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BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a door opening-closing control apparatus of a vehicle in which when authentication is established by intercommunication between a portable device carried by a driver and a door opening-closing control unit provided in the vehicle, door opening operation and door closing operation of a door of the vehicle by the portable device are allowed. 
         [0003]    2. Description of the Related Art 
         [0004]    Japanese Patent Application Laid-open No. 2007-23620 has made known a door opening-closing control apparatus in which intercommunication is performed between a portable device carried by a driver and a door opening-closing control unit provided in a vehicle, wherein when the driver having locked a sliding door and left the vehicle returns to the vehicle to approach the sliding door and authentication is established by the intercommunication between the portable device and the door opening-closing control unit, a door lock of the sliding door is automatically released, and a door opening-closing actuator is activated by touching of a door handle by the driver to automatically open the sliding door. 
         [0005]    In the door opening-closing control apparatus, even in a situation where the driver returns to the vehicle while holding a large amount of goods and has difficulty in opening the sliding door by operating an automatic door opening button of the portable device, the driver can open the sliding door only by touching the door handle while holding the goods, and convenience is improved. 
         [0006]    The conventional door opening-closing control apparatus described above includes a cancel switch of an automatic door opening control near a driver seat, and it is possible to be set such that, in a case where the driver leaves the vehicle with the cancel switch set to ON, no automatic door opening control is performed when the driver returns to the vehicle. Accordingly, the automatic door opening control cannot be reserved again in such cases where the driver who has no plan of shopping leaves the vehicle with the cancel switch set to ON and then unexpectedly buys so large amount of goods that both hands are occupied. The driver having returned to the vehicle thus needs to open the sliding door by putting the goods on the ground and then operating an automatic door opening button of the portable device. Hence, there is a problem of impairing the convenience. 
         [0007]    Moreover, as described above, in the conventional door opening-closing control apparatus, execution and non-execution of the automatic door opening control can be arbitrarily selected according to an intention of the driver. However, in both cases of execution and non-execution of the automatic door opening control, the door opening-closing control unit provided in the vehicle continues transmitting a request signal at predetermined time intervals to detect the portable device while the driver is away from the vehicle. Accordingly, there is a problem that dark current consumed by the door opening-closing control apparatus increases and a battery of the vehicle is wastefully consumed. 
       SUMMARY OF THE INVENTION 
       [0008]    The present invention has been made in view of the circumstances described above, and an object of the present invention is to enable automatic door opening or automatic door closing of a door of a vehicle in a case where a driver needs to return to or leave the vehicle while holding an unexpected amount of goods or the like. Moreover, another object of the present invention is to reduce dark current in a door opening-closing control apparatus of a vehicle in which execution and non-execution of automatic opening-closing control of a door can be selected, the dark current being consumed by a door opening-closing control unit in order to transmit a request signal. 
         [0009]    In order to achieve the objects, according to a first aspect of the present invention, there is provided a door opening-closing control apparatus of a vehicle in which when authentication is established by intercommunication between a portable device carried by a driver and a door opening-closing control unit provided in the vehicle, door opening operation and door closing operation of a door of the vehicle by the portable device are allowed, wherein the portable device includes a reservation setting device which stores an automatic door opening command for automatically opening the door, and in a case where the portable device is moved close to the vehicle and the authentication is established between the portable device and the door opening-closing control unit, the door opening-closing control unit automatically opens the door when receiving the automatic door opening command stored in the reservation setting device from the portable device. 
         [0010]    According to the first aspect, in the door opening-closing control apparatus of a vehicle, when the authentication is established by the intercommunication between the portable device carried by the driver and the door opening-closing control unit provided in the vehicle, the door opening operation and the door closing operation of the door of the vehicle by the portable device are allowed. The portable device includes the reservation setting device which stores the automatic door opening command for automatically opening the door, and in the case where the portable device is moved close to the vehicle and the authentication is established between the portable device and the door opening-closing control unit, the door opening-closing control unit automatically opens the door when receiving the automatic door opening command stored in the reservation setting device from the portable device. Accordingly, for example, in a case where the driver leaves the vehicle and then needs to return to the vehicle while holding an unexpectedly large amount of goods, the driver operates the portable device and reserves the automatic door opening command before returning to the vehicle so as to be able to automatically open the door when returning to the vehicle, and convenience is thereby improved. 
