Patent Publication Number: US-2022219621-A1

Title: Controlled detachment features of steering column mounted camera

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This PCT application claims the benefit of priority under 35 U.S.C. § 119 to United States Provisional Application No. 62/852,737, filed May 24, 2019, the contents of which are incorporated herein by reference in their entirety. 
    
    
     FIELD OF THE INVENTION 
     The present application generally relates to camera assembly for mounting in the interior of a motor vehicle. 
     BACKGROUND 
     Present motor vehicles incorporate numerous features for the control of vehicle functions and to provide a comfortable environment for vehicle occupants while providing access to information, media and communication functions. Another primary objective is to provide occupant protection. Occupant protection approaches can be divided into two primary areas; active and passive safety. Passive safety features include inflatable restraints, seatbelts and other functions deployed upon the occurrence of a vehicle impact or rollover event. Active safety functions are intended to reduce the likelihood of an impact, and include such features as blind spot detection, adaptive cruise control and other advanced driver assist systems (ADAS). Some technologies are enabled through the use of vehicle interior-mounted displays and cameras. An interior camera oriented toward the driver can be used for communication functions and can also monitor driver alertness and their position relative to the vehicle steering wheel and other structures. One location for mounting these devices is on the upper surface of a vehicle steering column. There are numerous challenges posed by providing such a mounting location. Steering columns are designed with crushable structures to absorbed impact energy upon a frontal impact. Typically a driver airbag is carried by the vehicle steering wheel and inflates to absorb impact energy. Whether or not a driver airbag inflates, compressive loads are placed on the steering column and its energy absorbing crushable features and enable it to stroke to absorb energy. Any cameras or other device mounted on the upper portion of the steering column need to accommodate such displacement and loading conditions. 
     Column mounted camera systems on the steering wheel pose a problem of becoming a hazard in a crash situation. Conventional MHI displays are provided in the vehicle instrument panel. In some applications, it is desirable to provide the display near the upper surface of the steering column. This forward positioning gives access to the driver for proper HMI input from the driver. Mounting any kind of module such as a camera in front of these displays may have adverse effects in a crash situation, as the packaging in and around the steering wheel is very dense and is sensitive and prone to damage due to mechanical vibration and shock. In a crash situation it is important that components not be free to move in an uncontrolled manner in the vehicle interior which could pose an occupant injury risk. In addition, the devices must not interfere with the proper deployment of an inflatable restraint carried by the steering wheel hub or other mounting positions. Further, it is desirable to protect the sensitive and expensive display components from mechanical damage in an impact or any other condition where a camera might become dislodged from its mounted position in front of the display. 
     SUMMARY 
     In accordance with the present invention a camera module mountable in a vehicle is provided. The camera module includes a camera and a mount. The mount is preferably adapted to be positioned at the upper surface of a vehicle steering column. The camera assembly is affixed to the mount through snap features that are configured to release though cam features during an impact to control the direction of the camera during dislodgement. A tether can be used attached to the camera assembly to further constrain its motion after detachment. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a frontal view of a motor vehicle steering wheel. 
         FIG. 2  is a side view of a motor vehicle steering wheel and steering column showing locations for mounting a display and camera assembly. 
         FIG. 3  is a pictorial view of a camera assembly detached from its mounting structure. 
         FIG. 4  is a pictorial view of the camera assembly affixed to its mounting structure. 
         FIG. 5  is a pictorial view showing the camera assembly in a mounted position and showing exemplary inertial forces acting on the camera assembly. 
         FIG. 6  is a side view showing the camera assembly dislodged from the mounting structure. 
         FIG. 7  is a pictorial view of the camera assembly mounted to the upper portion of a vehicle steering column. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  illustrates an example of a motor vehicle steering wheel assembly  10  shown from the perspective of a driver position behind the steering wheel. A small portion of camera assembly  12  can be seen in the upper open quadrant of steering wheel assembly  10 . 
       FIG. 2  is a side view of steering wheel assembly  10  showing steering column  14  and control stalk  16  and the position of display  18 , normally integrated into the vehicle&#39;s instrument panel. As shown, there is a close spacing in the fore-and-aft (vehicle forward traveling) direction between camera assembly  12  and display  18 . For reasons discussed previously, it is desirable to protect display  18  from damage and otherwise to control the movement of camera assembly  18  should it become dislodged from its mounted position in an impact or other event. 
