METHOD FOR DISTANCE DETERMINATION

Description

[0001] The invention relates to a method for determining distances.

[0002] A large number of different distance determination units, devices and methods for determining distances are generally known from the prior art.

[0003] WO 2009 / 112901 A1 describes wireless communication devices and methods that use acoustic rangefinding synchronized with RF communication signals. A communication terminal comprises an RF transceiver, a microphone, and a control unit.The controller synchronizes a clock in response to known time characteristics of received RF communication signals, determines a generation time relative to the clock synchronized with the RF communication signal at which the other communication terminal will generate an acoustic signal, determines a reception time of the acoustic signal relative to the clock synchronized with the RF signal when the acoustic signal is captured by the other communication terminal in the microphone signal, further determines a propagation time of the acoustic signal from the other communication terminal to the microphone based on a difference between the generation time and the reception time, and determines a distance to the other communication terminal in response to the propagation time of the acoustic signal.

[0004] A wireless electronic localization system is known from DE 10 2017 131 117 A1. In this localization system for wireless electronic distance determination between a first communication unit and a second communication unit that establishes a radio link with the first communication unit, the first communication unit is portable. The localization system includes time-of-flight measuring means for wireless distance determination between the first and second communication units. To implement the time-of-flight measuring means, the second communication unit has a sound source for generating an audible acoustic signal or an ultrasonic acoustic signal in response to a first radio signal received by the first communication unit, and the first communication unit has a microphone for receiving the acoustic signal generated by the second communication unit.Sound time-of-flight sensors are provided, which generate a distance signal from the sound time determined by the generation and reception of the acoustic signal. The second communication unit is designed such that the generation of the acoustic signal is triggered by the received first radio signal.

[0005] German patent DE 103 33 012 A1 describes an ultrasonic triangulation system and a corresponding method. The system comprises an ultrasonic transmitter, stationary ultrasonic receivers, and an ultrasonic evaluation unit. This unit calculates the transit times of the ultrasonic signal from the received electrical signals emitted by the receivers after receiving the transmitter's ultrasonic signal. A control computer coordinates and controls the system. The transmitter is battery-powered and operates wirelessly.The necessary trigger signal to be sent to the ultrasound transmitter, which serves both to mark the start of the time measurement in the ultrasound evaluation unit and to cause the mobile ultrasound transmitter to send an ultrasound signal, can be transmitted to the ultrasound transmitter by means of a wireless signal transmission device.

[0006] The invention is based on the objective of providing a method for determining distance that is improved compared to the prior art.

[0007] The problem is solved according to the invention by a method for determining distances with the features of claim 1.

[0008] Advantageous embodiments of the invention are the subject of the dependent claims.

[0009] A distance determination unit comprises an ultrasonic transmitter unit, configured and set up to transmit specified ultrasonic signals, an ultrasonic receiver unit, configured and set up to receive ultrasonic signals from other distance determination units, a radio transmitter unit, configured and set up to transmit specified radio signals, a radio receiver unit, configured and set up to receive radio signals from other distance determination units, a microcontroller, configured and set up to determine a distance to another distance determination unit based on at least one distance determination ultrasonic signal received from this other distance determination unit and at least one radio signal received from this other distance determination unit, and an electrical energy source, which is configured in particular as a battery or accumulator.Furthermore, the distance measuring unit comprises a storage unit, configured and set up to store a unique identification of the other distance measuring unit, which is transmitted in particular in the radio signal from the other distance measuring unit to the other distance measuring unit, and the determined distance of the other distance measuring unit, and / or an output unit, configured and set up to output the determined distance and / or an output signal corresponding to the determined distance and / or the unique identification of the other distance measuring unit. The output unit comprises, for example, several light sources, in particular of different colors, each configured as an LED.Depending on the measured distance, the system can, for example, illuminate a light source corresponding to that distance or distance range. For instance, a red light source might illuminate at a distance of less than one meter, a yellow light source at a distance between one and two meters, a green light source at a distance between two and three meters, and no light source at greater distances. Alternatively or additionally, the output unit could include an audible output to emit a warning tone, particularly when a predefined minimum distance of, for example, one meter is breached, and / or to provide spoken information.Alternatively or additionally, the output unit can, for example, include a vibration unit, particularly in the form of a vibration motor, to emit a vibration alarm, especially when a predetermined minimum distance of, for example, one meter is breached. The ultrasonic transmitter and receiver units can, for example, be designed as a single, integrated ultrasonic unit. Similarly, the radio transmitter and receiver units can, for example, be designed as a single radio unit. Radio technologies such as Bluetooth, BLE (Bluetooth Low Energy), or ZigBee are used.

[0010] A device for determining distance comprises at least two distance determination units. The distance determination units of the device can be identical or different, and in particular, each can have one or more of the additional features described below. In a method according to the invention for determining distance using such a device, a distance determination unit receives a distance determination ultrasound signal and a radio signal from at least one other distance determination unit and uses this signal to determine the distance to that other distance determination unit. The radio signal preferably contains the unique identification of the other distance determination unit. Thus, the unique identification of the other distance determination unit is advantageously transmitted from the other distance determination unit to the distance determination unit by means of the radio signal.Advantageously, the distance measuring unit stores the determined distance in the storage unit along with a unique identifier of the other distance measuring unit, in particular along with a time stamp, especially the date and time, at which the distance measurement and / or storage took place. Alternatively or additionally, the distance measuring unit advantageously outputs the determined distance and / or a corresponding output signal via the output unit, for example, along with the unique identifier of the other distance measuring unit.

[0011] The device with its distance measuring units and the method to be carried out with it enable the determination of the distance between any two distance measuring units, and thus, for example, between any two persons, each wearing one of these distance measuring units, for example on their clothing or on their body, particularly in the chest area, or, for example, between a person and an object, each wearing one of these distance measuring units. Furthermore, the device with its distance measuring units advantageously also enables the unambiguous identification of the respective distance measuring unit and thus, advantageously, also of the wearer of the respective distance measuring unit.of the person or object, since the unique identification of the additional distance-determining unit transmitting the radio signal and the distance-determining ultrasound signal is advantageously contained as information in the radio signal and is thus transmitted to the distance-determining unit via the radio signal. This distance-determining unit can then evaluate this radio signal with regard to the unique identification of the additional distance-determining unit transmitting the radio signal and the distance-determining ultrasound signal and store the determined distance together with the unique identification and, advantageously, additionally with a time stamp, in particular date and time, relating to the execution of the distance determination.

