Method for operating a vehicle occupant restraint device

Abstract

The present invention relates to a method for operating an occupant restraint system for protecting an occupant (2) in a vehicle seat (3) in an automatically driven vehicle (1), the occupant restraint system having restraining elements (R1-Rn) consisting of at least one airbag and a seat belt (4) with at least one seat belt tensioner, the control device of the occupant restraint system distinguishing between an upright position and a reclined position of at least a seat backrest (3.1) of the vehicle seat (3). According to the invention, the seat belt state of the occupant (2) in the front row of the vehicle (1) is detected at least in the longitudinal direction of the vehicle in order to activate the automatic driving mode of the vehicle (1). When the seat belt state is detected as the insertion of the seat belt buckle tongue into the seat belt buckle assigned to the vehicle seat (3), the automatic driving mode of the vehicle (1) is activated and the restraint elements (R1 to Rn) of the occupant restraint device are controlled and activated or operated in synchronization with each other depending on the setting state of the vehicle seat (3) and depending on the situational crash state from the time when an imminent crash of the vehicle (1) is detected.

Description

[Technical Field]

[0001] The present invention relates to a method for operating an occupant restraint system for protecting an occupant on a vehicle seat in an automatically driving vehicle, the occupant restraint system having as restraining elements at least one airbag and a seat belt with at least one seat belt tensioner, wherein a control device of the occupant restraint system distinguishes between at least an upright position and a reclined position of a seat backrest of the vehicle seat. [Background technology]

[0002] German Patent Application No. DE 10 2017 116 905 A1 discloses a vehicle occupant restraint system and a method for operating the same. The vehicle occupant restraint system for protecting a vehicle occupant in a vehicle seat comprises a plurality of restraining elements and a control device, wherein a first restraining element includes an airbag module with an airbag, and a second restraining element includes a seat belt with a seat belt retractor, the seat belt being operatively connected to a tightening device. The control device has at least one sensor element for determining the position of the vehicle seat, whereby the control device distinguishes between a first situation in which the vehicle seat with the vehicle occupant is in a position within a standard position range relative to the airbag of the first restraining element and a second situation in which the vehicle seat with the vehicle occupant is in a position outside the standard position. When the first situation occurs, the control device activates only the first and second restraint elements, whereas when the second situation occurs, a third restraint element integrated in the vehicle seat and / or operably connected to the vehicle seat can be activated and / or connected by the control device, whereby the vehicle seat is first moved to a position within the standard position area via the third restraint element. Summary of the Invention [Problem to be solved by the invention]

[0003] SUMMARY OF THE INVENTION It is an object of the present invention to provide a novel method for actuating a vehicle occupant restraint system. [Means for solving the problem]

[0004] This object is achieved according to the invention by a method having the features of claim 1.

[0005] Advantageous embodiments of the invention are the subject of the dependent claims.

[0006] The present invention relates to a method for activating an occupant restraint system for protecting an occupant in a vehicle seat, particularly an integrated seat belt seat, in an automatically driven vehicle, the occupant restraint system having at least one airbag and a seat belt with at least one seat belt tensioner as restraining elements, and a control device for the occupant restraint system for distinguishing at least between an upright position and a reclined position of the seat backrest of the vehicle seat. According to the present invention, in order to activate an automatic driving mode of the vehicle, the seat belt status of at least the front row occupants of the vehicle in the longitudinal direction of the vehicle is detected. When the seat belt status is detected as the insertion of the seat belt buckle tongue into the seat belt buckle assigned to the vehicle seat, the automatic driving mode of the vehicle is activated, and the restraint elements of the occupant restraint system are synchronized and activated or actuated depending on the setting state of the vehicle seat and on the situational crash conditions after the detection of an imminent collision of the vehicle, particularly a frontal collision.

[0007] The method is based on proven conventional restraint elements typically installed in vehicles and significantly reduces the risk of injury to an occupant in a reclined vehicle seat during a vehicle collision.

[0008] In this case, the method can relatively reliably meet almost all legal requirements and so-called rating requirements.

