AIRBAG ARRANGEMENT

Abstract

Airbag arrangement (12), comprising: an airbag (20) configured to be attached to a vehicle floor (16) of a vehicle (10); and at least one tether (28) connecting the airbag (20) and the vehicle floor (16) to control a height of the airbag (20) when it is deployed; wherein the airbag (20) is movable between a stowed position and a deployed position; wherein the airbag (20) is deflated in the stowed position; wherein the airbag (20) is inflated in the deployed position and spaced from the vehicle floor (16) to define an opening (26) between the airbag (20) and the vehicle floor (16); wherein the opening (26) is dimensioned to receive feet (F) of a vehicle occupant (VO), thereby limiting the movement of the legs (L) of the vehicle occupant (VO) when an external force is applied to the vehicle (10); wherein the airbag (20) defines a first airbag end (22) and a second airbag end (24) opposite the first airbag end (22), wherein the first airbag end (22) is attached directly to the vehicle floor (16), wherein the second airbag end (24) is attached directly to the vehicle floor (16), wherein the first airbag end (22) is spaced from the second airbag end (24) to define the opening (26) upon deployment of the airbag (20); wherein the airbag (20) includes a first tube (30), a second tube (32), and a chamber (34) disposed between the first (30) and second tubes (32), and the first tube (30) and the second tube (32) are angled obliquely to one another in the deployed position; and wherein the chamber (34) is arranged adjacent to the vehicle floor (16) and directly connects the first (30) and the second hose (32) to one another, so that the first (30) and the second hose (32) move away from one another when the airbag (20) is deployed.

Description

INTRODUCTION

[0001] The present disclosure relates generally to an airbag and, more particularly, to a lower leg airbag for a vehicle.

[0002] Vehicles contain airbags configured to deploy. When deployed, the airbag prevents a passenger's lower legs from contacting a rigid structure or other occupants inside the vehicle.

[0003] US 4 099 743 A discloses a passive restraint system having a head support element configured, together with a torso support element, from a stowed position to an operative position to limit the movement of the head and neck of a vehicle occupant at the time of an accident. The head support element is designed as an energy-absorbing cushion- or pillow-like element that is displaced by means of a cable from its stowed position under the dashboard of the vehicle to the operative position in which it rests against the chin of the vehicle occupant. The passive restraint system further comprises a pivotally mounted knee restraint element that, in an operative position, is displaced against the knees of the vehicle occupant to limit forward and downward movement of the vehicle occupant relative to the seat. SUMMARY

[0004] The present invention relates to an airbag arrangement having the features of independent claim 1. Advantageous embodiments of the invention are specified in the subclaims, the description and the drawings.

[0005] The present disclosure describes a vehicle system having an airbag assembly for protecting a lower portion of the legs of one or more vehicle occupants. The vehicle system may be a driver-operated vehicle, a shared autonomous vehicle (SAV), or an autonomous vehicle (AV). In SAVs and AVs, the seating assembly may allow the vehicle occupants to face one another. In other words, the vehicle seats of the vehicle system allow the vehicle occupants to sit facing one another. This seating arrangement is sometimes referred to as a campfire seating configuration. In such a seating arrangement, the vehicle occupant's legs may swing upward when the vehicle system is subjected to an external force. It is desirable to minimize the swinging movement of the legs to protect the lower portion of the vehicle occupant's legs.To this end, the present disclosure describes an airbag assembly configured to limit the movement of the legs (particularly the lower portion) of the vehicle occupant when the vehicle system is subjected to an external force. In particular, the presently disclosed airbag assembly prevents hyperextension of the vehicle occupant's knee when the vehicle system is subjected to an external force.

[0006] The present disclosure describes an airbag assembly including an airbag configured to be attached to a vehicle floor of a vehicle. The airbag is movable between a stowed position and a deployed position. In the stowed position, the airbag is deflated. In the deployed position, the airbag is inflated and spaced from the vehicle floor to define an opening between the airbag and the vehicle floor. The opening is sized to accommodate feet of a vehicle occupant, thereby limiting the movement of the vehicle occupant's legs when an external force is applied to the vehicle. The airbag defines first and second airbag ends opposite the first airbag end. The first airbag end is attached directly to the vehicle floor. The second airbag end is attached directly to the vehicle floor.The first airbag end is spaced from the second airbag end to define the opening upon deployment of the airbag. The airbag assembly further includes at least one tether connecting the airbag and the vehicle floor to control a height of the airbag during deployment. The airbag may have a circular shape in the deployed position. The airbag may have a rectangular shape in the deployed position. The airbag may have a triangular shape in the deployed position. The airbag may extend along an entire width of the vehicle floor in the deployed position.