[0012] The distance measuring unit is therefore advantageously designed as a so-called tag, according to the invention as a plaque, in particular as a so-called badge, for attaching to a person's clothing, for example in the form of a pin or name tag, or according to the invention as a sticker for attaching to a person's body or as a bracelet, in particular for attaching to a person's arm, or as a unit for attaching to an object, for example on a building or on an object.

[0013] The operation of the distance measuring unit, and thus of the device and the method, is based on the different propagation speeds of radio signals and ultrasound signals. Radio signals propagate at the speed of light, i.e., at 300,000 km / s. Ultrasound signals propagate through the Earth's atmosphere in air at the speed of sound, i.e., at 343 m / s, and thus considerably slower than radio signals. The distance measuring unit, the device, and the method are specifically designed for determining distances over short distances, for example, distances of a maximum of 5 m, and in particular, a maximum of 2.5 m. Especially at these short distances, it can be assumed that there is no delay, or at least no measurable delay, between the transmission and reception of radio signals.In contrast, a measurable delay occurs between the transmission of the respective ultrasound signal by the second distance measuring unit and its reception by the receiving distance measuring unit. This delay depends on the distance between the first and second distance measuring units. This delay can be, for example, several milliseconds. Specifically, this delay is proportional to the distance between the first and second distance measuring units.Therefore, if the radio signal and the distance-determining ultrasound signal are transmitted simultaneously by the further distance-determining unit, or if the distance-determining ultrasound signal is transmitted with a predetermined transmission delay relative to the radio signal known to the receiving distance-determining unit, or if the radio signal is transmitted with a predetermined transmission delay relative to the distance-determining ultrasound signal known to the receiving distance-determining unit, the distance between this distance-determining unit and the further distance-determining unit can be determined from the delay between the reception of the radio signal and the reception of the distance-determining ultrasound signal by the receiving distance-determining unit.

[0014] The ultrasound signal in question is specifically an ultrasound burst, i.e., a burst of ultrasound signals, for example, with a sound frequency of 50 kHz, a burst length (i.e., signal length) of, for example, 160 µs with 8 oscillations, and thus a wave packet length of 54.9 mm. As already mentioned, this ultrasound signal travels at 343 m / s and thus covers one meter in 2.9 ms. For example, this speed of sound, as the propagation speed of the ultrasound signal, is fixed in the respective distance measuring unit for use in the process. Alternatively, it can be adjusted, for example, depending on the air temperature, advantageously automatically by the respective distance measuring unit, which for this purpose may have a corresponding sensor unit for determining the air temperature.

[0015] The distance to the next distance measuring unit is thus advantageously determined based on the travel time of the received distance measuring ultrasound signal between the transmitting and receiving distance measuring units. Advantageously, the distance measuring unit receives a distance measuring ultrasound signal and a radio signal from at least one other distance measuring unit and determines the distance to this other distance measuring unit by determining and evaluating the different signal travel times.The distance determination described here is therefore not based on the known reflection principle, in which the ultrasound transmitter sends an ultrasound, receives the ultrasound signal reflected from an object and uses this to determine the distance to that object. Instead, in the functionality described here, the second distance determination unit sends the distance determination ultrasound signal, which is received by the other distance determination unit. This second distance determination unit then determines the distance from the received original distance determination ultrasound signal sent by the second distance determination unit, i.e., not by means of a reflected ultrasound signal.This method for determining distance therefore always requires at least two distance determination units: one distance determination unit (in this case, the additional distance determination unit) that transmits the distance determination ultrasound signal, and at least one distance determination unit that receives this transmitted distance determination ultrasound signal and uses it to calculate the distance to the additional distance determination unit. Thus, the distance is always determined by the distance determination unit receiving the distance determination ultrasound signal, and not, as in known methods, by the additional distance determination unit transmitting the distance determination ultrasound signal.

[0016] This transit time of the received distance-determining ultrasound signal is determined, for example, based on the time interval between the reception of the distance-determining ultrasound signal and the reception of the radio signal. As already mentioned, the radio signal transmitted by the additional distance-determining unit is received by the distance-determining unit without delay, or at least with an immeasurable and, in particular, negligible delay, especially over the aforementioned short distances of a maximum of 5 m, and in particular a maximum of 2.5 m. In contrast, the distance-determining ultrasound signal transmitted by the additional distance-determining unit is received with a measurable delay of, for example, several milliseconds, depending on the distance between the distance-determining unit and the additional distance-determining unit.Thus, the distance between the distance measuring unit and the next distance measuring unit can be determined from the time interval between the reception of the radio signal and the reception of the ultrasound signal, if these were sent simultaneously.

[0017] According to the invention, the distance measurement unit receives an activation ultrasound signal from the other distance measurement unit, then activates the radio receiver unit, and subsequently receives the distance measurement ultrasound signal and the radio signal. This embodiment of the method is particularly advantageous with regard to electrical energy consumption. The radio transmitter unit and the radio receiver unit have a significantly higher electrical energy consumption than the ultrasound transmitter unit and the ultrasound receiver unit.The embodiment of the method described here makes it possible to operate only the ultrasound receiving unit and the ultrasound transmitting unit (e.g., the combined ultrasound unit), or only the ultrasound receiving unit, continuously, while activating the radio transmitting unit and radio receiving unit, or the combined radio unit, only after receiving the activation ultrasound signal and / or, if intended, transmitting the distance-determining ultrasound signal and the associated radio signal. These components are then deactivated after the distance determination is complete or after the transmission of the radio signal is finished. This results in significant energy savings, enabling a considerably longer operating time for the distance-determining unit when using a battery or accumulator with the same capacity.

[0018] According to the invention, after receiving the activation ultrasound signal from the further distance measuring unit, the distance measuring unit sends a response ultrasound signal, and the further distance measuring unit receives the response ultrasound signal and then sends the distance measuring ultrasound signal and the radio signal. This further reduces electrical energy consumption, since the radio transmitter or the shared radio unit of the further distance measuring unit sending the activation ultrasound signal is only activated when the response ultrasound signal from the distance measuring unit subsequently determining the distance has been received, advantageously only when it has been received within a predetermined time window of, for example, 10 ms.