[0009] Vehicle seats with a reclined position do not require any additional adaptations to the occupant restraint system to use this method, so the occupant restraint system can be used with both an upright position of the seat backrest and a reclined position of the seat backrest and occupant.

[0010] The seat structure of the vehicle seat and its connection to the vehicle floor assembly basically only need to satisfy the strength requirements of a seat with an integrated seat belt, so no additional effort is required to carry out this method.

[0011] Simulation and prototype testing to determine feasibility are both relatively easy to carry out.

[0012] In one embodiment of the method, the reclined position of the vehicle seat is detected, and when an imminent vehicle collision is detected, the seat belt tensioners (retractors) of the seat belt are controlled to electrically tighten the seat belt in the shoulder belt region, and after the collision occurs, the lap tensioner and the seat-integrated retractor (retractor) are additionally controlled and pyrotechnically activated. By controlling all existing seat belt tensioners of the seat belt to tighten the seat belt, the occupant is optimally restrained in the vehicle seat, thereby reducing the load on the occupant during a collision and the resulting deceleration of the vehicle. The occupant contributes to the acceleration of the vehicle due to the collision.

[0013] In a further embodiment, when the pyrotechnic belt tightening is activated, the upright positioning of the seat backrest of the vehicle seat is initiated pyrotechnically by unlocking the seat backrest. The aim here is to raise the occupant in a force-controlled manner, driven by the impact energy at the time of the collision. The impact usually causes the seat backrest to raise without any additional force. This method thereby allows the seat backrest to be raised in a controlled manner. This raising of the seat backrest can largely avoid relatively serious damage to the occupant's lumbar spine.

[0014] When a vehicle seat, particularly a seat backrest, is in a reclined position, a relatively large force acts on the occupant's spine during a vehicle collision. This force is absorbed by the seat surface, which supports the occupant's pelvis, particularly by compression. This compression of the spine can be almost completely eliminated by raising the seat backrest.

[0015] In one development, the upright positioning of the seat backrest is braked before the seat backrest reaches its upright end position, thereby reducing the loads acting on the occupant due to the upright positioning and sudden undamped braking of the seat backrest and the associated risk of injury, in particular to the occupant's cervical spine.

[0016] In a further possible embodiment of the method, the motorized belt tensioning of the shoulder belt area and the lap belt area of ​​the seat belt is maintained with a predetermined force level during the upright positioning of the seat backrest until the upright end position is reached, so that the occupant is still restrained in the vehicle seat, but the lap belt area is now tightened with a maximum force level, thereby substantially preventing the occupant from slipping under the lap belt area of ​​the seat belt, also known as submarining.

[0017] In one embodiment, after the seat backrest reaches its upright end position, the vehicle seat is pyrotechnically unlocked and a controlled forward / backward movement in the direction of vehicle travel is performed. After the seat backrest is raised, the occupant assumes an optimal upper body position for a crash, at which point the vehicle seat is unlocked. The occupant is initially decelerated at a specific force level below the belt force limiter and is braked uniformly within the vehicle. Therefore, the deceleration does not occur at extreme values, but has a constant force level.

[0018] The occupant can experience less deceleration by starting to move forward, i.e., in the forward and backward direction of the vehicle seat in the direction of travel, and it is then possible to filter out the acceleration peaks acting on the vehicle, which means that the acceleration peaks do not affect the occupant.

[0019] The start point of the internal deceleration due to the fore-and-aft movement of the vehicle seat can be selected so that an initial moderate vehicle deceleration is first performed without internal deceleration, and the fore-and-aft movement of the vehicle seat is initiated by pyrotechnic unlocking at the same time as the maximum deceleration is applied to the vehicle, which is reached when the vehicle becomes immobilized in the event of a collision.

[0020] In a possible further development, the vehicle seat is damped in the region of its longitudinal end position arranged in the direction of travel. In other words, the vehicle seat is damped at the end of its internal deceleration path. This means that the longitudinal movement of the vehicle seat is not stopped abruptly, so that the loads caused by the abrupt stopping of the longitudinal movement of the vehicle seat do not act on the occupant. This makes it possible to virtually eliminate the risk of further injury to the occupant.