         [0011]    According to a second aspect of the present invention, there is provided a door opening-closing control apparatus of a vehicle in which when authentication is established by intercommunication between a portable device carried by a driver and a door opening-closing control unit provided in the vehicle, door opening operation and door closing operation of a door of the vehicle by the portable device are allowed, wherein the portable device includes a reservation setting device which stores an automatic door closing command for automatically closing the door, and in a case where the door opening-closing control unit receives the automatic door closing command stored in the reservation setting device from the portable device, the door opening-closing control unit automatically closes the door when the portable device is moved away from the vehicle and the intercommunication between the portable device and the door opening-closing control unit stops. 
         [0012]    According to the second aspect, in the door opening-closing control apparatus of a vehicle, when the authentication is established by the intercommunication between the portable device carried by the driver and the door opening-closing control unit provided in the vehicle, the door opening operation and the door closing operation of the door of the vehicle by the portable device are allowed. The portable device includes the reservation setting device which stores the automatic door closing command for automatically closing the door, and in the case where the door opening-closing control unit receives the automatic door closing command stored in the reservation setting device from the portable device, the door opening-closing control unit automatically closes the door when the portable device is moved away from the vehicle and the intercommunication between the portable device and the door opening-closing control unit stops. Accordingly, for example, in a case where the driver needs to leave the vehicle while holding an unexpectedly large amount of goods, the driver operates the portable device and reserves the automatic door closing command before carrying the goods so as to be able to automatically close the door after holding the goods, and convenience is thereby improved. 
         [0013]    According to a third aspect of the present invention, there is provided a door opening-closing control apparatus of a vehicle in which when authentication is established by intercommunication using a request signal and a response signal, door opening operation and door closing operation of a door of the vehicle by a portable device carried by a driver are allowed, the request signal being transmitted at a predetermined time interval by a door opening-closing control unit provided in the vehicle, and the response signal being transmitted by the portable device in response to the request signal, wherein the door opening-closing control unit includes a reservation setting device which stores an automatic door opening command for automatically opening the door, in a state where the automatic door opening command is stored in the reservation setting device, the door opening-closing control unit automatically opens the door when the portable device is moved close to the door and the authentication is established between the door opening-closing control unit and the portable device, and in a state where the automatic door opening command is not stored in the reservation setting device, the door opening-closing control unit does not transmit the request signal or sets a transmission time interval of the request signal longer than the predetermined time interval. 
         [0014]    According to the third aspect, In the door opening-closing control apparatus of a vehicle, when the authentication is established by the intercommunication using the request signal and the response signal, the door opening operation and the door closing operation of the door of the vehicle performed with the portable device carried by the driver are allowed, the request signal being transmitted at the predetermined time interval by a door opening-closing control unit provided in the vehicle, and the response signal being transmitted by the portable device in response to the request signal. 
         [0015]    The door opening-closing control unit includes the reservation setting device which stores an automatic door opening command for automatically opening the door. In the state where the automatic door opening command is stored in the reservation setting device, the door opening-closing control unit automatically opens the door when the portable device is moved close to the door and the authentication is established between the door opening-closing control unit and the portable device. Accordingly, for example, in a case where the driver needs to return to the vehicle while holding a large amount of goods, the driver reserves the automatic door opening command in the door opening-closing control unit in advance so as to be able to automatically open the door when returning to the vehicle, and convenience is thereby improved. 
         [0016]    Moreover, in the state where the automatic door opening command is not stored in the reservation setting device, the door opening-closing control unit does not transmit the request signal or sets the transmission time interval of the request signal longer than the predetermined time interval. Accordingly, it possible to prevent a battery of the vehicle from being wastefully consumed by reducing dark current consumed by the door opening-closing control unit. In this case, if the driver needs to open the door when returning to the vehicle, the door can be opened with the portable device without relying on the request signal, so there is no problem. 