[0019] In a non-inventive embodiment, the distance-determining ultrasound signal and the radio signal are transmitted simultaneously, or the transmission of the distance-determining ultrasound signal and the radio signal is initiated at least simultaneously. This is the simplest implementation, since the distance-determining unit receiving the radio signal and the distance-determining ultrasound signal can then directly determine the travel time of the distance-determining ultrasound signal, and thus the distance to the next distance-determining unit, from the time interval between the reception of the radio signal and the distance-determining ultrasound signal. Alternatively, it would also be possible, for example, to transmit the distance-determining ultrasound signal and the radio signal with a time delay.For this, however, it would be necessary, for example, to communicate this transmission time offset to the receiving distance determination unit, especially in the radio signal, or to specify such a uniform transmission time offset for all distance determination units so that this transmission time offset can be taken into account when determining the distance.

[0020] According to the invention, the further distance determination unit transmits several radio signals successively after the transmission of the distance determination ultrasound signal. Each radio signal contains information about its transmission interval relative to the distance determination ultrasound signal. The distance determination unit calculates the distance to itself from the transmission interval of the first fully received radio signal after the reception of the distance determination ultrasound signal. In this embodiment of the method, the receiving distance determination unit does not need to measure the time interval between the reception of the radio signal and the reception of the distance determination ultrasound signal, because this time interval is communicated, at least approximately, in the received radio signal. Thus, for example, it is not necessary for the distance determination unit to have a timer unit and / or real-time clock.

[0021] In one possible embodiment, the distance measurement unit, or the respective distance measurement unit of the device, includes a timing unit. This timing unit is used, for example, to independently determine the time interval between the reception of the radio signal and the reception of the distance ultrasound signal. Alternatively or additionally, this timing unit is used, for example, for one or more other functions. It is, for example, a component of the microcontroller. It is configured, for example, as a quartz crystal or an RC generator.

[0022] In one possible embodiment, the distance measurement unit or the respective distance measurement unit of the device comprises a real-time clock unit. This real-time clock unit makes it possible, in particular, to assign a time value, especially a date and time, to each measured distance and to store this data together, especially also together with the unique identification of the other distance measurement unit whose distance was measured. This allows it to be clearly determined later at what time which distance to which other distance measurement unit, and thus to which person or object as the carrier of this other distance measurement unit, was measured. For example, in this way, possible chains of infection can be identified in the case of diseases transmissible over short distances, and further transmission of disease can be prevented as early as possible.

[0023] According to the invention, the distance measuring unit or the respective distance measuring unit of the device comprises at least one sensor unit. By means of this sensor unit, or advantageously several sensor units, one or more further parameters can be recorded and, for example, stored and / or transmitted by means of a radio signal to another respective distance measuring unit, where they can be evaluated and / or stored. For example, sensor units are provided for determining air temperature, body temperature and / or skin conductance of the person wearing the respective distance measuring unit, acceleration and / or inclination.By determining the acceleration and / or inclination, it is possible, for example, to largely deactivate the distance detection unit, which is intended especially for people, in a stationary state, particularly with the exception of the sensor unit for determining the acceleration and / or inclination, so that the electrical energy consumption can be further reduced, especially when the distance detection unit is not in use, for example when it is stored away.

[0024] In one possible embodiment, the distance measuring unit or the respective distance measuring unit of the device comprises at least one data transmission interface. Data can be read from and / or stored in the storage unit of the distance measuring unit via this at least one data transmission interface, for example, via Bluetooth, BLE (Bluetooth Low Energy), RFID, or NFC. Data read from the storage unit includes, for example, the determined distances to other distance measuring units and their respective unique identification, in particular the time at which the respective distance was determined. The storage unit initially stores, for example, its own unique identification, such as a name and / or a passport or identity card identification number of the person to whom the distance measuring unit is assigned.The storage unit can also store additional information, which can optionally be transmitted via the data transmission interface, in particular from the further distance determination unit to the distance determination unit that determines the distance to this further distance determination unit, which can, for example, evaluate and / or store this information and / or take it into account when issuing a warning message via the output unit and, for example, output it accordingly.

[0025] The respective feature described above for the distance measuring unit, in particular the optional feature, can, for example, include one distance measuring unit or several or all distance measuring units of the device.

[0026] The solution described above thus enables, in particular, the detection of an approach between any two persons or objects, or between a person and an object, advantageously including their unique identification, and optionally the storage of the unique identification together with the respective determined distance and advantageously together with the time indication when the respective distance was determined.

[0027] The described solution thus enables, in particular, a determination of the distance between at least one distance determination unit and at least one further distance determination unit, preferably with simultaneous unambiguous identification of the at least one further distance determination unit to which the distance was determined, and thus advantageously an unambiguous assignment of objects or persons.

[0028] The described solution thus enables, in particular, the measurement of distances between persons, objects, and / or persons to objects; advantageously, a clear assignment of the determined distances through the unambiguous identification of the respective distance measurement unit to which the respective distance was determined; advantageously, the assignment of each determined distance and the respective unique information to a time indication of when the respective distance was determined; advantageously, the determination of distances to several further distance measurement units, for example, up to 100 further distance measurement units, within a predefined detection area; and advantageously, a fast measurement cycle.Thus, with multiple distance measuring units in the detection area, each of the distance measuring units can advantageously determine its distance to every other distance measuring unit within this detection area in the manner described above, and advantageously in a very short time, so that even in dynamically changing situations, for example with a large group of people with such distance measuring units within the detection area, or with people entering and leaving the area, all distances can advantageously be determined reliably. For example, a real-time display can be provided directly at the respective person or object via the display unit.in particular, assigned to the respective distance and the respective unique identification. Advantageously, a respective evaluable data set can be generated using the respective distance determination unit, in particular comprising at least the respective determined distance, the unique identification of the respective further distance determination unit to which the respective distance was determined, and the time (advantageously including date and time) of the respective distance determination. Advantageously, secure readability of the respective data set is enabled, in particular via the data transmission interface.For example, RFID and / or NFC are used for short-range communication, and Bluetooth and / or BLE for long-range communication. Advantageously, measures to prevent data manipulation are included. The energy-saving measures described above advantageously result in very low power consumption. This is particularly beneficial for battery or rechargeable battery operation of the distance measurement unit. The components of the distance measurement unit described above advantageously require very little installation space, enabling a small and lightweight design of the unit, for example, as a pin or sticker.

