Abstract:
A method of controlling the position of a front seat having an unbelted rearmost position forward of a belted rearmost position within a vehicle is provided. The method includes determining if a seatbelt associated with the front seat is fastened and allowing movement of the front seat rearward of the unbelted rearmost position if the seatbelt is fastened. Alternately, movement of the front seat rearward of the unbelted rearmost position is prevented if the seatbelt is not fastened. The front seat may be either a driver seat or a passenger seat. A vehicle apparatus operable to carry out the disclosed method is also provided.

Description:
TECHNICAL FIELD 
     The present invention relates to a method and apparatus for controlling seat position within a vehicle based on the seatbelt usage of occupants within the vehicle. 
     BACKGROUND OF THE INVENTION 
     A typical prior art vehicle front seat, such as a driver seat or passenger seat, is typically made adjustable for the comfort of the occupant. Front seats may be limited in their range of fore and aft movement. The limited movement of the front seats in the rearward direction may affect the comfort of tall individuals when seated in the front seat. 
     SUMMARY OF THE INVENTION 
     A method of controlling the position of a front seat having an unbelted rearmost position forward of a belted rearmost position within a vehicle is provided. The method includes determining if a seatbelt associated with the front seat is fastened and allowing movement of the front seat rearward of the unbelted rearmost position if the seatbelt is fastened. Alternately, movement of the front seat rearward of the unbelted rearmost position is prevented if the seatbelt is not fastened. 
     The front seat may be one of a driver seat and a passenger seat. The method may further include determining if the passenger seat is occupied prior to determining if the seatbelt is fastened. Further, the method may include determining if the passenger seat is rearward of the unbelted rearmost position if the seatbelt is not fastened and moving the passenger seat to the unbelted rearmost position if the passenger seat is rearward of the unbelted rearmost position. Alternately, the method may include maintaining the position of the passenger seat and preventing movement of the passenger seat rearward of the unbelted rearmost position if the passenger seat is at, or forward of, the unbelted rearmost position. 
     If the front seat is a driver seat, the method may further include moving the driver seat to the rearmost belted position to facilitate entry into the vehicle prior to determining if the seatbelt is fastened. A determination may be made as to whether the seatbelt is fastened after actuating an ignition switch and before moving a transmission selector out of park. As a result, the driver seat may be moved to the furthest forward of a preselected seating position and the unbelted rearmost position if the seatbelt is unfastened or the driver seat may be moved to a preselected position at one of a position forward of, rearward of, and at the unbelted rearmost position if the seatbelt is fastened. Another determination may be made as to whether the seatbelt is fastened after moving the transmission selector out of park. If the seatbelt is not fastened and the driver seat is rearward of the unbelted rearmost position, an audible and/or visual warning is provided and the driver seat is moved to the unbelted rearmost position. 
     A vehicle is also provided having a front seat, such as a driver seat or a passenger seat, movably mounted and movable in a fore and aft direction with respect to the vehicle. A power drive mechanism is operable to move the front seat. A seatbelt assembly is also provided along with a seatbelt monitoring system operable to determine if the seatbelt assembly is fastened. The front seat has an unbelted rearmost position and a belted rearmost position disposed rearward of the unbelted rearmost position. A controller is operatively connected with the power drive mechanism and the seatbelt monitoring system. The controller is sufficiently programmed to establish whether the seatbelt is fastened from the seatbelt monitoring system and command the power drive system to move the front seat rearward of the unbelted rearmost position if the seatbelt is fastened and to move the front seat forward of the unbelted rearmost position if the seatbelt is not fastened. The present invention may enable certain passenger vehicles to pass the Federal Motor Vehicle Safety Standard (FMVSS) unbelted occupant test, while providing a comfortable seating position to tall individuals who are belted. 
     The above features and advantages and other features and advantages of the present invention are readily apparent from the following detailed description of the best modes for carrying out the invention when taken in connection with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a partially cut away schematic side view of a vehicle having a fore and aft movable front seat mounted thereto and controlled by an electronic control unit in accordance with a method of the present invention; and 
         FIG. 2  is a method, presented in flowchart format, for controlling the position of the front seat as a function of seatbelt usage by the vehicle occupants. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to  FIG. 1 , a vehicle  10  includes front seats, namely a front driver seat  14  and a front passenger seat  16 , each including a lower seat portion  17  and  17 A and a seatback portion  18  and  18 A, respectively. Although the vehicle  10  is shown in  FIG. 1  as a van-type vehicle, those skilled in the art will recognize that the present invention may be applied to other passenger vehicle configurations, such as cars, trucks, etc. A console  19  separates the front driver seat  14  and the front passenger seat  16 . The vehicle  10  also includes a rear seat  20  located more rearwardly in the vehicle  10  than the seats  14  and  16 . For the following discussion, it should be understood that the general construction and operation of the front passenger seat  16  are substantially similar to that of the front driver seat  14 . Lower rails  22  are connected to a floor  24  of the vehicle  10  to form a seat track  26 . Upper rails  28  are connected to the driver seat  14  and are slidably engaged with the lower rails  22 . Those skilled in the art will recognize and understand a variety of seat track configurations that may be employed within the scope of the claimed invention. 