[0007] The airbag includes a first tube, a second tube, and a chamber disposed between the first and second tubes. The first and second tubes are angled obliquely to each other in the deployed position. The chamber is disposed adjacent to the vehicle floor and directly connects the first and second tubes such that upon airbag deployment, the first and second tubes are moved away from each other. Alternatively, the chamber may be spaced from the vehicle floor and directly connects the first and second tubes such that upon airbag deployment, the first and second tubes are moved away from each other. The airbag may be shaped substantially as a pyramidal truncated cone and has a height sufficient to limit the movement of the vehicle occupant's knees upon airbag deployment.

[0008] The airbag assembly may further include an inflator attached to the airbag such that the inflator is configured to inflate the airbag, a controller in electronic communication with the inflator, a tether length adjustment mechanism in electronic communication with the controller, an airbag position adjustment mechanism in electronic communication with the controller and a camera in electronic communication with the controller, an accelerometer in electronic communication with the controller, and a pressure sensor attached to a vehicle seat and in electronic communication with the controller. The pressure sensor is configured to detect whether the vehicle seat is occupied by the vehicle occupant. The tether length adjustment mechanism is configured to adjust a length of the at least one tether. The camera system is configuredto locate a position of the vehicle occupant's legs and measure a leg length. The airbag position adjustment mechanism is configured to adjust a position of the airbag relative to the vehicle floor. The controller is programmed to: detect, via the controller, that the vehicle occupant is sitting in the vehicle seat based on a pressure signal received from the pressure sensor; determine, via the controller, a position of the vehicle occupant relative to the vehicle floor based on image data from the camera system in response to determining that the vehicle occupant is sitting in the vehicle seat; determine, via the controller, the leg length of the vehicle occupant based on the image data from the camera system in response to determining that the vehicle occupant is sitting in the vehicle seat; command, via the controller, the airbag position adjustment mechanism,to adjust the position of the airbag relative to the vehicle floor based on the position of the vehicle occupant's legs; and commanding, via the controller, the tether length adjustment mechanism to adjust the height of the airbag relative to the vehicle floor based on the length of the vehicle occupant's legs. The controller is further programmed to: determine whether the vehicle has been subjected to the external force based on an acceleration signal from the accelerometer; and in response to determining that the vehicle has been subjected to the external force, command the inflator to inflate the airbag. The controller is further programmed to determine whether the vehicle has not been subjected to the external force based on an acceleration signal from the accelerometer, and in response to determining that the vehicle has not been subjected to the external force,determining the position of the vehicle occupant's legs relative to the vehicle floor based on the image data from the camera system.

[0009] The present disclosure also describes a method for controlling the operation of the airbag assembly. The method includes the steps of: (a) detecting, via the controller, that the vehicle occupant is sitting in the vehicle seat based on a pressure signal received from the pressure sensor; (b) determining, via the controller, a position of the vehicle occupant relative to the vehicle floor based on image data from the camera in response to determining that the vehicle occupant is sitting in the vehicle seat; (c) determining, via the controller, the length of the vehicle occupant's legs based on the camera image data in response to determining that the vehicle occupant is sitting in the vehicle seat; (d) commanding, via the controller, the airbag position adjustment mechanism to adjust the position of the airbag relative to the vehicle floor based on the position of the vehicle occupant's legs;and (e) commanding, via the control of the tether length adjustment mechanism, the height of the airbag relative to the vehicle floor based on the length of the vehicle occupant's legs;

[0010] The method may further include: determining, via the controller, whether the vehicle has been subjected to an external force based on an acceleration signal from the accelerometer; and in response to determining that the vehicle has been subjected to the external force, commanding, via the controller, the inflator to inflate the airbag. The method may further include: determining, via the controller, whether the vehicle has been subjected to an external force based on an acceleration signal from the accelerometer, and in response to determining that the vehicle has not been subjected to the external force, again determining, via the controller, the position of the vehicle occupant's legs relative to the vehicle floor based on the image data from the camera.

