Method for protecting an unprotected road user, electronic device, method for a motor vehicle, and motor vehicle

Abstract

The invention relates to a method for protecting an unprotected road user (10), to an electronic device (12), to a method for a motor vehicle (16, 16') and to a motor vehicle (16, 16'). Connectionless BT communication of a radio system of an electronic device (12) of an unprotected road user (10) with other road users (14) is used to determine a mutual distance on the basis of the received signal strengths of the connectionless BT communication signals. If the distance determined in this way is less than 15 m, a positioning method based on delay time measurements is carried out using UWB signals. This allows the UWB-based positioning method to be carried out in a more targeted way, as a result of which energy consumption and the load on local radio channels can be reduced.

Description

[0001] Description

[0002] Method for protecting a vulnerable road user, electronic device, method for a motor vehicle and motor vehicle

[0003] The invention relates to a method for protecting an unprotected road user, an electronic device, a method for a motor vehicle and a motor vehicle.

[0004] Some of the assistance systems in modern vehicles are designed to protect drivers and other road users. Such assistance systems are usually based on familiar radar technologies, camera-based technologies, or ultrasonic sensors. Examples include distance warning systems for parking, lane change assistants, lane keeping assistants, turning assistants, exit warning systems, blind spot assistants, and the like. Such assistance systems are often designed for a specific application. As the number of assistance systems increases, so does the number of sensors and control units installed in the vehicle. This drives up the costs of installing assistance systems.

[0005] Despite their high costs, existing assistance systems are unable to adequately protect vulnerable road users (VRUs). VRUs include pedestrians, cyclists, motorcyclists, scooter riders, electric scooter riders, wheelchair users, and the like. VRUs have in common that, unlike a motor vehicle, they do not enjoy any protection against impact forces. In other words, VRUs lack a crumple zone to absorb collision energy. Therefore, there is a desire to better protect VRUs in road traffic.

[0006] Document DE 102020 114 834 A1 discloses an ultra-wideband (UWB)-based collision avoidance system between road users. This system comprises a signal generating device, which can be carried by the first road user, to generate a UWB radio signal, and a detection device, which can be carried by the second road user, to receive the UWB radio signal and determine at least one item of position information from the signal generating device based on the detected UWB radio signal. Using an evaluation device, a collision is then predicted based on the detected position information from the signal generating device, and an output signal dependent thereon is output via an output device.

[0007] However, it has been shown that the known UWB-based methods for detecting position information of other road users work well between vehicles, but cause problems with VRLIs in the vehicle environment, as the electronic systems carried by VRLIs usually have a very limited energy storage capacity, which is quickly depleted due to the high energy consumption of UWB radio technology. Furthermore, the exchanged communication signals can frequently interfere or otherwise disrupt each other at busy intersections. As a result, the reliability of positioning suffers.

[0008] The invention is therefore based on the object of providing a more reliable method for detecting a VRU.

[0009] The object of the invention is achieved by a method for protecting a vulnerable road user, an electronic device, a method for a motor vehicle, and a motor vehicle according to the independent claims. Preferred developments are the subject of the respective dependent claims.

[0010] A first aspect relates to a method for protecting a vulnerable road user using an electronic device. The electronic device comprises a radio system with a transceiver having a BT antenna configured to transmit and receive Bluetooth (BT) signals and a UWB antenna configured to transmit and receive ultra-wideband (UWB) signals. The transceiver of the radio system is designed, in particular, to transmit and receive signals in the known BT frequency band between 2.402 GHz and 2.480 GHz using the BT antenna, preferably using Bluetooth Low Energy (BLE) radio technology, and to transmit and receive signals in very wide frequency ranges, in particular in a frequency range from 3.1 GHz to 10.6 GHz, preferably in a frequency range from 3.5 GHz to 9 GHz, and particularly preferably in a frequency range from 6 GHz to 8.5 GHz, using the UWB antenna.The transmission power of the UWB pulses is low. The bandwidth of the UWB signal is at least 500 MHz, and the UWB transceiver is preferably designed to transmit signals with a transmission power between 0.5 mW / -41.3 dBm / MHz. Furthermore, the transceiver is preferably designed according to the IEEE 802.15.4 standard (in particular the sections on the UWB PHY layer) and preferably according to the IEEE 802.15.4z standard. Due to the scattering of the signals over such large frequency ranges, UWB signals cause minimal interference with other radio signals.

