Restraint system for an occupant protection system of a vehicle

Abstract

Restraint system (3) for an occupant protection system of a vehicle (1), comprising an accident sensor (20) which detects at least one accident-relevant physical quantity, a vehicle seat (5), a belt system (30) which includes at least one belt (34) and an associated belt tensioner (36), and a first evaluation and control unit (32) which activates the belt tensioner (36) when the evaluation of the at least one physical quantity detected by the accident sensor (20) indicates an accident, wherein the belt tensioner (36) generates a tensile force in the associated belt (34) which presses a corresponding occupant into the vehicle seat (5), wherein the first evaluation and control unit (32) after the accident, depending on the current position of the vehicle (1), controls the belt tensioner (36) and releases the belt (34) in a controlled manner when the vehicle (1) is in a stable position.and wherein a second evaluation and control unit (10) evaluates the at least one physical quantity detected by the accident sensor (20) for accident detection and / or for determining the current position of the vehicle (1), characterized in that the second evaluation and control unit (10) reports the end of the accident and the stable position of the vehicle (1) to the first evaluation and control unit (32).

Description

[0001] The invention relates to a restraint system for an occupant protection system of a vehicle according to the preamble of independent claim 1. Furthermore, the invention relates to an operating method for such a restraint system of an occupant protection system of a vehicle.

[0002] Occupant protection systems that utilize predictive or environmental sensors are known from the prior art. For functions of driver assistance systems and / or occupant protection systems, such as AEB (Automatic Emergency Braking), sensors like radar, ultrasonic, or video sensors are used to detect the vehicle's surroundings. The aim is to acquire environmental information, such as critical objects on a collision course, that is relevant to the respective function. Furthermore, vehicles with pyrotechnic seatbelt pretensioners are known from the prior art. These pretensioners are activated upon detection of an accident and generate a tensile force in the corresponding seatbelt, which holds or presses the corresponding occupant in the vehicle seat. This is intended to prevent the occupant from suffering serious injuries and to ensure they are in the correct position for airbag deployment.

[0003] Furthermore, it is known that after an accident, additional functions are activated to limit the consequences. These functions include, for example, making an emergency call, unlocking the doors, or shutting off the fuel supply to minimize the risk of fire.

[0004] From DE 103 45 726 B4, for example, a restraint system for restraining an occupant in a motor vehicle is known, comprising a seat belt which is acted upon by a belt tensioner connectable to a control unit, at least one vehicle situation detection device for dynamically detecting vehicle situations, wherein the vehicle situation detection device is connectable to the control unit for sending the detected data, and at least one occupant parameter detection device for dynamically detecting occupant parameter data, wherein the occupant parameter detection device is connectable to the control unit for sending the detected data.During an accident phase, the control unit calculates the survival space between the occupant and any object the occupant may hit from the data recorded by the vehicle situation detection device and / or the occupant parameter detection device, and dynamically controls the force of the seatbelt tensioner accordingly for optimal utilization of the survival space in the vehicle.

[0005] From DE 10 2008 004 307 A1, a method for detecting the position of a vehicle is known. In this method, the data from at least one yaw rate sensor and one acceleration sensor are evaluated to detect whether the vehicle is upside down, and upon detection of an upside-down position, the vehicle is automatically unlocked.

[0006] German patent application DE 103 32 024 A1 discloses a method for controlling a reversible seat belt tensioner. In this method, after the end of a hazardous situation, the seat belt tensioner is transferred from a locked state to a comfortable state in which the tensioner is released.

[0007] Further controls for reversible belt tensioners are known from documents DE 10 2006 014 295 A1, DE 10 2006 051 786 B3, DE 10 2005 038 226 A1 and DE 10 2004 038 167 A1. Disclosure of the invention

[0008] The restraint system for an occupant protection system of a vehicle with the features of independent claim 1 and the operating method for a restraint system of an occupant protection system of a vehicle with the features of claim 8 have the advantage that, after a detected accident, a belt webbing of a belt system is released in a controlled manner. This advantageously prevents serious injuries that the occupants could sustain if, after an accident resulting in the vehicle rolling over or rolling onto its side, the tensioned belt webbing were released abruptly and uncontrollably.

