Method and device for detecting a correctly fastened vehicle safety belt

Abstract

A method (700) for detecting a correctly fastened vehicle safety belt (125), the method (700) comprising the following steps: - reading (710) a position of a marking unit (130) attached to the vehicle safety belt (125); and - Determining (720) whether the vehicle safety belt (125) is correctly fastened when the position of the marking unit (130) is in a predetermined relationship to a target position (310) of the marking unit (130) when the vehicle safety belt (125) is correctly fastened; characterized in that in the reading step (710), the position of a retaining lug for a belt buckle (140) of the vehicle safety belt (125) is read in as the marking unit (130), and in that in the determining step (720), at least one body parameter of a vehicle occupant (120) to be fastened with the vehicle safety belt (125) is determined using the position of the marking unit (130).

Description

State of the art

[0001] The invention is based on a method for detecting a correctly fastened vehicle seat belt and a corresponding device according to the preamble of the independent claims. The present invention also relates to a computer program.

[0002] Wearing a vehicle seatbelt is still often perceived by vehicle occupants as a restriction of personal freedom. For this reason, vehicle occupants use a variety of methods to trick technical systems that monitor correct seatbelt use and simulate correct seatbelt use. For example, such technical monitoring systems can be deactivated in a workshop (case 1), a dummy belt tongue can be inserted into a belt buckle to simulate a properly fastened seatbelt (case 2), the vehicle occupant can sit on a belt (case 3), the belt can be routed behind the seatback (case 4), a belt tongue from an unoccupied seat can be inserted into the buckle of an occupied seat (case 5), or a pull-out clip can be used to prevent the appearance of the belt (case 6).In the publication DE 10 2008 042 399 A1, possibilities have already been disclosed to detect some of these misuses and thus to maintain vehicle safety and the safety of the vehicle occupants.

[0003] The publication WO 2013 101 047 A1 discloses systems, methods and devices for tracking and interpreting brands in vehicles.

[0004] The document DE 10 2007 058 278 A1 discloses a safety belt system.

[0005] The document DE 103 41 578 A1 discloses a device and a method for detecting an object or a person on a seat of a means of transport.

[0006] The document DE 10 2006 008 919 A1 discloses a safety belt system for a motor vehicle. Disclosure of the invention

[0007] Against this background, the approach described here presents a method for detecting a correctly fastened vehicle seat belt, a device using this method, and finally a corresponding computer program according to the main claims. The measures listed in the dependent claims enable advantageous refinements and improvements of the device specified in the independent claim.

[0008] The approach presented here provides a method for detecting a correctly fastened vehicle seat belt, the method comprising the following steps: - Reading the position of a marking unit attached to the vehicle safety belt; and - Determining whether the vehicle safety belt is correctly fastened when the position of the marking unit is in a predetermined relationship to a target position of the marking unit when the vehicle safety belt is correctly fastened.

[0009] This method can be implemented, for example, in software or hardware or in a mixed form of software and hardware, for example in a control unit.

[0010] A vehicle safety belt can be understood as a personal protection device in a vehicle that is capable of restraining a vehicle occupant in a vehicle seat in the event of an impact. A marking unit can be understood as an element that indicates a specific position or status of the vehicle safety belt.

[0011] The approach presented here is based on the realization that, when a vehicle seat belt is correctly fastened, the belt must run over the vehicle occupant sitting in the seat in a specific area. Depending on the occupant's constitution, the belt may deviate from a specific target position in certain areas, but this deviation will usually not be too significant. The approach described thus offers the advantage of being able to correctly and clearly determine the position of the vehicle seat belt over the vehicle occupant using a marking unit that is technically simple to attach to the vehicle seat belt. In this way, conscious and unconscious misuse of the vehicle seat belt can be very easily detected and processed accordingly (e.g., warning message, storage for insurance companies / investigating authorities).

[0012] It is advantageous if, according to one embodiment of the approach described, the position of the marking unit attached to the vehicle safety belt is wirelessly read in during the reading step. Wireless reading can be understood, for example, as an optical or electromagnetic reading or detection of the position of the marking unit. Such an embodiment of the approach described here offers the advantage of a technically very simple, precise, yet convenient way for the vehicle occupant to detect a correctly fastened vehicle safety belt.

[0013] According to a further embodiment of the approach described here, the position of the marking unit can be read in during the reading step by evaluating an electromagnetically readable identification feature. By evaluating an electromagnetically readable identification feature, a method can be used very easily to detect the position of the marking unit. In this way, the position of the marking unit can be read in cost-effectively.