     The driver seat  14  is adjustable fore and aft, i.e., forward and rearward within the vehicle  10 , by sliding the upper rails  28  along the lower rails  22 . The adjustment of the driver seat  14  is preferably facilitated by a power drive mechanism  30 . The driver seat  14  is depicted in a driving position in which the driver seat  14  is adjacent a steering wheel  31  and other controls such as foot pedals (not shown). The seating position of the driver seat  14 , shown in  FIG. 1  as solid lines, corresponds to a rearmost unbelted position. The rear most unbelted position corresponds to the rearmost position within the vehicle  10  that the driver seat  14  will be allowed to move if the occupant or driver is unbelted. The seating position of the driver seat  14 , drawn in  FIG. 1  with phantom lines, corresponds to a rearmost belted seating position. The rearmost belted seating position corresponds to the rearmost position within the vehicle  10  that the drive seat  14  will be allowed to move if the driver is belted. It should be understood that the terms belted and unbelted refers to conditions in which the driver of the vehicle  10  has his/her seat belt  32  fastened and unfastened, respectively. Additionally, it should be apparent from  FIG. 1  that the rearmost belted seating position is located further rearward in the vehicle  10  than the rearmost unbelted position. 
     The vehicle  10  includes an ignition switch  34  and a transmission selector  36 . The ignition switch  34  is switchable between an “on” position and an “off” position. The transmission selector  36  is moveable between a park position and various transmission operating modes, such as reverse, neutral, and drive. For the vehicle  10  to be in an operational mode, the ignition switch  34  must be in the “on” position and the transmission selector  36  must be in a position other than park. The vehicle  10  also includes a power plant  38 , which provides motive force to propel the vehicle  10 . 
     A sensor  40  is sufficiently configured and positioned with respect to the ignition switch  34  to detect the position or state of operation of the ignition switch  34 . A sensor  42  is sufficiently configured and positioned with respect to the transmission selector  36  to detect the position or state of operation of the transmission selector  36 . A sensor  44  is mounted with respect to the lower seat portion  17  and operates to determine whether the seat is occupied. Additionally, a sensor  46  is operable to determine the position of the driver seat  14  within the vehicle  10 . An audible and/or visual warning system  47 , such as a buzzer or light, is positioned within the vehicle  10  to receive signals from the controller  50 . 
     A seatbelt monitoring system  48  is provided to determine the state of the seat belt  32 , i.e., whether the occupant is belted or unbelted. The sensors  40 ,  42 ,  44 , and  46  as well as the seatbelt monitoring system  48  are operatively connected to a controller  50 . The controller  50  is programmed in accordance with the method illustrated in  FIG. 2  to selectively limit the rearward-most position of the driver seat  14  and passenger seat  16  based on a plurality of conditions to be described in greater detail hereinbelow with reference to  FIG. 2 . 
     Referring now to  FIG. 2 , and with continued reference to  FIG. 1 , there is shown a method  52  operable to selectively restrict or limit the movement of the driver and/or passenger seats  14  and  16  to the rearmost belted position if the occupant of the seat is unbelted. The method  52  begins at step  54  when a signal is provided to the controller  50  such as a keyless entry request to unlock the vehicle  10 . The method  52  will then branch into a driver side branch  56  and a passenger side branch  58 , each of which will be described separately hereinbelow. From step  54  the driver side branch  56  of the method  52  proceeds to step  60  where the controller  50  commands the power drive mechanism  30  to move the driver seat  14  to the rearmost belted position to facilitate entry of the driver into the vehicle  10 . Once the driver is seated in the driver seat  14 , the driver may actuate the ignition switch  34  to the “on” position as indicated by step  62 . The sensor  40  will signal to the controller  50  that the ignition switch  34  has been switched to the “on” position. The method  52  will then proceed to step  64  where a determination is made as to whether the driver seatbelt  30  is fastened. The seatbelt monitoring system  48  will provide information to the controller  50  as to whether the seatbelt  30  is fastened. If the seatbelt  30  is not fastened, the method  52  proceeds to step  66 . 
