Safety system and method for determining parameters of a fastened safety belt in a motor vehicle

Abstract

The present invention relates to a safety belt system and a method for determining parameters of an occupant in a motor vehicle, comprising at least the following steps: providing a safety belt (1), providing a buckle tongue (2) movable along the safety belt (1), providing a belt buckle (3), fastening the safety belt (1) by inserting the buckle tongue (2) into the belt buckle (3), and determining the position of the buckle tongue (2) on the fastened safety belt (1). The safety belt system comprises a safety belt (1), a buckle tongue (2), at least one sensor (5), and an evaluation unit (6) connected to the at least one sensor (5).

Description

[0001] The present invention relates to a safety belt system comprising a safety belt, a buckle tongue, at least one sensor, and an evaluation unit connected to the at least one sensor, as well as to a method for determining parameters of a fastened safety belt in a motor vehicle, in particular by means of a safety belt system. In particular, the determined parameters of the fastened safety belt can be used to infer parameters of the occupant.

[0002] Safety systems, and in particular seat belt systems, generally serve to restrain vehicle occupants in the event of an accident. For this purpose, seat belt systems comprise a seat belt which, at its first end, can be wound onto a rotatably mounted belt spool of a belt retractor, a frame of the belt retractor being fastened in a vehicle. To create a three-point belt, the seat belt is fastened at its second end by means of an end fitting on the same side of the vehicle seat as the belt retractor. A belt tongue is slidably provided on the seat belt which, in order to divide the seat belt into the three-point geometry, can be locked in a belt buckle fastened on the other side of the vehicle seat. The buckle tongue inserted into the belt buckle thus divides the seat belt into a chest belt section and a lap belt section.

[0003] The belt spool in the belt retractor can be pre-tensioned in the winding direction so that the seat belt is automatically wound up after the belt tongue is unlocked. Furthermore, a blocking device with associated sensor devices can be provided, which blocks the belt spool against further rotation in the seat belt extension direction when predetermined values ​​of the belt webbing extension acceleration and / or vehicle deceleration are exceeded, so that the occupant is restrained by the seat belt when the belt spool is blocked and protected from impact with the vehicle's internal structure.

[0004] The belt retractor can incorporate force-limiting elements that allow for force-limited belt retraction after the belt reel is locked. Tensioners can also be provided, allowing the seat belt to be rewound onto the reel in an accident situation, for example, to pull the occupant back toward the seat.

[0005] The safety system may also include one or more airbags, which may be located at various points on the vehicle structure and inflate to cover the vehicle structure in the event of an accident, so that the occupant can be restrained by a combination of the seat belt and the airbag. In order to set and / or coordinate the adjustable level of force limitation, the timing of belt tensioning, and the timing of deployment of the at least one airbag, it is desirable to know the occupant's size. Typically, the occupant's size is determined using a seat occupancy mat and the position of the seat along the seat track and is used to set the occupant restraint parameters. However, the occupant size determined in this way is not always accurate.

[0006] From DE 10 2021 113 46 3B3 there is disclosed a safety belt device in which a diagonal belt section and a lap belt section are each connected to a belt retractor and are each fastened to a belt tongue, wherein the diagonal belt section is fastened at one end to a fitting, wherein the fitting is rotatably connected to the belt tongue, wherein a sensor is configured to detect the rotational angle position of the fitting relative to the belt tongue and / or a belt buckle.

[0007] The object of the present invention is therefore to eliminate the disadvantages described with reference to the prior art and, in particular, to provide a safety belt system and a method for determining parameters of a fastened safety belt in a motor vehicle, with which the occupant size can be determined in an alternative manner and as accurately as possible.

[0008] A possible solution to this problem is provided by the method and the safety belt system having the features of the respective independent claim, with further solutions and advantageous developments being specified in the preceding and subsequent descriptions as well as in the subclaims. Individual features of the advantageous developments can be combined with one another in a technically expedient manner, with features disclosed with reference to the method being applicable to the safety belt system and vice versa.