[0014] Particularly advantageous is an embodiment of the approach described here in which the position of a retaining lug for a belt buckle of the vehicle safety belt is read as a marking unit during the reading step. Such an embodiment offers the advantage that most systems already provide a retaining lug to prevent the belt buckle from slipping off, and this retaining lug can be easily and cost-effectively modified and used as a marking unit for the additional benefit of the approach proposed here.

[0015] The detection of a correctly fastened vehicle seat belt is particularly robust if, according to one embodiment of the approach described here, the position of the marking unit in the determining step corresponds to the target position within a tolerance range. For example, this tolerance range can form an area of ​​up to 20 cm around the expected target position of the marking unit.

[0016] An embodiment of the approach described here is conceivable in which the reading step is carried out using a reading interface that is permanently installed in the vehicle.

[0017] An embodiment of the approach described here is particularly advantageous in which the reading step is further carried out using a second reading interface, wherein the second reading interface is designed to read the position of the marking unit attached to the vehicle seat belt and / or of a further marking unit fastened to a further vehicle seat belt. Such an embodiment of the approach described here offers the advantage of particularly precise detection of the position of the marked unit, since the position of the reading interface is fixed in the vehicle. Furthermore, in particular the arrangement of the position of the reading interface in the area of ​​the dashboard offers a very favorable viewing angle of the expected position of the marking unit in the target position, so that the detection of the position of the marking unit can be carried out in a technically simple manner.

[0018] One embodiment of the approach described here is technically very simple to implement and robust in design. In this embodiment, the reading step is carried out using a reading interface integrated into a belt buckle or the seat. This embodiment of the approach described here offers the advantage that the reading interface is located in close proximity to the marking unit in the expected target position, thus making correct reading of this position technically simple. The arrangement in the seat surface or backrest can also enable very good position detection, with the advantage that most vehicles already have electrical components in the seat and therefore already have cables routed into the seat.

[0019] A further advantageous additional benefit is offered by a further embodiment of the approach described here, in which the determining step involves determining at least one body parameter of a vehicle occupant who is belted in or is to be belted in with the vehicle seat belt. Such a body parameter can be understood, for example, as a waist circumference of the vehicle occupant, a body weight of the vehicle occupant, or a compensation of the vehicle occupant. Such an embodiment of the approach described here offers the advantage of being able to control the deployment of one or more additional occupant protection devices, such as an airbag, by providing the body parameter, so that the occupant safety devices can be activated individually for each occupant, which in turn can increase occupant safety.

[0020] The approach presented here further provides a device configured to perform, control, or implement the steps of a variant of a method described here in corresponding devices. This embodiment of the invention in the form of a device also allows the problem underlying the invention to be solved quickly and efficiently.

[0021] In this case, a device can be understood as an electrical device that processes sensor signals and outputs control and / or data signals depending on them. The device can have an interface that can be implemented in hardware and / or software. In a hardware implementation, the interfaces can, for example, be part of a so-called system ASIC, which contains a wide variety of functions of the device. However, it is also possible for the interfaces to be separate integrated circuits or to consist at least partially of discrete components. In a software implementation, the interfaces can be software modules that are present, for example, on a microcontroller alongside other software modules.

[0022] Also advantageous is a computer program product or computer program with program code that can be stored on a machine-readable carrier or storage medium such as a semiconductor memory, a hard disk memory or an optical memory and is used to carry out, implement and / or control the steps of the method according to one of the embodiments described above, in particular when the program product or program is executed on a computer or a device.

[0023] Embodiments of the invention are illustrated in the drawings and explained in more detail in the following description. It shows: Fig. 1 is a block diagram of a device according to an embodiment; Fig. 2 illustrations of the use of the retaining lugs of the vehicle safety belt as a marking unit; Fig. 3 a representation of the position of the marking unit when the vehicle seat belt is correctly fastened; Fig. 4 a representation of an incorrectly fastened vehicle safety belt; Fig. 5 a representation of another incorrectly fastened vehicle safety belt; Fig. 6 is a block diagram of an embodiment of the detection device described here; and Fig. 7 a flowchart of a method according to an embodiment of the approach described here.

[0024] In the following description of advantageous embodiments of the present invention, the same or similar reference numerals are used for the elements shown in the various figures and having a similar effect, whereby a repeated description of these elements is omitted.