[0011] The present disclosure also describes a vehicle including a vehicle body and a vehicle floor attached to the vehicle body. The vehicle body and the vehicle floor together define a passenger compartment. The vehicle system further includes an airbag assembly as described above.

[0012] The above features and advantages, as well as other features and advantages of the present disclosure, will become apparent from the following detailed description of the best mode for carrying out the disclosure when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic perspective view of a vehicle having an airbag assembly according to aspects of the present disclosure; Fig. 2 is a schematic perspective view of a vehicle seat and the airbag assembly of Fig. 1, wherein the airbag assembly includes an airbag shown in the stowed position. Fig. 3 is a schematic perspective view of a vehicle seat and the airbag assembly of Fig. 1, wherein the airbag assembly includes an airbag shown in the deployed position. Fig. 4 is a schematic perspective view of an airbag having a rectangular shape. Fig. 5 is a schematic perspective view of an airbag having a triangular shape. Fig. Figure 6 is a schematic perspective view of an airbag with two tubes and a chamber adjacent to the vehicle floor. Fig. Figure 7 is a schematic perspective view of an airbag having two tubes and a chamber spaced from the vehicle floor. Fig. Figure 8 is a schematic side view of an airbag having a height sufficient to limit the movement of a vehicle occupant's knees. Fig. 9 is a schematic front view of the airbag assembly of Fig. 8. Fig. 10 is a schematic representation of a vehicle incorporating an airbag assembly of Fig. 1 includes. Fig. 11 is a flowchart for a method of controlling the operation of the airbag of Fig. 1. DETAILED DESCRIPTION

[0013] With reference to Fig. 1, the present disclosure describes a vehicle 10 having an airbag assembly 12 for protecting a lower portion of the legs L (e.g., tibia T, knees K, and feet F) of one or more vehicle occupants. The vehicle 10 may be a shared autonomous vehicle (SAV) or an autonomous vehicle (AV). In SAVs and AVs, the seating arrangement may allow the vehicle occupants to face one another. In other words, the vehicle seats 15 of the vehicle 10 allow the vehicle occupants to sit facing one another. This seating arrangement is sometimes referred to as a campfire seating configuration. In such a seating arrangement, the legs L of the vehicle occupant VO may swing upward when the vehicle 10 is subjected to an external force EF. It is desirable to minimize the swinging movement of the legs L to protect the lower portion of the legs L (e.g., tibia TG, knees K, and ankles A) of the vehicle occupant VO.To this end, the present disclosure describes an airbag assembly 12 configured to limit the movement of the legs (particularly the lower portion) of the vehicle occupant VO when the vehicle 10 is subjected to an external force EF. In particular, the presently disclosed airbag assembly 12 prevents hyperextension of the knee K of the vehicle occupant VO when the vehicle 10 is subjected to an external force EF.

[0014] With reference to Fig. 1, the vehicle 10 includes a vehicle body 12 and a vehicle floor 16 attached to the vehicle body 14. The vehicle body 14 and the vehicle floor 16 together define a passenger compartment 18 of the vehicle 10. The airbag assembly 12 includes an airbag 20 attached to the vehicle floor 16. In the illustrated embodiment, the airbag 20 is attached directly to the vehicle floor 16 to facilitate the protection of the lower thighs L of the vehicle occupant VO when the external force EF is applied to the vehicle body 14.