[0009] The object is achieved in particular by a method for determining parameters of a fastened safety belt in a motor vehicle, comprising at least the following steps: - Providing the seat belt, - Providing a lock tongue that can be moved along the seat belt, - Providing a seat belt buckle, - Fasten the seat belt by inserting the buckle tongue into the buckle, and - Determining an arrangement, for example a position or an angle of the buckle tongue relative to the fastened seat belt.

[0010] The object is also achieved by a safety belt system which comprises a safety belt, a buckle tongue, at least one sensor and an evaluation unit connected to the at least one sensor, wherein the evaluation unit is configured to determine an arrangement of the buckle tongue relative to the safety belt.

[0011] In other words, the basic concept of the invention provides, in particular, for determining the position, alignment, and / or angle of the buckle tongue relative to the fastened seat belt in order to determine, for example, a length of the lap belt portion of the fastened seat belt, a length of the chest belt portion of the fastened seat belt, and / or an angle of the lap belt portion relative to the chest belt portion or to the buckle tongue. This, in turn, can indirectly be used to determine a parameter of the occupant, such as height, weight, or contour, optionally in combination with additional measured values ​​from other sensors distributed in the motor vehicle. The parameters thus determined can, in turn, be used to optimally adapt the force limitation level of a belt retractor, the timing of belt tensioning, and / or the timing of deployment of one or more airbags to one another and / or to the occupant.

[0012] Typically, the seat belt is attached to the motor vehicle with an end fitting. It is therefore proposed, in particular, that based on the determined position of the buckle tongue on the fastened seat belt, the length of a lap belt section be determined. This length extends between the end fitting attached to the vehicle and the buckle tongue inserted into the belt buckle. The length of the lap belt section, in turn, corresponds to the pelvic circumference and / or abdominal circumference of the occupant, so that the determined length can be used to determine a parameter such as the occupant's weight, height, or the quotient of the occupant's length and weight.

[0013] If the length of a chest belt section is determined based on the specific position of the buckle tongue inserted into the belt buckle, it is helpful if the length of the section of the safety belt unwound from the belt reel is also known, so that the extension caused by the volume of the occupant's upper body can be deduced.

[0014] If the angle between the lap belt section and the chest belt section or the buckle tongue is determined, the determined angle can be used to determine whether the seat belt, and in particular the lap belt section, is correctly positioned. If incorrect seat belt positioning is determined, possibly using additional measurements, a warning signal can be generated. For example, if the angle between the lap belt section and the chest belt section is relatively small, this could be an indication that the lap belt section is positioned on the occupant's stomach and not in front of the pelvis. If the lap belt section is positioned in front of the occupant's pelvis, the angle to the chest belt section is relatively large.

[0015] The basic concept of the invention initially leaves open the location of the at least one sensor. The at least one sensor, embodied, for example, as an optical sensor (e.g., a single diode or camera), a capacitive sensor, or a resistance sensor, can be arranged on the seat belt, the buckle tongue, and / or another location in the motor vehicle.

[0016] The evaluation unit can be located in the immediate vicinity of the sensor, for example, in or on the vehicle seat. However, the evaluation unit can also be integrated into the vehicle's control unit. Ultimately, the key is to ensure that a signal generated by a sensor is fed to an evaluation unit.

[0017] In a preferred embodiment, at least one sensor is arranged on the buckle tongue, wherein the at least one sensor arranged on the buckle tongue is configured to receive a signal emitted by the seat belt. The signal subsequently generated by the sensor or a directly processed signal can be transmitted wirelessly, for example, to the evaluation unit.

[0018] However, it is preferred that the signal generated by the sensor or directly processed further be transmitted to the evaluation unit via a wired connection. For this purpose, it can be provided that the buckle tongue, which has the at least one sensor, is connected to the evaluation unit for signal transmission when inserted into the belt buckle. The buckle tongue thus has a contact area that is electrically connected to the sensor and that is in electrically conductive contact with a contact area formed on the belt buckle when the buckle tongue is inserted into the belt buckle. The contact area of ​​the belt buckle can then, in turn, be connected to the evaluation unit via a cable.