[0011] According to one method step, the BT antenna of the radio system is controlled to transmit a first BT pulse without a connection. In contrast to connection-oriented communication, in which a connection is first established between two radio systems, connectionless communication transmits a radio signal to the surrounding area without knowledge of a possible receiver (1-way transmitter). The first BT pulse is preferably a BLE pulse, for example, an advertisement pulse. Advertisement pulses are small-data pings that carry concise information. One example is a universally unique identifier (UUID) with a data size of 128 bits (16 bytes). Compared to connection-oriented communication, connectionless communication is faster and more energy-efficient.

[0012] In a further method step, response signals from a plurality of road users are received connectionlessly using the BT antenna. The response signals are preferably transmitted by second radio systems with second transceivers having BT antennas configured to transmit and receive BT signals and UWB antennas configured to transmit and receive UWB signals. According to the invention, the second radio systems are associated with another road user. For example, a road user is a motor vehicle or another VRU with the second radio system.

[0013] According to the invention, the response signals comprise identifiers of the plurality of road users. A road user identifier is an identifier that can be individually assigned to the road user's means of transport and is configured to distinguish one road user from another. Preferably, the response signals further comprise a classification of the (respective) road user. Based on the classification of the road user, the receiver of the response signal can determine which type of transport transmitted the response signal. In other words, the receiver of the response signal can distinguish whether the sender of the response signal is, for example, a motor vehicle or a VRU. In a further step of the method according to the invention, the BT antenna is controlled to transmit a second BT pulse without a connection.The transmission of the second BT pulse essentially serves the purpose of allowing the receiver of the second BT pulse to determine a mutual distance based on the received signal strength.

[0014] Furthermore, a distance between the radio system and the plurality of road users is determined based on the received signal strengths of the response signals (Received Signal Strength Indicator - RSSI). In other words, a preliminary distance determination is made based on the RSSI of the connectionless BT communication between the radio system and the plurality of road users.

[0015] In a further method step, the UWB antenna of the radio system is activated to perform a positioning method based on propagation time measurements to determine the positions of the plurality of road users if a distance between the radio system and one of the plurality of road users, determined based on the received signal strengths of the response signals, is less than 15 m, preferably less than 12 m, particularly preferably less than 9 m. In other words, the position determination using energy-intensive UWB communication is only performed when the undershoot of a predetermined distance between the two road users has been determined by means of a preliminary distance determination based on the RSSI of the connectionless BT communication.This limits the use of UWB communication for the purpose of mutual position detection to a maximum radius of 15 m, which is reasonable in terms of energy consumption. It is understandable that no meaningful results regarding mutual position detection using UWB communication can be achieved within a maximum radius of 15 m at speeds above 100 km / h. However, the speeds at which VRUs move are significantly lower, and collisions between VRUs and motor vehicles are more likely in urban areas at regulated speeds below 50 km / h. This means that the specified maximum radius of 15 m generally represents a good compromise between reduced energy consumption and sufficient protection for VRUs. Even smaller radiuses can achieve even lower energy consumption.Furthermore, the local radio channels are less heavily utilized due to the limited use of UWB communication for position determination, so that less interference and other disruptive signals are to be expected. Controlling the radio system preferably comprises at least the steps of controlling the UWB antenna to transmit a first UWB pulse to the second radio system at a time h and to receive a second UWB pulse from the second radio system at a time t2, determining a total propagation time based on the propagation times of the first UWB pulse, the second UWB pulse, and a processing time of the second radio system AT, and determining a distance between the radio system and the second radio system based on the total propagation time and the speed of light.

[0016] Because the first ping, in the form of the first BT pulse, originates from the VRU's electronic device, a VRU becomes visible to other road users. This eliminates the need for every vehicle to constantly send signal pings to be alerted to a VRU. This offers a significant advantage in terms of energy consumption. Another advantage is that BT radio technology has a greater range than UWB radio technology, allowing a preliminary estimation of mutual distances using connectionless BT communication before the more precise but more energy-intensive positioning process using UWB radio technology is performed.The VRU therefore already makes itself noticeable to road users in situations where visibility to it is obscured or poor, for example at night without lights, in the blind spot when turning and at traffic lights, obscured by other objects and the like.