         [0017]    According to a fourth aspect of the present invention, there is provided a door opening-closing control apparatus of a vehicle in which when authentication is established by intercommunication using a request signal and a response signal, door opening operation and door closing operation of a door of the vehicle by a portable device carried by a driver are allowed, the request signal being transmitted at a predetermined time interval by a door opening-closing control unit provided in the vehicle, and the response signal being transmitted by the portable device in response to the request signal, wherein the door opening-closing control unit includes a reservation setting device which stores an automatic door closing command for automatically closing the door, in a state where the automatic door closing command is stored in the reservation setting device, the door opening-closing control unit automatically closes the door when the portable device is moved away from the door and the intercommunication between the door opening-closing control unit and the portable device stops, and in a state where the automatic door closing command is not stored in the reservation setting device, the door opening-closing control unit does not transmit the request signal or sets a transmission time interval of the request signal longer than the predetermined time interval. 
         [0018]    According to the fourth aspect, in the door opening-closing control apparatus of a vehicle, when the authentication is established by the intercommunication using the request signal and the response signal, the door opening operation and the door closing operation of the door of the vehicle performed with the portable device carried by the driver are allowed, the request signal being transmitted at the predetermined time interval by the door opening-closing control unit provided in the vehicle, and the response signal being transmitted by the portable device in response to the request signal. 
         [0019]    The door opening-closing control unit includes the reservation setting device which stores the automatic door closing command for automatically closing the door. In the state where the automatic door closing command is stored in the reservation setting device, the door opening-closing control unit automatically closes the door when the portable device is moved away from the door and the intercommunication between the door opening-closing control unit and the portable device stops. Accordingly, for example, in a case where the driver needs to leave the vehicle while holding a large amount of goods, the driver reserves the automatic door closing command in the door opening-closing control unit in advance so as to be able to automatically close the door after holding the goods, and convenience is thereby improved. 
         [0020]    Moreover, in the state where the automatic door closing command is not stored in the reservation setting device, the door opening-closing control unit does not transmit the request signal or sets the transmission time interval of the request signal longer than the predetermined time interval. Accordingly, it possible to prevent the battery of the vehicle from being wastefully consumed by reducing the dark current consumed by the door opening-closing control unit. In this case, if the driver needs to open the door when returning to the vehicle, the door can be opened with the portable device without relying on the request signal, so there is no problem. 
         [0021]    According to a fifth aspect of the present invention, the portable device includes a door opening button used to transmit a door opening command for opening the door and a door closing button used to transmit a door closing command for closing the door, the automatic door opening command is stored by performing predetermined operation on the door opening button, and the automatic door closing command is stored by performing predetermined operation on the door closing button. 
         [0022]    According to the fifth aspect, reservation setting can be performed by utilizing the existing door opening button and door closing button, without adding special buttons and switches. 
         [0023]    According to a sixth aspect of the present invention, the portable device includes a slide switch, and the automatic door opening command or the automatic door closing command is stored by operating the slide switch. 
         [0024]    According to the sixth aspect, a state where the reservation setting is performed and a state where the reservation setting is not performed can be checked only by visually observing the slide switch. 
         [0025]    According to a seventh aspect of the present invention, the portable device includes a door opening button used to transmit a door opening command for opening the door and a door closing button used to transmit a door closing command for closing the door, the automatic door opening command is stored by operating the door opening button with the slide switch set at an ON position, and the automatic door closing command is stored by operating the door closing button with the slide switch set at the ON position. 
         [0026]    According to the seventh aspect, only one of the automatic door opening command and the automatic door closing command can be reserved. 
         [0027]    According to an eighth aspect of the present invention, the slide switch is switchable among an OFF position, an automatic door opening position, and an automatic door closing position. 
         [0028]    According to the eighth aspect, switching among three states can be performed by using one slide switch and operability is improved. Moreover, the state where the reservation setting is performed and the state where the reservation setting is not performed can be checked only by visually observing the slide switch. 
         [0029]    According to a ninth aspect of the present invention, the door is any of a sliding door, a tailgate, and a trunk lid. 
         [0030]    According to the ninth aspect, accordingly, it is possible to automatically open and close the door through which a large amount of goods are loaded and unloaded and further improve the convenience. 
