Patent Publication Number: US-2005140127-A1

Title: System and method for steering wheel adjustment

Description:
BACKGROUND  
      The present application claims priority to and benefit of U.S. Provisional Application Ser. No. 60/532,625, filed Dec. 29, 2003.  
      The present invention relates generally to the field of safety restraint systems. In particular, the invention relates to steering wheel positioning and/or airbag pressurization based on occupant characteristics.  
     SUMMARY OF THE INVENTION  
      According to an embodiment of the present invention, a steering wheel positioning method for a vehicle. The method includes sensing occupant characteristics of an occupant in a seat facing a steering wheel. An inflator control for an airbag in the steering wheel is adjusted based on the occupant characteristics, and the steering wheel is positioned based on the occupant characteristics and the inflator control.  
      Another embodiment of the present invention provides a steering wheel positioning system for a vehicle. The system includes an occupant characteristics sensing module, an inflator control module and a steering wheel control module. The occupant characteristics sensing module is adapted to determine characteristics of an occupant in a seat facing a steering wheel. The inflator control module is adapted to adjust inflator gas flow rate to an airbag in the steering wheel based on the occupant characteristics. The steering wheel control module is adapted to position the steering wheel based on the occupant characteristics and the inflator gas flow rate.  
      According to yet another embodiment of the present invention, a safety restraint control method for a vehicle is provided. The method includes sensing occupant characteristics of an occupant in a seat facing a steering wheel, and determining a position of the steering wheel. An inflator control for an airbag in the steering wheel is adjusted based on the occupant characteristics and the position of the steering wheel.  
      According to a safety restraint control system is provided. The system includes an occupant characteristics sensing module, a steering wheel position module and an inflator control module. The occupant characteristics sensing module is adapted to determine characteristics of an occupant in a seat facing a steering wheel. The steering wheel position module is adapted to determine a position of the steering wheel, and the inflator control module is adapted to adjust inflator gas flow rate to an airbag in the steering wheel based on the occupant characteristics and the position of the steering wheel.  
      It is to be understood that both the foregoing general description and the following detailed description are exemplary and exemplary only, and are not restrictive of the invention as claimed. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      These and other features, aspects, and advantages of the present invention will become apparent from the following description, appended claims, and the accompanying exemplary embodiments shown in the drawings, which are briefly described below.  
       FIG. 1  is a schematic illustration of an embodiment of a steering wheel adjustment system according to the present invention;  
       FIG. 2  is a flow chart illustrating a method for adjusting a steering wheel position;  
       FIG. 3  is a schematic illustration of an embodiment of a safety restraint control system according to the present invention;  
       FIG. 4  is a flow chart illustrating a method for adjusting a safety restraint component according to the present invention;  
       FIGS. 5A and 5B  illustrate an embodiment of a belt reacher system for use with the present invention;  
       FIGS. 6A and 6B  illustrate an embodiment of a belt buckle positioning system for use with the present invention;  
       FIGS. 7A and 7B  illustrate another embodiment of a belt buckle positioning system for use with the present invention; and  
       FIG. 8  illustrates an embodiment of a seatbelt height adjustment system for use with the present invention. 
    
    
     DETAILED DESCRIPTION  
      Referring to  FIG. 1 , an embodiment of a steering wheel adjustment system in a vehicle, such as an automobile, according to the present invention is illustrated. The steering wheel adjustment system  100  includes an occupant sensing module  110 . The occupant sensing module  110  is adapted to detect certain characteristics of an occupant of a seat facing the steering wheel of the vehicle. The occupant sensing module  110  may be capable of detecting or measuring such occupant characteristics as the weight of the occupant and the height of the head of the occupant in the seated position. Such occupant sensing modules are well known to those skilled in the art.  
      One embodiment of such a sensing module is a seat weight sensor (SWS). An SWS system may include one or more sensors positioned along or within the seat and are capable of detecting, measuring or sensing the weight of an occupant in the seat. Another embodiment of a sensing module includes an electric capacity sensor.  
      In other embodiments, the sensing module includes an image recognition sensor. The image recognition sensor may include one or more of a CCD camera, a CMOS camera, a 3D camera and a stereo camera. One such image recognition sensor is described in U.S. Provisional Patent Application Ser. No. 60/627,027, titled “Vehicle Safety Control System by Image Processing,” filed Nov. 12, 2004, which is hereby incorporated by reference in its entirety.  
      The occupant sensing module  110  communicates the occupant characteristics to an inflator gas flow control module  120 . The inflator gas flow control module  120  controls the flow rate of gas into an airbag during pressurization. For example, in the event of an airbag-deployment event, an airbag housed within the steering wheel or the steering wheel column is deployed by flowing gas into the airbag at a high rate. The inflator gas flow control module  120  controls the gas flow rate based on the occupant characteristics. The gas flow rate may be determined, for example, using a table look up or a set of polynomial coefficients. In one embodiment, the gas flow rate is set at a baseline rate and is adjusted along a substantially continuous set of levels based on the occupant characteristics. For example, the flow rate may be a linear or logarithmic function of the weight of the occupant. In another embodiment, the gas flow rate is adjusted at predetermined, discrete values based on the occupant characteristics. In this regard, the flow rate is stepped to higher or lower levels, each level corresponding to a range of weights for the occupant. In a preferred embodiment, the flow rate is set to a lower rate only when the occupant characteristics indicate that the driver is smaller than a fifth-percentile adult female.  
