TECHNICAL FIELD 
       [0001]    The present invention generally relates to a retained accessory power in a vehicle and, more particularly, to a retained accessory power detection system that provides accessory power to vehicle components. 
       BACKGROUND OF THE INVENTION 
       [0002]    Accessory power to operate various vehicle electrical components (e.g., a radio) is made available in many vehicles after the vehicle has been shut off. In the conventional system, the accessory power is typically retained and available if the driver&#39;s side door has not been opened. A controller monitors the door position and allows accessory power to be maintained in the vehicle if the door has not been opened for a given time period. When the vehicle door is opened, the controller terminates the availability of the accessory power, making it no longer available to an occupant in the vehicle. 
         [0003]    Oftentimes, accessory power is still desired by the occupants in the vehicle, despite the fact that the driver has left the vehicle. As an example, when the vehicle is being refuelled, the driver is frequently the person who refuels the vehicle, and thus leaves the vehicle by opening the door. In most retained accessory power environments, the action of opening the door terminates accessory power to the vehicle. This is an undesirable effect, as an occupant in the passenger seat or children in the backseat may wish to continue to hear the radio or be able to raise and lower windows. 
         [0004]    In addition, a separate controller is often used to characterize whether an occupant is in the passenger seat for purposes of whether airbag deployment should be allowed or suppressed in the event of a collision. For example, deployment is generally allowed in the case of a normally seated adult occupant and suppressed when a child is placed in the same seat and cinched down with a seatbelt or child seat anchor. The controller otherwise does not typically provide information to any other system in the vehicle. 
       SUMMARY OF THE INVENTION 
       [0005]    In one aspect of the present invention, a method is provided for retaining accessory power and includes the steps of determining that an ignition device is turned to an off position in a motor vehicle that includes at least a driver seat and passenger seat and at least a driver door and passenger door. A predetermined time period is established for retaining accessory power and retained accessory power is made available to predetermined vehicle components. The method further includes sensing whether the at least one vehicle door is closed and whether a seat is occupied by an occupant. Retained accessory power is provided and maintained if the at least one vehicle door is closed or an occupant is occupying a seat. 
         [0006]    In another aspect of the present invention, a method for retaining accessory power in a motorized vehicle includes the steps of sensing whether an ignition device in the motorized vehicle has been turned to an off position and sensing whether the at least one vehicle door is closed. The method also includes the steps of sensing via an occupancy detection system whether a seat is occupied by an occupant enabling or disabling deployment of an airbag inside the vehicle based on the sensed occupant. 
         [0007]    According to a further aspect of the present invention, a system that retains accessory power in a vehicle includes a door sensor that operably senses whether a vehicle door has been opened and an occupancy detection system that senses the presence of an occupant in a vehicle seat. A controller is operably connected to a vehicle ignition wherein, after an ignition device has been turned to an off position, the controller makes retained accessory power available to vehicle components if the occupancy detection system senses the presence of an occupant or if the door sensor senses that the vehicle door has not been opened. 
         [0008]    These and other features, advantages and objects of the present invention will be further understood and appreciated by those skilled in the art by reference to the following specification, claims and appended drawings. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    The present invention will now be described, by way of example, with reference to the accompanying drawings, in which: 
           [0010]      FIG. 1  is a side elevational partial view of a vehicle passenger compartment incorporating the retained accessory power system of the instant invention; 
           [0011]      FIG. 2  is a top view of a vehicle passenger compartment incorporating the retained accessory power system of the instant invention; 
           [0012]      FIG. 3  is a block diagram of the retained accessory power system according to one embodiment of the present invention; 
           [0013]      FIG. 4  is a flow diagram illustrating a method of control of the retained accessory power system according to one embodiment of the present invention; and 
           [0014]      FIG. 5  is a flow diagram illustrating a method of control of the retained accessory power system according to another embodiment of the present invention. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0015]    Referring to  FIGS. 1 and 2 , a retained accessory power system  10  is shown, utilized in a vehicle  12  having at least a driver seat  14  and a passenger seat  16  and preferably a driver seat  14 , passenger seat  16  and several back seats  17 . The retained accessory power system  10  is located inside the vehicle  12  and is operably connected with an ignition  18 , at least one vehicle door  20  (preferably the driver door) having a door sensor  22 , and at least one occupancy detection system  24 . The occupancy detection system  24  is typically included in a passenger seat  16  and may be included in additional seats such as the driver seat  14  and back seats  17  of the vehicle  12 . The occupancy detection system  24  may be operably connected with an airbag deployment device  25  that controls the deployment of an airbag in the event the vehicle  12  is in a collision. 
         [0016]    Referring to  FIG. 3 , the occupancy detection system  24  is also connected with a controller  26  that includes a microprocessor  28  and memory  30 . The memory  30  stores a retained accessory power control algorithm  32  that includes logic pertaining to whether retained accessory power  33  should be made available to predetermined vehicle components. The controller  26  is connected to a timer  31  that tracks the time retained accessory power will be made available to the predetermined vehicle components. The controller  26  is also operably connected to the vehicle ignition device  18  and initiates or suppresses retained accessory power  33  based on the ignition state of the ignition device  18 . The controller  26  is operably connected with the occupancy detection system  24  which is located in each of the vehicle seats and at least the passenger seat  16 . In addition, the vehicle door sensor  22  located in the at least one vehicle door  20  provides information to the controller  26  on whether the at least one vehicle door  20  has been opened or closed after the time the vehicle ignition device  34  is turned off. The controller  26  provides retained accessory power  33  to electrical components (devices) in the vehicle  12  ( FIGS. 1 and 2 ) such as the windows  36 , radio  38 , lights  40 , sun/moon roof  42 , and digital video disc player  44  if the retained accessory power control algorithm  32  logic requirements are met, as described further below. The retained accessory power  33  can be made controllable to power any number of electrically powered devices in the vehicle  12 . 