[0021] Furthermore, in one embodiment, when the vehicle seat reaches the region of the longitudinal end position, the force level of the electrically operated seat belt tightening is reduced by a predetermined amount in the shoulder belt region. By setting the shoulder belt force, i.e., the tightening force level of the belt force limiter, to a lower force level, the occupant, particularly the upper body, can move forward, thereby allowing the remaining body energy, particularly acceleration energy, to be dissipated. In other words, the end of the movement takes place within the vehicle seat. In this case, the force level at which the seat belt tightening force is reduced in the shoulder belt region can be set depending on the gravity of the occupant on the vehicle seat.

[0022] In a further embodiment, the driver airbag and / or passenger airbag are deployed in a first stage in response to the detection of seating. In particular, the driver airbag and / or passenger airbag are deployed in a first stage, thereby ensuring additional impact protection for the vehicle seat occupant against the relatively hard contours of the vehicle interior. In this case, the driver airbag and / or passenger airbag are lowered in inflation volume, thereby reducing the hardness of each airbag deployed in the first stage and appropriately reducing the relatively small amount of residual energy still remaining in each occupant. In other words, the lower inflation volume of each airbag reduces the risk of injury to the occupant colliding with the airbag.

[0023] If the occupant is a driver sitting in the driver's seat of a vehicle in manual driving mode, the driver airbag will deploy when the steering wheel is in a retracted position, for example.

[0024] In a further embodiment, in addition to the activation of the driver airbag and / or passenger airbag, a respective knee airbag is activated in the first stage to ensure additional impact protection for the vehicle seat occupant against the relatively hard contours of the vehicle interior, thus further reducing the risk of injury to the occupant.

[0025] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. [Brief explanation of the drawings]

[0026] [Figure 1] 1 is a cross-sectional schematic view of a vehicle with an occupant sitting in an upright position in a vehicle seat. [Figure 2] 1 is a schematic cross-sectional view of a vehicle with an occupant reclining in a vehicle seat; [Figure 3] 1 is a cross-sectional schematic view of a vehicle with an occupant in a reclined position in a vehicle seat when an imminent collision of the vehicle is detected; [Figure 4] 1 is a cross-sectional schematic view of a vehicle with an occupant reclining in a vehicle seat after a collision has occurred. [Figure 5] 1 is a cross-sectional schematic view of a vehicle when the seat backrest of a vehicle occupant's seat is positioned in an upright position. [Figure 6] 1 is a cross-sectional view of a vehicle after the seat backrest of the vehicle occupant's seat has been raised. [Figure 7] 1 is a schematic cross-sectional view of a vehicle when a vehicle seat is moved forward and backward in the traveling direction. FIG. [Figure 8] 1 is a cross-sectional schematic view of a vehicle with an occupant in the vehicle seat and with the driver airbag and knee airbag deployed; DETAILED DESCRIPTION OF THE INVENTION

[0027] In all the drawings, the same reference numerals are used to designate corresponding parts.

[0028] 1 shows a cross-sectional view of a vehicle with an occupant 2 sitting in a vehicle seat 3 with the seat backrest 3.1 in an upright position on the vehicle seat 3. This seating position of the occupant 2 can be referred to as, for example, a driving position.

[0029] FIG. 2 shows a cross-sectional view of a vehicle 1 with an occupant 2 sitting in a vehicle seat 3 in a reclined position (posture).

[0030] 3 to 8 show cross-sectional views of a vehicle 1 with an occupant 2 in a vehicle seat 3 before and during a collision, in particular a frontal collision.

[0031] According to a known occupant restraint device including a commonly known conventional vehicle fixed restraint element R1-Rn, a relatively high level of injury protection can be achieved for an occupant 2 on the vehicle seat 3 when the vehicle seat 3 is in an upright position (posture) and the occupant 2 on the vehicle seat 3 is in an upright seated position.

