Patent Publication Number: US-2022212617-A1

Title: Airbag device of vehicle and control method thereof

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority from and the benefit of Korean Patent Application No. 10-2021-0002237, filed on Jan. 7, 2021, which is hereby incorporated by reference for all purposes as if set forth herein. 
     BACKGROUND 
     Field 
     Exemplary embodiments of the present disclosure relate to an airbag device of a vehicle and a control method thereof, and more particularly, to an airbag device of a vehicle, capable of protecting an occupant in all directions in a vehicle interior and a control method thereof. 
     Discussion of the Background 
     An airbag for a vehicle is a safety device that deploys an airbag cushion in the event of a collision to attenuate an impact on an occupant and substantially prevents a passenger from being thrown out of a vehicle body. The airbag for a vehicle may be classified into a driver airbag (DAB) and a passenger airbag (PAB) for protecting passengers on front seats in the event of a head-on collision, a side airbag (SAB) and a curtain airbag (CAB) for protecting sides of passengers in the event of a lateral collision, a center airbag for substantially preventing injuries caused by a collision between a driver and an occupant on a passenger seat and a collision among occupants on back seats in the event of a lateral collision, and the like. 
     Since the airbag system in the related art described above is based on the premise that an occupant is normally seated in a vehicle seat, a situation in which the occupant is injured due to the deployment of the airbag frequently occurs depending on the seating state of the occupant. Furthermore, since the airbag system in the related art has a limitation of one-time deployment, there is a problem in that excessive time and money are required as related parts need to be entirely replaced after the airbag is deployed. 
     Furthermore, in the case of an autonomous vehicle, since the driving control right is transferred from an occupant to a vehicle system, the seating state of the occupant who has no driving control right is not a fixed normal seating state and may be changed very variously depending on an intended operation of the occupant. Therefore, the airbag system in the related art that based on the premise that an occupant is normally seated in a vehicle seat may not completely protect an occupant of an autonomous vehicle. Moreover, when considering that various entertainment facilities (for example, tables, displays, and the like) for an occupant who has no driving control right may be installed in the autonomous vehicle, there is a limitation in securing a mounting space for an airbag system installed in a fixed position (for example, a steering wheel central horn, a dashboard, and the like) in the related art. 
     SUMMARY 
     The present disclosure has been made to solve the above problems, and an object according to one aspect of the present disclosure is to provide an airbag device of a vehicle, which is configured to be reusable by overcoming the limitation of an airbag system limited to one-time deployment, to effectively protect an occupant from a collision by covering various seating states of the occupant, and to be compatible with an airbag system in the related art, and a control method thereof. 
     An airbag device of a vehicle in accordance with an aspect of the present disclosure includes: a detection unit configured to detect collision information of a vehicle and seating state information of an occupant; an airbag unit including a plurality of airbag modules respectively installed at a plurality of positions of an interior material formed in an interior space of the vehicle, each of the airbag modules being configured to be inflated in a contracted state as working gas is supplied and to be restored to the contracted state as the working gas is discharged; a valve unit configured to regulate the working gas supplied to the airbag unit; and a control unit configured to determine a hitting position defined as a position of the interior material, at which the occupant is expected to be hit, on the basis of the collision information of the vehicle and the seating state information of the occupant detected by the detection unit, and to control the valve unit to supply the working gas to a target airbag module installed at the hitting position among the plurality of airbag modules, thereby inflating the target airbag module. 
     In the present disclosure, the collision information of the vehicle may include information on an amount of impact on the vehicle, the seating state information of the occupant may include image information of the occupant in an interior space of the vehicle, and the control unit may determine the hitting position on the basis of an impact direction acquired from the information on the amount of impact and a pose of the occupant acquired from the image information. 
     In the present disclosure, the airbag module may be installed between the interior material and a vehicle body frame, and may be configured to be inflated as working gas is supplied and to expand the interior material toward the occupant. 
     The present disclosure may further include a tether part configured to couple the interior material to the vehicle body frame so that a position of the interior material is changed with respect to the vehicle body frame and to substantially prevent scattering of the airbag module, and the tether part may be implemented with a stretchable elastic material and may be configured to closely fix the interior material to the vehicle body frame in a contracted state of the airbag module, and to be extended along with inflation of the airbag module. 