[0009] In certain types of accidents, such as a rollover, there is a high risk of injury even after the accident if the occupant, for example, abruptly releases the seatbelt. If the vehicle is upside down, this can lead to head or cervical spine injuries. After an accident that has resulted in the vehicle being upside down or on its side, the occupant will initially be secured to the seatbelt. In this upside-down or onside position, carelessly releasing the seatbelt can cause the occupant to strike the roof or side panels of the vehicle from a height of several centimeters, impacting their head. This poses a risk of head or cervical spine injuries.Embodiments of the present invention are advantageously able to detect a stable sideways or roof position of the vehicle after an accident and to release the seatbelt in a controlled manner, so that the occupant can be slowly laid on their side or on their shoulder. This advantageously reduces the risk of injury and facilitates the rescue of the occupant, since the seatbelt can be removed without risk or simply cut by the rescue teams. Thus, embodiments of the present invention provide an autonomous means of minimizing the risk of injury to the occupants after an accident.

[0010] Embodiments of the present invention provide a restraint system for an occupant protection system of a vehicle, comprising an accident sensor which detects at least one accident-relevant physical quantity, a vehicle seat, a belt system comprising at least one webbing and an associated belt tensioner, and a first evaluation and control unit which activates the belt tensioner when the evaluation of the at least one physical quantity detected by the accident sensor indicates an accident. The belt tensioner generates a tensile force in the associated webbing, which presses a corresponding occupant into the vehicle seat. Following the accident, the first evaluation and control unit activates the belt tensioner depending on the current position of the vehicle and releases the webbing in a controlled manner when the vehicle is in a stable position.

[0011] Furthermore, an operating procedure is proposed for such a restraint system of an occupant protection system of a vehicle, which detects and evaluates at least one accident-relevant physical quantity, whereby a tensile force is generated in the belt which presses a corresponding occupant into a vehicle seat if the evaluation of the at least one physical quantity indicates an accident. After the accident, depending on the current position of the vehicle, the belt (34) is released in a controlled manner if the vehicle is in a stable position.

[0012] In this context, the term "evaluation and control unit" can be understood as an electrical device, such as a control unit, particularly an airbag control unit, which processes or evaluates acquired sensor signals. The evaluation and control unit can have at least one interface, which may be implemented in hardware and / or software. In the case of a hardware implementation, the interfaces may, for example, be part of a so-called system ASIC, which incorporates various functions of the evaluation and control unit. However, it is also possible that the interfaces are separate integrated circuits or consist at least partially of discrete components. In the case of a software implementation, the interfaces may be software modules that are present, for example, on a microcontroller alongside other software modules.A computer program product with program code stored on a machine-readable medium such as semiconductor memory, hard disk memory or optical memory, and used to perform the evaluation when the program is executed by the evaluation and control unit, is also advantageous.

[0013] In this context, accident sensor technology is understood to be a component unit comprising at least one sensor element which directly or indirectly detects an accident-relevant physical quantity or a change in an accident-relevant physical quantity and preferably converts it into an electrical sensor signal.

[0014] Possible sensor elements include optical elements, such as a photographic plate and / or a fluorescent surface and / or a semiconductor, which detect the incidence or intensity, wavelength, frequency, angle, etc., of the received wave, such as infrared sensor elements. Acoustic sensor elements are also conceivable, such as ultrasonic sensor elements, radio frequency sensor elements, radar sensor elements, and / or sensor elements that react to a magnetic field, such as Hall effect sensor elements, magnetoresistive sensor elements, and / or inductive sensor elements that register changes in a magnetic field, for example, via the voltage generated by magnetic induction.

[0015] The acquired sensor signals are evaluated by the accident sensors or a downstream evaluation and control unit and converted into sensor data. This data comprises a desired physical quantity, derived from at least one physical quantity detected by the respective sensor element, along with its corresponding unit. For example, a sensor element might determine the change in path over a specific time period, and the evaluation and control unit might then calculate a velocity and / or acceleration from this data. Other calculable physical quantities include mass, rotational speed, force, energy, and / or other conceivable quantities, such as the probability of a specific event occurring.

[0016] The measures and further developments listed in the dependent claims enable advantageous improvements to the restraint system specified in independent claim 1 for an occupant protection system of a vehicle.