         [0031]    Note that a left sliding door  12 L, a right sliding door  12 R and a tailgate  13  of embodiments correspond to a door of the present invention, an electronic key  31  of the embodiments corresponds to the portable device of the present invention, a lock button  32  of the embodiments corresponds to the door closing button of the present invention, an unlock button  33  of the embodiments corresponds to the door opening button of the present invention, and an electronic key ECU  37  of the embodiments corresponds to the reservation setting device of the present invention. 
         [0032]    The above and other objects, characteristics and advantages of the present invention will be clear from detailed descriptions of the preferred embodiments which will be provided below while referring to the attached drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0033]      FIG. 1  is a view showing an entire configuration of a door opening-closing control apparatus according to one embodiment. 
           [0034]      FIG. 2  is a view showing a configuration of an electronic key. 
           [0035]      FIG. 3  is a flowchart explaining automatic door opening control of a door according to a first embodiment. 
           [0036]      FIG. 4  is a flowchart explaining automatic door closing control of the door according to the first embodiment. 
           [0037]      FIG. 5  is a flowchart explaining automatic door opening control of a door according to a second embodiment. 
           [0038]      FIG. 6  is a flowchart explaining automatic door closing control of the door according to the second embodiment. 
           [0039]      FIG. 7  is a view showing a configuration of an electronic key according to a third embodiment. 
           [0040]      FIG. 8  is a view showing a configuration of an electronic key according to a fourth embodiment. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     First Embodiment 
       [0041]    A first embodiment of the present invention is described below based on  FIGS. 1 to 4 . 
         [0042]    As illustrated in  FIG. 1 , a five-door vehicle of the embodiment includes a left front door  11 L, a right front door  11 R, a left sliding door  12 L, a right sliding door  12 R, and a tailgate  13 . The left sliding door  12 L, the right sliding door  12 R, and the tailgate  13  form the door of the present invention and are capable of being automatically locked and unlocked by an actuator, respectively, and being automatically opened and closed by an actuator, respectively. Hereafter, the term “doors” alone refers to the left sliding door  12 L, the right sliding door  12 R, and the tailgate  13 . 
         [0043]    A door opening-closing control unit  14  includes an electronic key authentication ECU  15 , a door lock control ECU  16 , and a door opening-closing control ECU  17  which are connected to one another by a data bus  18 , the door opening-closing control unit  14  being mounted on the vehicle so as to control locking and unlocking of the left front door  11 L, the right front door  11 R, the left sliding door  12 L, the right sliding door  12 R and the tailgate  13  by a door lock actuator  20  such as a solenoid, and so as to control opening and closing of the left sliding door  12 L, the right sliding door  12 R, and the tailgate  13  by a door opening-closing actuator  21  such as an electric motor. 
         [0044]    Antennas  19  for intercommunication with an electronic key  31  (see  FIG. 2 ) to be described later are connected to the electronic key authentication ECU  15 . The door lock actuator  20  for locking and unlocking the left front door  11 L, the right front door  11 R, the left sliding door  12 L, the right sliding door  12 R, and the tailgate  13  is connected to the door lock control ECU  16 . The door opening-closing actuator  21  for automatically opening and closing the doors (the left sliding door  12 L, the right sliding door  12 R, and the tailgate  13 ) and a buzzer  22  for notifying a driver that reservation setting of an automatic door opening command and an automatic door closing command are performed are connected to the door opening-closing control ECU  17 . 
         [0045]    The antennas  19  are provided respectively for the left sliding door  12 L, the right sliding door  12 R, and the tailgate  13 , and a communicable range of each of the antennas  19  is about 1 m (see areas shaded by diagonal lines in  FIG. 1 ). The electronic key  31  can communicate with each of the antennas  19 , and the electronic key authentication ECU  15  can recognize in which one of the communicable ranges of the left sliding door  12 L, the right sliding door  12 R, and the tailgate  13  the electronic key  31  exists. 