     At step  66 , the driver seat  14  is moved either to a preselected position or to the unbelted rearmost position whichever is furthest forward in the vehicle  10 . The preselected position may be stored within the controller  50  such that specific drivers may have stored seating positions, such systems are often referred to in the art as “memory seats”. The step  66  then loops to step  64  to monitor the status of the seatbelt  30 . If the seatbelt  30  is fastened, the method  52  proceeds from step  64  to step  68 . At step  68 , the driver seat  14  is moved to the preselected position. This preselected position may be fore or aft of the unbelted rearmost position, as such, the driver seat  14  may be moved rearward within the vehicle  10  until the belted rearmost position is reached. The method  52  then proceeds to step  70  where the driver places the transmission selector  36  in an out-of-park position, such as reverse, neutral, or drive. The sensor  42  will communicate to the controller  50  that the transmission selector is in an out-of-park mode of operation. The method  52  then proceeds to step  72 . 
     At step  72 , a determination is made as to whether the seatbelt  30  remains fastened. If the seatbelt remains fastened, the method  52  will proceed to step  74  where unrestricted movement of the driver seat  14  is allowed. The method  52  will loop to step  72  from step  74  to continuously monitor the status of the seatbelt  30 . If, at step  72 , it is determined that the seatbelt  30  is not fastened, the method  52  will proceed to step  76  where movement of the driver seat  14  rearward of the unbelted rearmost position is disallowed. The method  52  will then proceed from step  76  to step  78  where a determination is made as to whether the driver seat position is rearward of the unbelted rearmost position. If the driver seat  14  is not rearward of the unbelted rearmost position, then the method  52  loops to step  72  to continuously monitor the status of the seatbelt  30 . Alternately, if the driver seat  14  is rearward of the unbelted rearmost position, the method  52  proceeds to step  80 . At step  80 , the warming system  47  provides the driver with an audible and/or visual indication of an impending adjustment to the driver seat  14 . The driver seat  14  will then move to the unbelted rearmost position. Preferably, the driver seat  14  will be moved sufficiently slowly such that the movement is as imperceptible to the driver as possible. Subsequent to step  82 , the method  52  will loop to step  72  to continuously monitor the status of the seatbelt  30 . 
     Turning now to the passenger side branch  58  of the method  52 , the method  52  will proceed from step  54  to step  84 . At step  84 , a determination is made as to whether an occupant or passenger is present in the passenger seat  16 . This is accomplished thorough the use of the sensor  44 . If the passenger seat  16  is not occupied, the method  52  will loop to step  54  to begin the passenger side branch  58  anew. If a passenger is seated in the passenger seat  16 , the method  52  will proceed to step  86 . At step  86 , a determination is made as to whether the passenger seatbelt  30  is fastened. The seatbelt monitoring system  48  will provide information to the controller  50  as to whether the seatbelt  30  is fastened. If the seatbelt  30  is fastened, the method  52  proceeds to step  88 . At step  88 , the passenger seat  16  is allowed to move to any position either fore or aft of the unbelted rearmost position. That is, the passenger seat  16  may move rearward of the unbelted rearmost position until the passenger seat  16  reaches the belted rearmost position. The method  52  will then loop to step  86  to continuously monitor the status of the seatbelt  30 . If, at step  86 , a determination is made that the seatbelt  30  is not fastened, the method will proceed to step  90 . 
     At step  90 , a determination is made as to whether the position of the passenger seat  16  is rearward of the unbelted rearmost position. If the position of the passenger seat is rearward of the unbelted rearmost position, the method will proceed to step  92  where the controller  50  will command the passenger seat  16  to the unbelted rearmost position. As described hereinabove with reference to the driver seat  14 , it is preferred that the movement of the passenger seat  16  to the unbelted rearmost position be accomplished slowly such that the movement of the passenger seat  16  is as imperceptible to the passenger as possible. The method will loop from step  92  to step  86  to continuously monitor the status of the seatbelt  30 . 
     Referring back to step  90 , if it is determined that the passenger seat  16  is not rearward of the unbelted rearmost position; the method  52  will proceed to step  94 . At step  94 , the position of the passenger seat  16  is maintained, while movement of the passenger seat  16  rearward of the unbelted rearmost position is prevented. From step  94 , the method  52  loops to step  86  to continuously monitor the status of the seatbelt  30 . 
     While the best modes for carrying out the invention have been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention within the scope of the appended claims.