Safety system for detecting misuse of a seat belt

Abstract

Safety system (10) for detecting incorrect use of a safety belt (11) in a vehicle, wherein the safety system (10) - comprises at least one vehicle seat (14) and a safety belt (11) associated with the vehicle seat (14), wherein - the safety belt (11) has at least one RFID transponder, and - the vehicle seat (14) has at least one RFID reader (17) in the backrest (15) and / or in the seat surface (16), wherein - the safety system (10) is designed to detect incorrect use of the safety belt (11) if at least one RFID transponder (18) can be read by at least one RFID reader (17), characterized in that at least one RFID transponder (18) is integrated into a yarn in the safety belt (11).

Description

[0001] The present invention relates to a safety system for detecting misuse of a safety belt in a vehicle according to the preamble of claim 1 and a method for detecting misuse according to claim 13.

[0002] Safety systems for detecting misuse or non-use of seat belts are known in the art. Such safety systems are also known as seat belt warning systems. Typically, a sensor is used on the belt buckle to detect whether a belt tongue is inserted into the buckle. This is usually combined with vehicle seat occupancy detection. Other safety systems can also detect, for example, using RFID, whether the intended belt tongue is inserted into the buckle, making it more difficult to fool the safety system.

[0003] Depending on the specific requirements of vehicle restraint systems, it may be necessary to install a safety system to detect further misuse. This applies in particular if a vehicle restraint system does not take into account the unbelted state of an occupant in the design of the restraint system, particularly the seat belt and airbag. Such a design may be advantageous or necessary, for example, if the vehicle seat is intended to enable reclining positions, or if the vehicle design does not allow for a conventional airbag configuration due to new dashboard designs or large distances between the occupant and the dashboard.

[0004] To detect incorrect use, safety systems are known that can recognize incorrect belt positions. Examples of such incorrect use can be a chest belt running behind the shoulder or back, or a lap belt running behind the back or under the buttocks. Known safety systems, for example, use the constant monitoring of seat belt extension as a measurement to indirectly detect incorrect use. Furthermore, force sensors in the seat belt are known that are used to record breathing and can thus determine correct use. Furthermore, optical safety systems, particularly in the infrared range, which use a camera to detect the position of the seat belt are also known. The seat belt can have optical markings for this purpose, which are particularly visible in the infrared range.However, the function of such systems can be impaired if the seat belt is covered by clothing or body parts, such as arms or stomach, even if the seat belt is positioned as intended.

[0005] US 2020 / 0148164 A1 discloses an electronic tag programmed with an identification in a seatbelt assembly. The identification is read via an electronic device embedded in a seat.

[0006] Furthermore, DE 10 2018 129 082 A1 discloses a restraint device for an occupant. One or more sensors are arranged within the occupant seat and configured to detect elements when they are located near the one or more sensors to indicate that the restraint device has not been properly applied by the occupant.

[0007] DE 10 2021 213 665 A1 discloses a knitting method in which a linear element can be reliably fixed to a knitted fabric without being exposed to the front side of the knitted fabric.

[0008] Furthermore, DE 10 2007 058 278 A1 discloses a safety belt system with at least one transponder coupled to a component of the safety belt system and a reading device matched to the transponder, which can detect a predetermined influence on the transponder or the presence and absence of the transponder.

[0009] From US 2021 / 0347323 A1, a seatbelt routing module is known which is configured to determine the routing of a seatbelt with respect to an occupant in a vehicle seat based on the input of a belt webbing output sensor and to determine the seatbelt routing based on the input of a sensor in the vehicle cabin.

[0010] The invention is based on the object of providing a safety system for detecting incorrect use of a safety belt and a corresponding method which enable reliable detection of an incorrect position of a safety belt.

[0011] To achieve this object, a security system having the features of claim 1 is proposed. Further preferred embodiments of the invention can be found in the subclaims, in the figures, and the associated description.

[0012] To achieve this objective, a safety system for detecting misuse of a seat belt in a vehicle is proposed. The safety system comprises at least one vehicle seat and a seat belt associated with the vehicle seat. It is proposed that the seat belt has at least one RFID transponder, and that the vehicle seat has at least one RFID reader in the backrest and / or in the seat surface. The safety system is configured to detect misuse of the seat belt if at least one RFID transponder can be read by at least one RFID reader.

