Seatbelt pretensioner operation depending on information about occupants

Abstract

The invention relates to a method for operating a reversible belt tensioner (2) of a safety belt arranged on a vehicle seat (1) during the driving operation of a vehicle, characterized in that the belt tensioner (2) is controlled depending on a determined (S1) driving situation and on a determined (S2) information about an occupant occupying the vehicle seat (1) and / or about the vehicle seat (1) with the safety belt to exert a time-limited belt tension (S3).

Description

[0001] The invention relates to a method for operating a reversible belt tensioner of a safety belt arranged on a vehicle seat during the driving operation of a vehicle, and to a corresponding system for a vehicle.

[0002] Automatic seatbelt pretensioners for motor vehicles, particularly passenger cars, are known in the prior art. Their purpose is to tighten, for example, a predetermined amount of time before entering a curve, the seatbelt of an occupant, thus minimizing any play between the occupant and the belt. Such play can have serious consequences in the event of a collision, as the occupant can accelerate relative to the vehicle until restrained by the seatbelt. In particular, this reduces the forward movement of the occupant during braking or skidding in an actual or imminent accident. The purpose of the seatbelt pretensioner is precisely to prevent such acceleration.This system takes advantage of the well-known fact that an occupant restrained by a tightly fitting seatbelt tends to suffer significantly fewer injuries in the event of a vehicle accident than one restrained by a loose belt. Therefore, the automatic seatbelt tensioner proactively increases the belt tension before the vehicle enters a traffic situation with an increased risk of accident, thus ensuring that the seatbelt fits snugly against the occupant.

[0003] In this context, DE 10 2020 006 623 A1 relates to a method for the dynamic restraint of an occupant strapped to a vehicle seat with a seat belt, wherein the lateral acceleration of the vehicle and the road ahead are determined, and the seat belt is tightened with a predetermined force for a predetermined time before entering a curve with a predetermined curvature, wherein various turning angles of junctions and turns are each assigned a comfort speed at which the junction or turn can be comfortably negotiated, and wherein, in the event of the vehicle approaching a junction or turn at an instantaneous speed that exceeds the comfort speed assigned to the turning angle by a predetermined value,The seat belt is tightened with a predetermined belt force before reaching the junction or turn.

[0004] DE 10005010 A1 further relates to a method for restraining an occupant on a vehicle seat, wherein, upon detection of a critical driving condition, the occupant is pulled into the vehicle seat by a force via a belt tensioner and is then held in a retracted position on the vehicle seat by a holding force, wherein the holding force is chosen to be less than the force used to pull the occupant back.

[0005] DE 10 2004 020 049 A1 also relates to a safety device for a motor vehicle with a vehicle seat adjustable in its seating position by a seat adjustment drive and a seat control unit with an evaluation of safety-relevant data for driving operation, wherein the seat control unit controls the seat adjustment drive in such a way that, before the occurrence of an expected accident event, a procedure of the vehicle seat into a safety-technically optimal seating position for an occupant is initiated, wherein the procedure of the vehicle seat into its safety-technically optimal seating position by means of the seat control unit takes place in individual adjustment steps for the respective components of the vehicle seat in a predetermined sequence one after the other.

[0006] DE 10 2012 025 269 A1 further relates to a method for restraining an occupant of a vehicle with a safety belt device assigned to a vehicle seat of the occupant, wherein an impending collision of the vehicle is detected and a belt tensioner of the safety belt device is activated to tighten a safety belt, wherein the belt tensioner is activated in the event of a detected rear-end collision impending the vehicle and the safety belt is tightened before the rear-end collision occurs, and wherein the occupant is positioned towards a seat back by means of the safety belt.

[0007] DE 10 2018 002 559 A1 relates to a method for the dynamic restraint of an occupant strapped to a vehicle seat with a safety belt, whereby a lateral acceleration of the vehicle and a road course ahead of the vehicle are determined, wherein the safety belt is tightened with a predetermined belt force for a predetermined time period before entering a curve which has a predetermined curvature.