[0017] The electronic device is preferably configured as a mobile terminal, for example, a smartphone, or as an electronic device integrated into the vehicle of the VRU. Vehicles of the VRU include, for example, bicycles, motorcycles, scooters, electric scooters, wheelchairs, and the like. The electronic device integrated into the vehicle is preferably configured as a retrofit kit. Particularly preferably, the integrated electronic device is connected to a power source of the vehicle, for example, a battery. Advantageously, an existing battery, such as in electric bikes, electric scooters, electric scooters, and the like, can be used to power the electronic device.Due to the reduced energy consumption, the electronic device can also be used as a comparatively simple transponder with a conventional device battery, which is used to power small portable devices such as watches, radios, toys, flashlights, and the like. The device battery is preferably non-rechargeable. This type of transponder can also be used to attach items of clothing or other objects, particularly to protect children. In a preferred embodiment, a road user sequence is created based on the received response signals, particularly based on the provisionally determined distances. The second BT pulse then includes the generated road user sequence, and the UWB antenna of the radio system is controlled to perform the positioning method according to the road user sequence.For example, road users are sorted by distance, starting with the shortest distance (or the strongest signal). In other words, subsequent positioning using UWB communication is then preferentially performed depending on the road users' distances from the electronic device. This takes into account the fact that road users closest to the VRU usually also pose the greatest accident risk for the VRU. In the road user sequence, time periods for ultra-wideband (UWB) communication with the VRU's radio system are specified for each received identifier.Based on the previously transmitted road user sequence, each road user can adjust the time, or rather, the time period, at which the respective positioning procedure between the road user's second radio system and the radio system of the electronic device should be carried out. In other words, each road user learns their individual UWB time slot from the received road user sequence. This makes it possible to prevent or at least reduce, in an orderly manner, interference or other disruptions to the UWB radio communication between the electronic device and the second radio systems of the plurality of road users.

[0018] Preferably, the generated road user sequence is compressed or subjected to compression. The second BT pulse then includes the generated compressed road user sequence in order to reduce the required data size of the second BT pulse. For example, for each road user identified using the received response signals, a 48-bit value is provided, each containing the received Bluetooth address of the road user. Using a freely selectable hash algorithm, the road user sequence is compressed via the index to 2 bytes, i.e., 16 bits per road user. The road user receiving the second BT pulse can then calculate its position in the road user sequence from the compressed road user sequence using the index from the hash algorithm.In a further preferred embodiment, the transmission power of the BT and / or UWB antenna is adjusted based on the distances determined using the received signal strengths of the response signals and / or based on the positions of the plurality of road users determined using UWB. For example, in addition to a predetermined transmission power, the BT and / or UWB antenna(s) are also operated with a reduced or increased transmission power in order to verify the plausibility of the determined distance and / or the position of the road user. The transmission range of the signals is known to correlate with the transmission power. If the range of the signal is reduced accordingly to a value below the determined distance, the transmitted pulse should not induce a response signal from the road user due to a lack of range, or no response signal should be detected.

[0019] In particular, dynamic effects and interactions with other (interfering) objects in the environment occur due to changes in location caused by the movement of road users. These effects can be reduced by varying the transmission power.

[0020] Preferably, the distances between the radio system and the plurality of road users are determined using different transmission powers of the BT and / or UWB antenna.

[0021] In a further preferred embodiment, the electronic device comprises an inertial measuring unit configured to detect a movement of the electronic device, and the method is only carried out once a movement of the electronic device has been detected. The inertial measuring unit is preferably configured to detect accelerations and angular velocities of the electronic device in order to determine a direction of movement and speed of the VRU. The radio system of the electronic device is preferably configured for satellite-based radio communication (GPS) in order to determine a location, a direction of movement, and / or a speed of movement of the VRU. By correlating / activating the method with the movement of the VRU, a sensible balance is struck between reduced energy consumption and adequate protection of the VRU.Most accidents involving VRUs occur because the VRU is moving or has recently moved, for example when crossing a road. Therefore, it is not necessary for the electronic device to be active and communicating with passing road users when a VRU is sitting in a sidewalk café, for example. Furthermore, the electronic device preferably switches off or goes into a power-saving sleep mode if no movement of the electronic device has been detected for a predefined period of time and / or no response signals have been received from the multitude of road users. From this, it can be concluded that there is no danger to the stationary VRU or that there are no other road users in the vicinity who could pose a collision risk. The predefined period of time is preferably between 10 seconds and one minute, particularly preferably up to 30 seconds.