[0013] An RFID transponder (radio-frequency identification) can also be referred to as a radio tag, which has a digital identifier. The identifier can be read by an RFID reader. In possible embodiments, the identifier can also be a simple, uncoded response signal or confirmation signal. The RFID transponder is preferably a passive RFID transponder and therefore does not require its own power source. For this purpose, the RFID reader preferably generates a high-frequency alternating electromagnetic field, which inductively transfers energy from the RFID reader to the RFID transponder. The RFID transporter then transmits its identifier, which is received by the RFID reader. The RFID transponder is also preferably a so-called smart tag. The RFID transponder and the RFID reader preferably operate in a frequency range of 3 to 30 MHz.Furthermore, the RFID transponder, and in particular the RFID reader, has a short range, for example, less than 10 cm. The RFID reader preferably performs a regular query of RFID transponder identifiers, whereby RFID readers can be operated with comparatively low energy consumption.

[0014] According to the proposed solution, the short range of RFID (radio-frequency identification) can be advantageously used to immediately detect an incorrect position of a seat belt. When the seat belt with the at least one RFID transponder comes close to an RFID reader in the vehicle seat, the identifier of the corresponding RFID transponder can be read. Accordingly, the proximity of the seat belt to the part of the backrest or seat surface in which the RFID reader is arranged is detected. The invention has recognized that the detection of such a proximity, for example, of less than 10 cm, corresponds to an incorrect position of the seat belt in relation to an occupant. If the seat belt is correctly positioned, a distance between the RFID transponder and the RFID reader is created by the occupant's body.Furthermore, the body further reduces the range compared to air. This means that, even if the seatbelt is correctly fastened, the signal strength is reduced by the occupant's body to such an extent that the RFID transponder's ID can no longer be read by the RFID reader. The safety system therefore works even with very heavy occupants who, for example, cover a lap belt between their pelvis and abdomen, preventing the optical system from functioning properly.

[0015] In advantageous embodiments, a data processing device is provided that compares the identifiers detected by the at least one RFID reader with identifiers stored in the data processing device. Furthermore, in possible embodiments, the data processing device can detect the signals from a seat belt buckle sensor and / or a seat occupancy detection system and, for example, switch the at least one RFID reader on or off accordingly.

[0016] Preferably, at least one RFID transponder is arranged on a chest belt section of the safety belt between a belt tongue and an upper attachment point.

[0017] Using an RFID transponder in the chest strap section, misuse of the seat belt can be very reliably detected when the seat belt is positioned behind the occupant's back, in combination with an RFID reader in the backrest. In such a scenario, the seat belt in a typical 3-point configuration runs from the tongue, which is inserted into the buckle, to an upper attachment point, where the belt retractor is usually located. Accordingly, an RFID transponder in the chest strap section lies on a corresponding belt path on the backrest in the event of misuse. In a typical 3-point configuration with a belt retractor at the upper attachment point, the exact position of the RFID transponder is determined by the extension of the seat belt for the lap belt section.The RFID reader, which is integrated into the backrest cushion or located behind the backrest cushion, can thus communicate with the RFID transponder of the chest belt section when the chest belt section is running along and / or resting against the backrest of the vehicle seat. If the RFID reader recognizes the identifier or a signal from the RFID transponder in the chest belt section, the safety system detects misuse.

[0018] Furthermore, at least one RFID transponder is preferably arranged on a lap belt section of the safety belt between a lower attachment point and a belt tongue.

[0019] An RFID transponder in the lap belt section can detect misuse if the seat belt is routed below or behind the occupant, together with a reader in the seat cushion and / or in the backrest. In such a scenario, the belt runs from the tongue, which is inserted into the buckle, to the lower attachment point in a typical 3-point configuration. The lap belt section thus runs in the transition area between the seat cushion and backrest of the vehicle seat, so that the proximity of the RFID transponder in the lap belt section, for example, to an RFID reader in the backrest or in the seat cushion, is sufficient to capture an identifier or even a simple signal and thus detect misuse of the lap belt section.In a typical 3-point configuration with a belt retractor at the upper attachment point, if the seat belt is incorrectly routed under the occupant, this misuse can be reliably detected by the clear belt path of the lap belt section.

[0020] In an advantageous embodiment, at least one RFID transponder is woven and / or sewn into the seat belt. This allows for excellent embedding and attachment of an RFID transponder in the seat belt. In further embodiments, it may also be possible to bond the RFID transponder to a seat belt.