[0008] DE 10 2019 002 308 A1 further relates to a method for the dynamic restraint of an occupant strapped to a vehicle seat with a seat belt, wherein a lateral acceleration of the vehicle and a road course ahead of the vehicle are determined, wherein, based on image data of a vehicle environment captured by means of at least one vehicle-side camera and / or based on captured data from a navigation map, a lateral acceleration to be expected in the course of a curve ahead of the vehicle is predicted, wherein, in the event that the predicted lateral acceleration exceeds a situation-dependent predetermined trigger threshold for tightening the seat belt, a belt force acting on the seat belt is increased before the lateral acceleration acts on the occupant.

[0009] DE 10 2021 002 042 A1 also relates to a method for operating a reversible belt tensioner of a safety belt assigned to a vehicle seat and fitted during the driving operation of a vehicle, wherein the belt tensioner is controlled to exert a time-limited belt tension depending on determined weather conditions prevailing on a road section immediately in front of the vehicle.

[0010] DE 10 2020 006 623 A1 also relates to a method for the dynamic restraint of an occupant strapped to a vehicle seat with a safety belt, wherein the lateral acceleration of the vehicle and the road ahead are determined, and the safety belt is tightened with a predetermined belt force for a predetermined time period before entering a curve with a predetermined curvature, wherein various turning angles of junctions and turns are each assigned a comfort speed at which the junction or turn can be driven through comfortably, wherein in the event of the vehicle approaching a junction or turn at an instantaneous driving speed that exceeds the comfort speed assigned to the turning angle by a predetermined value,The seat belt is tightened with a predetermined belt force before reaching the junction or turn.

[0011] The object of the invention is to improve the operation of a reversible belt tensioner in the vehicle, particularly with regard to a child seat that may be installed in the vehicle.

[0012] The invention is defined by the features of the independent claims. Advantageous further developments and embodiments are the subject of the dependent claims.

[0013] A first aspect of the invention relates to a method for operating a reversible belt tensioner of a safety belt arranged on a vehicle seat during the driving operation of a vehicle, characterized in that the belt tensioner is controlled, depending on a determined driving situation and on information determined about an occupant occupying the vehicle seat and / or about the vehicle seat with the safety belt, to exert a time-limited belt tension.

[0014] A preferred application of this method is the suppression of reversible seatbelt pretensioning when a child seat is detected. The seatbelt pretensioning is controlled based on two categories of information. First, the current driving situation is determined. This can take into account the road layout or a sign indicating an impending accident or at least a higher probability of one. Second, information about an occupant and / or the vehicle seat itself is used. Accordingly, in addition to the traffic situation, further information relating to the vehicle seat and / or an occupant is also used to adjust the seatbelt pretensioning accordingly.

[0015] Information about the occupant can be obtained using a classic classification system that determines whether a person is occupying the vehicle seat. This can be done, among other things, using capacitive, weighing, optical, or other sensors in the vehicle interior. Further occupant parameters, such as age and / or weight, can then be estimated and used to decide whether to activate the reversible seatbelt pretensioner.

[0016] This approach is particularly advantageous when detecting and considering a child seat as "seat occupancy" and leads to increased safety. When a child seat is detected, further information about it is recorded, specifically the type of child seat (e.g., whether it's a bucket seat, child seat, or booster) and / or its orientation (e.g., forward- or rear-facing). The information that a child seat is used, especially in the front passenger seat, and at least one other characteristic of the child seat, is then used to control the reversible seatbelt pretensioner. Locking the pretensioner can be helpful or even counterproductive, depending on the type and size of the child seat. Appropriate control logic determines whether the reversible pretensioner is activated to apply temporary belt tension or not.Preferably, the seatbelt tightening is only performed when it is detected that a person is occupying the vehicle seat.

[0017] The condition of the seatbelt system itself can also be used to automatically decide whether a temporary belt tensioning action is required. This allows the system to determine whether the vehicle seatbelt is being used solely to secure the child seat or whether it is also currently being used to secure the child in the child seat.

[0018] In addition, a currently recorded seating position in the vehicle can be used to automatically decide whether a time-limited belt tightening action is performed, and / or a belt routing is determined.

[0019] Sensory detection of a current or upcoming driving situation allows for an additional dimension to be incorporated into the control of the reversible seatbelt pretensioner. For example, during hard braking, the child seat can be held in its original position by a time-limited belt tension, while during skidding, the time-limited belt tension is preferably not applied by the pretensioner.