[0029] The solution according to the invention thus enables the functions described above while simultaneously minimizing the size and very low energy consumption. Furthermore, this solution allows multiple distance measurement units to interact equally within a detection range, for example, in the same way as collision-free UHF RFID solutions, meshed wireless sensor networks, and Bluetooth beacon applications.

[0030] Essential to achieving the low-power requirement, i.e., low energy consumption, is the use of a dual ultrasound burst: the activation ultrasound signal, acting as a wake-up burst, and the distance-determination ultrasound signal, acting as a measurement burst. Advantageously, all ultrasound signals used are configured as ultrasound bursts, as described above. This advantageously applies to the activation ultrasound signal, the response ultrasound signal, and the distance-determination ultrasound signal, depending on whether the respective signal is used or not.

[0031] Advantageously, the respective distance measurement unit is otherwise in energy-saving sleep mode, i.e., advantageously when it is not performing distance measurements and is not transmitting ultrasound and / or radio signals. For example, only the ultrasound unit or only its ultrasound receiver unit is activated in this mode, in order to be able to receive the activation ultrasound signal from another distance measurement unit.

[0032] To save further electrical energy and achieve high data security, data is advantageously not sent immediately, but pre-processed in the microcontroller and then remains stored in the internal secure storage unit and is advantageously only sent on request.

[0033] The output of the determined distance and / or a distance warning via the output unit, for example by means of a warning tone and / or a light source or multiple light sources, advantageously occurs within a very short time, in particular immediately after the distance is determined, and is thus immediately available to the object or person on which the distance measuring unit is located. Advantageously, the determined distance and / or the distance warning, in particular together with the unique identification of the distance measuring unit to which the distance was determined, is also stored in the memory unit and can be read out at a later time. This makes it possible, in particular, to read this data from the memory units of all distance measuring units of the device and to perform a complex distance analysis.

[0034] Exemplary embodiments of the invention are explained in more detail below with reference to drawings.

[0035] It shows: Figure 1 is a schematic representation of two persons, each holding a distance measuring unit of a device for determining distance; Figure 2 is a schematic representation of an embodiment of a distance measuring unit; Figure 3 is a schematic representation of another embodiment of a distance measuring unit; Figure 4 is a schematic representation of another embodiment of a distance measuring unit; Figure 5 is a schematic representation of an embodiment of a method for determining distance; and Figure 6 is a schematic representation of another embodiment of a method for determining distance.

[0036] Corresponding parts are marked with the same reference symbols in all figures.

[0037] Figure 1Figure 1 shows a schematic representation of a person P1, hereinafter also referred to as the first person P1, and another person P2, hereinafter also referred to as the second person P2, each of whom has a distance measuring unit A1, A2 of a device 1 for determining distance AB. The distance measuring unit A1 is hereinafter also referred to as the first distance measuring unit A1, and the further distance measuring unit A2 is hereinafter also referred to as the second distance measuring unit A2. These two distance measuring units A1, A2 can determine their distance a to each other in the manner described below, in particular in a method for determining distance AB described below. This is described below using the distance measuring unit A1, hereinafter referred to as the first distance measuring unit A1, as an example, but advantageously also occurs, either before or after, in the reverse manner, i.e.,h. then the second distance determination unit A2 takes the role of the first distance determination unit A1 and the first distance determination unit A1 takes the role of the second distance determination unit A2, and the distance determination procedure AB described in more detail below is carried out in the same way.

[0038] The device 1 can have more than these two distance-measuring units A1, A2, for example, up to 100 distance-measuring units A1, A2, or more or fewer. Advantageously, the device 1 always includes those distance-measuring units A1, A2 that are located within a predetermined detection range of each other and can therefore determine the distance a between them. Advantageously, several first distance-measuring units A1 can be present simultaneously, each determining its distance a to the same second distance-measuring unit A2 in the manner described below.

[0039] In the Figures 2 to 4 Various embodiments of the distance determination unit A1, A2 are shown as examples.

[0040] Each distance determination unit A1, A2 comprises an ultrasonic transmitter unit US, configured and set up to transmit predefined ultrasonic signals ABUS, AUS, AWUS; an ultrasonic receiver unit UE, configured and set up to receive ultrasonic signals ABUS, AUS, AWUS from further distance determination units A2, A1; a radio transmitter unit FS, configured and set up to transmit predefined radio signals FUS; a radio receiver unit FE, configured and set up to receive radio signals FUS from further distance determination units A2, A1; and a microcontroller 2, configured and set up to determine the distance a to the further distance determination unit A2, A1 based on at least one distance determination ultrasonic signal ABUS received by this further distance determination unit A2, A1 and at least one radio signal FUS received by this further distance determination unit A2, A1.and an electrical energy source not shown in detail in the figures, which is in particular designed as a battery or accumulator. Furthermore, the distance determination unit A1, A2 comprises, as shown in the , Figures 2 and 4 shown, a storage unit 3, designed and configured for storing a, in particular unique, identification of the further distance determination unit A2, A1, which was advantageously transmitted by means of the radio signal FUS from the further distance determination unit A2, A1 to the distance determination unit A1, A2, and of the determined distance a of the further distance determination unit A2, A1, advantageously together with a time indication, comprising in particular date and time, at which the distance determination AB was carried out, and / or, as shown in the Figures 2 to 4shown, an output unit 4, designed and configured to output the determined distance a and / or an output signal corresponding to the determined distance a and, for example, additionally to output the unique identification of the further distance determination unit A2, A1.

[0041] The radio signal FUS includes, for example, the unique identification of the additional distance measurement unit A2, A1, optionally further data, in particular of the person P2, P1, who carries the additional distance measurement unit A2, A1, for example health data, for example a time signal and / or a delay time until the transmission of the distance measurement ultrasound signal ABUS, and for example a signal strength of the ultrasound signal and / or the radio signal FUS.