[0021] According to the invention, at least one RFID transponder is integrated into a yarn in the seat belt. Such a yarn can preferably be integrated into the seat belt during the manufacturing process, which offers advantages during installation and assembly in a vehicle. Furthermore, an RFID transponder integrated into a yarn is not perceived as such by an occupant, which is desirable. Such an RFID transponder can, for example, have a diameter of 1.2 mm in the region of the largest diameter and a diameter of 0.5 mm in the region of the other sections, with the length being, for example, 130 mm.

[0022] It is further proposed that at least one RFID transponder be arranged within a cavity in the seat belt. A cavity in the seat belt can be achieved, for example, through the manufacturing process, wherein the cavity in the seat belt is preferably tubular, and the cavity is comparable, for example, to a flattened hose. An RFID transponder, for example, can be inserted and / or sewn into such a cavity. Furthermore, an RFID transponder integrated into a yarn can, for example, be guided in a tubular cavity in a seat belt.

[0023] It is further proposed that at least one RFID transponder be arranged on the seat belt. This allows, for example, easy replacement of an RFID transponder due to good accessibility.

[0024] According to a further development, it is proposed that at least one RFID transponder be arranged in a button on or in the seat belt. In this way, the RFID transponder can be particularly well protected against mechanical influences. Furthermore, a direct assignment to a safety mechanism can be made clear to the user. In advantageous embodiments, the button can also be designed to hold the belt tongue above the button when the belt tongue is not inserted into the belt buckle. The belt tongue can therefore be held at a certain height above the lower attachment point, for example by the button when the belt is not fastened. In this advantageous embodiment, the button is part of the lap belt section when the belt is fastened.

[0025] In a preferred embodiment, it is proposed that the safety system sends a corresponding signal upon detecting misuse. The safety system can, for example, send an electrical signal to another system in a vehicle. In further embodiments, the safety system can emit a corresponding acoustic and / or visual signal. In principle, the signal can be used directly or indirectly to warn the occupant. In possible embodiments, other systems, such as restraint systems, in the vehicle can also be controlled accordingly.

[0026] It is further proposed that the security system be configured to detect the position of at least one RFID transponder. Position detection in this sense goes beyond detecting the proximity of an RFID transponder to an RFID reader, in the sense that the RFID transponder is within range of the RFID reader. Position detection includes, for example, distance detection, for example, based on the signal strength of the RFID transponder, or, for example, possible direction finding or triangulation using multiple RFID readers.

[0027] In possible embodiments, a plurality of RFID readers are provided in the vehicle seat, and the security system is configured to detect the position of at least one RFID transponder by means of the plurality of RFID readers.

[0028] Using a large number of RFID readers, for example, in the seatback, a larger detection area can be covered. This can, for example, make the detection of the chest belt section largely independent of the seat belt's extension for the lap belt section. Furthermore, the position of the RFID transponder can be determined through communication with one or more readers.

[0029] In a further possible embodiment, a plurality of RFID transponders are provided in the safety belt, and the safety system is configured to detect the position of the safety belt by means of the plurality of RFID transponders.

[0030] This makes it possible, for example, to detect incorrect use, such as a chest belt section being pulled behind the occupant's back, even with very different extension lengths. Furthermore, several RFID transponders can be within range of an RFID reader at the same time, allowing conclusions to be drawn about the position of the seat belt.

[0031] In advantageous embodiments, a plurality of RFID readers are provided in the seat surface and / or in the backrest and a plurality of RFID transponders are provided in the safety belt, so that a belt position, in particular an incorrect belt position, of the safety belt can be reliably detected.

[0032] According to a further development, it is proposed that the security system is arranged in a vehicle and at least one further RFID reader is arranged in the vehicle at a distance from the seat surface and the backrest.

[0033] In this possible embodiment, an RFID reader is arranged in front of the vehicle seat, for example, in the interior of the vehicle, so that a passenger on the vehicle seat is located between the backrest and seat surface on the one hand and this RFID reader. The RFID reader can be arranged, for example, in a dashboard or a steering wheel, whereby a correct belt path, for example, of a chest belt section in front of a passenger's chest, can preferably be detected when the identifier or a signal from an RFID transponder is received by the RFID reader in front of the vehicle seat.