     In the present disclosure, the airbag module may include a protective film skin configured to cover the interior material, and cushion parts installed between the protective film skin and an outer surface of the interior material. 
     In the present disclosure, the vehicle may be applied with a conventional airbag system that is installed independently of the airbag unit at a position different from a position where the airbag unit is installed and is controlled to protect an occupant by the control unit when the occupant is seated according to a predefined normal seating condition, and when control for the airbag unit and control for the conventional airbag system are defined as first control and second control, respectively, the control unit may complementarily perform the first control and the second control according to the seating state information of the occupant. 
     In the present disclosure, the control unit may perform the first control when a pose of the occupant acquired from the image information does not satisfy the normal seating condition and perform the second control when the pose of the occupant satisfies the normal seating condition. 
     In the present disclosure, the valve unit may include a main valve and a plurality of sub-valves respectively provided in flow paths connected from the main valve to the plurality of airbag modules, and the main valve may be integrated into a valve unit constituting an air suspension system applied to the vehicle. 
     In the present disclosure, the control unit may control the valve unit to supply the working gas to the conventional airbag system, and a first flow path, through which the working gas is supplied from the valve unit to the airbag unit, and a second flow path, through which the working gas is supplied from the valve unit to the conventional airbag system, may share at least partially a common flow path. 
     A control method of an airbag device of a vehicle in accordance with an aspect of the present disclosure includes: a step in which a control unit acquires collision information of the vehicle and seating state information of an occupant detected by a detection unit; a step in which the control unit determines a hitting position defined as a position of the interior material, at which the occupant is expected to be hit, on the basis of the acquired collision information of the vehicle and seating state information of the occupant; and a step in which the control unit controls a valve unit to supply working gas to a target airbag module installed at the hitting position among a plurality of airbag modules, thereby inflating the target airbag module. 
     In the present disclosure, the collision information of the vehicle may include information on an amount of impact on the vehicle, the seating state information of the occupant may include image information of the occupant in an interior space of the vehicle, and in the step of determining, the control unit may determine the hitting position on the basis of an impact direction acquired from the information on the amount of impact and a pose of the occupant acquired from the image information. 
     In the present disclosure, the vehicle may be applied with a conventional airbag system that is installed independently of the airbag unit at a position different from a position where the airbag unit is installed and is controlled to protect an occupant by the control unit when the occupant is seated according to a predefined normal seating condition, and the control unit may complementarily control the airbag unit and the conventional airbag system according to the seating state information of the occupant. 
     In the present disclosure, the seating state information of the occupant may include image information of the occupant in an interior space of the vehicle, and the method may further include, after the step of acquiring: a step in which the control unit determines whether a pose of the occupant acquired from the image information satisfies the normal seating condition; and a step in which the control unit controls the conventional airbag system when it is determined that the pose of the occupant satisfies the normal seating condition, wherein the step of determining and the step of inflating are performed when it is determined that the pose of the occupant does not satisfy the normal seating condition. 
     In accordance with an aspect of the present disclosure, the present disclosure may protect an occupant in all directions in a vehicle interior by installing an airbag device in an interior material formed in an interior space of a vehicle instead of a fixed position in the related art, may reuse an airbag by adopting a structure in which working gas for deploying an airbag module is secured through an air suspension system applied to the vehicle and simultaneously is naturally discharged and disappear after the airbag is deployed, and may more completely protect the occupant of the vehicle from a collision through a method of complementarily operating the airbag device with a conventional airbag system previously applied to the vehicle. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram for explaining the configuration of an airbag device of a vehicle in accordance with an embodiment of the present disclosure. 
         FIG. 2  to  FIG. 6  are exemplary views illustrating the structure of an airbag unit in the airbag device of a vehicle in accordance with an embodiment of the present disclosure. 
         FIG. 7  is an exemplary view illustrating a structure in which working gas is supplied from an air suspension system in the airbag device of a vehicle in accordance with an embodiment of the present disclosure. 