[0019] In this context, it is particularly provided that at least one signal generator is arranged on the safety belt, wherein the at least one signal generator is set up and designed such that the signals emitted by the at least one signal generator differ from one another at at least two points on the safety belt.

[0020] In particular, it can be provided that the signal emitted by the at least one signal generator and received by the at least one sensor can be used to directly determine the location of the buckle tongue on the seat belt. Additionally and alternatively, the angle of the buckle tongue to the seat belt can be directly determined. In other words: at every location in the relevant area of ​​the seat belt, the at least one sensor receives a signal emitted by the seat belt that is different from any other location in the relevant area of ​​the seat belt. Thus, the signals generated by the at least one sensor and transmitted to the evaluation unit can also be clearly assigned to a position of the buckle tongue on the seat belt.

[0021] For example, it can be provided that a width of the signal generator tapers continuously along the longitudinal direction of the safety belt, wherein the width of the signal generator can be determined by means of the at least one sensor at the point on the safety belt at which the buckle tongue is located, so that the position of the buckle tongue on the safety belt can be determined directly.

[0022] Alternatively, it can be provided that the signals emitted by the signal generator are repeated along the safety belt, so that when the buckle tongue moves along the safety belt, the length of the movement and thus the position of the buckle tongue on the safety belt can be determined.

[0023] Preferably, it can be provided that several signal transmitters are arranged one behind the other in the longitudinal direction of the safety belt, which signal transmitters differ from one another in their width (relative to the longitudinal direction of the safety belt).

[0024] In particular, if the at least one sensor, particularly one arranged on the belt buckle, is designed as an optical sensor (for example, in the form of a diode), it can be provided that the at least one signal generator comprises at least one optically reflective element, wherein the light reflected by the optically reflective element is to be considered a signal emitted by the signal generator. Based on the intensity of the reflected light detected by the at least one sensor, the position of the buckle tongue on the seat belt can then be determined.

[0025] In this context, it can also be provided that one or each optical sensor is assigned an LED whose emitted light is reflected by the optically reflective element.

[0026] Alternatively, it can be provided that the at least one signal generator comprises at least one electrically conductive element, in which case the at least one sensor can be designed in particular to determine a resistance of the at least one electrically conductive element.

[0027] In a further embodiment, it can be provided that the at least one signal generator comprises at least one inductively excitable element, in which case the at least one sensor is in particular a sensor with which the inductance of the inductively excitable element can be determined.

[0028] In a further embodiment, it can be provided that the at least one sensor is arranged in or on the seat belt. In particular, in this case, several sensors are arranged one behind the other in the longitudinal direction of the seat belt. The sensors arranged in or on the seat belt are preferably force sensors. When the belt tongue is pulled along the seat belt, a force is exerted on the seat belt and thus also on the force sensors arranged in or on the seat belt, so that the position of the buckle tongue relative to the seat belt can be determined.

[0029] In particular, to determine an angle from the lap belt section to the chest belt section or to the buckle tongue, it can be provided in this context that at least two rows of several sensors each are arranged next to one another transversely to the longitudinal direction of the seat belt. In particular, a row of several sensors is formed on each of the two edges of the seat belt, which are arranged one behind the other in the longitudinal direction of the seat belt. Based on the signals generated by the sensors, conclusions can be drawn about the orientation of the buckle tongue relative to the seat belt, which in turn can be used to determine the angle of the lap belt section to the chest belt section.

[0030] The sensors or signal generators arranged in or on the seat belt can, for example, be located in a tube section formed by two fabric layers of the seat belt. Alternatively, the sensors or signal generators can be woven into the seat belt fabric.

[0031] The invention and the technical environment are explained below using the figures as examples. They show schematically Fig. 1: a safety belt system comprising a safety belt, a buckle tongue, a buckle and an end fitting, Fig. 2: a top view of the seat belt and the buckle tongue with several sensors and a signal generator, Fig. 3: a sectional view through the view of the Fig. 2, Fig. 4: an alternative design of the signaling devices on a safety belt, Fig. 5: an alternative arrangement of the sensors on a seat belt, Fig. 6: a sectional view through an embodiment of the Fig. 5, Fig. 7: a perspective view of a further embodiment of a safety belt with a buckle tongue inserted into a belt buckle and Fig. 8: a detailed view of the safety belt and the buckle tongue from Fig. 7.