[0020] By combining both pieces of information – information about the driving situation on the one hand and information about seat occupancy and / or the seat occupant on the other – a reversible seatbelt tensioning can be achieved that is appropriate for the respective occupant and the exact situation. This method can be applied to all seats in the vehicle equipped with a reversible seatbelt tensioner.

[0021] The seatbelt tensioner has a corresponding actuator to increase tension in the seatbelt webbing, at least temporarily, thereby minimizing geometric play between the occupant's body and the belt, and thus preventing the occupant from moving relative to the vehicle for a certain period of time during a collision or other strong acceleration (including emergency braking) and then being very suddenly brought to the current state of motion of the vehicle, which would result in a very high kinematic acceleration relative to the Earth for the occupant.

[0022] According to an advantageous embodiment, the information is determined by an occupant classification system, which ascertains whether the vehicle seat is occupied by a person. This system can also differentiate between whether the person is an adult, a young person, or a child, particularly a child in a child seat. The seatbelt tensioner is then activated by the control unit based on this information.

[0023] According to another advantageous embodiment, the occupant classification is carried out at a passenger seat.

[0024] According to a further advantageous embodiment, the occupant classification is carried out by detecting a pressure applied to the vehicle seat.

[0025] For this purpose, the pressure applied to the vehicle seat is measured, specifically with a suitably calibrated pressure sensor. Starting from the initial value recorded during calibration, an additional pressure is measured. If a certain threshold of this additional pressure is exceeded, the occupancy of the seat is detected. A pressure-sensitive or a pressure-resistant sensor can be used.

[0026] Additionally or alternatively, an interior camera can determine whether a vehicle seat is occupied. Unlike a pressure sensor, image recognition technology can distinguish from the camera images whether the mass on the vehicle seat is cargo or a human occupant. Image recognition using the interior camera can also differentiate whether a child seat is installed on the vehicle seat and, if so, its orientation.

[0027] According to a further advantageous embodiment, the information obtained about the occupant occupying the vehicle seat includes the occupant's position on the vehicle seat.

[0028] According to a further advantageous embodiment, the information obtained about the vehicle seat includes a vehicle seat position in the vehicle.

[0029] According to a further advantageous embodiment, the information obtained about the vehicle seat includes a belt routing.

[0030] According to a further advantageous embodiment, the application of the belt tensioning is suppressed by the reversible belt tensioner when a child seat is detected on the vehicle seat.

[0031] According to a further advantageous embodiment, the information includes the presence of a child seat and a characteristic of the child seat, wherein the application of the belt tensioning by the reversible belt tensioner is suppressed or adjusted when a child seat and / or a specific characteristic of the child seat is detected. A characteristic of the child seat includes, in particular, the type of child seat, i.e., whether it is a shell, a child seat, or a booster, and especially its orientation (whether it is forward-facing or rear-facing).

[0032] Another aspect of the invention relates to a system for a vehicle, comprising a reversible belt tensioner designed to exert a temporary belt tension of a safety belt arranged on a vehicle seat, and comprising a control unit, characterized in that the control unit is designed to control the belt tensioner, depending on a determined driving situation and on information about an occupant occupying the vehicle seat and / or about the vehicle seat with the safety belt, to exert a temporary belt tension.

[0033] Advantages and preferred further developments of the proposed system result from an analogous and substantive transfer of the above statements made in connection with the proposed procedure.

[0034] Further advantages, features and details will become apparent from the following description, in which - possibly with reference to the drawing - at least one embodiment is described in detail.

[0035] They show: Fig. 1: Schematic representation of a method for operating a reversible seatbelt tensioner according to an embodiment of the invention. Fig. 2: A vehicle seat with a belt tensioner according to an embodiment of the invention.

[0036] The representations in the figures are schematic and not to scale.

[0037] Fig. Figure 1 shows a method for operating a reversible belt tensioner 2 of a seat belt arranged on a vehicle seat 1 during vehicle operation. First, a driving situation is determined S1, and information about an occupant of the vehicle seat 1 and / or about the vehicle seat 1 with the seat belt is determined S2. Depending on the information determined in steps S1 and S2, the belt tensioner 2 is controlled to apply a time-limited belt tension S3. For example, belt tensioning is triggered during a vehicle skidding situation with a rear-facing child seat installed in the front passenger seat. During skidding, lateral acceleration acts on the child seat. If belt tensioning is applied, the reversible belt tensioner tightens until the required belt force is reached. As a result, the child seat does not remain in its originally installed position.During emergency braking, the child seat experiences longitudinal acceleration relative to the vehicle. The belt tensioner counteracts this movement, decelerating the child seat along with the vehicle. This keeps the child seat in its originally installed position.