[0015] With reference to the Fig. 1, Fig. 2 and Fig. 3, the airbag 20 is between a stowed position ( Fig. 2) and an extended position ( Fig. 3) movable (i.e., inflatable). In the illustrated embodiment, the airbag 20 may extend along an entire width W of the vehicle floor 16 in the deployed position to protect the maximum number of vehicle occupants VO when the vehicle 10 is subjected to an external force EF. Alternatively, the airbag 20 may be sized for a single person. In the stowed position, the airbag 20 is deflated. In the deployed position, the airbag 20 is inflated. The airbag 20 defines a first airbag end 22 and a second airbag end 24 opposite the first airbag end 22. The first airbag end 22 is directly attached to the vehicle floor 16 to enhance the structural connection between the vehicle floor 16 and the airbag 20. The second airbag end 24 is directly attached to the vehicle floor 16 to enhance the structural connection between the vehicle floor 16 and the airbag 20.In the extended position, the airbag 20 is spaced from the vehicle floor 16 to form an opening 26 (. Fig. 3) between the airbag 20 and the vehicle floor 16. The opening 26 is sized to accommodate the feet F (and optionally the ankles A and / or the tibia T, also referred to as the lower legs) of the vehicle occupant VO, thereby limiting the movement of the vehicle occupant's legs L when the external force EF is applied to the vehicle 10. The first airbag end 22 is spaced from the second airbag end 24 to define the opening 26 upon deployment of the airbag 20. The airbag assembly 12 includes one or more tethers 28 interconnecting the airbag 20 and the vehicle floor 16 to control the angle and height of the airbag 20 during deployment. The height H of the airbag 20 is measured from the vehicle floor 16 to the uppermost portion 21 of the airbag 20 to the lowermost portion 23 of the airbag 20 in the deployed position. In the illustrated embodiment, the airbag 20 has a circular tubular shape ( Fig. 3) in the deployed position to facilitate manufacture. However, the airbag 20 may also have other suitable shapes. For example, the airbag 20 may, as shown in Fig. 4, have a rectangular shape that jointly defines the opening 26 with the vehicle floor 16 when the airbag 20 is in the deployed position. Alternatively, the airbag 20 may, as shown in Fig. 5, have a triangular shape which together defines the opening 26 with the vehicle floor 16 when the airbag 20 is in the deployed position.

[0016] With reference to Fig. 6, the airbag 20 includes a first tube 30, a second tube 32, and a chamber 34 disposed between the first tube 30 and the second tube 32. The first tube 30 and the second tube 32 are angled obliquely relative to one another in the deployed position. The chamber 34 is adjacent to the vehicle floor 16 and directly connects the first tube 30 and the second tube 32. Thus, upon deployment of the airbag 20, the chamber 34 inflates, causing the first tube 30 and the second tube 32 to move away from one another. As a result, the airbag 20 protects more vehicle occupants VO in the vehicle 10. One or more tether straps 28 may connect the vehicle floor 16 and the first tube 30 and / or the second tube 32 to one another to control the height H of the airbag 20. In the Fig. 6, the chamber 34 has a triangular shape to facilitate the movement of the first tube 30 and the second tube 32 away from each other during deployment of the airbag 20. As shown in Fig. 7, the chamber 34 may alternatively have a tubular shape.

[0017] With reference to the Fig. 8 and Fig. 9, the airbag 20 is shaped substantially as a pyramidal truncated cone to facilitate limiting the movement of the knees K of the vehicle occupant VO during deployment of the airbag 20. Further, the height H of the airbag is sufficient to limit the movement of the knees K of the vehicle occupant VO during deployment. As discussed above, the height H of the airbag 20 is measured from the vehicle floor 16 to the uppermost portion 21 of the airbag 20 to the lowermost portion 23 of the airbag 20 in the deployed position. The airbag assembly 12 may include one or more tethers 28 interconnecting the vehicle floor 16 and the airbag 20.In this embodiment, the tether straps 28 may be directly connected to the airbag 20 at a position between the lowermost portion 23 and the uppermost portion 21 of the airbag 20 to allow the airbag 20 to reach its maximum height H upon deployment, thereby limiting the movement of the knees K of the vehicle occupant VO. In the illustrated embodiment, the opening 26 defined between the vehicle floor 16 and the airbag 20 has a rectangular shape for receiving the feet F of the vehicle occupant VO. However, it is envisaged that the opening 26 may alternatively have a triangular or circular shape.