[0022] In a preferred embodiment, based on the result of the positioning method, a check is made to determine whether a collision course exists between the unprotected road user and at least one of the plurality of road users. The method according to the invention is preferably repeated at periodic intervals to update the road users in the vicinity of the VRU and their positions. This allows, for example, speeds, accelerations, or directions of movement to be determined from the determined positions of the road users, which can be used to determine the collision course.

[0023] Furthermore, it is preferably provided that, based on the result of the check, a warning is issued and / or a countermeasure is implemented to avoid a collision or reduce collision damage. The warning can be issued visually, acoustically, and / or tactilely (vibration) via the electronic device to warn the VRU of the potential collision. As a countermeasure, for example, an emergency call can be made if a collision is imminent and can no longer be avoided.

[0024] The countermeasure preferably comprises transmitting information about a determined collision course and / or a warning about a potential collision to the plurality of road users using the radio system. The information can be transmitted using the BT antenna and / or the UWB antenna, preferably in a connectionless manner. This allows the driver of the vehicle (or the driving system of a self-steering vehicle) to be warned of the potential collision in order to initiate appropriate countermeasures to avoid the collision or to mitigate collision damage on the part of the road user.

[0025] In a further preferred embodiment, the radio system is controlled by the at least one road user to respond to a positioning method based on travel-time measurements of at least one of the plurality of road users for determining the position of the unprotected road user. In particular, the received response signal from the road user comprises a request from the road user to perform a positioning method based on travel-time measurements. Consequently, mutual position determination is enabled, allowing for evaluation by both the electronic device and the road user.

[0026] In a further preferred embodiment, the first and / or second BT pulse includes a classification of the unprotected road user. This allows the receiver of the BT pulses to determine the type of movement of the VRU. Based on the type of movement of the VRU, for example pedestrian, cyclist, motorcyclist, scooter rider, electric scooter rider, wheelchair user or the like, the road user can already make initial distinctions regarding possible reactions. For example, a different (average) movement speed can be assumed for a pedestrian than for a motorcyclist. In other words, the receiver of the BT pulse can already rule out the occurrence of certain situations based on the received classification of the VRU or use average values ​​stored in a memory unit for the respective type of VRU for a possible evaluation.

[0027] In a further preferred embodiment, the electronic device has a second UWB antenna configured to transmit and receive UWB signals, which is also used to carry out the positioning method based on time-of-flight measurements. Since motor vehicles often have more than one UWB antenna, the position of the electronic device relative to the motor vehicle can often be determined by means of direction finding (triangulation) between at least two of the UWB antennas of the motor vehicle and the UWB antenna of the electronic device. However, the electronic device is always dependent on the road user, for example the motor vehicle, having at least two UWB antennas. This dependence can be reduced by a second UWB antenna in the electronic device. Furthermore, direction finding can be carried out, for example, using another electronic device of a VRU, which in turn has only one UWB antenna.This means that a position between two VRUs, such as two motorcyclists, can be determined and evaluated accordingly.

[0028] A further aspect comprises an electronic device. The electronic device is configured to protect an unprotected road user. The electronic device comprises a radio system with a transceiver having a BT antenna configured to transmit and receive BT signals and a UWB antenna configured to transmit and receive UWB signals. The electronic device is preferably the electronic device described above. The electronic device further comprises a control unit configured to carry out the further method described herein. The features and their advantages described with the further method can be implemented analogously with the electronic device and can therefore be combined with one another as desired.

[0029] Another aspect includes a method for a motor vehicle. The motor vehicle includes a second radio system with a second transceiver having a BT antenna configured to transmit and receive BT signals and a UWB antenna configured to transmit and receive UWB signals. The motor vehicle is preferably the above-described motor vehicle of a road user.

[0030] According to one step of the method, a first BT pulse is received connectionlessly using the BT antenna. The first BT pulse was preferably transmitted by the electronic device described herein.

[0031] In a further method step, the BT antenna of the second radio system is controlled to transmit a response signal to the first BT pulse without a connection, wherein the response signal comprises an identification of the motor vehicle.

[0032] According to a further method step, a second BT pulse is received connectionlessly using the BT antenna. The second BT pulse is preferably transmitted by the electronic device described herein. Based on the received signal strength (RSSI) of the second BT pulse, a distance between the second radio system and a radio system transmitting the second BT pulse is determined.

