Abstract:
A system for controlling movement of a motor vehicle door includes at least one sensor that detects a distance from the vehicle to an object near the vehicle. The sensor is also configured to provide input to an automatic parallel parking system of the vehicle. The system may include at least one ultrasonic sensor on each side of the vehicle to detect the distances to objects on opposite sides of a vehicle. The system utilizes a plurality of detected distances and vehicle positions or velocities to determine a location of the detected object relative to the vehicle. The system selectively actuates the door brake to prevent the vehicle door from contacting the detected object as the door is opened.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention generally relates to a system that stops a vehicle door as it opens to prevent contact of the vehicle door with a nearby object. 
       BACKGROUND OF THE INVENTION 
       [0002]    Vehicle doors typically include one or more detent points within their swing arc to hold the door at a fixed point short of fully open to help prevent door contact with adjacent objects. The detent point is typically a compromise between providing sufficient room for driver ingress/egress and door protection. Typically, a single detent cannot account for all door swing/opening scenarios. 
         [0003]    Various infinite/variable door check or stop systems have been developed for the motor vehicle market. These systems may be designed to hold the door in position at whatever point door movement stops in the swing arc. In this manner a door can be opened as near to an adjacent object as desired, and the door check will hold it in position until the user applies a “overcoming” force to move the door out of that detent position. However, such systems suffer from various drawbacks. 
         [0004]    Automatic door check systems that attempt to arrest door movement prior to contacting an adjacent object have also been developed. Such systems typically utilize one or more sensors (e.g. ultrasonic) mounted in the door to detect distance to adjacent objects and automatically stop door movement before contact. However, such systems may be costly, and the positioning of the sensor(s) may negatively affect the appearance of the vehicle door. 
       SUMMARY OF THE INVENTION 
       [0005]    One aspect of the present invention is a system for controlling movement of a vehicle door relative to a primary vehicle structure. The system includes at least one ultrasonic sensor configured to detect a distance from a vehicle primary structure to an object in the vicinity of the vehicle. The ultrasonic sensor also provides input to a vehicle automatic parallel parking system. The system preferably includes at least two ultrasonic sensors configured to detect the distances to objects on opposite sides of a vehicle. The system utilizes a plurality of detected distances to a detected object taken at different times, and a plurality of vehicle positions or velocities at different times before a vehicle stops, and which correspond to the times at which the detected distances are taken. The system determines a location of the detected object relative to the vehicle primary structure, and the system selectively actuates the door brake to prevent the vehicle door from contacting the detected object as the door is opened. The system may also utilize vehicle yaw rate in addition to the vehicle velocity (or distance/odometer reading), and record the information at each buffer point of a rolling buffer. This data can be used to create a two dimensional mapping of objects next to the vehicle. The vehicle geometry and door swing path information can be utilized to selectively actuate the door brake. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]    In the drawings: 
           [0007]      FIG. 1  is a partially schematic plan view of a motor vehicle including a door control system according to one aspect of the present invention; 
           [0008]      FIG. 2  is a schematic view of object mapping conducted utilizing data from an ultrasonic sensor; 
           [0009]      FIG. 3  shows the door swing path intersection to an adjacent object; and 