[0034] Furthermore, to achieve the object, a method for detecting incorrect use of a safety belt in a vehicle with a safety system according to one of claims 1 to 12 is proposed, wherein the safety system detects incorrect use of the safety belt when at least one RFID transponder is read by at least one RFID reader.

[0035] For example, RFID transponders can be interrogated by an RFID reader at regular intervals, such as every 20 seconds. If an identifier or signal from a corresponding RFID transponder is received, the security system triggers a misuse event.

[0036] A received identifier of an RFID transponder is preferably compared with an identifier stored in the security system in order to exclude sources of error caused by external RFID transponders, which are carried by an occupant, for example.

[0037] The invention will be explained below using preferred embodiments with reference to the attached figures. Fig. 1 a schematic representation of a security system; Fig. 2 a schematic representation of a safety system with an occupant and correct routing of the seat belt; Fig. 3 a safety system with an occupant with a chest portion of the seat belt behind the back; Fig. 4 a safety system with an occupant with a lap belt portion of the safety belt below the occupant; Fig. 5 a safety system with an occupant having a chest belt section behind the back and a lap belt section below the occupant; and Fig. 6 another embodiment of a security system with an RFID reader in front of the vehicle seat.

[0038] Fig. 1 shows an embodiment of a safety system 10 for detecting incorrect use of the safety belt 11. The safety system 10 comprises a vehicle seat 14 and an associated safety belt 11, which in this embodiment are shown in the left illustration of the Fig. 1 in a front view. The right illustration of the Fig. 1 shows a side view of the safety system 10 and the vehicle seat 14.

[0039] In this exemplary embodiment, the safety belt 11 has a typical 3-point configuration with a lower attachment point 21 and an upper attachment point 20 for the safety belt 11 on one side of the vehicle seat 14. On the other side, a belt buckle 25 is arranged, into which the belt tongue 19 of the safety belt 11 can be inserted. Furthermore, a belt retractor is provided at at least one of the attachment points 20, 21, for example at the upper attachment point 20. The safety belt 11 has a chest belt section 12 between the belt tongue 19 in the belt buckle 25 and the upper attachment point 20 and a lap belt section 13 between the belt tongue 19 in the belt buckle 25 and the lower attachment point 21.

[0040] In this exemplary embodiment, the safety belt 11 has two RFID transponders 18, one RFID transponder 18 being arranged on the chest belt section 12 and one RFID transponder 18 being arranged on the lap belt section 13 of the safety belt 11. In alternative exemplary embodiments, multiple RFID transponders 18 can also be arranged on the safety belt 11.

[0041] The vehicle seat 14 has a backrest 15 and a seat surface 16, wherein, in this exemplary embodiment, an RFID reader 17 is integrated into the backrest 15 and the seat surface 16. The RFID readers 17 are, for example, embedded in the upholstery of the vehicle seat 14 and are preferably supplied with power by an on-board electrical system of the vehicle 23. Furthermore, a data connection to an on-board electrical system of the vehicle 23 can be provided, via which a signal detecting misuse can be transmitted to other systems in the vehicle 23.

[0042] Fig. 2 shows the same embodiment with an occupant 22 on the vehicle seat 14. The occupant 22 keeps the RFID transponders 18 in the safety belt 11 at a distance from the associated RFID readers 17 in the vehicle seat 14. In addition, the body of the occupant 22 is located between the RFID transponders 18 and the RFID readers 17, which further reduces the possible range. The RFID readers 17 check at regular intervals and / or during certain operating states of the vehicle 23, e.g., inserting the belt tongue 19 into a belt buckle 25, whether an identifier can be read from one of the RFID transponders 18. In the scenario of Fig. 2 the distances are too large for a corresponding transmission, so that no misuse is detected.

[0043] In Fig. 3 schematically shows a scenario in which the chest strap section 12 of the safety belt 11 is guided by the occupant 22 behind the back of the occupant 22. This corresponds to incorrect use, since the safety belt 11 can only exert a very limited restraining function on the occupant 22. As shown in the side view on the right side of the Fig. 3, the distance between the RFID transponder 18 in the chest belt section 12 and the RFID reader 17 in the backrest 15 is reduced to such an extent that the RFID transponder 18 can be read by the RFID reader 17. Furthermore, the shielding provided by the body of the occupant 22 is eliminated. Since the RFID transponder 18 is read by the reader 17, incorrect use of the seat belt 11 on the vehicle seat 14 is detected. A corresponding signal can be output, for example, to a data bus of the vehicle 23 by the safety system 10.