[0033] Furthermore, the second radio system is activated to respond to a positioning method of a radio system of an electronic device of an unprotected road user based on time-of-flight measurements if a determined distance between the second radio system and the radio system transmitting the second BT pulse is less than 15 m and the identifier of the electronic device preferably indicates a VRU. The identifier of the electronic device may have been transmitted with the first and / or second BT pulse. The electronic device is preferably the electronic device described herein.

[0034] The UWB antenna of the second radio system is also controlled to perform a positioning procedure based on time-of-flight measurements to determine the position of the unprotected road user.

[0035] The method for a motor vehicle is essentially designed to complement the above-mentioned method for protecting a VRU. In this respect, the features and their advantages described in the method for protecting a VRU can be implemented analogously to the method for a motor vehicle and can therefore be combined with each other as desired.

[0036] For example, the second BT pulse includes the road user sequence and the positioning procedure based on runtime measurements is then carried out according to the road user sequence.

[0037] A further aspect encompasses a motor vehicle. The motor vehicle comprises a second radio system with a second transceiver having a BT antenna configured to transmit and receive BT signals and a UWB antenna configured to transmit and receive UWB signals, and a control unit. The control unit is configured to carry out the method described herein for a motor vehicle. The features described with the method and their advantages can be implemented analogously with the motor vehicle and can therefore be combined with one another as desired. The motor vehicle and the electronic device preferably form a system for protecting a vulnerable road user. The above-mentioned control unit of the motor vehicle and / or the above-mentioned control unit of the electronic device are preferably implemented by electrical or electronic parts or components (hardware) or by firmware (ASIC).Additionally or alternatively, the functionality of the control device / control unit is implemented by executing a suitable program (software). The control device / control unit is also preferably implemented using a combination of hardware, firmware, and / or software. For example, individual components of the control device / control unit are designed as separate integrated circuits or arranged on a common integrated circuit to provide individual functionalities.

[0038] The individual components of the control device / control unit are further preferably embodied as one or more processes that run on one or more processors in one or more electronic computing devices and are generated when executing one or more computer programs. The computing devices are preferably designed to cooperate with other components, for example, a central locking system, an engine controller, etc., in order to implement the functionalities described herein. The instructions of the computer programs are preferably stored in a memory, such as a RAM element. However, the computer programs can also be stored in a non-volatile storage medium, such as a CD-ROM, a flash memory, or the like.

[0039] It will also be apparent to the person skilled in the art that the functionalities of several computing units (data processing devices) can be combined or combined in a single device or that the functionality of a particular data processing device can be distributed across a plurality of devices in order to implement the functionality of the control device / control unit.

[0040] A further aspect of the invention relates to a computer program comprising instructions which, when the program is executed by a computer, such as a control unit of an electronic device having a radio system with a BT antenna configured to transmit and receive BT signals and a UWB antenna configured to transmit and receive UWB signals or a control unit of a motor vehicle having a second radio system with a second transceiver with a BT antenna configured to transmit and receive BT signals and a UWB antenna configured to transmit and receive UWB signals, cause the computer to carry out one of the methods according to the invention, in particular a method for protecting an unprotected road user or a method for a motor vehicle.

[0041] Further preferred embodiments of the invention emerge from the remaining features mentioned in the subclaims.

[0042] The various embodiments of the invention mentioned in this application can be advantageously combined with one another, unless otherwise stated in the individual case.

[0043] The invention is explained below in exemplary embodiments with reference to the accompanying drawings. They show:

[0044] Figure 1 is a schematic representation of a traffic situation with two

[0045] Motor vehicles and an unprotected road user with an electronic device according to one embodiment and

[0046] Figure 2 is a schematic representation of the method according to the invention according to one embodiment.

[0047] Figure 1 shows a schematic representation of a traffic situation that is dangerous for a vulnerable road user (VRU) 10. It depicts a road intersection 18 at which the VRU 10 and two other road users 14 meet. The VRU 10 is depicted as a cyclist for example. However, the invention is not limited to cyclists. Rather, the VRU 10 can also be a pedestrian, motorcyclist, scooter rider, electric scooter rider, wheelchair user, and the like. The other road users 14 are, for example, two motor vehicles 16, 16'. However, the other road users 14 can also be VRUs.