           [0010]      FIG. 4  is a flow chart of data flow for automatic door check operation according to one aspect of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0011]    For purposes of description herein, the terms “upper,” “lower,” “right,” “left,” “rear,” “front,” “vertical,” “horizontal,” and derivatives thereof shall relate to the invention as oriented in  FIG. 1 . However, it is to be understood that the invention may assume various alternative orientations, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawing, and described in the following specifications are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise. 
         [0012]    With reference to  FIG. 1 , a motor vehicle  1  includes a primary vehicle structure  2 , and front doors  3 A and  3 B, and rear doors  4 A and  4 B. Front door  3 A is pivotally mounted to primary vehicle structure  2  for rotation about a generally vertical axis  5 . 
         [0013]    The vehicle  1  may include a door brake  8  comprising a powered actuator (not shown) that can be actuated by a vehicle controller  9  to stop movement of door  3 A relative to primary vehicle structure  2 . Vehicle  1  may also include a door position sensor  7  that senses an angle of the door  3 A. Sensor  7  may comprise part of the door brake  8 , or it may comprise a separately-positioned component. The door angle sensor  7  provides information to controller  9  concerning the angular position of door  3 A relative to primary vehicle structure  2 . The door brake  8  may comprise a known door brake or check actuator, and the details of door brake  8  will not therefore be described in detail herein. Doors  3 B,  4 A, and  4 B may also include door angle sensor  7  and door brakes  8 . 
         [0014]    Motor vehicle  1  may also include one or more ultrasonic sensors  10 A and  10 B positioned in front quarter panels  11 A and  11 B, respectively, or other suitable location. Signals  12 A and  12 B from ultrasonic sensors  10 A and  10 B can be utilized to determine a location of an object relative to the primary vehicle structure  2 . Sensors  10 A and  10 B may provide input to an automatic system for parallel parking (not shown) of motor vehicle  1 . Automatic systems for parallel parking may include actuators that steer the front wheels, and control forward and rearward motion of a motor vehicle. Such systems are known, and the details of the automatic parallel parking system of vehicle  1  will not therefore be described in detail herein. The sensors  10 A and  10 B typically point to the side of the vehicle, and provide parking space and distance measurements among other functions. Since the sensors provide distance-to-object information, the sensors can be utilized to provide maximum door swing distance to an adjacent object for an automatic doorstop function. 
         [0015]    The door swing limiting function can be performed using a rolling buffer of latitudinal distance to an adjacent object versus distance traveled over time where the buffer contains only the last amount of configurable distance traveled (for example 2 to 3 meters). The latitudinal information as determined from the side sensor  10 A (or  10 B) along with the vehicle velocity as determined by a velocity sensor  13  and vehicle yaw rate that may also be determined by sensor  13  or other sensor recorded at each buffer point can be used to create a two dimensional mapping of objects next to the vehicle. As shown in  FIG. 5 , object mapping using sensor  10 A may be determined as follows: 
         [0016]    Origin ( 0 , 0 ) Final stopping point of the side ultrasonic sensor 
         [0017]    p Yaw rate in radians per second at time interval t i    
         [0018]    v Vehicle velocity in meters per second at time interval t i    
         [0019]    t Interval time period. It is assumed that all interval time periods are equal (t 0 ) 
         [0020]    u Ultrasonic measured distance to object at time interval t i    
         [0021]    θ Resultant angle traveled as a result of the yaw rate over the time interval t i    
         [0022]    i Interval count 
         [0023]    x,y Cartisian coordinates of the ultrasonic sensor relative to the final stopping point at time interval t i    
         [0024]    d Final distance of vehicle to object based on ultrasonic measured distance across longitudinal distance y i    
         [0025]    The overall angle, θ, is the summation of each angle θ i , where θ i =p i t i,    
         [0026]    Assume t i =t 0  where t 0  is a constant value. 
         [0000]      y 0 =a 0 =c 0 =v 0 t 0    
         [0000]      x 0 =b 0 =0 
         [0000]      c 0 =v 0 t 0    
         [0000]    
       