         [0046]    As illustrated in  FIG. 2 , the electronic key  31  is provided with a lock button  32 , an unlock button  33 , a left sliding door opening-closing button  34 , a right sliding door opening-closing button  35 , and a tailgate opening-closing button  36 . The electronic key  31  includes an electronic key ECU  37 . The lock button  32 , the unlock button  33 , the left sliding door opening-closing button  34 , the right sliding door opening-closing button  35 , and the tailgate opening-closing button  36  are connected to the electronic key ECU  37 . Moreover, an antenna  38  for performing intercommunication with the electronic key authentication ECU  15  of the door opening-closing control unit  14  is connected to the electronic key ECU  37 . 
         [0047]    Next, description is given of an operation of locking and unlocking the left front door  11 L, the right front door  11 R, the left sliding door  12 L, the right sliding door  12 R, and the tailgate  13  by the electronic key  31 . 
         [0048]    The electronic key authentication ECU  15  of the door opening-closing control unit  14  transmits a request signal from the antennas  19  of the doors  12 L,  12 R,  13  at predetermined time intervals. When the driver with the electronic key  31  exists inside one of the communicable ranges around the doors  12 L,  12 R,  13  (for example, ranges within a distance of about 1.0 m from the doors  12 L,  12 R,  13 ), a reception level of the request signal received by the antenna  38  of the electronic key  31  exceeds a threshold, and the intercommunication between the electronic key authentication ECU  15  and the electronic key ECU  37  becomes possible. When the intercommunication between the electronic key authentication ECU  15  and the electronic key ECU  37  becomes possible, the electronic key ECU  37  transmits a response signal including an ID code to the electronic key authentication ECU  15 , and the electronic key authentication ECU  15  checks the ID code included in the response signal against an ID code stored in advance. When the two ID codes match, the electronic key authentication ECU  15  authenticates the electronic key  31  as the key of an own vehicle. 
         [0049]    When the driver presses the lock button  32  of the electronic key  31  in the state where the authentication is established between the electronic key  31  and the door opening-closing control unit  14  as described above, the door lock control ECU  16  drives the door lock actuator  20  to lock all of the left front door  11 L, the right front door  11 R, the left sliding door  12 L, the right sliding door  12 R, and the tailgate  13 . Meanwhile, when the driver presses the unlock button  33  of the electronic key  31 , the doors  11 L,  11 R,  12 L,  12 R,  13  are all unlocked. 
         [0050]    For example, when the driver presses the left sliding door opening-closing button  34  of the electronic key  31  inside the communicable region around the left sliding door  12 L in a situation where the left sliding door  12 L is closed, the door lock control ECU  16  activates the door lock actuator  20  to release a door lock and the door opening-closing control ECU  17  activates the door opening-closing actuator  21  to automatically open the left sliding door  12 L. Meanwhile, when the driver presses the left sliding door opening-closing button  34  of the electronic key  31  inside the communicable region around the left sliding door  12 L in a situation where the left sliding door  12 L is open, the door opening-closing control ECU  17  activates the door opening-closing actuator  21  to automatically close the left sliding door  12 L and the door lock control ECU  16  activates the door lock actuator  20  to operate the door lock. 
         [0051]    Similarly, when the driver presses the right sliding door opening-closing button  35  of the electronic key  31  inside the communicable range around the right sliding door  12 R, the right sliding door  12 R can be automatically closed or opened. Moreover, when the driver presses the tailgate opening-closing button  36  of the electronic key  31  inside the communicable range around the tailgate  13 , the tailgate  13  can be automatically closed or opened. 
         [0052]    Next, description is given of automatic door opening control of the left sliding door  12 L, the right sliding door  12 R, and the tailgate  13  by reservation in the first embodiment. 
         [0053]    In the case where the driver having left the vehicle for shopping buys an unexpectedly large amount of goods and returns to the vehicle with both hands occupied by the goods, the driver cannot operate the electronic key  31  to open the left sliding door  12 L, the right sliding door  12 R, or the tailgate  13  in order to load the goods onto the vehicle, unless the driver puts the goods on the ground. In the embodiment, by storing an automatic door opening command in the electronic key  31  in advance before the driver holds the goods in both hands, one of the doors  12 L,  12 R,  13  is automatically opened when the driver returns to the vehicle. Accordingly, there is no need to put goods on the ground and operate the electronic key  31 , and the convenience is improved. 
