, a processing unit, and a transmitter with an integrated energy source. The energy source can be, for example, a battery or a capacitor, or it can be generated or supplied by extracting energy from the environment, for example, through energy harvesting. The beacon's function is preferably to locally collect data and process it accordingly so that it can be transmitted to base stations via a transmitter.

[0041] Radio technology is preferably understood to mean a system that can transmit and receive signals using transmitting and receiving devices, particularly antennas. The signal can be transmitted optically, acoustically, or, in particular, electromagnetically. The purpose of signal transmission can be to transmit information in the form of data to be transferred from transmitter to receiver and / or to collect location information.

[0042] Localization can be understood as the determination of the position and / or orientation of an object, for example a beacon, in space, particularly in three-dimensional space. A base station is preferably a typically stationary unit whose primary task is to receive signals emitted by beacons. Furthermore, signals for controlling beacons can also be emitted. The base station contains at least one receiving device and typically a processing unit for processing the data. It can be advantageous to connect several base stations to one another, especially if they are used for localization purposes.

[0043] It is also conceivable that the radio and / or wave-based sensor technology is designed in such a way that movements of the body are recorded with the help of a beacon attached to the body surface.

[0044] It is also conceivable that a beacon includes an inertial sensor that determines the orientation of the beacon.

[0045] It is also conceivable that the radio and / or wave-based sensor technology is designed in such a way that it determines the position of the sensor on the human body and that this measurement data is used to precisely assign the measurements of each beacon to specific body positions.

[0046] Preferably, an imaging measuring arrangement is provided which is suitable both for generating an image of the body shell and for receiving the radio signals of the beacons and for displaying the positions of the beacons in a spatially correct manner in the image of the body shell.

[0047] It is conceivable that the system, procedure or arrangement is used for a diagnostic or therapeutic purpose in medicine, psychology or the health sector.

[0048] It should be noted here that the terms "a" and "an" do not necessarily refer to exactly one of the elements, although this represents a possible embodiment, but can also refer to a plurality of the elements. Likewise, the use of the plural also includes the presence of the element in question in the singular, and conversely, the singular also encompasses several of the elements in question. Furthermore, all features of the invention described herein can be combined with one another as desired or claimed in isolation from one another.

[0049] Further advantages, features, and effects of the present invention will become apparent from the following description of preferred embodiments with reference to the figures, in which identical or similar components are designated by the same reference numerals. Herein:

[0050] Fig. 1 : an embodiment of a system according to the invention.

[0051] Fig. 2: another embodiment of a system according to the invention.

[0052] The system in Fig. 1 comprises one or more beacons 200 attached to a body shell of a human 10. The beacons may include sensors. Typically, twelve beacons 200 distributed over the entire body are used. To increase the level of detail, significantly more beacons 200 can be attached. If the measurement range is limited to specific regions of the body, the number of beacons 200 can also be significantly reduced.

[0053] The beacons 200 process the data in such a way that it can be transmitted via radio technology. One or more base stations 100 receive the signals and process them so that both the sensor signals are extracted and the position and / or orientation of the beacons 200 can be deduced. The advantage is that this enables, for the first time, the simultaneous location and transmission of the sensor data via a common radio transmission channel. A beacon 200 is attached to the body, for example, using an adhesive layer or an elastic band, and records parameters such as acceleration data. Additional parameters such as orientation can be recorded by sensors contained in the beacon 200.

[0054] The use of electromagnetic waves in the frequency range from 3 MHz to 3 THz has proven advantageous. This includes, for example, the frequency bands of modern communication systems such as WLAN or the 5G or 6G mobile communications standards. The internationally standardized IMS frequency band from 61 to 61.5 GHz is also particularly suitable. This frequency band provides sufficient bandwidth, which enables the use of a large number of beacons 200, for example, by allowing them to be differentiated by the base station 100 using individual transmission frequencies. The use of electromagnetic waves in the aforementioned frequency band has proven advantageous, in particular when phase-based positioning methods such as those in DE 10 2019 110 512 are used. The disclosure content of DE 10 2019 110 512 A1 is hereby incorporated in its entirety into the present description.In addition, electromagnetic waves in the frequency range mentioned can penetrate a wide variety of materials, such as clothing, with little loss.