[0032] When the seating position of the occupant 2 on the vehicle seat 3 is changed, in particular in relation to a reclining position, and the seat backrest 3.1 is tilted accordingly, the functionality and protective effect of the restraint elements R1 to Rn of the occupant restraint device, which are shown in detail in the following figures, are limited.

[0033] In the reclining position, the so-called relaxed position, the restraint elements R1 to Rn do not fulfill or fulfill only insufficiently their protective function for the occupant 2, so that even if the restraint elements R1 to Rn are activated or operated, there is a relatively high risk of injury to the occupant 2.

[0034] The vehicle 1 is equipped with an assistance system for automatic driving, in particular autonomous driving, and the driving task is entirely performed by the vehicle 1, in particular by the assistance system, so that the driver as an occupant 2 of the vehicle 1 has the opportunity to perform other activities, for example by relaxing in a reclined vehicle seat 3.

[0035] The following describes a method for operating an occupant restraint system for a vehicle 1, which optimizes injury protection for an occupant 2 in a reclined position of a vehicle seat 3, thereby substantially ensuring the protective function of the reclined occupant 2. In particular, the method enables relatively safe kinematic retention of the occupants 2, i.e., the driver and front passenger, from a reclined position during a collision of the vehicle 1, particularly a frontal collision.

[0036] The vehicle seat 3 is an integrated seat belt seat, with the components of the seat belt 4 located on or integrated into the vehicle seat 3. The connection of the vehicle seat 3 to the main floor of the vehicle 1 is designed in terms of its strength to the requirements of the load case for the vehicle seat 3.

[0037] The occupant restraint device of the vehicle 1 has, as restraint elements R1 to Rn, a seat belt 4 with an electric retractor R1, a pyrotechnic retractor not shown in detail, an electric lumbar tensioner R2, a two-stage deployable driver's airbag R3, a two-stage deployable passenger airbag not shown in detail, an extendable and / or deformable steering column R4, a seat slide R5 with a pyrotechnic actuable moving mechanism, a seat backrest 3.1 as a so-called kinematic backrest R6 with a pyrotechnic actuable kinematic mechanism, and a knee airbag R7.

[0038] To activate the automatic driving mode, particularly the autonomous driving mode, of the vehicle 1, the occupants 2 in the first seat row, i.e., the driver and possibly the front passenger, must be wearing their seat belts 4, with the seat belt buckle tongues (not shown) inserted into the corresponding seat belt buckles. The seat belt status, i.e., whether each occupant 2 in the first seat row has fastened their seat belt 4, is detected, for example, by a seat belt buckle switch. When such a seat belt status is detected, the autonomous driving mode of the vehicle 1 can be activated.

[0039] Furthermore, the method of operating the occupant restraint system assumes that there are no other occupants in the rear seat area.

[0040] FIG. 3 is a cross-sectional view of a vehicle 1 with an occupant 2 in a reclining position when an impending collision, particularly a frontal collision, is detected for the vehicle 1.

[0041] At this time, before a collision occurs, the retractor R1 is activated and electrically tightens the installed seat belt 4, thereby securing the occupant 2 to the vehicle seat 3, in particular the seat backrest 3.1.

[0042] In particular, activation of the retractor R1 is performed in response to detection signals from surrounding sensors of the vehicle 1, for example based on detection signals from at least one radar-based sensor.

[0043] When a vehicle 1 crashes, the seat-integrated retractor R1 is pyrotechnically activated, activating the electric lumbar tensioner R2, which causes the seat belt 4 to tighten at all three endpoints, as shown in FIG.

[0044] Simultaneously with the electric and pyrotechnic seat belt tensioners, the movement of the seat backrest 3.1, i.e. the kinematic backrest R6, is initiated. In particular, this is initiated by the airbag unit, e.g., by the airbag control device. For this purpose, a locking mechanism, e.g., comprising two locking bolts, is pyrotechnically released, so that the occupant 2 is raised by the kinematic backrest R6, i.e., placed in an upright position.

[0045] In other words, the objective is to use the impact energy from the collision to raise occupant 2 with controlled force.