[0018] With reference to Fig. 10, the vehicle body 14 and the vehicle floor 16, as discussed above, define the passenger compartment 18 of the vehicle 10. One or more vehicle seats 15 are disposed within the passenger compartment 18. The vehicle 10 includes a controller 36 for controlling the operation of the airbag assembly 12. The controller 36 may also include hardware elements such as a processor (P) and circuitry, including, but not limited to, a timer, an oscillator, an analog / digital (A / D) circuit, a digital / analog (D / A) circuit, a digital signal processor, and the necessary input / output units, as well as other signal conditioning and / or buffer circuitry. The memory (M) may include both tangible permanent storage space such as read-only memory (ROM), e.g.magnetic, solid-state, and / or optical memory as well as a sufficient amount of RAM (Random Access Memory), EEPROM (Electrically-Erasable Programmable Read-Only Memory), etc. A method 100 (. Fig. 11) may be recorded in the memory (M) and executed by the processor (P) in the overall control of the airbag arrangement 12.

[0019] With further reference to Fig. 10, the vehicle 10 further includes a camera system 38 mounted to the vehicle body 14 and points to the vehicle occupant VO for capturing images of the vehicle occupant VO. The camera system 38 is in electronic communication with the controller 36. The camera system 38 is configured to locate a position of the legs L of the vehicle occupant VO and measure the length of the legs of the vehicle occupant VO based on the recorded images of the vehicle occupant VO. The vehicle 10 further includes an acceleration sensor 40 (or other sensor suitable for detecting when the vehicle 10 is subjected to the external force EF). The acceleration sensor 40 is in electronic communication with the controller 36 and is configured to detect when the vehicle 10 is subjected to the external force EF. The vehicle 10 further includes a pressure sensor 42 mounted to the vehicle seat 15.The pressure sensor 42 is in electronic communication with the controller 36 and is configured to detect whether the vehicle seat 15 is occupied by the vehicle occupant VO.

[0020] With further reference to Fig. 10, the airbag assembly 12 includes an inflator 44 attached to the airbag 20. The inflator 44 may be a pyrotechnic actuator and is configured to inflate the airbag 20 in response to sensing that the external force F is applied to the vehicle 10. The inflator 44 is in electronic communication with the controller 36. The airbag assembly 12 includes a tether length adjustment mechanism 46 in electronic communication with the controller 36. The tether length adjustment mechanism 46 is configured to adjust the length of one or more tether straps 28. The airbag assembly 12 may include a tether length adjustment mechanism 46 for each bracket 28. In the illustrated embodiment, each tether length adjustment mechanism 46 is attached to one of the tether straps 28 and includes a roller 48 attached to the tether strap 28 for winding the tether strap 28.The tether length adjustment mechanism 46 further includes a tether 50 attached to the reel 48 and in electronic communication with the controller 36. As such, the controller 36 is configured to activate the tether 50, causing the reel 48 to rotate. Depending on the direction of rotation of the reel 48, activating the tether motor 50 causes the reel 48 to wind or unwind the tether 28 to adjust the length of the tether 28.

[0021] The airbag assembly 12 further includes a tether length adjustment mechanism 52 in electronic communication with the controller 36. The airbag position adjustment mechanism 52 is configured to adjust a position of the airbag 20 relative to the vehicle floor 16. The airbag position adjustment mechanism 52 includes a rack 54 and a pinion gear 56 that are meshed together. The rack 54 is attached to the airbag 20, and the pinion gear is meshed with the rack 54. By rotating the pinion gear 56, the rack 54 moves linearly, thereby adjusting the position of the airbag 20 relative to the vehicle floor 16. The airbag position adjustment mechanism 52 further includes a position motor 58 attached to the pinion gear 56 and in electronic communication with the controller 36. As such, the controller 36 is configured to activate the position motor 58, causing the pinion 56 to rotate.Rotating the pinion 56 causes the rack 54 to move linearly. Since the pinion 56 is coupled to the airbag 20, the linear movement of the pinion 56 causes the airbag 20 to move, thereby adjusting the position of the airbag 20 relative to the vehicle floor 16.

[0022] With reference to Fig. 11 is the control 36 ( Fig. 10) programmed to execute the method 100 to control the operation of the airbag 20 ( Fig.10). The method 100 begins at block 102. At block 102, the controller 36 detects that the vehicle occupant VO is sitting on the vehicle seat 15 based on a pressure signal received from the pressure sensor 42. The method 100 then proceeds to block 104. At block 104, the controller 36 activates the camera system 38 (or other suitable sensing system) to determine the position of the legs L of the vehicle occupant VO relative to the vehicle floor 16 based on the image data from the camera system 38 in response to determining that the vehicle occupant VO is sitting on the vehicle seat 15. At block 104, the controller 36 detects the length of the legs L of the vehicle occupant VO based on the image data from the camera system 38 in response to determining that the vehicle occupant OC is sitting on the vehicle seat 15. The method 100 then proceeds to block 106.