[0048] According to the invention, the VRU 10 is equipped with an electronic device 12 according to one embodiment. The electronic device 12 is configured to protect the unprotected road user 10. The electronic device 12 is integrated into the bicycle of the VRU 10, which is designed as an e-bike. Alternatively, the electronic device 12 is a transponder with a non-rechargeable device battery, which is carried by the VRU 10. The electronic device 12 comprises a radio system with a transceiver having a BT antenna configured to transmit and receive BT signals and a UWB antenna configured to transmit and receive UWB signals. Furthermore, the electronic device 12 comprises a control unit, which is configured in particular to carry out a method for protecting the VRU 10, as illustrated in connection with Figure 2.The electronic device 12 further comprises an inertial measurement unit with a gyroscope and acceleration sensors that generate sensor data including angular velocities and accelerations of the electronic device 12. Preferably, the control unit of the electronic device 12 is configured to determine a direction and speed of movement of the VRU 10 from the sensor data of the inertial measurement unit of the electronic device 12.

[0049] The two motor vehicles 16, 16' each comprise a second radio system with a second transceiver having a BT antenna configured to transmit and receive BT signals and at least two UWB antennas configured to transmit and receive UWB signals, and a control unit connected to the second radio system. The control unit is configured in particular to carry out a further method for protecting the unprotected road user 10, as described in connection with Figure 2.

[0050] In the exemplary traffic situation depicted in Figure 1, the motor vehicles 16, 16' meet on opposite sides of the intersection (from left and right in the image plane), while the VRU 10 encounters the intersection 18 in a lateral direction relative to the motor vehicles 16, 16' (from bottom to top in the image plane). Assuming all road users 10, 14 were to drive straight through the intersection 18, there would be a high risk of the VRU 10 colliding with the first motor vehicle 16 or the second motor vehicle 16', respectively. Since the VRU 10 is not protected against impact forces, i.e., has no crumple zone, the consequences of the accident for the VRU 10 would be severe.

[0051] In order to defuse the situation just described, according to the invention, protection of the VRU 10 is realized by means of radio communication between the electronic device 12 of the VRU 10 and the two second radio systems of the motor vehicles 16, 16'. The radio communication is indicated by way of example by the arrows between the motor vehicles 16, 16' and the VRU 10. The radio communication here comprises Bluetooth communication with a range represented by way of example by a BT radius 20, for example 30 or 60 m, and UWB communication with a range represented by way of example by a UWB radius 22, for example 15 m. The BT radius 20 around the VRU 10 is indicated in Figure 1 by a dashed circle, while the UWB radius 22 around the VRU 10 is a circle with a dash-dot line.Since both motor vehicles 16, 16' are located within the BT radius 20, the BT communication explained in more detail with regard to Figure 2 can take place with both motor vehicles 16, 16'.

[0052] Figure 2 shows a schematic representation of two methods according to the invention, each according to an embodiment. The methods according to the invention each relate to the perspective of one of the two sides of the radio communication, i.e., on the one hand, from the perspective of the VRU 10 and, on the other, from the perspective of the road user 14 or the motor vehicles 16, 16'. Three vertical timelines are shown in Figure 2, with the left timeline describing the communication from the perspective of the first motor vehicle 16, the middle timeline describing the communication from the perspective of the VRU 10, and the right timeline describing the communication from the perspective of the second motor vehicle 16'. The communication sequences of the two motor vehicles 16, 16' are essentially the same, so that the method steps of the second motor vehicle 16' marked with an apostrophe correspond analogously to the method steps of the first motor vehicle 16.A repeated description of the process steps of the motor vehicle 16' is therefore omitted.

[0053] In a first method step 50, the BT antenna of the radio system of the VRU 10 is controlled to transmit a first BT pulse without a connection.

[0054] The two motor vehicles 16, 16' located in the BT radius 20 receive the first BT pulse without a connection using the BT antennas of the second radio systems (method step 70, 70') and each control the BT antenna of the second radio systems to transmit a response signal to the first BT pulse without a connection, wherein the response signal comprises an identifier of the respective motor vehicle 16, 16' (method step 72, 72').

[0055] In a second method step 52, the response signals of the two motor vehicles 16, 16' are received using the BT antenna of the radio system of the VRU 10.

[0056] According to a third method step 54, the BT antenna of the radio system of the VRU 10 is controlled to transmit a second BT pulse without a connection.

[0057] In a fourth method step 56, a signal strength of the response signals (RSSI) is determined in order to determine a preliminary distance of the motor vehicles 16, 16' from the VRU 10. The order of method steps 54 and 56 can also be interchanged, as shown, for example, in Figure 2.