[0038] Fig. Figure 2 shows a vehicle seat 1 with a reversible belt tensioner 2, which is designed to exert a temporary belt tension on a seat belt arranged on the vehicle seat 1. The belt tensioner 2 of the vehicle seat 1 is controlled by a control unit, which decides when the reversible belt tensioner 2 should execute the temporary belt tension in order to temporarily increase the tension in the webbing of the seat belt of the vehicle seat 1. For this purpose, the control unit checks, as described in the procedure of Fig.The control unit describes the current driving situation of the vehicle in order to increase the tension in the seat belt in certain driving situations. For example, before a sharp curve at high speed, at an accident hotspot according to a digital map, or when initiating hard braking. The control unit also checks information about whether vehicle seat 1 is occupied by an occupant. It can classify whether a sensor unit detects a person in vehicle seat 1 or a child seat. And if a child seat is detected, its orientation on vehicle seat 1 is determined.

[0039] Although the invention has been further illustrated and explained in detail by means of preferred embodiments, the invention is not limited by the disclosed examples, and other variations can be derived from them by a person skilled in the art without departing from the scope of protection of the invention. It is therefore clear that a multitude of possible variations exist. It is also clear that the embodiments mentioned as examples are truly only examples and are not to be understood in any way as limiting, for example, the scope of protection, the possible applications, or the configuration of the invention.Rather, the preceding description and the description of the figures enable the person skilled in the art to implement the exemplary embodiments in concrete terms, whereby the person skilled in the art, with knowledge of the disclosed inventive concept, can make various changes, for example with regard to the function or the arrangement of individual elements mentioned in an exemplary embodiment, without leaving the scope of protection defined by the claims and their legal equivalents, such as further explanations in the description. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2020 006 623 A1 [0003, 0010] DE 10005010 A1

[0004] DE 10 2004 020 049 A1

[0005] DE 10 2012 025 269 A1

[0006] DE 10 2018 002 559 A1

[0007] DE 10 2019 002 308 A1

[0008] DE 10 2021 002 042 A1

[0009]

Claims

[1] Method for operating a reversible belt tensioner (2) of a safety belt arranged on a vehicle seat (1) during the driving operation of a vehicle, characterized by , that the belt tensioner (2) is controlled depending on a determined (S1) driving situation and on a determined (S2) information about an occupant occupying the vehicle seat (1) and / or about the vehicle seat (1) with the safety belt to exert a temporary belt tension (S3). [2] Method according to claim 1, wherein the information is determined by an occupant classification which determines whether the vehicle seat (1) is occupied by a person. [3] Method according to claim 2, wherein the occupant classification is carried out at a passenger seat. [4] Method according to one of claims 2 to 3, wherein the occupant classification is carried out by detecting a pressure applied to the vehicle seat (1). [5] Method according to any of the preceding claims, wherein the information obtained about the occupant occupying the vehicle seat (1) includes a position of the occupant on the vehicle seat (1). [6] Method according to any of the preceding claims, wherein the information obtained about the vehicle seat (1) includes a vehicle seat position in the vehicle. [7] Method according to one of the preceding claims, wherein the information obtained about the vehicle seat (1) includes a belt path. [8] Method according to one of the preceding claims, wherein the application of the belt tensioning is suppressed by the reversible belt tensioner (2) when a child seat is detected on the vehicle seat (1). [9] Method according to any of the preceding claims, wherein the information includes the presence of a child seat and a property of the child seat, wherein the application of the belt tensioning by the reversible belt tensioner (2) is suppressed or adapted when a child seat and / or a certain property of the child seat is detected. [10] System for a vehicle, comprising a reversible belt tensioner (2) designed to exert a time-limited belt tension of a safety belt arranged on a vehicle seat (1), and comprising a control unit, characterized by , that the control unit is designed to actuate the belt tensioner (2) depending on a determined driving situation and on information determined about an occupant occupying the vehicle seat (1) and / or about the vehicle seat (1) with the safety belt to exert a temporary belt tension.

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