[0055] If the method from DE 10 2019 110 512 A1 is used, it is advantageous for each beacon 200 to transmit its measurement signals in a separate frequency band, i.e., with an individual transmission frequency. This makes it easy for all beacons 200 to transmit simultaneously without interference from one another. This is extremely advantageous for locating and tracking highly dynamic movements, since the simultaneous transmission of all beacons 200 also allows the positions and vector velocities of all beacons 200 to be recorded simultaneously in a base station, thus eliminating the need for complex and error-prone time and movement correction calculation methods to compensate for different measurement times. The proposed preferred concept thus enables, on the one hand, optimal accuracy of the recorded body part positions and movements, and of the overall body poses and movements, while, on the other hand, requiring comparatively little computing effort.

[0056] The wireless transmission of the sensor data can be achieved, for example, by modulating the transmission signal, for example, by amplitude modulation, since this does not impair the positioning capability. The emitting device and processing unit of the receiver(s) can also be used to receive signals sent to the beacon 200. These can be, for example, control signals 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, capacitor, or by extracting energy from the environment, for example, through energy harvesting.

[0057] One or more base stations 100 are used to receive the signals transmitted by the beacon 200. Multiple base stations, each with at least one, preferably several, receiving antennas 100, are advantageous for three-dimensional spatial positioning. This is especially true when the orientation of the beacons 200 changes due to body movements and a direct connection to all base stations 200 cannot be guaranteed at all times.

[0058] In principle, all known positioning methods can be used to locate the position of the Beacon 200, such as evaluating the received power or signal propagation time. However, phase-based methods, which evaluate the phase angle of the received signal and can therefore be used independently of the signal modulation used, are particularly advantageous.

[0059] A particularly robust method is the evaluation of the difference in the reception phase between different receiving devices. A particularly advantageous evaluation method is the method using a Kalman filter presented in patent DE 10 2019 110 512 A1 and US 2021 / 0389411 A1, since, unlike conventional methods, this method does not evaluate the angle of the received signal as an intermediate step. Reference is made in full to the aforementioned patent and all embodiments and methods contained therein.

[0060] It is particularly advantageous if the previously described arrangement is combined with an imaging sensor system based on a camera, depth camera, laser scanner, or ultrasound, but in particular with an imaging radar system. Radars such as those used in security personnel scanners can be used as the imaging radar system. Multimodal sensor arrangements are also particularly suitable. The advantage of this combination arises from the fact that the absolute position of the beacons 200 on the body shell is of great importance. The imaging sensor system used should therefore be able to image both the body shell and the beacons 200 on the body shell. Radar systems are particularly well suited for this purpose, since the beacons 200 can be located and imaged with a radar sensor system even when they are concealed by clothing.

[0061] A further, extremely advantageous embodiment arises when the antennas and / or the electronic signal receiving devices of the imaging radar system are also used to receive the beacon signals. In this case, the imaging radar system and the beacons 200 should preferably operate in a common frequency band. The advantage of this embodiment is that the image of the body shell and the position of the beacons 200 are recorded in an identical reference coordinate system. A further advantage is that the shared use of hardware for different tasks leads to a cost reduction of the overall system.

[0062] Fig. 2 shows an exemplary system or arrangement with a multimodal sensor arrangement for detecting beacons 200. It depicts an imaging MIMO-FSK radar as the primary modality 20 and a depth camera as the assisting modality 30, which are oriented offset from one another. The MIMO-FSK radar or primary modality 20 preferably has receiving antennas 21 and transmitting antennas 22.

[0063] The object 10 in Fig. 2 is, for example, a moving person or a body part and is provided with beacons 200. Individual points of the person or the body part move in Fig. 2 with a velocity vector V with the reference symbol 11, which can be decomposed into the Cartesian components Vi and V2.