         [0054]    Specifically, in step S 11  of a flowchart of  FIG. 3 , when the driver gets off the vehicle and presses the lock button  32  of the electronic key  31 , the left front door  11 L, the right front door  11 R, the left sliding door  12 L, the right sliding door  12 R, and the tailgate  13  are thereby all locked. In step S 12 , the driver leaves the vehicle and moves outside a communicable range of the electronic key ECU  37  of the electronic key  31  and the electronic key authentication ECU  15  of the door opening-closing control unit  14 , in which intercommunication therebetween is possible. Then, in step S 13 , when the driver presses the unlock button  33  of the electronic key  31  twice or long, the automatic door opening command is stored in the electronic key ECU  37 . 
         [0055]    In step S 14 , the driver returns to the vehicle and enters the communicable range around one of the left sliding door  12 L, the right sliding door  12 R, and the tailgate  13  which is desired by the driver to be opened. In step S 15 , when the intercommunication between the electronic key authentication ECU  15  and the electronic key ECU  37  becomes possible, the electronic key ECU  37  having received the request signal transmitted by the electronic key authentication ECU  15  transmits the response signal including the ID code, and the electronic key authentication ECU  15  having received the response signal checks the ID code to perform authentication. 
         [0056]    In step S 16 , when the authentication is established, the door lock control ECU  16  drives the door lock actuator  20  based on a door opening command signal included in the response signal to unlock one of the left sliding door  12 L, the right sliding door  12 R, and the tailgate  13  which the driver is close to, and the door opening-closing control ECU  17  drives the door opening-closing actuator  21  to automatically open this door. At this time, the buzzer  22  is sounded to notify the driver that the automatic door opening control is performed based on the reservation-set door opening command signal. 
         [0057]    The doors  12 L,  12 R,  13  can be thus automatically opened respectively even when the driver holds goods in both hands and cannot operate the electronic key  31 . Hence, there is no need to put the goods on the ground and operate the electronic key  31 , and the convenience is improved. Moreover, since there is no need to perform the reservation setting of the automatic door opening control in the door opening-closing control unit  14 , the driver can perform the reservation setting of the automatic door opening control without a problem even when the reservation becomes necessary after the driver leaves the driver seat. 
         [0058]    Moreover, the antennas  19  are provided respectively in the left sliding door  12 L, the right sliding door  12 R, and the tailgate  13 , and the electronic key authentication ECU  15  recognizes one of the communicable ranges of the doors  12 L,  12 R,  13  in which the driver exists and automatically opens only the corresponding door without opening the other doors. Accordingly, it is possible to selectively and automatically open only the door desired by the driver to be opened. As a result, it is possible to avoid unnecessary automatic door opening and also prevent, for example, a case where, while the tailgate  13  is automatically opened and the driver is loading goods, a suspicious person enters the vehicle from the left sliding door  12 L or the right sliding door  12 R which are simultaneously and automatically opened. Moreover, since the driver can determine which one of the doors  12 L,  13 R,  13  is to be automatically opened after approaching the vehicle, the driver does not have to consider a state of the vehicle and determine which one of the doors  12 L,  12 R,  13  is to be automatically opened at the time of the reservation. 
         [0059]    Next, description is given of automatic door closing control of the left sliding door  12 L, the right sliding door  12 R, and the tailgate  13  by reservation. 
         [0060]    The following case sometimes occurs. The driver gets out of the driver seat and opens one of the left sliding door  12 L, the right sliding door  12 R, and the tailgate  13  in order to carry goods loaded on the vehicle to another place by holding the goods with hands. However, the amount of the goods loaded on the vehicle is unexpectedly large, and the driver cannot close the one of the left sliding door  12 L, the right sliding door  12 R, and the tailgate  13  by operating the electronic key  31  while holding the goods with hands. In the embodiment, by storing an automatic door closing command in the electronic key  31  in advance before the driver holds the goods in both hands, the one of the doors  12 L,  12 R,  13  which is open is automatically closed when the driver leaves the vehicle while holding the goods. Accordingly, there is no need to put the goods on the ground and operate the electronic key  31 , and the convenience is improved. 