[0058] The motor vehicles 16, 16' receive the second BT pulse without a connection using the BT antennas of the second radio systems (method step 74, 74'). Figure 1 shows, by way of example, that the first motor vehicle 16 is closer to the VRU 10 than the second motor vehicle 16' is to the VRU 10. The distance between the first motor vehicle 16 and the VRU 10 is less than 15 m, while the distance between the second motor vehicle 16' and the VRU 10 is greater than 15 m. The stated distance limit of 15 m is chosen as an example and can also assume a smaller value, for example, 12 m, 9 m, or 6 m. Distance-controlled UWB communication reduces energy consumption and local utilization of the UWB radio channels, which is particularly advantageous in high-frequency areas and when the energy storage capacity of the electronic devices 12 of the VRUs 10, such as transponders with device batteries, is low.

[0059] Preferably, the second BT pulse contains information about an individual UWB time slot for the first motor vehicle 16 and no UWB time slot for the second motor vehicle 16', since the latter is too far away (>15 m). Thus, the control units of the two motor vehicles 16, 16' know exactly whether and at what times they can expect UWB communication with the VRU 10, so that interference or other disruptive influences on the UWB communication can be prevented or at least reduced.

[0060] The motor vehicles 16, 16' each determine a distance between themselves and the VRU 10 based on the received signal strength of the second BT pulse (method step 76, 76').

[0061] In a further method step 58, the UWB antenna of the radio system of the VRU 10 is controlled to perform a positioning method based on time-of-flight measurements to determine the positions of the first motor vehicle 16, since the distance between the radio system of the VRU 10 and the first motor vehicle 16, determined based on the received signal strengths of the response signals, is less than 15 m. To this end, the UWB antenna transmits a first UWB pulse to the second radio system of the motor vehicle 16 at a time t1. The second radio system receives the first UWB pulse using the two UWB antennas (method step 78) and transmits two second UWB pulses to the radio system of the VRU 10 at a time t2 (method step 80). The second UWB pulses comprise the processing time of the second radio system AT16 and in turn represent new requests for determining the position of the VRU 10 from the perspective of the motor vehicle 16.In other words, the second UWB pulses simultaneously represent the first UWB pulse described above from the perspective of the motor vehicle 16.

[0062] In a further method step 60, the radio system of the VRU 10 receives the second UWB pulses and transmits a third UWB pulse at a time ts to the second radio system of the motor vehicle 16. The third UWB pulse contains the processing time of the AT™ radio system.

[0063] The second radio system of the motor vehicle 16 receives the third UWB pulse using the two UWB antennas in a further method step 82.

[0064] The control unit of the electronic device 12 of the VRU 10 then determines the total propagation time based on the propagation times of the first UWB pulse, the second UWB pulse, and the processing time of the second radio system AT, while the control unit of the motor vehicle 16, in turn, determines the total propagation time based on the propagation times of the second UWB pulse, the third UWB pulse, and the processing time of the radio system AT™. The distance between the radio system and the second radio system is then determined based on the respectively determined total propagation time and the speed of light (method steps 62 and 84, respectively). Because UWB communication takes place via at least three UWB antennas, the position of the motor vehicle 16 or the VRU 10 can be determined by direction finding (triangulation).

[0065] As further shown in Figure 2, the UWB antenna of the radio system of the VRU 10 is not controlled (64) to carry out a positioning method based on time-of-flight measurements to determine the position of the second motor vehicle 16', since the latter is located at a distance of more than 15 m from the VRU 10, as determined based on the received signal strength of the second BT pulse.

[0066] By repeating the process described in Figure 2, the preliminary distances of the motor vehicles 16, 16' from the VRU 10 can be continuously updated, and the execution of the positioning process based on time-of-flight measurements using UWB can be carried out or not carried out depending on the respective distance between the motor vehicles 16, 16' in order to save energy. Based on the updated distances and the updated positions of the motor vehicle(s) 16, 16' determined via UWB communication, the directions of movement, speeds, and accelerations of the motor vehicles 16, 16' (or of the VRU 10 from the perspective of the motor vehicles 16, 16') can then be determined. Consequently, trajectories to the motor vehicles 16, 16' can be constructed and checked for collisions using a trajectory of the VRLI 10.The trajectory of the VRLI 10 can be determined, for example, using the sensor data from the inertial measurement unit of the electronic device 12. If a collision course is detected, appropriate measures can be taken, such as issuing a warning or initiating a countermeasure to avoid the collision or mitigate collision damage.