[0017] A particular advantage is that a second evaluation and control unit can evaluate the at least one physical parameter detected by the accident sensors for accident detection and / or to determine the vehicle's current position. For example, the second evaluation and control unit can report the end of the accident and the vehicle's stable position to the first evaluation and control unit. The vehicle's stable position could refer to, for example, a roof position, a side position, or an upright position. One possible embodiment of the invention is distributed across two evaluation and control units. For example, the second evaluation and control unit could be designed as an airbag control unit, which detects after the accident that a stable roof or side position has been achieved.This information can then be transmitted via a communication link, which can be implemented, for example, as a communication bus and / or a direct cable connection, to the first evaluation and control unit, which can be designed as a seatbelt system control unit and controls and operates the seatbelt system. Alternatively, the functionalities of the two evaluation and control units can be integrated into a single control unit.

[0018] In an advantageous embodiment of the restraint system, the first evaluation and control unit can monitor the activation of the seatbelt pretensioner and / or determine the current tensile force acting on the webbing. This tensile force can be measured, for example, by a force sensor integrated into the pretensioner or retractor. Furthermore, the first evaluation and control unit can continuously reduce the tensile force acting on the webbing via the pretensioner until it reaches a point where the occupant's weight no longer generates a significant tensile force.

[0019] In a further advantageous embodiment of the restraint system, the crash sensor system can comprise a sensor unit with at least one acceleration sensor, which the second evaluation and control unit uses to determine the current vehicle position. For example, a first acceleration sensor can detect acceleration in the vertical direction. At least a second acceleration sensor can detect acceleration in the lateral direction. For example, a second acceleration sensor can detect acceleration in the transverse direction of the vehicle, and a third acceleration sensor can detect acceleration in the longitudinal direction of the vehicle. Furthermore, the second evaluation and control unit can detect a stable vehicle position if the values ​​of the at least one acceleration sensor remain constant over a predetermined period. The first acceleration sensor enables the detection of the vehicle's roof position.The second accelerometer, positioned laterally in the vehicle, is advantageous for detecting the vehicle's rollover. In a rollover, the first accelerometer displays a characteristic value of approximately 0g, while the second accelerometer displays a value of approximately + / -1g. A stable rollover is indicated when the acceleration values ​​remain constant for a certain period of time. A stable rollover can be recognized by the fact that the first accelerometer displays a characteristic value of approximately + / -1g for an extended period, depending on its orientation, while the second accelerometer displays only a small acceleration value of approximately 0g.

[0020] Exemplary embodiments of the invention are shown in the drawing and are explained in more detail in the following description. In the drawing, identical reference numerals denote components or elements that perform the same or analogous functions. Brief description of the drawings Fig. Figure 1 shows a schematic block diagram of an embodiment of a restraint system according to the invention for an occupant protection system of a vehicle. Fig. Figure 2 shows a schematic representation of various stable positions of a vehicle with the restraint system. Fig. 1 and the corresponding acceleration values. Fig. Figure 3 shows a schematic flowchart of an embodiment of an operating method according to the invention for the restraint system made of Fig. 1. Embodiments of the invention

[0021] As from Fig. As can be seen in Figure 1, the illustrated embodiment of a restraint system 3 according to the invention for an occupant protection system of a vehicle 1 comprises an accident sensor 20, which detects at least one accident-relevant physical quantity, a vehicle seat 5, a belt system 30, which includes at least one belt 34 and an associated belt tensioner 36, and a first evaluation and control unit 32, which activates the belt tensioner 36 when the evaluation of the at least one physical quantity detected by the accident sensor 20 indicates an accident. The belt tensioner 36 generates a tensile force in the associated belt 34, which presses a corresponding occupant into the vehicle seat 5. After the accident, the first evaluation and control unit 32, depending on the current position of the vehicle 1, activates the belt tensioner 36 and releases the belt 34 in a controlled manner when the vehicle 1 is in a stable position.