[0032] The Fig. The safety belt system shown in Figure 1 comprises a safety belt 1, a buckle tongue 2 movable along the safety belt 1, and a belt buckle 3. The belt buckle 3 is connected to an evaluation unit 6. The safety belt 1 is secured to a motor vehicle by means of an end fitting 4 and extends to a belt retractor (not shown).

[0033] In the Fig. In the state shown in Figure 1, the buckle tongue 2 is inserted into the belt buckle 3, thus dividing the safety belt 1 into a lap belt section 1.1 and a chest belt section 1.2. A length 8 of the lap belt section 1.1 and a length of the chest belt section 1.2 depend on the external contour of an occupant.

[0034] The present invention is based, among other things, on determining, in particular, the position of the buckle tongue 2 inserted into the belt buckle 3 relative to the safety belt 1 in order to be able to determine the length 8 of the lap belt section 1.1. The length 8 of the lap belt section 1.1 can be used to determine a contour and thus a parameter of the occupant, which can be used to control further elements of a safety system.

[0035] In the Fig. 2 to 6 and 8 show exemplary sensors and signal transmitters with which the length 8 of the lap belt section 1.1 and / or its orientation relative to the chest belt section 1.2 or to the buckle tongue 2 can be determined.

[0036] According to the Fig. In the embodiment shown in Figure 2, the safety belt 1 has exactly one signal generator 7, which extends in the longitudinal direction of the safety belt 1 and whose width changes continuously along the longitudinal direction. In the buckle tongue 2, however, several sensors 5 are arranged next to one another. The buckle tongue 2 also has a contact point 9 which is electrically conductively connected to the sensors 5 and which comes into contact with a contact point 9 formed on the belt buckle 3 when the buckle tongue 2 is inserted into the belt buckle 3 (see Fig. 3).

[0037] Due to the different width of the signal generator 7 at different locations on the safety belt 1, the sensors 5 generate different signals depending on where on the safety belt 1 the buckle tongue 2 is arranged.

[0038] The design of the Fig. 4 differs from the design of the Fig. 2 and Fig. 3 in that the signal transmitters 7 are arranged one behind the other in the longitudinal direction of the safety belt 1, wherein the signal transmitters 7 differ from one another in their width. Depending on the position at which the buckle tongue 2 is located on the safety belt 1 of the embodiment of the Fig. 4, the sensors 5 receive different signals from the signal generators 7 and thus generate different signals themselves, which are transmitted to the evaluation unit 6.

[0039] The signal generator(s) 7 can be designed as optically reflective elements, in which case the sensors are designed, for example, as light-sensitive diodes. Alternatively, the signal generator(s) 7 can be designed as electrically conductive elements, in which case the sensors can be designed, for example, as sensors for determining electrical resistance.

[0040] According to the embodiment of the Fig. 5 to 8, a plurality of sensors 5 are arranged one behind the other in the longitudinal direction of the safety belt 1, wherein the sensors 5 are designed as force sensors and are connected to an evaluation unit 6 by means of electrically conductive connectors at the end of the safety belt in the region of the end fitting 4.

[0041] If a buckle tongue 2 is moved along a safety belt 1 equipped with corresponding sensors 5, the sensors 5 generate a force upon passing through the buckle tongue 2, causing the associated sensor 5 to generate a signal that is transmitted to the evaluation unit 6. The position of the buckle tongue 2 on the safety belt 1 can thus be determined.