         [0061]    Specifically, in step S 21  of a flowchart of  FIG. 4 , the driver gets off the vehicle and opens one of the left sliding door  12 L, the right sliding door  12 R, and the tailgate  13  in order to unload goods in a vehicle compartment. When the driver determines at this time that the amount of goods to be unloaded is large, in step S 22 , the driver presses the lock button  32  of the electronic key  31  twice or long inside the communicable range near the one of the doors  12 L,  12 R,  13 , and the automatic door closing command is thereby stored in the electronic key ECU  37 . When the driver knows in advance that the amount of goods is large, the driver may store the automatic door closing command in the electronic key ECU  37  before opening the one of the doors  12 L,  12 R,  13 . 
         [0062]    In this case, since the driver is inside the communicable range near one of the doors  12 L,  12 R,  13 , the reception levels of the request signal and the response signal are equal to or greater than the thresholds, and the intercommunication between the electronic key ECU  37  of the electronic key  31  and the electronic key authentication ECU  15  of the door opening-closing control unit  14  is performed. Accordingly, in step S 23 , the door opening-closing control unit  14  receives a door closing command signal from the electronic key ECU  37 , and the door opening-closing control ECU  17  causes the buzzer  22  to sound so as to notify the driver that reservation setting of the automatic door closing control is performed. 
         [0063]    In subsequent step S 24 , the driver holds the goods in the vehicle compartment in both hands and leaves the vehicle through one of the doors  12 L,  12 R,  13  which the driver has opened and then moves outside the communicable range. The reception levels of the request signal and the response signal thereby fall below the thresholds and, in step S 25 , the intercommunication between the electronic key ECU  37  of the electronic key  31  and the electronic key authentication ECU  15  of the door opening-closing control unit  14  stops. Then, the door opening-closing control ECU  17  drives the door opening-closing actuator  21  to automatically close the one of the left sliding door  12 L, the right sliding door  12 R, and the tailgate  13  which the driver has opened, according to a command from the electronic key authentication ECU  15  of the door opening-closing control unit  14 . Moreover, the door lock control ECU  16  drives the door lock actuator  20  to lock all of the left front door  11 L, the right front door  11 R, the left sliding door  12 L, the right sliding door  12 R, and the tailgate  13 . 
         [0064]    The doors  12 L,  12 R,  13  can be thus automatically closed respectively even when the driver holds goods in both hands and cannot operate the lock button  32  of the electronic key  31 . Hence, there is no need to put the goods on the ground and operate the electronic key  31 , and the convenience is improved. Moreover, since there is no need to perform the reservation setting of the automatic door closing control in the door opening-closing control unit  14 , the driver can perform the reservation setting of the automatic door closing control without a problem even when the reservation becomes necessary after the driver leaves the driver seat. 
         [0065]    Moreover, since the automatic door closing command and the automatic door opening command can be stored in the electronic key  31  by utilizing the existing lock button  32  and unlock button  33 , increase in cost can be suppressed to the minimum. 
       Second Embodiment 
       [0066]    Next, description is given of automatic door opening control of a left sliding door  12 L, a right sliding door  12 R, and a tailgate  13  in a second embodiment. In the embodiment, a door opening-closing control apparatus only needs to be configured as in the aforementioned first embodiment. 
         [0067]    In the case where a driver leaves a vehicle for shopping and returns to the vehicle with both hands occupied by a large amount of goods, the driver cannot operate an electronic key  31  to open the left sliding door  12 L, the right sliding door  12 R, or the tailgate  13  in order to load the goods onto the vehicle, unless the driver puts the goods on the ground. In the embodiment, by storing an automatic door opening command in a door opening-closing control unit  14  in advance before the driver leaves the vehicle, one of the doors  12 L,  12 R,  13  is automatically opened when the driver returns to the vehicle. Accordingly, there is no need to put goods on the ground and operate the electronic key  31 , and the convenience is improved. 