[0046] In the event of a collision, i.e., an impact, the seat backrest 3.1 rises without any further force. Here, the upright positioning is controlled, in that the upright positioning of the seat backrest 3.1 is damped before the seat backrest 3.1 reaches its upright end position. In particular, damped damping of the seat backrest 3.1 is achieved by at least one end position damper, not shown in detail. Such end position damping reduces the peak load acting on the occupant 2 as the seat backrest 3.1 reaches its upright end position.

[0047] The consumer element for force-controlling the upright positioning of the seat backrest 3.1 can be realized directly on the recliner, i.e. on the vehicle seat 3, by known techniques, for example by cutting, wire drawing, etc.

[0048] By raising the seat backrest 3.1, the risk of injury to the occupant 2, and in particular to his lumbar spine, can be significantly reduced, since in the upright end position of the seat backrest 3.1 compression of the lumbar spine is largely avoided.

[0049] The belt force exerted by the seat belt 4 on the occupant 2 is greater than the force that urges the seat backrest 3.1 into an upright position. The belt force can then be very large due to the switchability of the force level.

[0050] During the upright position of the seat backrest 3.1 shown in Figure 5, the occupant 2 is secured to the seat cushion 3.2 of the vehicle seat 3 forming the seating surface by the maximum force level of the lumbar tensioner R2, as shown in Figure 6, thereby preventing him from slipping under the lumbar belt area of ​​the seat belt 4. The clamping force acting on the shoulder belt area of ​​the seat belt 4 also remains relatively high until the upright end position of the seat backrest 3.1 is reached.

[0051] When the seat backrest 3.1 reaches its upright end position, thereby placing the occupant 2 in the optimal upper body position for a crash, a controlled longitudinal movement of the vehicle seat 3 in the direction of travel of the vehicle 1 is initiated explosively, as shown in Figure 7. For this purpose, for example, the locks of the vehicle seat 3, in particular the lock of the seat slide R5 by means of the bolts to the seat rails, are released explosively. The longitudinal movement of the vehicle seat 3 and the occupant 2 takes place inside the vehicle 1, and is therefore referred to as internal deceleration.

[0052] At this time, the occupant 2 and the vehicle seat 3 are initially decelerated only at a specific force level lower than the force level of the seat belt force limiter and are braked uniformly inside the vehicle 1. At this time, the occupant 2 is decelerated less due to forward movement, so that load peaks acting on the occupant 2 can be largely avoided.

[0053] The start point of the internal deceleration can be selected, whereby an initial, gradual vehicle deceleration is initially performed without internal deceleration. Internal deceleration, i.e., the vehicle seat 3 begins to move forward and backward, when the vehicle 1 reaches its maximum deceleration value. The maximum deceleration value of the vehicle 1 is reached when the vehicle 1 is no longer able to move in a collision, i.e., in an accident event. A uniform deceleration allows for the adjustment of an approximately rectangular characteristic curve.

[0054] At the end of the internal deceleration path of the vehicle seat 3 carrying the occupant 2, i.e., in the region of the longitudinal end position of the vehicle seat 3, the vehicle seat 3 is braked in a damped manner. The clamping force acting on the shoulder belt region of the seat belt 4 is reduced to a predetermined force level, so that the upper body of the occupant 2 on the vehicle seat 3 can move forward, as shown in Figure 8, thereby dissipating residual energy from the collision, in particular kinetic energy.

[0055] For example, the force level can be set according to the weight of the occupant 2, thereby providing a specific forward movement path for the occupant 2 until the occupant 2 completes its movement.

[0056] 8, a driver's airbag R3 and a knee airbag R7 are additionally activated in the first stage. The driver's airbag R3 activated in the first stage retracts the steering column R4 of the vehicle 1, and thus the steering wheel 5, so that a collision and / or impact with a relatively hard contour of the vehicle interior is largely avoided, i.e., additional collision and / or impact protection is ensured, and the head and chest of the occupant 2 can be relatively softly received.

[0057] Alternatively or additionally, if the seating detection detects that the passenger seat of the vehicle 1 is occupied, the passenger airbag is deployed in a first stage.