[0023] At block 106, the controller 36 instructs the airbag position adjustment mechanism 52 to adjust the position of the airbag 20 relative to the vehicle floor 16 based on the position and leg length L of the vehicle occupant VO, thereby adjusting the deployment position of the airbag 20. The method 100 then proceeds to block 108. At block 108, the controller 36 instructs the tether length adjustment mechanism 46 to adjust the height H of the airbag 20 relative to the vehicle floor 16 based on the leg length L of the vehicle occupant VO. The method 100 then proceeds to block 110.

[0024] At block 110, the controller 36 determines whether the vehicle 10 has been subjected to the external force EF based on an acceleration signal from the acceleration sensor 40 (or other suitable sensor). In other words, the controller 36 is programmed to detect an external force applied to the vehicle 10. If the controller 36 determines that the vehicle 10 has been subjected to the external force EF, the method 100 proceeds to block 112. At block 112, the controller 36 commands the inflator 44 to inflate the airbag 20 in response to determining that the vehicle 10 has been subjected to the external force EF.

[0025] If the controller 36 determines that the vehicle 10 has not been subjected to the external force EF, the method 100 proceeds to block 114. At block 114, the controller again determines the position of the legs L of the vehicle occupant VO relative to the vehicle floor 16 based on the image data from the camera system 38. The method 100 then returns to block 106.

[0026] While the best modes for carrying out the disclosure have been described in detail, those skilled in the art described herein will recognize various alternative designs and embodiments in which the invention may be practiced within the scope of the claims set forth below.

Claims

[1] Airbag arrangement (12), comprising: an airbag (20) configured to be attached to a vehicle floor (16) of a vehicle (10); and at least one tether (28) connecting the airbag (20) and the vehicle floor (16) to control a height of the airbag (20) when it is deployed; wherein the airbag (20) is movable between a stowed position and a deployed position; wherein the airbag (20) is deflated in the stowed position; wherein the airbag (20) is inflated in the deployed position and spaced from the vehicle floor (16) to define an opening (26) between the airbag (20) and the vehicle floor (16); wherein the opening (26) is dimensioned to receive feet (F) of a vehicle occupant (VO), thereby limiting the movement of the legs (L) of the vehicle occupant (VO) when an external force is applied to the vehicle (10); wherein the airbag (20) defines a first airbag end (22) and a second airbag end (24) opposite the first airbag end (22), wherein the first airbag end (22) is attached directly to the vehicle floor (16), wherein the second airbag end (24) is attached directly to the vehicle floor (16), wherein the first airbag end (22) is spaced from the second airbag end (24) to define the opening (26) upon deployment of the airbag (20); wherein the airbag (20) includes a first tube (30), a second tube (32), and a chamber (34) disposed between the first (30) and second tubes (32), and the first tube (30) and the second tube (32) are angled obliquely to one another in the deployed position; and wherein the chamber (34) is arranged adjacent to the vehicle floor (16) and directly connects the first (30) and the second hose (32) to one another, so that the first (30) and the second hose (32) move away from one another when the airbag (20) is deployed. [2] The airbag assembly (12) of claim 1, wherein the airbag (20) has a circular shape in the deployed position. [3] The airbag assembly (12) of claim 1, wherein the airbag (20) has a rectangular shape in the deployed position. [4] The airbag assembly (12) of claim 1, wherein the airbag (20) has a triangular shape in the deployed position. [5] The airbag assembly (12) of claim 1, wherein the airbag (20) extends along an entire width of the vehicle floor (16) in the deployed position. [6] The airbag assembly (12) of claim 1, wherein the chamber (34) is spaced from the vehicle floor (16) and directly connects the first (30) and second tubes (32) such that the first (30) and second tubes (32) move away from each other upon deployment of the airbag (20).

Images