[0042] The output unit 4 comprises, for example, several light sources 4.1, 4.2, 4.3, particularly of different colors, each configured as an LED. Depending on the determined distance a, it may then be provided, for example, that a light source 4.1, 4.2, 4.3 assigned to the respective distance a or distance range illuminates, for example, a red light source 4.1 at a distance a of less than one meter, a yellow light source 4.2 at a distance a between one and two meters, and a green light source 4.3 at a distance a between two and three meters. Alternatively or additionally, the output unit 4 may, for example, include an audio output 4.4 for emitting a warning tone, particularly when a predetermined minimum distance of, for example, one meter is not reached, and / or, for example, for emitting voice information. Alternatively or additionally, the output unit 4 may, for example, include a vibration unit.Alternatively or additionally, output unit 4 can also send output information via the radio transmitter unit FS, for example using BLE. Furthermore, output, such as a warning, can also be provided for body sensor data that deviates from the specifications.

[0043] The ultrasound transmitting unit US and the ultrasound receiving unit UE are, for example, designed as a single ultrasound unit U, as shown in the embodiment according to Figure 2 The radio transmitting unit FS and the radio receiving unit FE are, for example, configured as a single radio unit F, as also shown in the embodiment according to Figure 2 The radio technologies used include Bluetooth, BLE (Bluetooth Low Energy), RFID, and NFC.

[0044] Furthermore, the microcontroller 2 is advantageously also intended for central process control, in particular for carrying out the procedure, and especially for controlling the other components of the distance determination unit A1, A2. This microcontroller 2 can, for example, also be integrated into the radio unit F.

[0045] Advantageously, the distance determination unit A1, A2, or the respective distance determination unit A1, A2 of the device 1, comprises a timer unit (not shown in the figures), in particular a quartz crystal or an RC generator. This timer unit is used, for example, to independently determine the time interval between the reception of the radio signal FUS and the reception of the distance determination ultrasound signal ABUS. Alternatively or additionally, this timer unit is used, for example, for one or more other functions. In particular, this timer unit is used to generate the radio signals FUS and / or to determine and transmit a time base between the distance determination units A1, A2.

[0046] In one possible embodiment, the distance measuring unit A1, A2, or the respective distance measuring unit A1, A2 of the device 1, comprises a real-time clock unit 5. This real-time clock unit 5 makes it possible, in particular, to assign a time value, especially a date and time, to each measured distance a and to store this data together, especially also together with the unique identification of the further distance measuring unit A2, A1, whose distance a was measured. This makes it possible to later determine unambiguously at what time which distance a was measured to which further distance measuring unit A2, A1 and thus to which person P2, P1 or to which object as the carrier of this further distance measuring unit A2, A1.For example, in this way, possible chains of infection can be identified in the case of diseases that can be transmitted over short distances, and further transmission of the disease can be prevented as early as possible.

[0047] In one possible embodiment, the distance measuring unit A2, A1, or the respective distance measuring unit A2, A1 of the device 1, comprises at least one sensor unit 6. By means of this sensor unit 6, or advantageously several sensor units 6, one or more further parameters can be acquired and, for example, stored and / or transmitted by means of the radio signal FUS to another respective distance measuring unit A2, A1, where they can be evaluated and / or stored. For example, at least one sensor unit 6 can be used to determine air temperature and / or humidity and / or gases, at least one body sensor unit 6.1 can be used to determine body temperature and / or skin conductance and / or pulse and / or other body parameters of the person P1, P2 wearing the respective distance measuring unit A1, A2, and / or at least one accelerometer unit 6.2. A unit is provided for determining acceleration and / or inclination and / or a magnetic field sensor unit for determining direction. The determined air temperature can, for example, be used to adjust the value of the speed of sound used to determine the distance a from the time-delayed reception of the distance-determining ultrasonic signal ABUS relative to the radio signal FUS, thereby improving the accuracy of the distance measurement. By determining the acceleration and / or inclination, it is possible, for example, to largely deactivate the distance-determining unit A1, A2, which is intended especially for persons P1, P2, in a stationary state, with the exception of the acceleration sensor unit 6.2 to determine the acceleration and / or inclination, so that the electrical energy consumption can be reduced, especially when the distance measurement unit A1, A2 is not in use, for example when it is stored away.

[0048] In one possible embodiment, the distance measurement unit A1, A2, or the respective distance measurement unit A1, A2 of the device 1, comprises at least one data transmission interface 7. Data can be read from and / or stored in the storage unit 3 of the distance measurement unit A1, A2 via this at least one data transmission interface 7, for example, via Bluetooth, BLE (Bluetooth Low Energy), RFID, or NFC. It can be configured, for example, as an HF interface or a UHF interface. For example, the determined distances a to the respective other distance measurement units A2, A1, and their respective identification numbers can be read out.The storage unit 3 initially stores, for example, the unique identification of the distance determination unit A1, A2, for example in the form of a name and / or a passport or identity card identification of the person P1, P2 to whom the distance determination unit A1, A2 is assigned.

[0049] Data interface 7 is appropriately access-protected, in particular to ensure the security of personal data and identification data.

[0050] The storage unit 3 is, in particular, non-volatile memory. It is specifically access-protected. Read and / or write access to the memory, for example via the data transmission interface 7, may be provided.

[0051] For example, storage unit 3 has several storage areas 3.1, 3.2, and 3.3. The first storage area, 3.1, is intended, for example, for storing its own identification data. This first storage area, 3.1, is advantageously access-protected. For example, read and write access is possible via NFC or RFID, and read-only access via BLE or Bluetooth. The second storage area, 3.2, is intended, for example, for storing the determined distances a to other distance measurement units A2 and A1, their respective identification, and a respective time, in particular time and date, of the respective distance measurement AB. Distance warning messages issued by output unit 4 can also be stored here. For example, the respective signal strength of the ultrasound signal ABUS, AUS, AWUS, and / or radio signal FUS can also be recorded and stored. The third storage area, 3.3 is intended, for example, for storing further data, such as sensor data acquired by means of sensor unit 6, in particular body sensor unit 6.1, and / or data on the health status of person P1, P2, to whom the respective distance determination unit A1, A2 is assigned. The sensor data are advantageously stored together with the time of their acquisition.