[0058] The knee airbag R7, which is activated in the first stage, also ensures additional crash protection for the occupant 2 in the vehicle seat 3 against the relatively hard contours of the vehicle interior, and supports the kinematic behavior of the occupant 2, thereby further reducing the risk of injury to the occupant 2.

[0059] In the first stage of deployment of the driver airbag R3 and knee airbag R7, they have a low filling level, which reduces the impact on the occupant 2 in the event of a collision. [Prior art documents] [Patent documents]

[0060] [Patent Document 1] German Patent Application Publication No. 102017116905 [Explanation of symbols]

[0061] 1 vehicle 2 crew members 3 Vehicle seats 3.1 Seat backrest 3.2 Seat cushion 4 Seatbelts 5 Steering wheel R1 Restraint element / retractor R2 Restraint element / lumbar tensioner R3 Restraint element / driver airbag R4 Restraint element / steering column R5 Restraint element / seat slide R6 Restraint Elements / Kinematic Backrest R7 Restraint element / knee airbag

Claims

1. A method of operating an occupant restraint system for protecting an occupant (2) in a vehicle seat (3) in an automatically operating vehicle (1), comprising: The occupant restraint device has at least one airbag and a seat belt (4) equipped with at least one seat belt tensioner as restraint elements (R1 to Rn), The method for operating the vehicle seat (3) comprises the steps of: (a) providing a control device for the occupant restraint system for distinguishing between an upright position and a reclined position of at least the seat backrest (3.1) of the vehicle seat (3); - in order to activate the autonomous driving mode of the vehicle (1), the seatbelt status of at least a front row occupant (2) of the vehicle (1) in the longitudinal direction of the vehicle is detected, - when the seat belt state is detected as an insertion of the seat belt buckle tongue into the seat belt buckle assigned to the vehicle seat (3), the automatic driving mode of the vehicle (1) is activated, The restraining elements (R1 to Rn) of the occupant restraint device are controlled, activated or actuated in synchronization with one another depending on the setting state of the vehicle seat (3) and depending on the situational crash conditions from the point in time when an imminent crash of the vehicle (1) is detected, the retractor (R1) of the seat belt (4) is controlled and electrically tightens the seat belt (4) in the shoulder belt region when the reclining position of the vehicle seat (3) is detected and an imminent crash of the vehicle (1) is detected, and after the occurrence of a crash, an additional lap tensioner (R2) and the retractor (R1) are controlled and pyrotechnically activated. A method of operation characterized by:

2. Upon activation of the pyrotechnic belt tightening, the upright positioning of the seat backrest (3.1) of the vehicle seat (3) is initiated pyrotechnically by unlocking the seat backrest (3.1).

2. The method of claim 1, wherein:

3. The upright positioning of the seat backrest (3.1) is braked before the seat backrest (3.1) reaches its upright end position.

3. The method of claim 2, wherein:

4. During the upright positioning of the seat backrest (3.1) until the upright end position is reached, the motorized seat belt tensioning of the shoulder belt area and the lap belt area of ​​the seat belt (4) is maintained with a predetermined force level.

4. The method of claim 3, wherein:

5. After the seat backrest (3.1) has reached the upright end position, the vehicle seat (3) is unlocked by pyrotechnics and a forward / backward movement in the direction of travel of the vehicle (1) is performed.

5. The method according to claim 3 or 4.

6. The vehicle seat (3) is braked in a damped manner in the region of the longitudinal end positions.

6. The method of claim 5.

7. When the vehicle seat (3) reaches the region of the longitudinal end position, the force level of the electrically operated tightening of the seat belt (4) in the shoulder belt region is reduced by a predetermined amount.

7. The method of claim 6.

8. The driver's airbag (R3) and / or passenger's airbag will deploy in the first stage upon detection of an occupant being seated.

7. The method of claim 6.

9. In addition to the activation of the driver airbag (R3) and / or the passenger airbag, each knee airbag (R7) is activated in the first stage.

9. The method of claim 8.

Images