      The occupant sensing module  110  and the inflator gas flow control module  120  communicate information to a steering wheel adjustment module  130 . In this regard, the occupant sensing module  110  communicates the occupant characteristics, while the gas flow control module  120  transmits the gas flow rate. The steering wheel adjustment module  130  is adapted to cause the steering wheel to be positioned to improve safety based on the adjusted flow rate. The positioning of the steering wheel may include adjustment of the steering angle and/or the extension of the steering column. The steering angle refers to the vertical angle of the steering column, and the extension refers to the protrusion of the steering column into the cab of the vehicle. The steering angle and extension may be determined using, for example, a one- or multi-dimensional table look up or a set of polynomial coefficients.  
       FIG. 2  illustrates the adjustment of the steering angle and/or extension according to an embodiment of the invention. Initially, at block  210 , the inflator gas flow rate may be set at a baseline level determined, for example, to be applicable to a majority of the population. At block  220 , the occupant characteristics of the occupant of the driver seat are determined. As noted above, the occupant characteristics may include, without limitation, the weight of the occupant and the height of the head of the occupant.  
      At block  230 , a determination is made as to whether or not the occupant characteristics indicate the need to adjust the inflator flow rate level. As described above with reference to  FIG. 1 , the required flow rate level may be determined through a table lookup or a set of polynomials and may be either continuous or discrete. If no adjustment is required, the process terminates.  
      If the determination at block  230  indicates a need to adjust the inflator flow rate level, the flow rate may be adjusted to the desired level, and a second determination is made at block  240  to determine whether the occupant characteristics and the adjusted inflator flow rate level dictate an adjustment of the steering wheel angle and/or extension. If no adjustment to the steering wheel angle or extension is required, the process terminate.  
      If the determination at block  240  indicates a need to adjust the steering wheel position, the appropriate adjustment is determined (block  250 ). As indicated above with reference to  FIG. 1 , the adjustment may include adjustment of the steering wheel angle and/or the extension. Thus, the steering wheel is automatically set at a safe position for the driver.  
      In one embodiment, the adjustments to the steering wheel position are made each time the occupant seats himself in the vehicle. Adjustments may be made thereafter on a regular basis to accommodate a driver who tends to shift sitting positions during a long drive, for example.  
       FIG. 3  illustrates an embodiment of a safety restraint control system according to the present invention. In certain cases, an occupant may manually adjust the steering wheel to a position that is comfortable or otherwise desirable for the occupant. In this regard, the safety restraint control system adjusts the inflator gas flow rate to a safe level.  
      In this embodiment, the safety restraint control system  300  includes an occupant sensing module  310  and similar to that described above with reference to  FIG. 1 . The occupant sensing module  310  communicates occupant characteristics to an inflator gas flow control module  330 . A steering wheel position module  320  is provided to determine the current position of the steering wheel. As noted above, the position of the steering wheel may include the steering wheel angle and the extension. The steering wheel position module  320  communicates information relating to the steering wheel position to the inflator gas flow control module  330 .  
      The inflator gas flow control module  330  then adjusts the gas flow rate at a level based on the occupant characteristics received from the occupant sensing module  310  and the steering wheel position module  320 . As an example, if the occupant characteristics indicate an occupant smaller than the fifth-percentile adult female, and the steering wheel position information indicates that the driver has positioned the steering unusually close to his/her face (i.e., large extension), the gas flow rate may be adjusted to compensate for both the size of the occupant and the proximity of the steering wheel to the head of the occupant.  
       FIG. 4  illustrates the adjustment of the inflator gas flow rate according to an embodiment of the invention. Initially, at block  410 , the inflator gas flow rate may be set at a baseline level determined, for example, to be applicable to a majority of the population. At block  420 , the occupant characteristics of the occupant of the driver seat are determined. As noted above, the occupant characteristics may include, without limitation, the weight of the occupant and the height of the head of the occupant. At block  430 , the steering wheel position (e.g., weight of the occupant, height of the head of the occupant, etc.) is determined.  
      At block  440 , a determination is made as to whether the occupant characteristics and the steering wheel position dictate an adjustment of the inflator flow rate level. As described above, the required flow rate level may be determined through a table lookup or a set of polynomials and may be either continuous or discrete. If no adjustment is required, the process terminates.  
      If the determination at block  440  dictates an adjustment of the inflator gas flow rate, the appropriate adjustment is determined (block  450 ) and is applied during an airbag-deployment event. Thus, improved safety may be achieved despite the occupant&#39;s manual adjustment of the steering wheel to an otherwise unsafe position.  
      The adjustments to the inflator gas flow rate may be made each time the occupant seats himself in the vehicle. Adjustments may be made thereafter on a regular basis to accommodate a driver who tends to shift sitting positions during a long drive, for example.  