         FIG. 8  is a flowchart for explaining a control method of the airbag device of a vehicle in accordance with an embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS 
     Hereinafter, an airbag device of a vehicle and a control method thereof in accordance with an embodiment of the present disclosure will be described in detail with reference to the accompanying drawings. In this process, the thicknesses of lines or the sizes of elements illustrated in the drawings may be exaggerated for the purpose of clarity and convenience of explanation. Furthermore, terms to be described later are terms defined in consideration of functions thereof in the present disclosure and may be changed according to the intention of a user or an operator, or practice. Accordingly, such terms should be defined based on the disclosure over the present specification. 
       FIG. 1  is a block diagram for explaining the configuration of an airbag device of a vehicle in accordance with an embodiment of the present disclosure,  FIG. 2  to  FIG. 6  are exemplary views illustrating the structure of an airbag unit in the airbag device of a vehicle in accordance with an embodiment of the present disclosure, and  FIG. 7  is an exemplary view illustrating a structure in which working gas is supplied from an air suspension system in the airbag device of a vehicle in accordance with an embodiment of the present disclosure. 
     Referring to  FIG. 1  to  FIG. 7 , the airbag device of a vehicle in accordance with an embodiment of the present disclosure may include a detection unit  100 , an airbag unit  200 , a valve unit  300 , and a control unit  400 . 
     The detection unit  100  may detect collision information of a vehicle and seating state information of an occupant and transmit the detected information to the control unit  400  to be described below. The collision information of the vehicle may include information on the amount of impact caused by a collision between the vehicle and an external object, and the detection unit  100  may include a collision sensor (for example, an acceleration sensor, a gyro sensor, and the like) in order to detect the collision information. The seating state information of the occupant may include image information of the occupant in an interior space of the vehicle, and the detection unit  100  may include an image recognition sensor (for example, a camera sensor) in order to detect the seating state information. The collision information of the vehicle and the seating state information of the occupant detected by the detection unit  100  may be used for determining a hitting position as will be described below. 
     The airbag unit  200  is defined as a configuration including a plurality of airbag modules  210  respectively installed at a plurality of positions of an interior material IM formed in the interior space of the vehicle. The interior material IM in which the airbag modules  210  are installed may include a head lining interior material, a dashboard interior material, a pillar interior material, and a door interior material of the vehicle, and other trim interior materials inside the vehicle. Each of the airbag modules  210  may be installed for each interior material IM as described above, and may be selectively operated according to a hitting position determined by the control unit  400 . 
     In the present embodiment, each of the airbag modules  210  may be configured to be inflated in a contracted state as working gas is supplied from the valve unit  300  to be described below, and then to be restored to the contracted state as the working gas is discharged.  FIG. 2  illustrates a door part of the vehicle, and  FIG. 3  to  FIG. 6  each illustrate an example of a structure in which the airbag module  210  of the present embodiment is implemented for a door interior material. 
       FIG. 3  illustrates a stack structure of a vehicle body frame F, the airbag module  210 , and the interior material IM, and  FIG. 4  illustrates an overall structure of the cross-section A-A of  FIG. 2  together with a partially enlarged view. Referring to  FIG. 3  and  FIG. 4 , the airbag module  210  may be installed between an inner surface of the interior material IM and the vehicle body frame F, and may be configured to be inflated as working gas is supplied between an outer layer  211  and an inner layer  212  of the airbag module  210  and to expand the interior material IM toward the occupant. That is, the airbag module  210  initially exists in a contracted state, and is inflated when working gas is supplied under the control of the control unit  400  in the event of a collision of the vehicle. As the airbag module  210  is inflated, the interior material IM is expanded toward the occupant to form a cushion, so that the occupant may be protected. In such a case, in order to effectively protect the occupant, the interior material IM that hits the occupant may be implemented with an appropriate material according to the intention of a designer. 