[0044] In Fig. Figure 4 shows another scenario with a safety system 10. In this case, the lap belt section 13 of the seat belt 11 runs below the occupant 22, who has only properly fastened the chest belt section 12. This reduces the distance between the RFID transponder 18 on the lap belt section 13 and the RFID reader 17 in the seat surface 16 to such an extent that the identifier of the RFID transponder 18 can be read. Accordingly, misuse with an incorrect belt path of the seat belt 11 can also be detected here.

[0045] Fig. 5 shows a further scenario of an occupant 22 on the vehicle seat 14, wherein both the chest belt section 12 and the lap belt section 13 have an unintended course, so that the safety belt 11 cannot exert any restraining function on the occupant 22. According to the Fig. 3 and Fig. 4, misuse of the chest belt section 12 as well as the lap belt section 13 is detected.

[0046] Another example is shown in the Fig. 6, in which the security system 10 has a further RFID reader 24 which, in contrast to the RFID readers 17, is not arranged in the vehicle seat 14 but in front of the vehicle seat 14, so that with the further RFID reader 24, for example, a correct belt path of the chest belt section 12 can be detected when the RFID transponder 18 in the chest belt section 12 comes sufficiently close to the further RFID reader 24 in front of the vehicle seat 14.

Claims

[1] Safety system (10) for detecting incorrect use of a safety belt (11) in a vehicle, wherein the safety system (10) - comprises at least one vehicle seat (14) and a safety belt (11) associated with the vehicle seat (14), wherein - the safety belt (11) has at least one RFID transponder, and - the vehicle seat (14) has at least one RFID reader (17) in the backrest (15) and / or in the seat surface (16), wherein - the safety system (10) is designed to detect misuse of the safety belt (11) if at least one RFID transponder (18) can be read by at least one RFID reader (17), characterized by that at least one RFID transponder (18) is integrated into a yarn in the safety belt (11). [2] Security system (10) according to claim 1, characterized bythat at least one RFID transponder (18) is arranged on a chest belt section (12) of the safety belt (11) between a belt tongue (19) and an upper fastening point (20). [3] Security system (10) according to claim 1 or 2, characterized by that at least one RFID transponder (18) is arranged on a lap belt section (13) of the safety belt (11) between a lower fastening point (21) and a belt tongue (19). [4] Security system (10) according to one of claims 1 to 3, characterized by that at least one RFID transponder (18) is woven and / or sewn into the safety belt (11). [5] Security system (10) according to one of claims 1 to 4, characterized by that at least one RFID transponder (18) is arranged within a cavity in the safety belt (11). [6] Security system (10) according to one of claims 1 to 5, characterized bythat at least one RFID transponder (18) is arranged on the safety belt (11). [7] Security system (10) according to one of claims 1 to 6, characterized by that at least one RFID transponder (18) is arranged in a button on or in the safety belt (11). [8] Security system (10) according to one of claims 1 to 7, characterized by that the security system (10) sends a corresponding signal when misuse is detected. [9] Security system (10) according to one of claims 1 to 8, characterized by that the security system (10) is configured to detect the position of at least one RFID transponder (18). [10] Security system (10) according to one of claims 1 to 9, characterized bythat a plurality of RFID readers (17) are provided in the vehicle seat (14), and the security system (10) is configured to detect the position of at least one RFID transponder (18) by means of the plurality of RFID readers (17). [11] Security system (10) according to one of claims 1 to 10, characterized by that a plurality of RFID transponders (18) are provided in the safety belt (11), and the safety system (10) is arranged to detect the position of the safety belt (11) by means of the plurality of RFID transponders (18). [12] Security system (10) according to one of claims 1 to 11, characterized by that the security system (10) is arranged in a vehicle (23) and at least one further RFID reader (24) is arranged in the vehicle at a distance from the seat surface (16) and the backrest (15). [13] Method for detecting misuse of a safety belt (11) in a vehicle with a safety system (10) according to one of claims 1 to 12, characterized by , that - the safety system (10) detects incorrect use of the safety belt (11) when at least one RFID transponder (18) is read by at least one RFID reader (17).

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