[0067] List of reference symbols for vulnerable road users (VRU) electronic device

[0068] Road user, 16' motor vehicle

[0069] Road intersection BT-perimeter UWB-perimeter first process step second process step third process step fourth process step fifth process step sixth process step seventh process step eighth process step , 70' first step of a further process , 72' second step of a further process , 74' third step of a further process , 76' fourth step of a further process fifth step of a further process sixth step of a further process seventh step of a further process eighth step of a further process

Claims

Patent claims 1. A method for protecting a vulnerable road user (10) using an electronic device (12), wherein the electronic device (12) comprises a radio system with a transceiver having a BT antenna configured to transmit and receive BT signals and a UWB antenna configured to transmit and receive UWB signals, and the method comprises the following steps: Controlling (50) the BT antenna of the radio system for connectionless transmission of a first BT pulse, connectionless reception (52) of response signals from a plurality of road users (14) using the BT antenna, wherein the response signals comprise identifiers of the plurality of road users (14), controlling (54) the BT antenna for connectionless transmission of a second BT pulse, Determining (56) a distance between the radio system and the plurality of road users (14) based on the received signal strengths of the response signals and Controlling (58) the UWB antenna of the radio system to carry out a positioning method based on propagation time measurements to determine the positions of the plurality of road users (14) when a distance between the radio system and a road user of the plurality of road users (14) determined based on the received signal strengths of the response signals is less than 15 m.

2. The method of claim 1, further comprising the step: Generating a road user sequence based on the received response signals, wherein the second BT pulse comprises the generated road user sequence and the UWB antenna of the radio system is controlled to perform the positioning method according to the road user sequence.

3. The method according to claim 2, wherein the generated road user sequence is compressed and the second BT pulse comprises the generated compressed road user sequence.

4. Method according to one of the preceding claims, wherein the transmission power of the BT and / or UWB antenna is adjusted based on the distances determined by means of the received signal strengths of the response signals and / or based on the positions of the plurality of road users (14) determined by means of UWB.

5. The method according to claim 4, wherein the distances between the radio system and the plurality of road users (14) are determined using different transmission powers of the BT and / or UWB antenna.

6. Method according to one of the preceding claims, wherein the electronic device (12) comprises an inertial measuring unit which is configured to detect a movement of the electronic device (12) and the method is only carried out when a movement of the electronic device (12) has been detected.

7. The method according to claim 6, wherein the electronic device (12) switches off or switches to an energy-saving sleep mode if no movement of the electronic device (12) has been detected for a predetermined time and / or no response signals have been received from the plurality of road users (14).

8. Electronic device (12), comprising: a radio system with a transceiver having a BT antenna configured to transmit and receive BT signals and a UWB antenna configured to transmit and receive UWB signals, and a control unit connected to the radio system, which is configured to carry out the method according to one of the preceding claims.

9. A method for a motor vehicle (16, 16'), wherein the motor vehicle (16, 16') comprises a second radio system with a second transceiver having a BT antenna configured to transmit and receive BT signals and a UWB antenna configured to transmit and receive UWB signals, and the method comprises the following steps: connectionless receiving (70, 70') of a first BT pulse using the BT antenna, Controlling (72, 72') the BT antenna of the second radio system for connectionless transmission of a response signal to the first BT pulse, wherein the response signal comprises an identifier of the motor vehicle (16, 16'), connectionless reception (74, 74') of a second BT pulse using the BT antenna, Determining (76, 76') a distance between the second radio system and a radio system transmitting the second BT pulse based on the received signal strength of the second BT pulse, controlling (78) the second radio system to respond to a positioning method based on runtime measurements of the radio system transmitting the second BT pulse if a determined distance between the second radio system and the radio system transmitting the second BT pulse is less than 15 m, and Controlling (80) the UWB antenna of the second radio system to perform a positioning method based on time-of-flight measurements to determine the position of the radio system transmitting the second BT pulse.

10. Motor vehicle (16, 16'), comprising: a second radio system with a second transceiver with a BT antenna configured to transmit and receive BT signals and a UWB antenna configured to transmit and receive UWB signals, and a control unit connected to the second radio system, which is configured to carry out the method according to claim 9.

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