Abstract:
A stationary steering wheel assembly includes a steering wheel connected to an axially extending column. The assembly also includes a steering wheel locking component engageable with the steering wheel and moveable between a first position and a second position, the first position locking the steering wheel to prevent rotation and the second position unlocking the steering wheel to allow rotation of the steering wheel.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This patent application claims priority to U.S. Provisional Patent Application Ser. No. 62/184,525, filed Jun. 25, 2015, which is incorporated herein by reference in its entirety. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The embodiments described herein relate to steering wheel assemblies and, more particularly, to a stationary steering wheel assembly, as well as methods associated with controlling the stationary steering wheel assembly. 
         [0003]    As autonomously driven vehicles are developed, a number of opportunities will evolve related to comfort, entertainment and functionality for drivers. Steering wheels are commonly limited to standard driving positions due to the need for a driver to handle the steering wheel during operation of the vehicle. These limitations may be unnecessary during an autonomous driving mode of a vehicle. 
       SUMMARY OF THE INVENTION 
       [0004]    According to one aspect of the disclosure, a stationary steering wheel assembly includes a steering wheel connected to an axially extending column. The assembly also includes a steering wheel locking component engageable with the steering wheel and moveable between a first position and a second position, the first position locking the steering wheel to prevent rotation and the second position unlocking the steering wheel to allow rotation of the steering wheel. 
         [0005]    According to another aspect of the disclosure, a stationary steering wheel assembly includes a steering wheel. Also included is a steering shaft operatively coupled to the steering wheel. Further included is a lower shaft operatively coupled to the steering shaft. Yet further included is a steering shaft locking component engageable with the steering shaft and moveable between a first position and a second position, the first position locking the steering shaft to prevent axial translation and the second position unlocking the steering shaft to allow axial translation of the steering shaft. 
         [0006]    According to yet another aspect of the disclosure, a method of controlling a stationary steering wheel assembly of an autonomous vehicle is provided. The method includes disengaging a steering wheel locking component from a steering wheel in a standard driving mode to allow rotation of the steering wheel. The method also includes engaging a steering shaft locking component with a steering shaft in the standard driving mode to prevent translation of the steering shaft and to allow rotation of the steering shaft upon rotation of the steering wheel. 
         [0007]    These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which: 
           [0009]      FIG. 1  is schematic illustration of a retractable steering column assembly; and 
           [0010]      FIG. 2  is a perspective view of the retractable steering column assembly. 
       
    
    
     DETAILED DESCRIPTION 
       [0011]    Referring now to the Figures, where the invention will be described with reference to specific embodiments, without limiting same,  FIG. 1  illustrates a stationary steering wheel assembly  10 . The stationary steering wheel assembly  10  facilitates translation of a steering wheel  12  and a steering shaft  14  in a retractable manner. The stationary steering wheel assembly  10  also facilitates decoupling the steering wheel  12  from the steering shaft  14  to maintain the steering wheel  12  in a stationary (i.e., non-rotational) condition. These features are provided while maintaining a mechanical link between the road wheels of a vehicle and the steering wheel  12 . This is particularly beneficial in embodiment where the assembly  10  is employed in a passenger vehicle equipped with Advanced Driver Assist System(s) to allow the vehicle to be autonomously controlled using sensing, steering, and/or braking technology. When the ADAS system is activated, the steering wheel is not required for vehicle control. Retraction of the steering wheel  12  and steering shaft  14  toward, and possibly into, the instrument panel greatly enhances user comfort by providing a driver with more space. The additional space provided facilitates additional workspace area or leg room, for example. 
         [0012]    The embodiments described herein provide a retractable steering wheel while the vehicle is in an autonomous, or partially autonomous, driving mode. The operating conditions described herein for the steering wheel are standard driving mode, autonomous driving mode, and a transition mode therebetween. 
         [0013]    In the standard driving mode, the steering wheel assembly  10  is extended to a location that is comfortably reached by a driver in a manner that allows the driver to fully handle and control the steering wheel. In this extended position, the steering wheel  12  is coupled to the steering shaft  14  and the steering shaft  14  is coupled to a lower shaft  16 . The lower shaft  16  is operatively coupled to additional steering components that control the road wheels of the vehicle, thereby allowing the driver to control the road wheels in the standard driving mode. 
         [0014]    The steering wheel  12  coupling to the steering shaft  14  is made, at least in part, with a splined relationship and/or a groove-roller arrangement at location  18  ( FIGS. 1 and 2 ). The steering shaft  14  is coupled to the lower shaft  16  with a ball screw  20 . A steering shaft locking component  22  is extended in the standard driving mode to radially force an engagement member  24 , such as a rolling ball, into an engagement feature  26  (also referred to herein as a receptacle) on the steering shaft  14 , such as a groove dimensioned to at least partially receive the engagement member  24 . In some embodiments, the steering shaft locking component  22  is a solenoid. Engagement of the engagement member  24  and the engagement feature  26  prevents the steering shaft  14  from translating and only allows rotation thereof. Torque and position from the driver are transmitted from the steering wheel  12  to the steering shaft  14  through the spline interface  18  described above and from the steering shaft  14  to the lower shaft  16  through balls and tracks of the ball screw  20 . The lower shaft  16  is attached to a rack assisted electronic positioning system (EPS) that steers the road wheels. Feedback from the road wheels to the driver is transmitted in the reverse fashion. 
         [0015]    During the autonomous driving mode, the driver will activate the ADAS system through some vehicle interface such as a switch or button. Upon activation, a steering wheel locking component  28  locks the steering wheel  12  from rotating by moving between a first position and a second position. In some embodiments, the first position and the second position are radial positions, such that radial engagement is facilitated by the steering wheel locking component  28 . As a matter of safety and visual feedback, in some embodiments the retracted steering wheel remains stationary while the vehicle is in the autonomous driving mode. One way to accomplish the stationary steering wheel function while still maintaining a mechanical link to the road wheel steering system is to incorporate a differential gear in the steering linkage system, as described below. 
         [0016]    In some embodiments, the steering wheel locking component  28  is a solenoid ( FIG. 1 ) that extends and retracts for rotationally locking and unlocking the steering wheel  12  by radially engaging and disengaging a ball or the like  42  with the steering wheel  12 . 
         [0017]    A separate actuation system (not shown) that is not part of the column and wheel locking mechanisms at least partially retracts the steering wheel assembly  10  into the instrument panel of the vehicle. The rack EPS system steers the vehicle according to the ADAS system commands while the driver provides no steering inputs. As the rack EPS system moves the road wheels, the lower  16  shaft is rotated. When the lower  16  shaft rotates, the ball screw  20  forces the steering shaft  14  to translate in the upper spline  18  since the steering wheel  12  is fixed. As the steering shaft  14  translates, a centering spring pack  30  is compressed one way or the other depending on the direction of rotation of the lower shaft  16 . 
         [0018]    When the driver wants to transition back to the standard driving mode, the ADAS system is deactivated. Upon deactivation, the steering shaft locking component  22  is extended forcing the ball to the steering shaft  14 . The centering spring  30 , along with the rack EPS actuator, will provide force to direct the steering shaft  14  back to a center axial position. When the center position is achieved, the ball is forced into the track and the steering shaft  14  is locked axially. At this point, the ADAS system is informed through sensing that the steering wheel  12  is ready to be handed back to the driver. The steering wheel locking component  28  is released to allow rotation of the steering wheel and the separate actuation system extends the steering wheel assembly  10  back to the driver&#39;s preferred position. 
         [0019]    While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description.