       FIG. 3  provides a pictorial view of camera assembly  12 . As shown camera assembly  12  includes a generally flat housing base  22  and upwardly extending panel  24  providing a mount for an imaging sensor and associated optical components  26  (not shown in detail). On the bottom surface of panel  24  there is provided four downwardly projecting legs  28  each having lower ramped barbs or teeth  30 . Teeth  30  feature a ramped lower surface  32  and a forward projecting barb  34 . Housing base  22  features four of teeth  30  with a pair aligned on each lateral side of the base, although other numbers could be provided. 
       FIG. 4-6  show camera assembly  12  mounted to camera mounting structure  36 . Camera mounting structure  36  may be a separately formed component affixed (removably or permanently) to steering column shroud  38  or may have its features integrated into a larger part of shroud  38  (or another component). Mounting structure  36  incorporates rectangular first apertures  40  for receiving legs  28  for locking in place camera assembly  12 . Referring in particular to  FIG. 5 , legs  28  are received into apertures  40  which are dimensioned to cause deflection of the legs, squeezing them together laterally and then allowing them to snap into a final install position with teeth  30  engaged with a underside surface below apertures  40 . In accordance with this invention features are provided for causing the separation between camera assembly  12  and mounting structure  36  to happen in a controlled and predicted manner. For example, inertial forces may act on camera assembly  12  in an impact or other obstacles such as an inflating airbag or other forces may act on camera assembly  12 , causing it to become detached from mounting structure  36 . 
     Referring to  FIGS. 5 and 6 , mounting structure  36  includes first apertures  40  for receiving legs  28  and second aperture  46  separated from aperture  40 . Cavity  48  extends between the two apertures  40  and  46 , with tab feature  50  between them. Tab feature  50  provides a weakened area which will fail when loads act on camera assembly  12  as will be described further as follows. In the installed position, leg teeth  30  snap in position with barbs  34  hooked onto a lower surface of mounting structure  36 . Mounting structure  36  provides curved ramp (or cam) surfaces  42  creating a curved pathway  44  for movement of legs  28  in the event that loads act on camera assembly  12  causing it to become dislodged. Curved pathway  44  extends between the two apertures and provides a surface for legs  28  to ride along upon the occurrence of camera assembly  12  being released from mounting structure  36 . The ramp or cam surfaces  42  may be radiused forward and upward (in the vehicle forward travel direction) to assist and control pivoting of camera module  12  during dislodgment. 
       FIG. 5  shows camera assembly  12  fastened in position to mounting structure  36 . As shown, legs  28  are snapped into position.  FIG. 5  shows an example colliding structure  54  contacting camera assembly  12 . Colliding structure  54  is just an example of any object that might contact or act on camera assembly  12  causing it to become detached. Similar detachment can occur strictly through inertial forces acting on the camera assembly  12 . Colliding structure  54  is only exemplary of any force input causing detachment of camera assembly  12 . 
     As illustrated in  FIG. 6 , when sufficient loads are applied to camera assembly  12 , tab feature  50  preferably fails to release the camera assembly. In the event of such detachment, legs  28  riding along ramp surfaces  42  produce an upward displacement of camera assembly  12  as it separates from mounting structure  36 . This produces a predictable and controlled trajectory for camera assembly  12  upon its separation. As shown by  FIGS. 3-4 and 7  cable  56  is attached to camera assembly  12  and includes an electrical connector  58 . Cable  56  acts as a tether providing a structural connection to restrain motion of camera assembly  12  after release from the mounting structure  36 . Preferably, cable  56  has necessary tensile properties with a suitable strong connection with camera assembly  12  and electrical connector  58  which would be attached to an associated vehicle interior component. Routing of cable  56  is shown in a diagrammatic manner in  FIG. 7 . In practice, cable  56  and electrical connector  58  would be enclosed by shroud  38  or other interior panels. The length of the cable  56  is chosen to prevent the fully dislodged camera assembly  12  from entering the airbag deployment zone or from traveling into the instrument display  18 . Cable  56  may be attached to the side of camera assembly  12  such that the tension in the cable will direct the camera unit to the side when dislodged. In some implementation, more than one cable or tether may be used. 
     It is also contemplated within this disclosure that camera assembly  12  may be replaced by a different attachment unit or electronic unit and that the ramp surfaces  52  may be provided to extend or curve in another manner to direct the unit in a different direction. The weakened areas provided by tab portion  50  may be material within the mounting structure  36  that breaks away as the unit is dislodged. Camera assembly leg barbs  34  may have an edge that may be sharp to cut into or otherwise aid in the breaking away of the weakened areas during dislodgement. 
     Further, it is contemplated within this disclosure that the snap features and the ramp or cam features may be located on either the camera assembly or the mounting structure to control the direction of dislodgement of the camera during an impact. 
     As a person skilled in the art will readily appreciate, the above description is meant as an illustration of the principles of this application. This description is not intended to limit the scope or application of the claim in that the assembly is susceptible to modification, variation and change, without departing from spirit of this application, as defined in the following claims.