[0022] In the illustrated embodiment, a second evaluation and control unit 10 evaluates the at least one physical quantity detected by the accident sensor system 20 for accident detection and to determine the current position of the vehicle 1. Depending on the type of detected accident, the second evaluation and control unit 10 activates an airbag system 40, which includes at least one airbag (not shown) and corresponding ignition circuits. The second evaluation and control unit 10 reports the end of the accident and the stable position of the vehicle 1 to the first evaluation and control unit 32 via a communication link (not specified). In the illustrated embodiment, the accident sensor system 20 comprises a sensor unit 22 with two acceleration sensors az, ay, which the second evaluation and control unit 10 uses to determine the current position of the vehicle.Here, a first acceleration sensor az is oriented to detect acceleration in the vertical direction, i.e., in the vehicle's vertical direction z. A second acceleration sensor ay is oriented to detect acceleration in the lateral direction, i.e., in the vehicle's transverse direction y. This allows for a measurement of the acceleration in the vehicle's vertical direction. Fig. 2 a) roof position shown, one in Fig. 2 b) and d) side position shown or a position shown in Fig. 2 c) The depicted normal position can be distinguished as the stable position of the vehicle 1. In addition, the accident sensor system 20 can include a third acceleration sensor, which is oriented so that it detects the acceleration in the longitudinal direction x of the vehicle.

[0023] As from Fig. 2 a) As can be seen further, the first acceleration sensor az in the illustrated embodiment shows a value of approximately -1g in the roof position, while the second acceleration sensor ay shows a value of approximately 0g. As can be seen from Fig. 2 b) As can be further seen, in the illustrated embodiment, the second acceleration sensor ay indicates a value of approximately -1g in a first lateral position, in which the vehicle 1 lies on its left side when viewed in the direction of travel, while the first acceleration sensor az indicates a value of approximately 0g. As can be seen from Fig. 2 c) As can be seen further, the first accelerometer az in the illustrated embodiment displays a value of approximately 1g in the normal position, while the second accelerometer ay displays a value of approximately 0g. As can be seen from Fig. 2 d) As can be further seen, in the illustrated embodiment, the second acceleration sensor ay indicates a value of approximately 1g in a second lateral position, in which the vehicle 1 is lying on its right side when viewed in the direction of travel, while the first acceleration sensor az indicates a value of approximately 0g. A stable position of the vehicle 1 exists when the detected and output values ​​of the acceleration sensors az and ay remain constant above at least a predetermined threshold for a specified period of time.

[0024] Before transmitting the detected stable position of the vehicle 1 to the first evaluation and control unit 32, the second evaluation and control unit 10 checks whether the algorithms implemented in the vehicle 1 for accident detection or for activating the airbag system 40 are still active or have been terminated. This additional query of the status of the other algorithms for accident detection and activation of the airbag system 40 advantageously prevents the seat belts 34 of the occupied vehicle seats 5 from being loosened even though a subsequent accident is being detected. The termination of the other algorithms for accident detection and activation of the airbag system 40 and the detected stable position of the vehicle 1 together indicate the end of the accident event. The first control unit 32 receives this information and checks whether a pyrotechnic and / or electromagnetic activation of the seat belt tensioners 36 of the individual vehicle seats 5 has taken place.This advantageously allows only the seat belt straps 34 of occupied vehicle seats 5 to be checked. Alternatively, this check can be omitted if the vehicle 1's accident sensors 20 are unable to distinguish all known types of accidents. An example would be the lack of rollover detection for occupant protection. In this case, the vehicle 1 can be lying on its roof without the seat belt tensioners 36 being activated. In such cases, the detection of a stable roof or side position serves as rollover detection without activating the restraint system 3. Instead of checking for activation of the seat belt tensioners 36, it is sufficient to check whether a tensile force is acting on the seat belt strap 34. In the illustrated embodiment, this check is performed by evaluating a tensile force sensor 38. To enable controlled release of the seat belt strap 34, it is first checked whether a tensile force is acting on the seat belt strap 34.This tensile force is continuously and controllably reduced by a mechanism of the belt tensioner 36 or a belt retractor (not shown) until a state is reached in which the occupant's weight exerts no significant tensile force on the belt 34. This releases the occupant from their fixed position on the vehicle seat 5 and slowly brings them into a stable position. Controlled belt release can be advantageously used in all accidents that have resulted in the vehicle being on its side or roof. A flowchart is shown in [reference]. Fig. depicted.