     In the embodiment of  FIG. 3  and  FIG. 4 , a tether part T is further provided, and the tether part T performs a function of coupling the interior material IM to the vehicle body frame F so that the position of the interior material IM is changed with respect to the vehicle body frame F, and substantially preventing scattering of the airbag module  210 . Specifically, the tether part T may be configured to closely fix the interior material IM to the vehicle body frame F in the contracted state of the airbag module  210 , and to be extended along with the inflation of the airbag module  210 . A space in which the airbag module  210  may be inflated may be secured according to the extension/contraction operation of the tether part T, and the position of the interior material IM may be changed with respect to the vehicle body frame F. In order to perform the above operation, the tether part T may be implemented with a stretchable elastic material.  FIG. 4  illustrates an example in which the tether parts T are provided at both ends of the interior material IM, respectively, but the number of tether parts T may be selected as an appropriate number according to the intention of a designer and experimental results within the range in which a space in which the airbag module  210  may be inflated is secured and the position of the interior material IM may be changed with respect to the vehicle body frame F. 
     Meanwhile, the airbag module  210  may be configured to be restored to the contracted state as working gas is discharged after being inflated. In such a case, in an embodiment in which a part of the surface of the airbag module  210  and the surface of the interior material IM may be implemented in an uncoated state so that working gas is naturally discharged through the uncoated region on the surface of the airbag module  210  and the surface of the interior material IM. In another embodiment, a physical through structure may be adopted in which a vent hole is formed in the airbag module  210  and the interior material IM and working gas is discharged therethrough. In such a case, the size of the vent hole may be optimized and predefined by experimental results of a designer to the extent that when working gas is introduced into the airbag module  210 , the amount of inflow gas is made relatively larger than that of outflow gas discharged through the vent hole, which does not cause no influence on the inflation of the airbag module  210 . 
     Accordingly, when a vehicle collision occurs, working gas is supplied into the airbag module  210  initially existing in the contracted state to inflate the airbag module  210 , the tether part T is extended as the airbag module  210  is inflated, and the interior material IM is expanded toward the occupant to form a cushion, so that the occupant may be protected. Then, the working gas is discharged through the above uncoated region or the vent hole, the tether part T is compressed, and the interior material IM is closely fixed to the vehicle body frame F by the compressed tether part T, so that the airbag module  210  may be restored to the initial contracted state. 
       FIG. 5  and  FIG. 6  illustrate an example of another implementation structure of the airbag module  210 .  FIG. 5  illustrates a stack structure of the vehicle body frame F, the interior material IM, and the airbag module  210 , and  FIG. 6  illustrates an overall structure of the cross-section A-A of  FIG. 2  together with a partially enlarged view. In such an embodiment, the airbag module  210  is installed on an outer surface of the interior material IM. Specifically, as illustrated in  FIG. 5 , the airbag module  210  may include a protective film skin  215  configured to cover the interior material IM, and cushion parts  213  and  214  installed between the protective film skin  215  and the outer surface of the interior material IM. The protective film skin  215  may be formed in a structure of surrounding the outer side of the cushion parts and perform a function of substantially preventing damage to the cushion parts, and may be implemented with a material of leather or propylene-based PU, PO, or PP. 
     In the example of  FIG. 5  and  FIG. 6 , the cushion parts  213  and  214  of the airbag module  210  initially exist in a contracted state, and when working gas is supplied between the cushion parts  213  and  214  under the control of the control unit  400  as a vehicle collision occurs, the cushion parts  213  and  214  are inflated to form a cushion, so that an occupant may be protected. In order to discharge the working gas, as in the example of  FIG. 3  and  FIG. 4 , a structure may be adopted in which a part of the surface of the cushion part and the surface of the protective film skin  215  is implemented in an uncoated state or a structure in which a vent hole is formed in the surface of the cushion part and the surface of the protective film skin  215 . 
     Next, the valve unit  300  may operate to regulate working gas supplied to the airbag unit  200 , under the control of the control unit  400 . As illustrated in  FIG. 7 , the valve unit  300  may include a main valve  310  and a plurality of sub-valves  320  respectively provided in flow paths connected from the main valve  310  to the plurality of airbag modules  210 , and the main valve  310  may be integrated into a valve unit constituting an air suspension system (ASS) previously applied to the vehicle. 
       FIG. 7  illustrates a structure in which working gas is supplied from the air suspension system (ASS) to the airbag modules  210  through the valve unit  300 . The air suspension system (ASS) includes a reservoir, a compressor, the valve unit, and an air spring, and air compressed by the compressor is supplied to the air spring or the air is discharged from the air spring and stored in the reservoir. At this time, each on-off valve v of the valve unit selectively regulates the flow path. 