      In addition to, or in place of, adjustments to the steering wheel angle and extension, other vehicle settings may be adjusted in response to the determined occupant characteristics. For example, the position or shape of the vehicle seat, seat cushion or seat back may be correspondingly adjusted. Further, the side view and rear view mirrors may be adjusted according to the determined occupant characteristics.  
      In other embodiments, the various components of a seatbelt mechanism may be appropriately adjusted. For example,  FIGS. 5A and 5B  illustrate an embodiment of a belt reacher system for adjustment of a seatbelt buckle, or tongue, position.  FIGS. 5A and 5B  illustrate the belt reacher system  10  in a retracted position and an extended position, respectively. The reacher system  10  is mounted on or adjacent to a vehicle seat  2  adapted to accommodate a passenger or driver therein. The belt reacher system  10  includes an extension module  17  adapted to position a seatbelt tongue  18  for easy access by the occupant of the seat  2 . In this regard, when the occupant sits in the seat  2 , the sensor module determines the occupant characteristics and causes the belt reacher system  10  to accordingly position the tongue  18 . In this regard, the extension module  17  is provided with a housing  13  from which one or more extension may protrude. In the illustrated embodiment, three extensions  14 ,  15 ,  16  protrude serially from the housing  13  to position the tongue  18  for easy access by the occupant. Once the occupant removes the tongue from the extension module  17  and engages the tongue  18  with a buckle (not shown), the extension module  17  may return to its retracted position, as shown in  FIG. 5A .  
       FIGS. 6A and 6B  illustrate an embodiment of a belt buckle positioning system for moving a belt buckle between an engaged and a disengaged position. In this regard, the belt buckle positioning system  42  is provided with a buckle  6  adapted to engage a tongue  5  ( FIG. 6B ). The belt buckle positioning system  42  includes a buckle  6  mounted on a buckle bar  43  which is adapted to pivot about a pivot point  46 . The buckle bar  43  includes an opening  43   a  for engaging a drive bar  44  with a connector pin  47 . The drive bar  44  is connected to a drive assembly  48  driven by a motor  45 . In response to the determination of occupant characteristics while the buckle  6  is in a disengaged position ( FIG. 6A ), the motor  45  may be actuated to drive the screw assembly  48 . As the screw assembly  48  is driven, a screw  50  of the screw assembly  48  causes a drive block  49  to extend toward the drive bar  44  and to drive the drive bar  44 . As the drive bar  44  is driven, the buckle bar  43  rotates about the pivot point  46 , causing the buckle  6  to be positioned in the engaged position ( FIG. 6B ). The amount of rotation of the buckle bar  43  and, thus, the engaged position, may be determined according to the determined occupant characteristics.  
       FIGS. 7A and 7B  illustrate another embodiment of belt buckle positioning system for moving a belt buckle between an engaged and a disengaged position. In this regard, the belt buckle positioning system  42   a  is provided with a buckle  6   a  adapted to engage a tongue  5  ( FIG. 7B ). The belt buckle positioning system  42   a  includes a buckle  6   a  mounted on a buckle bar  43   a  which is adapted to extend and retract between a disengaged position ( FIG. 7A ) and an engaged position ( FIG. 7B ). The buckle bar  43   a  is connected to a drive assembly  48   a  driven by a motor  45   a . In response to the determination of occupant characteristics while the buckle  6   a  is in a disengaged position ( FIG. 7A ), the motor  45   a  may be actuated to drive the screw assembly  48   a . As the screw assembly  48   a  is driven, a screw  50   a  of the screw assembly  48   a  causes a drive block  49   a  to extend toward the buckle bar  43   a  and to drive the buckle bar  43   a . As the buckle bar  43   a  is driven, the buckle  6   a  is extended into the engaged position ( FIG. 7B ). The amount of extension of the buckle bar  43   a  and, thus, the engaged position, may be determined according to the determined occupant characteristics.  
       FIG. 8  illustrates an embodiment of a seatbelt height adjustment system for use with embodiments of the present invention. The seatbelt height adjustment system  800  is positioned for use by an occupant  820  in a vehicle seat  810 . The occupant  820  is secured in the seat  810  by a seatbelt including a shoulder belt  830 . Once the occupant  820  is seated in the vehicle seat  810 , occupant characteristics may be determined according to the sensors described above. Based on the determined occupant characteristics, the vertical position of an anchor  840  of the shoulder belt may be adjusted, thereby adjusting the height of the shoulder belt  830 .  
      The term module is used in describing certain embodiments to refer to certain aspects of the invention. A module may be a software, firmware or hardware component. Further, it will be understood by those skilled in the art that the functions performed by the various modules can be combined into one or more modules. For example, the functions performed by a single module may be divided to be performed by two or more modules, and the functions performed by two or more modules may be combined to be performed by a single module.  
      Given the disclosure of the present invention, one versed in the art would appreciate that there may be other embodiments and modifications within the scope and spirit of the invention. Accordingly, all modifications attainable by one versed in the art from the present disclosure within the scope and spirit of the present invention are to be included as further embodiments of the present invention. The scope of the present invention is to be defined as set forth in the following claims.