[0025] As from Fig. As can be seen further in Figure 1, the second evaluation and control unit 20, in order to limit the consequences of the accident after the accident has ended, controls further functions in the illustrated embodiment. For example, a first function 12 makes an emergency call, a second function unlocks the doors, and a third function 16 shuts off the fuel supply to minimize the risk of fire.

[0026] As from Fig.As can be seen in Figure 3, the illustrated embodiment of an operating method according to the invention for a restraint system 3 of an occupant protection system of a vehicle 1 detects and evaluates at least one accident-relevant physical quantity in step S100. In step S200, a tensile force is generated in the webbing 34, which presses a corresponding occupant into a vehicle seat 5 if the evaluation of the at least one physical quantity indicates an accident. In step 300, after the accident, it is checked whether the vehicle has a stable position 1. Depending on whether a stable position of the vehicle 1 has been detected, the webbing 34 is released in a controlled manner in step S400. This method can be implemented, for example, in software or hardware, or in a hybrid form of software and hardware, for example, in a control unit that has the functionalities of the first and second evaluation and control units 10, 32.

[0027] Embodiments of the present invention provide a restraint system for an occupant protection system of a vehicle and an associated operating method which advantageously release a webbing strap of a seat belt system in a controlled manner after a detected accident. This advantageously prevents serious injuries that the occupants could sustain if, after an accident resulting in the vehicle rolling over or becoming on its side, the tensioned webbing strap is released abruptly and uncontrollably.

Claims

[1] Restraint system (3) for an occupant protection system of a vehicle (1), comprising an accident sensor system (20) which detects at least one accident-relevant physical variable, a vehicle seat (5), a belt system (30) which comprises at least one belt strap (34) and an associated belt tensioner (36), and a first evaluation and control unit (32) which activates the belt tensioner (36) when the evaluation of the at least one physical variable detected by the accident sensor system (20) indicates an accident, wherein the belt tensioner (36) generates a tensile force in the associated belt strap (34) which presses a corresponding occupant into the vehicle seat (5), wherein the first evaluation and control unit (32) controls the belt tensioner (36) after the accident depending on a current position of the vehicle (1) and releases the belt strap (34) in a controlled manner when a stable position of the vehicle (1) is present,and wherein a second evaluation and control unit (10) evaluates the at least one physical variable detected by the accident sensor system (20) for accident detection and / or for determining the current position of the vehicle (1), , characterized by that the second evaluation and control unit (10) reports the end of the accident and the stable position of the vehicle (1) to the first evaluation and control unit (32). [2] Restraint system according to claim 1, characterized by that the stable position of the vehicle (1) relates to a roof position, a side position or a normal position of the vehicle (1) or stable positions in between. [3] Restraint system according to claim 1 or 2, characterized by that the first evaluation and control unit (32) checks the triggering of the belt tensioner (36) and / or determines a current tensile force acting in the belt webbing (34). [4] Restraint system according to claim 3, characterized bythat the first evaluation and control unit (32) continuously reduces the tensile force acting in the belt strap (34) via the belt tensioner (36) to a state in which a weight of the occupant does not generate any appreciable tensile force in the belt strap (34). [5] Restraint system according to one of claims 1 to 4, characterized by that the accident sensor system (20) comprises a sensor unit (22) with at least one acceleration sensor (az, ay), which the second evaluation and control unit (10) evaluates to determine the current vehicle position. [6] Restraint system according to claim 5, characterized by that a first acceleration sensor (az) detects an acceleration in the vertical direction (z) and / or at least a second acceleration sensor (ay) detects an acceleration in the lateral direction (y). [7] Restraint system according to claim 5 or 6, characterized bythat the second evaluation and control unit (10) detects a stable position of the vehicle (1) when the values ​​of the at least one acceleration sensor (az, ay) are constantly above at least one predetermined threshold value over a predetermined period of time. [8] Operating method for a restraint system (3) of an occupant protection system of a vehicle (1), which detects and evaluates at least one accident-relevant physical variable, wherein a tensile force is generated in the belt strap (34) which presses a corresponding occupant into a vehicle seat (5) if the evaluation of the at least one physical variable indicates an accident, characterized by that after the accident, depending on the current position of the vehicle (1), the belt strap (34) is relaxed in a controlled manner if the vehicle (1) is in a stable position.

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