     The main valve  310  included in the valve unit  300  may be integrated into the valve unit as one on-off valve v constituting the valve unit of the air suspension system (ASS), which makes it possible to implement a structure in which air compressed by the compressor is supplied to the airbag modules  210  through the main valve  310  and the sub-valves  320 . Accordingly, a structure is implemented in which working gas is supplied from the air suspension system (ASS) through the main valve  310  and the sub-valves  320  to inflate the airbag modules  210 , and the airbag modules  210  are restored to a contracted state as the working gas is naturally discharged, which makes it possible to implement a reusable airbag system by overcoming the limitation of an airbag system limited to one-time deployment in the related art. 
     Meanwhile, a conventional airbag system (CAS), which is installed independently of the airbag unit  200  at a position different from a position where the airbag unit  200  is installed, may be applied to a vehicle to which the present embodiment is applied. The conventional airbag system (CAS) may include at least one of a driver airbag, a passenger airbag, a side airbag, a curtain airbag, and a center airbag, which are mounted by default on a vehicle, and when an occupant is seated according to a predefined normal seating condition, the conventional airbag system (CAS) may be controlled to protect the occupant by the control unit  400 . The aforementioned normal seating condition may be predefined in the control unit  400  as a condition for determining whether the occupant is sitting in a vehicle seat in a general pose. For example, the control unit  400  may calculate a similarity or overlap rate between a current pose of the occupant acquired from the image information of the occupant and a reference pose predefined as corresponding to a state in which the occupant is generally seated in the vehicle seat, and determine that the normal seating condition is satisfied when the calculated value is equal to or greater than a reference value. An algorithm for calculating the aforementioned similarity or overlap rate may be predefined in the control unit  400 . 
     As is well known, the aforementioned conventional airbag system (CAS) operates to inflate by receiving working gas generated by an inflator. In addition, the present embodiment adopts a structure in which the conventional airbag system (CAS) may be inflated by additionally receiving working gas from the main valve  310  (that is, the aforementioned air suspension system (ASS)) of the valve unit  300 . That is, the present embodiment adopts a configuration of further improving a protective operation of the conventional airbag system (CAS) by expanding and applying a configuration, which operates the airbag unit  200  provided in the present embodiment by receiving working gas from the air suspension system (ASS) to the conventional airbag system (CAS) previously applied to the vehicle. In such a case, as illustrated in  FIG. 7 , a first flow path, through which the working gas is supplied from the main valve  310  to the airbag unit  200 , and a second flow path, through which the working gas is supplied from the main valve  310  to the conventional airbag system (CAS), may share at least partially a common flow path. Accordingly, it is possible to minimize space requirements that occur when the configuration of the present embodiment is expanded and applied to the conventional airbag system (CAS). Meanwhile, a check valve CV, which regulates the supply of the working gas in order to limit an unnecessary operation of the conventional airbag system (CAS), may be provided on the second flow path (that is, a flow path of the second flow path not corresponding to the common flow path) extending from the aforementioned common flow path. 
     Next, the control unit  400  may determine a hitting position defined as the position of the interior material IM, at which the occupant is expected to be hit, on the basis of the collision information of the vehicle and the seating state information of the occupant detected by the detection unit  100 , and control the valve unit  300  to supply the working gas to a target airbag module installed at the hitting position among the plurality of airbag modules  210 , thereby inflating the target airbag module. The control unit  400  that performs the above operation may be functionally integrated into an ECU that controls the aforementioned air suspension system (ASS). 
     First, a process of determining the hitting position is described. As described above, the collision information of the vehicle may include the information on the amount of impact on the vehicle, and the seating state information of the occupant may include the image information of the occupant in the interior space of the vehicle. Accordingly, the control unit  400  may determine the hitting position on the basis of an impact direction acquired from the information on the amount of impact and a pose of the occupant acquired from the image information. 
     That is, since the information on the amount of impact corresponds to vector information including the magnitude of the amount of impact and the impact direction and the position of a head of the occupant may be detected through the pose of the occupant acquired from the image information, the control unit  400  may determine the position of the interior material IM, at which the head of the occupant is expected to be hit, that is, the hitting position, on the basis of the impact direction and the current position of the head of the occupant. 