[0025] Fig. 1 shows a schematic representation of a vehicle 100 with a device 110 for detecting a correctly fastened vehicle safety belt. In the vehicle 100 there is a vehicle seat 115 on which a vehicle occupant 120, in this case the driver of the vehicle 100, is sitting. Without limiting the generality, the approach described here can also be used to detect a correctly fastened vehicle safety belt for vehicle occupants sitting in the rear seats of the vehicle. The vehicle occupant 120 is belted in with the vehicle safety belt 125. In order to be able to recognize whether the vehicle safety belt 125 has been correctly fastened, a device 110 for detecting a correctly fastened vehicle safety belt 125 is provided. For the correct function of the device 110, a marking unit 130 is attached to the vehicle safety belt 125, which can be, for example, in the form of an RFID tag, i.e.a small (for example passive) radio transmitter unit, or a magnet, designed as a retaining lug to prevent the belt buckle 140, which is to be inserted into a belt buckle 135, from slipping. This type of marking unit 130 then enables a read-in interface 145, which is designed, for example, in the form of an electromagnetic transmitter, to detect the position of the marking unit 130 in the area above the vehicle seat and to output a corresponding position signal 150 to a unit 155 for determination. The read-in interface 145 can be installed in a front area of ​​the vehicle interior, for example in the dashboard 157, in order to have the best possible position for detecting or recognizing the position of the marking unit 130. It is also conceivable in the . Fig. 1, in which the reading interface 145 is arranged in the vehicle seat 115, for example in the seat surface or backrest of the vehicle seat 115. Such an embodiment offers the advantage of a particularly close positioning of the reading interface 145 to the marking unit 130, wherein the connection to the communication connections such as electrical lines is technically easy to implement, since in most vehicles, lines for signal transmission and / or power supply are already routed into the vehicle seat 115.

[0026] In the determining unit 155, the position of the marking unit 130 contained in the position signal can then be compared with a target position that the marking unit 130 would have if the vehicle safety belt 125 were correctly fastened. If this determined or read position of the marking unit 130 lies, for example, within a predetermined tolerance range around the target position, it can be assumed that the vehicle safety belt 125 was correctly fastened. Otherwise, an error signal 160 can be output, and a warning unit 165 can issue a warning to the vehicle occupant 120, or even interrupt or prevent the travel of the vehicle 100 and / or adapt the braking strategy for autonomous braking maneuvers and the steering / evasive strategy for autonomous evasive maneuvers. It is also conceivable to change the triggering strategies of the restraint devices, in particular the airbag.

[0027] In addition to designing the marking unit 130 as an RFID tag, it is also conceivable to provide an optical code, for example a barcode, as the marking unit. In this case, the reading interface 145 can be designed as an optical sensor, preferably a camera, to detect the position of the marking unit 130.

[0028] It is also conceivable that (in the Fig. 1) arrangement of the reading interface 145 in the area of ​​the belt buckle 135 in the seat surface or backrest of the vehicle seat. In this case, a mostly standard cabling could be used to connect a belt buckle sensor according to the state of the art, so that only this known belt buckle sensor would have to be replaced with a corresponding sensor for detecting the position of the marking unit 130.

[0029] Furthermore, the device 110 presented here can also detect when, for example, another vehicle safety belt 170, such as the one on the front passenger seat 175, is inserted into the belt buckle 135 of the driver's seat 115. In this case, the marking unit 130 of the additional vehicle safety belt 170 would also not be in the tolerance range above the driver's seat 115, but rather in an area above the front passenger seat 175. Thus, the approach described here can very easily detect incorrect operation of the vehicle safety belts 125 or 170, which would not be possible with the simple evaluation of a correctly inserted belt buckle 140 into the belt buckle 135. The same is of course also conceivable for the rear seat area.

[0030] Furthermore, it would also be conceivable to provide an additional reading interface 180 installed in the area of ​​the B-pillar 185 of the vehicle 100. Such an additional reading interface 180 could, for example, very precisely detect whether the vehicle safety belt 125 is being used at all or is just hanging slackly and unused in the area of ​​the B-pillar 185. This additional reading interface 180 would thus offer an additional possibility for detecting a correctly fastened vehicle safety belt 125.

[0031] An important aspect of the approach described here is therefore the possibility of creating a device or a sensor system that is installed, for example, in or as a retaining lug 130 of the belt system 125.

