Abstract:
A steering wheel position control system for a vehicle comprises a controller for a vehicle. The controller includes a processor and a memory. The memory stores instructions executable by the processor. The controller is programmed to receive values from the sensors. The controller commands a pivot mechanism to bias a steering wheel to a stowed position based on values from the sensors. The controller also deploys an air bag based on values from the sensors, wherein the steering wheel is pivoted out of a space envelope of the deployed airbag.

Description:
BACKGROUND 
       [0001]    In an autonomous vehicle capable of driving from one location to another without one or more inputs typically provided by a human operator, e.g., steering, a steering wheel is no longer needed to pilot the vehicle. However, present vehicles typically rely on a steering wheel for housing a driver-side airbag. Further, even in an autonomous vehicle intended to be driven entirely without human operator steering input, the lack of a steering wheel and the associated inability to manually steer the vehicle can result in a potential stranding of the vehicle and/or a dangerous inability for an operator to assume control, e.g., upon a loss of autonomous function due to weather and other reasons. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0002]      FIG. 1  is a schematic side view of an exemplary interior seat and steering wheel arrangement of a vehicle with a steering wheel in a first position. 
           [0003]      FIG. 2  is a schematic side view of the exemplary interior seat and steering wheel arrangement of  FIG. 1  with the steering wheel in a second position and an air bag deployed. 
           [0004]      FIG. 3  is a perspective view of the exemplary interior seat and steering wheel arrangement of  FIG. 1 . 
           [0005]      FIG. 4  is a perspective view of the exemplary interior seat and steering wheel arrangement of  FIG. 2  with the steering wheel in a second position and an air bag deployed. 
           [0006]      FIG. 5  is a schematic of an exemplary steering wheel position control system. 
           [0007]      FIG. 6  is a flow chart of exemplary logic for the steering wheel position control system of  FIG. 5 . 
       
    
    