         [0017]    Referring to  FIG. 4 , the retained accessory power control algorithm  32  performs a method for retaining accessory power in a motorized vehicle  12 . The method includes setting the ignition position to run (step  51 ) and determining whether the ignition  18  is turned off (step  50 ). If the ignition  18  is not turned to an off position, then the vehicle  12  ( FIGS. 1 and 2 ) is presumed to be running and standard electrical power is still available to components in the vehicle  12 . If the ignition  18  is determined to be turned to an off position, a timer is activated in step  52  and then a retained accessory power state is turned on in step  60 . In step  54  the retained accessory power control algorithm checks whether the at least one vehicle door  20  (via the vehicle door sensor  22 ) has been opened while the ignition  18  has been turned off, or was opened before the ignition  18  was turned off and has remained open. If so, then the retained accessory power control algorithm  32  senses whether any other seat is occupied in step  56 . Alternatively, the retained accessory power control algorithm  32  may determine if just the passenger seat  16  is occupied in step  56 . If any seat is occupied or, alternatively, just the passenger seat  16  is occupied  56 , then the retained accessory power state remains on in step  60 . If no other seats are occupied, then the retained accessory power state is turned off in step  62  and retained accessory power  33  is no longer made available to components in the vehicle  12  such as the windows  36 , radio  38 , lights  40 , sun/moon roof  42 , and digital video disc player  44  ( FIG. 3 ). When the retained accessory power is turned on in step  60 , the timer, which started in step  52 , allots a predetermined amount of time for providing retained accessory power  33 . If a seat is determined to be occupied in step  56  and the retained accessory power state is on in step  60 , then the retained accessory power control algorithm  32  will further evaluate whether the predetermined time to provide retained accessory power has expired in step  64 . If the predetermined time in step  64  has expired, then the retained accessory power state will be turned off in step  62 . If the predetermined time period has not expired in step  64 , then the retained accessory power state will remain on in step  60  until the predetermined time period is determined to have expired in step  64 . 
         [0018]    Referring to  FIG. 5 , in an alternative embodiment, the retained accessory power control algorithm  32  performs a method for retaining accessory power in a motorized vehicle. The method includes setting the ignition  18  position to run (step  51 ) and determining whether the ignition  18  is turned off (step  50 ). If the ignition  18  is not turned to an off position, then the vehicle  12  is presumed to be running and standard electrical power is still available to components in the vehicle  12 . If the ignition  18  is determined to be turned to an off position, a timer is activated in step  52  and then a retained accessory power state is turned on in step  60 . In step  54  the retained accessory power control algorithm checks whether the at least one vehicle door  20  (via the vehicle door sensor  22 ) has been opened while the ignition  18  has been turned off, or was opened before the ignition  18  was turned off and has remained open. If so, then the retained accessory power control algorithm  32 ′ assesses whether any other seat is occupied in step  56 . Alternatively, the retained accessory power control algorithm  32 ′ may determine if just the passenger seat  16  is occupied in step  56 . If any seat is occupied or, alternatively, just the passenger seat  16  is occupied  56 , then the retained accessory power state remains on in step  60 . If no other seats are occupied, then the retained accessory power state is turned off in step  62  and retained accessory power  33  is no longer made available to components in the vehicle  12  such as the windows  36 , radio  38 , lights  40 , sun/moon roof  42 , and digital video disc player  44  ( FIG. 3 ). When the retained accessory power is turned on in step  60 , the timer, which started in step  52 , allots a predetermined amount of time for providing retained accessory power  33 . If a seat is determined to be occupied in step  56  and the retained accessory power state is on in step  60 , then the retained accessory power control algorithm  32 ′ will further evaluate whether the predetermined time to provide retained accessory power has expired in step  64 . If the predetermined time in step  64  has expired, then the retained accessory power state will be turned off in step  62 . If the predetermined time in step  64  has not expired, then the retained accessory power control algorithm  32 ′ will determine whether any seat has been unoccupied and reoccupied in step  70  during the predetermined time in step  64  that retained accessory power  33  is to be on (step  60 ). If any seat has not been unoccupied and reoccupied in step  70 , then the predetermined time in step  64  continues to run and retained accessory power  33  will terminate when the predetermined time in step  64  has expired. If any seat has been unoccupied and reoccupied in step  70 , then the timer, which started in step  52 , is reactivated and the predetermined time in step  64  for providing retained accessory power  33  begins anew starting from when the seat was reoccupied in step  70 . 
         [0019]    A vehicle that incorporates a retained accessory power system that utilizes both a door sensor and an occupancy detection system to provide retained accessory power is desirable, as it could be programmed to provide retained accessory power to the occupants of a vehicle even when the driver side door has been opened. A retained accessory power system utilizing both an occupancy detection system and a vehicle door sensor would prove useful and would be an improvement in the art. 
         [0020]    It will be understood by those who practice the invention and those skilled in the art, that various modifications and improvements may be made to the invention without departing from the spirit of the disclosed concept. The scope of protection afforded is to be determined by the claims and by the breadth of interpretation allowed by law.
A method for retaining accessory power in a motorized vehicle includes the steps of sensing whether an ignition in the motorized vehicle has been turned to an off position and sensing whether the vehicle doors are closed. The method also includes an occupancy detection system that senses whether a seat is occupied by an occupant and that is also used to enable or disable deployment of an airbag inside the vehicle.