[0032] Fig. 2 shows illustrations of such a retaining lug as a marking unit 130 for securing the belt buckle when the belt is retracted, thereby preventing the belt buckle from slipping down when the vehicle safety belt 125 is not fastened. The marking unit 130 is designed to communicate, for example, wirelessly with a receiver installed in the vehicle, such as the read-in interface 145, in order to distinguish a correctly belted person or a vehicle occupant 120 from a misuse situation of the vehicle safety belt 125.

[0033] Fig. 3 shows a front view of a vehicle occupant 120 and a representation of the location and position of the marking unit 130 as a retaining lug for the belt buckle 140, wherein this retaining lug should be located in a tolerance range 300 around the target position 310 when the vehicle safety belt 125 is correctly fastened.

[0034] In the Fig. 4 and Fig. 5 shows illustrations of misuse of the vehicle safety belt 125 and 170. In the Fig. 4 shows the fastening of the vehicle safety belt 125 when the vehicle seat 115 is unoccupied, wherein the vehicle occupant, when using the vehicle seat 115, sits on the vehicle safety belt 125 with the belt buckle 140 already fastened in the belt buckle 135. In this case, the marking unit 130 will not be in the expected target position, since this target position will only be reached when the vehicle safety belt 125 is guided over the vehicle occupant 120. In the Fig. 5 shows a situation in which the additional vehicle safety belt 170 is guided over the front passenger seat 175 and into the belt buckle 135 of the driver's seat. Here, too, the misuse of the additional vehicle safety belt 170 is detected because the marking unit 130 of the vehicle safety belt 125 for the driver's seat will not be located in front of the vehicle occupant on the driver's seat 115, and the marking unit 130 of the vehicle safety belt 170 of the front passenger seat is additionally not in a desired position when the front passenger seat 175 is occupied and the vehicle safety belt is correctly fastened. An important aspect of the approach described here is the exploitation of the fact that the retaining lug, which is usually fastened in the belt strap 125 and serves as a marking unit 130 for the belt buckle 140, is always located in a specific (tolerance) range in front of the person 120 in a target position when the person 120 is correctly belted.This target position is usually a few cm in front of the backrest 110 and a few cm above the seat.

[0035] There are several advantages to using the approach described here: - Easy integration of the transmitter unit as a marking unit 130 (preferably RFID technology) into the existing components of the restraint system - No power supply or power cable in the belt up to the retaining lug required if RFID technology or alternative technology is used (passive system) - All misuse cases 2 to 6 described above for a vehicle safety belt are recognizable (if the design is appropriate) - Elimination and thus savings potential of the lock sensor in a certain embodiment - Wear-free technology, thus ensuring longevity.

[0036] For the system presented here, a corresponding sensor or marking unit 130 is integrated into the webbing of the vehicle safety belt 125. A first advantageous embodiment can be seen when the retaining lug for the belt buckle is used as a carrier for the marking unit 130.

[0037] Fig. 6 again shows a block diagram of an embodiment of the approach described here. An element is used as a marking unit 130, which is externally stimulated by a transmitting device of a reading interface 145 and then sends a value back to a receiving device of the reading interface 145 (for example, using RFID technology). The returned value can be used to check whether it is the correct value (for example, a code for the correct tag as the marking unit 130). Furthermore, the distance (e.g., 10 cm) and / or direction can be determined by measuring the signal propagation time of the signal 600 transmitted to the marking unit 130 and received again. By checking the values ​​(e.g., threshold value, characteristic map) in an evaluation or determination unit 155, the correct or incorrect position of the belt webbing 125 can then be determined.Preferably, the determination unit 155 is a module of an existing control unit, such as the airbag or seat control unit. Other evaluation units, such as the automatic belt retractor 610 in the B-pillar 185, are also conceivable. Since the retraction mechanism makes it highly unlikely that an occupant 120 will permanently hold the belt 125 in front of their body without inserting it into the belt buckle 135, the sensor in the belt buckle 135 can be omitted from this perspective. If it is detected that the belt 125 has not been correctly fastened by the vehicle occupant 115, a warning or blocking of the use of the vehicle 100 can be issued via a corresponding warning unit 165.

[0038] In an extended embodiment, a second sensor 180 can be installed in the B-pillar 185 to detect non-use or to detect one of the misuse cases (e.g., a dangling belt 125). For example, if the passenger's seat belt 125 is fastened on the driver's side—in addition to a faulty ID, the dangling belt 125 for the driver's seat 115 and thus the marking unit 130 on the second sensor 180 of the B-pillar 185 will also be detected. Logically, this indicates misuse of the belt system.