     When the hitting position is determined, the control unit  400  may operate to control the valve unit  300  to supply the working gas to an airbag module (defined as a target airbag module) installed at the hitting position among the plurality of airbag modules  210 , thereby inflating the target airbag module. That is, when the hitting position and the target airbag module are determined, the control unit  400  may control the target airbag module to be inflated by opening the main valve  310  and opening the sub-valve  320  connected to the target airbag module. Accordingly, even in various poses of the occupant, for example, even when the occupant is sleeping while lying on the seat, standing, reading a book or watching a display while sitting on the seat, and the like, a target airbag module for protecting the occupant may be determined and operated, thereby effectively protecting the occupant. 
     The control unit  400  may also complementarily control the airbag unit  200  and the conventional airbag system (CAS) according to the seating state information of the occupant. For convenience of description, the control of the control unit  400  for the airbag unit  200  and the control of the control unit  400  for the conventional airbag system (CAS) are defined as first control and second control, respectively. 
     The control unit  400  may perform the first control when the pose of the occupant acquired from the image information of the occupant does not satisfy the normal seating condition described above. That is, when the occupant is in an abnormal seating state in which the occupant is sleeping while lying on the seat, standing, or reading a book or watching a display while sitting on the seat, instead of in a general pose, the occupant may not be sufficiently protected through the conventional airbag system (CAS). Thus, the control unit  400  may determine a hitting position and perform the first control for inflating a target airbag module. In such a case, the control unit  400  may close the check valve CV described above so that the second control is unnecessarily performed. 
     On the other hand, the control unit  400  may perform the second control when the pose of the occupant acquired from the image information of the occupant satisfies the normal seating condition. That is, when the occupant is sitting in the vehicle seat in a general pose, the occupant may be protected only by the conventional airbag system (CAS). Thus, the control unit  400  may perform only the second control without performing the unnecessary first control. 
       FIG. 8  is a flowchart for explaining a control method of the airbag device of a vehicle in accordance with an embodiment of the present disclosure. Hereinafter, the control method of the airbag device of a vehicle in accordance with an embodiment of the present disclosure is described with reference to  FIG. 8 , and the following description is focused on the time-series configuration of the control method, except a description overlapping the aforementioned description. 
     First, the control unit  400  acquires the collision information of the vehicle and the seating state information of the occupant detected by the detection unit  100  (S 100 ). 
     Next, the control unit  400  determines whether the pose of the occupant acquired from the image information of the occupant satisfies the normal seating condition (S 200 ). 
     When it is determined in step S 200  that the pose of the occupant does not satisfy the normal seating condition, the control unit  400  determines the hitting position defined as the position of the interior material IM, at which the occupant is expected to be hit, on the basis of the collision information of the vehicle and the seating state information of the occupant acquired in step S 100  (S 300 ). 
     Then, the control unit  400  performs the first control for controlling the valve unit  300  to supply the working gas to a target airbag module installed at the hitting position among the plurality of airbag modules  210 , thereby inflating the target airbag module (S 400 ). 
     Meanwhile, when it is determined in step S 200  that the pose of the occupant satisfies the normal seating condition, the control unit  400  performs the second control for inflating the conventional airbag system (CAS) (S 500 ). 
     As described above, the present embodiment may protect an occupant in all directions in a vehicle interior by installing an airbag device in an interior material formed in an interior space of a vehicle instead of a fixed position in the related art, may reuse an airbag by adopting a structure in which working gas for deploying an airbag module is secured through an air suspension system applied to the vehicle and simultaneously is naturally discharged and disappear after the airbag is deployed, and may more completely protect the occupant of the vehicle from a collision through a method of complementarily operating the airbag device with a conventional airbag system previously applied to the vehicle. 
     Although the present disclosure has been described with reference to the embodiments illustrated in the drawings, the embodiments of the disclosure are for illustrative purposes only, and those skilled in the art will appreciate that various modifications and other equivalent embodiments are possible from the embodiments. Thus, the true technical scope of the present disclosure should be defined by the following claims.