     DETAILED DESCRIPTION 
       [0008]    A movable steering wheel can be moved between a driving position and a stowed position. The movable steering wheel has no airbag. Therefore, a driver-side airbag is mounted in a location other than on the steering wheel, such as a roof location or a dashboard location. A driver side arrangement symmetrical with that of the front passenger side could be employed for driver side airbag location and design. Such commonality would reduce development costs by enabling a single crash safety analysis/program to be done with the steering wheel in either position. Another benefit of such a system is the ability to easily move the steering wheel into the driving position to enable manual operation of the vehicle when manual operation is needed or desired. 
         [0009]    Relative orientations and directions (by way of example, upper, lower, bottom, rearward, front, rear, back, outboard, inboard, inward, outward, let, right) are set forth in this description not as limitations, but for the convenience of the reader in picturing at least one embodiment of the structures described. 
         [0010]      FIG. 1  and  FIG. 2  show a portion of an exemplary vehicle  10  with a passenger cabin  12  defined in part by a roof  14  and a windshield  16 . An exemplary driver seat  18  and an exemplary stowable steering wheel  20  are located in passenger cabin  12  with seat  18  oriented in a conventional forward-facing direction. Steering wheel  20  is illustrated in a driving position. A driver or occupant  22  is illustrated in seat  18 . 
         [0011]    Steering wheel  10  is fixed to a steering support module  24  extending from an instrument panel region  26  of a dashboard  28 . A driver airbag  30  shown in  FIG. 2  and  FIG. 4  in its deployed mode is located in the vehicle dashboard  28  as shown in  FIG. 4  or alternatively in the roof rather than steering wheel  20 . The volume taken up by the deployed airbag  30  may be characterized as a space envelope  32  of airbag  30 , shown in phantom in  FIG. 4 . Steering wheel  20  and steering support module  24  can be pivoted away from the reach of driver  22 , to a stowed position on a lower side of the dashboard when not needed as illustrated in  FIG. 2 . Steering wheel  20  can also be moved back to the place illustrated in  FIG. 1 , within the driver&#39;s reach. A pivot mechanism  34 , shown in the exemplary schematic of  FIG. 5  illustrating an exemplary steering wheel position control system  35 , disposed between module  24  and dashboard  28  enables steering support module  24  to sustain and transmit driver torque to the vehicle&#39;s steering gear (not shown) when module  24  and steering wheel  20  are in the driving position. In one example of a pivot mechanism  34 , steering wheel and support module  24  are spring-biased toward the stowed position. A selectively disengageable latch (not shown) of pivot mechanism  34  retains the spring biased steering support module in the driving position. One exemplary embodiment employs an electromechanically displaceable latch. The latch can be disengaged electronically by an electrically controlled actuator (not shown). Pivot mechanism  34 , more specifically the actuator, is electrically connected to an electronic control unit  36 . Steering wheel  20  is restored to the driving position by lifting steering wheel  20  up against the spring load until engagement of the latch is achieved. 
         [0012]    If the vehicle steering is provided by a conventional mechanical steering linkage, an exemplary module  24  includes an upper portion of a steering column. Alternatively, if the steering system is a steer-by-wire system, an exemplary module includes a combination of a feedback motor, sensors  38 , and a bearing-mounted stub shaft. Each type of steering system would require a distinct pivot mechanism  34 . Further details of the pivot mechanism  34  are not needed in this disclosure because a functional pivot mechanism is within the range of skill of one skilled in the art to provide. 
         [0013]    Steering wheel  20  is smaller in size than most conventional steering wheels, with a maximum outer radius of approximately five inches in one exemplary embodiment. Steering wheel  20  can be oval or yoke shaped to further reduce its size. When steering wheel  20  pivots to the stowed position, it can be disconnected from the steering system to enable storage in a predetermined rotational orientation independent of the steering orientation of the vehicle wheels, and reoriented when the steering wheel is restored to the driving position. If the steering system is a steer-by-wire system, the above-described disconnect and subsequent reconnection can be achieved through controller software as discussed below. If the steering system is a conventional mechanical steering linkage, an exemplary clutch connection could be employed in which a clutch (not shown) is released in the stowed position and engaged in the drive position. Engagement and disengagement of the clutch is achieved with the pivoting of module  24 . 
         [0014]    Steering wheel  20  and module  24  drop and pivot downward to the stowed position, a location on a lower side of the dashboard  28 , when deployment of driver airbag  30  is anticipated or underway. Steering wheel  20 , if in the driving position, drops out of the way of airbag  30  to allow deployment of airbag  30 . When stowed, steering wheel  20  and module  24  do not interfere with the deployment of airbag  30 . The driver, when seated in an upright position, is not able to reach steering wheel  20  when it is in the pivoted, stowed position. 
         [0015]    The steering system is electrically connected to, and/or may be understood as including, the electronic control unit  36 , alternatively characterized as a controller or a computer. Electronic control unit  36  is also electrically connected to the airbag, and to sensors  38  which can include, by way of example, seat weight load sensors, vehicle speed sensors, accelerometers indicating changes in vehicle speed as may be indicative of an impact event, and seat position sensors. Sensors  38  provide electrical signals to electronic control 36 unit indicative of their respective parameters. While  FIG. 5  includes lines indicative of the electrical connections being provided by wires, such electronic connections may alternatively be made without wire using wireless communications technology. 
         [0016]    The electronic control unit  36  includes at least one electronic processor and associated memory. The processor&#39;s operating system software is stored in memory for access by the processor. Also, control software for executing certain predetermined tasks is maintained in memory. The memory also includes a buffer region, or more simply a buffer, facilitating the storage and manipulation of data. The precise structure of electronic control unit  36  is not critical to the present description and is within the knowledge of those skilled in the art. Electronic control unit  36  is programmed by control software to cause steering wheel  20  and module  24  to pivot to the stowed position responsive to data from sensors  38  that is determined by electronic control unit  36  to be indicative of an impact event. In an exemplary embodiment, the pivoting of steering wheel  20  and module  24  to the stowed position occurs when the actuator of pivot mechanism  34  displaces the latch to a disengaged position, allowing a spring bias on module  24  to pivot module  24  and steering wheel  20  from the drive position to the stowed position. Electronic control unit  36  is also programmed by software to deploy the driver airbag  30  responsive to data from sensors  38  determined by electronic control unit  36  to be indicative of an impact event. 
         [0017]    The exemplary logic of  FIG. 6  illustrates steps for a method of moving or positioning steering wheel  20 . A program  40  is initiated with start block  42 . In decision block  44 , a determination is made, based on signals available to electronic control unit  36 , on whether the vehicle is in a “Run” mode of operation. When the vehicle is determined to not be in the run mode, program  40  moves to an end block  46 . When the vehicle is determined to be in the run mode, program  40  moves to process block  48 . Process block  48  directs electronic control unit  36  to read a value of at least one sensor  38 . Upon reading sensor  38  in accord with process block  48 , program  40  moves to decision block  50 . Decision block  50  determines whether, based on the value from sensor  38 , an impact event has occurred. When occurrence of an impact event is not determined, the program moves back to decision block  44 . When the occurrence of an impact event is determined, the program moves to blocks  52  and  54  to deploy airbag  30  and pivot steering wheel  20 . The sequencing of pivoting and deployment is established to ensure that steering wheel  20  does not interfere with the deployment of airbag  30 , and does not pose an impingement risk to driver  22 . For example, airbag  30  may be deployed simultaneously with, or even before steering wheel  20  is pivoted if it is known that steering wheel  20  will clear space envelope  30  before airbag  30  is fully deployed. 
         [0018]    It is to be understood that the present disclosure, including the above description and the accompanying figures and below claims, is intended to be illustrative and not restrictive. Many embodiments and applications other than the examples provided would be apparent to those of skill in the art upon reading the above description. The scope of the invention should be determined, not with reference to the above description, but should instead be determined with reference to claims appended hereto, along with the full scope of equivalents to which such claims are entitled. Unless otherwise stated or qualified herein, all claim terms are intended to be given their plain and ordinary meanings. It is anticipated and intended that future developments will occur in the arts discussed herein, and that the disclosed systems and methods will be incorporated into such future embodiments. In sum, it should be understood that the disclosed subject matter is capable of modification and variation.