[0052] In the method for determining distance AB using device 1, the first distance determination unit A1 receives the distance determination ultrasound signal ABUS and the radio signal FUS from at least one second distance determination unit A2 and determines the distance a to this second distance determination unit A2, as described in the Figures 5 and 6This is illustrated by two exemplary embodiments. Advantageously, the first distance determination unit A1 stores the determined distance a together with the unique identification of the second distance determination unit A2 in the storage unit 3, advantageously together with a time stamp, including date and time, relating to the execution of the distance determination AB. Alternatively or additionally, the first distance determination unit A1 advantageously outputs the determined distance a and / or an output signal corresponding to the determined distance a via the output unit 4, for example together with the unique identification of the second distance determination unit A2.

[0053] The operation of the distance measurement units A1 and A2, and thus of the device 1 and the method, is based on the different propagation speeds of the radio signal FUS (speed of light, 300,000 km / s) and the distance measurement ultrasound signal ABUS (speed of sound, 343 m / s). This results in a delay when the second distance measurement unit A2 simultaneously transmits the radio signal FUS and the distance measurement ultrasound signal ABUS. This delay corresponds to the distance 'a' between the first and second distance measurement units A1 and A2.

[0054] The distance a to the second distance determination unit A2 is thus advantageously determined by the first distance determination unit A1 based on the travel time of the received distance determination ultrasound signal ABUS between the transmitting second distance determination unit A2 and the receiving first distance determination unit A1. In the examples shown, this travel time of the received distance determination ultrasound signal ABUS is determined based on the time interval between the reception of the distance determination ultrasound signal ABUS and the reception of the radio signal FUS.

[0055] In the examples shown here according to Figure 5 and Figure 6The first distance measuring unit A1 is designed to first receive an activation ultrasound signal AUS from the second distance measuring unit A2, then activate the radio receiving unit FE, and subsequently receive the distance measuring ultrasound signal ABUS and the radio signal FUS. In the example shown here, according to... Figure 6 After receiving the activation ultrasound signal AUS, the first distance measuring unit A1 sends a response ultrasound signal AWUS to the second distance measuring unit A2, and the second distance measuring unit A2 receives the response ultrasound signal AWUS and then sends the distance measuring ultrasound signal ABUS and the radio signal FUS.

[0056] The two in the Figures 5 and 6 The embodiments of the method shown will now be described in detail.

[0057] Depicted are in Figure 5 and Figure 6The two distance measurement units A1 and A2 with their radio transmitters FS, radio receivers FE, ultrasonic transmitters US, and ultrasonic receivers UE are shown. The diagram illustrates the distance AB of the distance a between the first and second distance measurement units A1 and A2 by the first distance measurement unit A1. This distance a is 0.5 m in the example shown. Figure 5 and Figure 6 each a timeline Z and in Figure 5 in addition a spacer bar W.

[0058] In the example according to Figure 5The second distance measurement unit, A2, first transmits the activation ultrasound signal OFF via its ultrasonic transmitter US, and then, at a predetermined time interval, transmits the distance measurement ultrasound signal ABUS via its ultrasonic transmitter US and simultaneously the radio signal FUS via its radio transmitter FS. Its radio receiver FE and ultrasonic receiver UE are deactivated during this time, resulting in correspondingly low electrical energy consumption. In the first distance measurement unit, A1, only the ultrasonic receiver UE is initially activated. The radio transmitter FS, radio receiver FE, and ultrasonic transmitter US are deactivated, which means that even with continuous operation of the ultrasonic receiver UE, electrical energy consumption remains very low.

[0059] The first distance measuring unit A1 receives the activation ultrasound signal AUS, transmitted by the second distance measuring unit A2, with its ultrasound receiver UE. Due to the distance a of 0.5 m, the signal is received with a time delay compared to the transmission time. Upon receiving this activation ultrasound signal AUS, it activates its radio receiver FE. This receiver remains activated until it receives the radio signal FUS, after which it is advantageously deactivated. It then receives the radio signal FUS transmitted by the second distance measuring unit A2 via its radio receiver FE, at or at least substantially at the transmission time, due to the high propagation speed of the radio signal FUS.The distance-determining ultrasound signal ABUS, transmitted by the second distance-determining unit A2, is received by the first distance-determining unit A1 via its ultrasound receiver UE with a time delay due to the low propagation speed. This time delay corresponds to the distance a between the two distance-determining units A1 and A2, as can be clearly seen from the timeline Z and distance line W. Using this time difference between the reception of the radio signal FUS and the reception of the distance-determining ultrasound signal ABUS, the first distance-determining unit A1 then performs the distance determination AB and, based on the propagation speed of the distance-determining ultrasound signal ABUS of 343 m / s, calculates the distance a between the two distance-determining units A1 and A2 as 0.5 m.

[0060] After receiving the radio signal FUS, the radio receiver FE is advantageously deactivated again. After receiving the distance-measuring ultrasound signal ABUS, the ultrasound receiver UE is advantageously deactivated again.

[0061] The time interval between the transmission of the activation ultrasound signal AUS and the transmission of the radio signal FUS and the distance-determining ultrasound signal ABUS can be determined, for example, by a desired distance range within which distances are to be determined (for a distance range of, for example, 3 m, this is 10 ms), in addition to a switch-on delay of the radio receiver unit FE. Advantageously, the first distance-determining unit A1 performs a level evaluation of the activation ultrasound signal AUS and the distance-determining ultrasound signal ABUS to ensure that both ultrasound signals AUS and ABUS were transmitted by the same distance-determining unit, i.e., by the second distance-determining unit A2.

[0062] If the first and second distance determination units A1, A2 are a greater distance 'a' from each other, there is a correspondingly greater time delay between the reception of the radio signal FUS and the distance determination ultrasound signal ABUS by the first distance determination unit A1, from which the corresponding distance 'a' can be determined. For example, only distances up to a predefined maximum value should be determined.As mentioned above, this is ensured by the time interval between the transmission of the activation ultrasound signal AUS and the transmission of the distance determination ultrasound signal ABUS and the radio signal FUS, because if the distance a between the two distance determination units A1, A2 is too large, the first distance determination unit A1 receives the activation ultrasound signal AUS only after the radio signal FUS has already been transmitted by the second distance determination unit A2, or at least so late that it can no longer activate its radio receiving unit FE before the radio signal FUS is transmitted by the second distance determination unit A2.Therefore, although it will receive the activation ultrasound signal AUS if it is still positioned sufficiently close to the second distance measuring unit A2, and will subsequently activate its radio receiver FE, it will no longer receive the radio signal FUS. Consequently, no distance measurement AB is taken. To conserve electrical energy, it is advantageously provided that the first distance measuring unit A1 deactivates its radio receiver FE again after a predetermined period without receiving a radio signal FUS.