[0039] In an expanded embodiment of the approach described here, a receiving unit can be installed in the belt buckle 135. Since the belt buckle switches are susceptible to failure over their lifetime, another system can be used here to ensure that the occupant is correctly belted. For this purpose, the tag as marking unit 130 is then excited accordingly and recognized accordingly via the receiver in the belt buckle. It is also conceivable to place additional tag elements as marking units 130 in the belt 125 so that different positions can be queried when the belt 125 is retracted. These positions also provide an indication of where they are located relative to the receiving units or the reading interface 145, and thus conclusions can be drawn about the body stature of the vehicle occupant 120. This situation is not further illustrated in a figure.

[0040] The approach presented here can be implemented particularly advantageously using the following components: - a marking unit 130 as a tag element - the use of RFID technology is advantageous - a read-in interface 145 preferably with a transmitting element for “stimulating” the marking unit 130 and a receiving element for measuring the values ​​emitted by the transmitting element - an evaluation or determination unit 155 - whereby this determination unit 155 can advantageously be designed as a module of the seat control unit or the airbag control unit, - a belt strap 125 and - a belt buckle 135

[0041] The transmitting and receiving elements can be designed as a single unit in the form of a read-in interface 145; however, it is also conceivable for the individual components of the read-in interface 145 to be installed as separate components at different locations in the vehicle 100. The evaluation unit 155 can additionally utilize a seat occupancy detection function. It is also advantageous to integrate the components of the read-in interface 145 into a seat occupancy mat or into the seat.

[0042] Fig.7 shows a flowchart of an embodiment of the approach described here as a method 700 for detecting a correctly fastened vehicle seat belt. The method 700 comprises a step 710 of reading a position of a marking unit attached to the vehicle seat belt and a step 720 of determining the correctly fastened vehicle seat belt if the position of the marking unit is in a predetermined relationship to a target position of the marking unit when the vehicle seat belt is correctly fastened.

[0043] If an embodiment includes an “and / or” link between a first feature and a second feature, this should be read as meaning that the embodiment according to one embodiment includes both the first feature and the second feature and according to another embodiment includes either only the first feature or only the second feature.

Claims

[1] A method (700) for detecting a correctly fastened vehicle safety belt (125), the method (700) comprising the following steps: - reading (710) a position of a marking unit (130) attached to the vehicle safety belt (125); and - determining (720) the correctly fastened vehicle safety belt (125) when the position of the marking unit (130) is in a predetermined relationship to a target position (310) of the marking unit (130) in the correctly fastened state of the vehicle safety belt (125); characterized by in that in the step of reading (710) the position of a retaining lug for a belt buckle (140) of the vehicle safety belt (125) is read in as a marking unit (130) and in that in the step of determining (720) using the position of the marking unit (130) a determination of at least one body parameter of a vehicle occupant (120) to be belted in with the vehicle safety belt (125) takes place. [2] Method (700) according to claim 1, characterized by that in the reading step (710) the position of the marking unit (130) attached to the vehicle safety belt (125) is read wirelessly. [3] Method (700) according to one of the preceding claims, characterized by that in the reading step (710) the position of the marking unit (130) is read in by evaluating an electromagnetically readable identification feature (600). [4] Method (700) according to one of the preceding claims, characterized by that in the step of determining (720) the position of the marking unit (130) corresponds within a tolerance range (300) to the target position (310). [5] Method (700) according to one of the preceding claims, characterized by that the step of reading (710) is carried out using a reading interface (145) installed in a fixed location in the vehicle. [6] Method (700) according to claim 5, characterized bythat the step of reading (710) is further carried out using a second reading interface (180), wherein the second reading interface (180) is designed to read the position of the marking unit (130) attached to the vehicle safety belt (125) and / or of a further marking unit (130) attached to a further vehicle safety belt (170). [7] Method (700) according to one of claims 5 or 6, characterized by that the step of reading (710) is carried out using a reading interface arranged in a belt buckle (135) or integrated in the seat. [8] Device (110) which is configured to carry out and / or control the method (700) according to one of the preceding claims. [9] Computer program configured to execute and / or control the method (700) according to one of the preceding claims. [10] A machine-readable storage medium on which the computer program according to claim 9 is stored.

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