[0042] According to the embodiment of the Fig. 7 and Fig. 8, a row of several sensors 5 is arranged one behind the other in the longitudinal direction of the safety belt 1 at the edges of the safety belt 1. The two rows are thus arranged next to each other transversely to the longitudinal direction. With these sensors 5, it can be detected how the buckle tongue 2 is aligned with the safety belt 1. In particular, an angle of the buckle tongue 2 to the longitudinal direction of the safety belt 1 can be determined. With the two rows of sensors, in particular, an angle 10 of the lap belt section 1.1 to the chest belt section 1.2 can also be determined (see in particular Fig. 7).

[0043] As can be seen in particular from the Fig. As can be seen from Figure 8, the buckle tongue 2 comes into contact with sensors 5 of the different rows, which are arranged at different locations in the otherwise parallel rows of sensors, particularly when the buckle tongue 2 is at an angle other than 90° to the longitudinal direction of the safety belt 1. Thus, when viewed from the Fig. 8 the lock tongue 2 with the sensor 5 of the Fig. 8 top row in the appendix, which is from the left in Fig. 8 is arranged in fifth place, while the lock tongue 2 is connected to the sensor 5 of the Fig. 8 bottom row in the appendix, which is from the left in Fig. 8 is arranged in third place. List of reference symbols 1 seat belt 1.1 1.2 Lap belt section Chest belt section 2 lock tongue 3 belt buckle 4 End fitting 5 Sensor 6 Evaluation unit 7 signal generators 8 Length of the lap belt section 9 Contact point 10 angles

Claims

[1] Method for determining parameters of a fitted seat belt (1) in a motor vehicle, comprising at least the following steps: - Providing the safety belt (1), - Providing a locking tongue (2) that can move along the seat belt (1), - Providing a seatbelt buckle (3), - Fastening the seat belt (1) by inserting the buckle tongue (2) into the buckle (3), - Determining an arrangement of the locking tongue (2) relative to the fitted safety belt (1). [2] Method according to claim 1, wherein a length (8) of a lap belt section (1.1) of the applied safety belt (1) is determined between an end fitting (4) and the buckle tongue (2). [3] Method according to claim 1 or 2, wherein an angle (10) of the pelvic belt section (1.1) to the buckle tongue (2) and / or to the chest belt section (1.2) is determined. [4] Seat belt system, comprising - a seat belt (1), - a locking tongue (2) that can be moved along the seat belt (1), - at least one sensor (5) and - an evaluation unit (6) connected to at least one sensor (5), characterized by , that the evaluation unit (6) is configured to determine an arrangement of the locking tongue (2) relative to the safety belt (1). [5] Seat belt system according to claim 4, comprising a belt buckle (3), wherein the evaluation unit (6) is configured to determine a position of the buckle tongue (2) inserted into the belt buckle (3) relative to the seat belt (1). [6] Seat belt system according to claim 4 or 5, comprising a buckle (3), wherein the evaluation unit (6) is configured to determine an angle (10) of the lap belt section (1.1) to the buckle tongue (2) inserted into the buckle (3) and / or to the chest belt section (1.2) of the fitted seat belt (1). [7] Seat belt system according to one of claims 4 to 6, wherein at least one sensor (5) is arranged on the buckle tongue (2) which is configured to receive a signal emitted by the seat belt (1). [8] Seat belt system according to claim 7, wherein the locking tongue (2) is connected to the evaluation unit (6) for signal transmission in a state inserted into the belt buckle (3). [9] Seat belt system according to one of claims 4 to 8, wherein at least one signal transmitter (7) is arranged on the seat belt (1), wherein the signals emitted by the at least one signal transmitter (7) differ from each other at at least two points on the seat belt (1). [10] Seat belt system according to claim 9, wherein the at least one signal transmitter (7) comprises at least one optically reflective element. [11] Seat belt system according to claim 9, wherein the at least one signal transmitter (7) comprises at least one electrically conductive element. [12] Safety belt system according to claim 9, wherein the at least one signal transmitter (7) comprises at least one inductively excitable element. [13] Seat belt system according to one of claims 4 to 12, wherein at least two sensors (5) are arranged on the seat belt (1). [14] Seat belt system according to claim 13, wherein at least two rows of several sensors (5) are arranged side by side transversely in the longitudinal direction of the seat belt (1).

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