[0063] In the other embodiment of the method according to Figure 6The second distance measuring unit A2 also initially transmits the activation ultrasound signal OFF via its ultrasound transmitter US. However, it simultaneously activates its ultrasound receiver UE for a predetermined period and waits for a response ultrasound signal AWUS from at least one first distance measuring unit A1. Its radio receiver FE remains deactivated. If it does not receive such a response ultrasound signal AWUS within this predetermined period, it transmits neither the radio signal FUS nor the distance measuring ultrasound signal ABUS. In the example shown here, however, this activation ultrasound signal OFF is received by the first distance measuring unit A1, whose radio transmitter FS and radio receiver FE are deactivated to conserve energy.The first distance measurement unit A1 then transmits the response ultrasound signal AWUS to the second distance measurement unit A2 via its ultrasound transmitter US. A2 receives this response ultrasound signal AWUS with its ultrasound receiver UE. Advantageously, it performs a level evaluation of the received response ultrasound signal AWUS to ensure that it is indeed a response ultrasound signal AWUS and not a reflection of its activation ultrasound signal AUS. Subsequently, at a predetermined time, i.e., with a predetermined delay from the activation ultrasound signal AUS, it transmits the radio signal FUS via its radio transmitter FS and simultaneously the distance measurement ultrasound signal ABUS via its ultrasound transmitter US. Its radio receiver FE remains deactivated during this process to conserve energy.

[0064] In addition to transmitting the response ultrasound signal AWUS as described above, the first distance measuring unit A1, after receiving the activation ultrasound signal AUS, also activates its radio receiver FE. This allows it to receive the radio signal FUS transmitted by the second distance measuring unit A2 via its radio receiver FE, and, due to the distance a, the distance measuring ultrasound signal ABUS via its ultrasound receiver UE with a corresponding time delay. Thus, due to the high propagation speed of the radio signal FUS, it receives the radio signal FUS transmitted by the second distance measuring unit A2 via its radio receiver FE at the time of transmission, or at least substantially at the time of transmission.The distance-determining ultrasound signal ABUS, transmitted by the second distance-determining unit A2, is received by the first distance-determining unit A1 via its ultrasound receiver UE with a time delay due to the low propagation speed. This time delay corresponds to the distance a between the two distance-determining units A1 and A2. Using this time difference between the reception of the radio signal FUS and the reception of the distance-determining ultrasound signal ABUS, the first distance-determining unit A1 then performs the distance AB and, based on the propagation speed of the distance-determining ultrasound signal ABUS of 343 m / s, determines the distance a between the two distance-determining units A1 and A2 to be 0.5 m.

[0065] After receiving the radio signal FUS, the radio receiver FE is advantageously deactivated again. After receiving the distance-measuring ultrasound signal ABUS, the ultrasound receiver UE is advantageously deactivated again.

[0066] The time interval between the transmission of the activation ultrasound signal OFF and the transmission of the radio signal FUS and the distance-determining ultrasound signal ABUS can be determined, for example, by a desired distance range within which distances are to be determined (for a distance range of, for example, 3 m, this is 10 ms), in addition to a switch-on delay of the radio receiver unit FE. However, an additional time interval dT between the transmission of the activation ultrasound signal OFF and the radio signal FUS and the distance-determining ultrasound signal ABUS can also be specified, for example, configurable between 0 and 100 ms.

[0067] If the first and second distance determination units A1, A2 have a larger distance a from each other, there is a correspondingly larger time delay between the reception of the radio signal FUS and the distance determination ultrasound signal ABUS by the first distance determination unit A1, from which the corresponding distance a can be determined.

[0068] For example, only distances up to a predefined maximum value should be determined. This is ensured here, on the one hand, by the reception window of the ultrasound receiver UE of the second distance measuring unit A2, because if the first distance measuring unit A1 is too far away a from the second distance measuring unit A2, it will receive the activation ultrasound signal AUS too late. It will then also activate its radio receiver FE and send the response ultrasound signal AWUS, but this response ultrasound signal AWUS will no longer be received by the second distance measuring unit A2, as it has already deactivated its ultrasound receiver UE. The second distance measuring unit A2 will then not send a radio signal FUS or a distance measuring ultrasound signal ABUS.Alternatively, if the second distance measuring unit A2 has already received a response ultrasound signal AWUS from another first distance measuring unit A1 in time and subsequently transmits the radio signal FUS and the distance measuring ultrasound signal ABUS, the further first distance measuring unit A1, which is too far away, will not receive the radio signal FUS, because it received the activation ultrasound signal AUS from the second distance measuring unit A2 too late and therefore only activated its radio receiving unit FE after the radio signal FUS had already been transmitted by the second distance measuring unit A2, or at least activated it so late that its radio receiving unit FE was no longer activated until the radio signal FUS was transmitted.Therefore, although it will receive the activation ultrasound signal AUS if it is still positioned sufficiently close to the second distance measuring unit A2, and will subsequently activate its radio receiver FE, it will no longer receive the radio signal FUS. Consequently, no distance measurement AB is taken. To conserve electrical energy, it is advantageously provided that the first distance measuring unit A1 deactivates its radio receiver FE again after a predetermined period without receiving a radio signal FUS.

[0069] In this process, techniques such as "Listen Before Talk" can be applied both before the transmission of the respective ultrasound signal AUS, AWUS, ABUS and before the transmission of the radio signal FUS by the currently active distance measurement unit A1, A2. This prevents interference with ongoing processes. Additionally, common anti-collision technologies such as channel hopping and / or frequency hopping can be used for the ultrasound signals AUS, AWUS, ABUS and / or for the radio signal FUS to avoid data and / or signal collisions.

[0070] During the transmission of the FUS radio signal, signal strengths of the radio transmission can also be transmitted and evaluated.

[0071] The ultrasound receiving unit UE can, for example, determine and evaluate the signal strength of the received ultrasound signal ABUS, AUS, AWUS.