      
       d 
       0 
       =u 
       0 
       −x 
       0 
       =u 
       0  
      
     
         [0000]        a   1   =c   1  cos θ 0   =v   1   t   1  cos ( p   0   t   0 )
 
         [0000]        b   1   =c   1  sin θ 0   =v   1   t   1  sin ( p   0   t   0 )
 
         [0000]      c 1 =v 1 t 1    
         [0000]        x   1   =b   0   +b   1 =0 +v   1   t   1  sin ( p   0 t 0 ) 
         [0000]        y   1   =a   0   +a   1   =v   0   t   0   +v   1   t   1  sin ( p   0   t   0 ) 
         [0000]        d   1   =u   1   −x   1   =u   1   −v   1   t   1  sin ( p   0   t   0 ) 
         [0000]        a   2   =c   2  cos (θ 0 +θ 1 )= v   2   t   2  cos ( p   0   t   0   +p   1   t   1 )
 
         [0000]        b   2   =c   2  sin (θ 0 +θ 1 )= v   2   t   2  sin ( p   0   t   0   +p   1   t   1 )
 
         [0000]      c 2 =v 2 t 2    
         [0000]        x   2   =b   0   +b   1   +b   2   =v   1   t   1  sin ( p   0   t   0 )+ v   2   t   2  cos ( p   0   t   0   +p   1   t   1 ) 
         [0000]        y   2   =a   0   +a   1   +a   2   =v   0   t   0   +v   1   t   1  sin ( p   0   t   0 )+ v   2   t   2  sin ( p   0   t   0   +p   1   t   1 ) 
         [0000]        d   2   =u   2   −x   2   =u   2   −[v   1   t   1  sin ( p   0   t   0 )+ v   2   t   2  cos ( p   0   t   0   +p   1   t   1 )] 
         [0000]    . . . 
         [0000]        a   i   −c   i  cos (Σ 0→i θ n )= v   i   t   i  cos ( t   0 Σ 0→i−1   p   n ) where  t   i   =t   0  
 
         [0000]        b   i   =c   i  sin (Σ 0→i θ n )= v   i   t   i  sin ( t   0 Σ 0→i−1   p   n ) where  t   i   =t   0  
 
         [0000]      c i =v i t i    
         [0000]        x   i =Σ 0→i   b   n   =v   1   t   1  sin ( p   0   t   0 )+ v   2   t   2  cos ( t   0 Σ 0→1   p   n )+ . . . + v   i   t   i  cos ( t   0 Σ 0→i−1   p   n )
 
         [0000]        y   i =Σ 0→i   a   n   =v   0   t   0   +v   1   t   1  sin ( p   0   t   0 )+ v   2   t   2  sin ( t   0 Σ 0→1   p   n )+ . . . + v   i   t   i  sin ( t   0 Σ 0→i−1   p   n )
 
         [0000]        d   i   =u   i   −x   i   =u   i   −[v   0   t   0   +v   1   t   1  sin ( p   0   t   0 )+ v   2   t   2  sin ( t   0 Σ 0→1   p   n )+ . . . + v   i   t   i  sin ( t   0 Σ 0→i−1   p   n )]
 
         [0027]    With further reference to  FIG. 3 , knowing the system host vehicle geometry, it only remains to determine if the door swing path will intersect with any adjacent objects and at what arc point this will occur. Determining the door angle position (Θ door ) such as with a hall-effect sensor or other method, it can ascertained when the door  3 A is approaching an adjacent object  15  (y door =d buffer ) and activate an electric door brake  8 , or other method, to halt movement of door  3 A. 
         [0028]    In  FIG. 3 , P 1  represents the door pivot point, and the curved line P 2  represents the door swing path. The variables shown in  FIG. 3  are defined as follows: 
         [0029]    x sensor =Distance in x direction from sensor to the door pivot point 
         [0030]    x door =Distance in x direction of door tip travel 
         [0031]    y door =Distance in y direction of door tip travel 
         [0032]    θ door =Angular position of door 
         [0033]    r door =Door width 
         [0034]    d buffer =Distance to adjacent object at (x sensor +x door ) position as stored in the buffer. 
         [0035]    Door swing limit is at the point where door tip travel in the y direction (y door ) is equal to the distance to the adjacent object (d buffer ) at (x sensor +x door ) as stored in the buffer. 
         [0000]        Y   door   =d   buffer  at ( x   sensor   +x   door ) 
         [0000]    where 
         [0000]      x door =r door  sin θ door  
 
         [0000]    and 
         [0000]      y door =r door  cos θ door  
 
         [0036]    An example of potential data flow for automatic door check operation according to one aspect of the present invention is shown in  FIG. 4 . The door brake is initiated at the block  20  of  FIG. 4 . The controller  9  first determines if the vehicle is in motion as designated  22  in  FIG. 4 . If the vehicle is in motion, the adjacent object buffer is populated at  24 , and the controller again determines if the vehicle is in motion. If the controller determines that the vehicle is not in motion, the controller then determines if the vehicle is in park at  26 . If not, the controller then again determines if the vehicle is in motion at  22 . However, if the vehicle is in park, the controller then determines if the door is open at  28 . If the door is not open, the door brake sequence ends. If the door is open, the controller then determines if the door position is within the bounds of the buffered values at  30 . If not, the door brake is actuated or applied at  32 . However, if the door position is within the bounds of the buffered values, the door brake is released (or allowed to remain released) at  34 . 
         [0037]    It is to be understood that variations and modifications can be made on the aforementioned structure without departing from the concepts of the present invention, and further it is to be understood that such concepts are intended to be covered by the following claims unless these claims by their language expressly state otherwise.