[0064] The depth camera or the assisting modality 30 is connected to a computer 40 by a connection 35, via which distance characteristics of the object 10 detected by the depth camera or the assisting modality 30 are transmitted.

[0065] The MIMO-FSK radar or primary modality 20 is connected to the computer 40 by a connection 25, via which the speed and distance characteristics of the object 10 detected by the MIMO-FSK radar or primary modality 20 and the beacon signals are transmitted.

[0066] The computer 40 may be connected to a monitor 41 on which the results of the algorithms executed on the computer 40 for determining the image and movement of the object 10 and for determining the position of the beacons 200 on the body shell and the movement of the beacons 200 can be displayed.

Claims

Patent claims System for determining the position, orientation and / or movement of a beacon, with at least one receiver and one 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 has means which are designed to receive the waves and to determine a position, orientation and / or movement of the beacon therefrom, 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 transmitters of the further beacons differs or differs from the frequency band of the transmitter of the beacon.System according to claim 1, characterized in that the beacon can be arranged on an object or a living being or on a shell of an object or a living being and the system has means which are designed such that the position of the beacon can be determined with respect to the living being or the body shell. System according to claim 1 or 2, characterized in that the system further comprises a, preferably radio- and / or wave-based, sensor system and / or an imaging measuring arrangement, wherein the system has means designed to control the sensor system and / or the imaging measuring arrangement such that the sensor system and / or the imaging measuring arrangement can detect a position and / or movement of the beacon and / or the system has means designed to display the position of the beacon spatially correctly in an image of the object or the living being or the shell of an object or a living being. System according to one of the preceding claims, characterized in that the beacon further comprises a sensor, wherein the transmitter and the receiver are further designed to transmit data from the sensor to the receiver by means of the waves.System according to one of the preceding claims, characterized in that the frequency bands lie in a range between 61 and 61.5 GHz and / or that the carrier frequencies used in the frequency bands used have a frequency spacing of 4 MHz. System according to one of the preceding claims, characterized in that the transmitter has an antenna, the system having means designed to use the position of the antenna to determine the position and / or movement and to image the beacon. System according to one of the preceding claims, characterized in that the system does not have means designed to synchronize the beacon and / or the transmitter of the beacon with other beacons and / or transmitters of beacons. System according to one of the preceding claims, characterized in that the beacon has an inertial sensor system that is designed to determine the orientation of the beacon in space. System according to one of the preceding claims, characterized in that the receiver has means that are designed to receive the waves with a sampling rate greater than 10 kHz. System according to one of the preceding claims, characterized in that the system is part of a sports, training, or fitness measurement or fitness information system or is used for a diagnostic or therapeutic purpose in medicine, psychology, or in the health sector. System according to one of the preceding claims, characterized in that the system comprises more than two beacons and / or more than one receiver.A method with a system according to one of the preceding claims, comprising the following steps: a) providing the beacon; b) detecting the position and / or movement of the beacon, characterized in that a further beacon is provided, wherein the frequency band of the transmitter of the further beacon differs from the frequency band of the transmitter of the beacon. A method according to claim 12, characterized in that the method further comprises the steps of: c) generating an image of an object or living being or the shell of the object or living being; d) displaying the position of the beacon, preferably spatially correct, in the image of the living being or the body shell. Method according to claim 12 or 13, characterized in that the method further comprises the step: e) transmitting data from the transmitter to the receiver. Method according to one of claims 12 to 14, characterized in that the method further comprises the step: f) determining the orientation of the beacon in space. Method according to one of claims 12 to 15, characterized in that the method is used in a sports, training, or fitness measurement or fitness information system or for a diagnostic or therapeutic purpose in medicine, psychology or in the health sector. Computer program comprising instructions that cause the system of one of claims 1 to 11 to carry out the method steps of one of claims 12 to 16. Computer-readable medium on which the computer program according to claim 17 is stored.

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