[0072] The data collected in the respective distance measurement unit A1, A2, or parts thereof, can be read from the distance measurement unit A1, A2 by other end devices, for example smartphones, RFID readers, gateways, via the radio unit F RF interface (BLE) and / or via the data transmission interface 7.

[0073] The respective distance measurement units A1 and A2 can, for example, be set to a permanent "advertising mode" when certain data, particularly sensor data (e.g., regarding health status), is detected. This allows nearby receivers, such as smartphones, to analyze the data and register an alarm.

[0074] The respective distance measurement units A1 and A2 can, for example, acquire and evaluate further sensor data as described. This can include environmental parameters such as gases, ambient temperatures, and humidity, as well as person / object parameters such as body temperature, perspiration, and heart rate.

[0075] The data from the various data storage devices can be used during runtime, for example, to adjust the behavior of the respective distance measurement units A1 and A2, or correlated with each other during evaluation. For example, depending on the sensor data collected, the distance measurement units A1 and A2 can adjust their advertising behavior.

[0076] A registration of interference signals on both the ultrasound channels and the radio channels, and thus a disruption of the distance determination AB, can be stored, for example, by the respective distance determination unit A1, A2 in the storage unit 3, in particular in the second storage area 3.2, and / or displayed by the output unit 4. REFERENCE MARK LIST

[0077] 1. Distance measuring device 2. Microcontroller 3. Storage unit 3.1, 3.2, 3.3 Memory area 4. Output unit 4.1, 4.2, 4.3 Light source 4.4 Sound output 5. Real-time clock unit 6. Sensor unit 6.1 Body sensor unit 6.2 Accelerometer unit 7. Data transmission interface a. Distance A1. First distance measuring unit A2. Second distance measuring unit AB. Distance measurement ABUS. Distance measurement ultrasound signal OFF. Activation ultrasound signal AWUS. Response ultrasound signal dT. Additional time interval FF. Radio unit FEF. Radio receiver unit FSF. Radio transmitter unit FUSF. Radio signal P1, P2. Person U. Ultrasound unit UEU. Ultrasound receiver unit US. Ultrasound transmitter unit W. Distance bar Z. Time bar

Claims

1. Method for distance determination (AB) by means of a device (1) for distance determination (AB) comprising at least two distance determination units (A1, A2), wherein the respective distance determination unit (A1, A2) comprises: - an ultrasonic transmitting unit (US) for transmitting predefined ultrasonic signals (ABUS, AUS, AWUS), - an ultrasonic receiving unit (UE) for receiving ultrasonic signals (ABUS, AUS, AWUS) from further distance determination units (A2, A1), - a radio transmitting unit (FS) for transmitting predefined radio signals (FUS), - a radio receiving unit (FE) for receiving radio signals (FUS) from further distance determination units (A2, A1), - a microcontroller (2) for determining a distance (a) to a further distance determination unit (A2, A1) based on at least one distance determination ultrasonic signal (ABUS) received from this further distance determination unit (A2, A1) and at least one radio signal (FUS) received from this further distance determination unit (A2, A1), - an electrical energy source, - a storage unit (3) for storing an identification and the determined distance (a) of the further distance determination unit (A2, A1) and / or an output unit (4) for outputting the determined distance (a) and / or an output signal corresponding to the determined distance (a), and - at least one sensor unit (6), characterized in that - the at least one sensor unit (6) is in the form of a sensor unit (6) for determining an air temperature and / or air humidity or in the form of a sensor unit for determining gases or in the form of a body sensor unit (6.1) for determining a body temperature and / or skin conductivity and / or the pulse and / or other body parameters of a person (P1, P2) carrying the distance determination unit (A1, A2) or in the form of a magnetic field sensor unit for determining the compass direction, and - the distance determination unit (A1, A2) is in the form of a badge for affixing to clothing of a person (P1, P2) or in the form of a sticker for affixing to a body of a person (P1, P2), wherein a distance determination unit (A1) receives a distance determination ultrasonic signal (ABUS) and a radio signal (FUS) from at least one further distance determination unit (A2) and uses them to determine a distance (a) to this further distance determination unit (A2) and stores the determined distance (a), together with an identification of the further distance determination unit (A2), in the storage unit (3) and / or outputs the determined distance (a) and / or an output signal corresponding to the determined distance (a) via the output unit (4), wherein the distance determination unit (A1) receives an activation ultrasonic signal (AUS) from the further distance determination unit (A2), then activates the radio receiving unit (FE) and then receives the distance determination ultrasonic signal (ABUS) and the radio signal (FUS), wherein the distance determination unit (A1), after receiving the activation ultrasonic signal (AUS) from the further distance determination unit (A2), transmits a response ultrasonic signal (AWUS) and the further distance determination unit (A2) receives the response ultrasonic signal (AWUS) and then transmits the distance determination ultrasonic signal (ABUS) and the radio signal (FUS), and wherein the further distance determination unit (A2), starting at the time of transmitting the distance determination ultrasonic signal (ABUS), transmits a plurality of radio signals (FUS) in succession, each of which contains as information their temporal transmission distance to the distance determination ultrasonic signal (ABUS), wherein the distance determination unit (A1) determines the distance (a) to this further distance determination unit (A2) from the temporal transmission distance of the first fully received radio signal (FUS) after receiving the distance determination ultrasonic signal (ABUS).

2. Method according to Claim 1, wherein the distance (a) to the further distance determination unit (A2) is determined by means of a propagation time of the received distance determination ultrasonic signal (ABUS).

3. Method according to Claim 2, wherein the propagation time of the received distance determination ultrasonic signal (ABUS) is determined by means of a time interval between the reception of the distance determination ultrasonic signal (ABUS) and the reception of the radio signal (FUS).

4. Method according to one of the preceding claims, wherein the identification of the further distance determination unit (A2) is transmitted from the further distance determination unit (A2) to the distance determination unit (A1) by means of the radio signal (FUS).

5. Method according to one of the preceding claims, wherein the respective distance determination unit (A1, A2) comprises a timer unit.

6. Method according to one of the preceding claims, wherein the respective distance determination unit (A1, A2) comprises a real-time clock unit (5).

7. Method according to one of the preceding claims, wherein the respective distance determination unit (A1, A2) comprises at least one data transmission interface (7).