         [0068]    Specifically, in step T 11  of a flowchart of  FIG. 5 , the driver gets off the vehicle. When the driver is inside a communicable region around one of the left sliding door  12 L, the right sliding door  12 R, and the tailgate  13 , in step T 12 , authentication is established between an electronic key authentication ECU  15  of the door opening-closing control unit  14  and an electronic key ECU  37  of the electronic key  31 , and intercommunication is performed therebetween. From this state, in the case of reserving the automatic door opening control in step T 13 , in step T 14 , the driver presses an unlock button  33  of the electronic key  31  twice or long to store the automatic door opening command in the electronic key authentication ECU  15  of the door opening-closing control unit  14 , and then leaves the vehicle. In the case where the automatic door opening control of the doors  12 L,  12 R,  13  is reserved as described above, in step T 15 , the electronic key authentication ECU  15  of the door opening-closing control unit  14  continues transmitting a request signal at normal time intervals. 
         [0069]    In the case where the automatic door opening control of the doors  12 L,  12 R,  13  is reserved, the following operations are performed. In step T 16 , the driver returns to the vehicle while holding goods in both hands and enters the communicable range around one of the left sliding door  12 L, the right sliding door  12 R, and the tailgate  13  which is desired by the driver to be opened. In step T 17 , the intercommunication between the door opening-closing control unit  14  and the electronic key  31  becomes possible, the electronic key ECU  37  having received the request signal transmitted by the electronic key authentication ECU  15  transmits a response signal including an ID code, and the electronic key authentication ECU  15  having received the response signal checks the ID code to perform authentication. 
         [0070]    When the authentication is established, in step T 18 , a door lock control ECU  16  drives a door lock actuator  20  based on the door opening command stored in advance in the electronic key authentication ECU  15  to unlock one of the left sliding door  12 L, the right sliding door  12 R, and the tailgate  13  which the driver is close to, and a door opening-closing control ECU  17  drives a door opening-closing actuator  21  to automatically open this door. At this time, the door opening-closing control ECU  17  causes a buzzer  22  to sound to notify the driver that the automatic door opening control is performed based on the reservation-set door opening command. 
         [0071]    The doors  12 L,  12 R,  13  can be thus automatically opened respectively even when the driver holds goods in both hands and cannot operate the electronic key  31 . Hence, there is no need to put the goods on the ground and operate the electronic key  31 , and the convenience is improved. 
         [0072]    Moreover, antennas  19  are provided respectively in the left sliding door  12 L, the right sliding door  12 R, and the tailgate  13 , and the electronic key authentication ECU  15  recognizes one of the communicable ranges of the doors  12 L,  12 R,  13  in which the driver exists and automatically opens only the corresponding door without opening the other doors. Accordingly, it is possible to selectively and automatically open only the door desired by the driver to be opened. As a result, it is possible to avoid unnecessary automatic door opening and also prevent, for example, a case where, while the tailgate  13  is automatically opened and the driver is loading goods, a suspicious person enters the vehicle from the left sliding door  12 L or the right sliding door  12 R which are simultaneously and automatically opened. 
         [0073]    Meanwhile, in the case where the automatic door opening control is not reserved in step T 13  described above, the following operations are performed. In step T 19 , the driver presses the lock button  32  of the electronic key  31  and leaves the vehicle with all of a left front door  11 L, a right front door  11 R, the left sliding door  12 L, the right sliding door  12 R, and the tailgate  13  being locked. Then, in step T 20 , when the driver moves outside the communicable range and the intercommunication between the door opening-closing control unit  14  and the electronic key  31  stops, the door opening-closing control unit  14  stops transmission of the request signal. This can reduce dark current consumed by the door opening-closing control unit  14  and prevent a battery of the vehicle from being wastefully consumed. 
         [0074]    In step T 21 , even when the driver returns to the vehicle and enters the communicable range near the door  12 L,  12 R or  13 , the intercommunication does not automatically start because the door opening-closing control unit  14  has stopped transmission of the request signal. However, in step T 22 , when the driver presses the unlock button  33  of the electronic key  31 , a door unlock command signal including the ID code is transmitted. Then, when the electronic key authentication ECU  15  of the door opening-closing control unit having received the door unlock command signal completes the authentication, the door lock control ECU  16  drives the door lock actuator  20  to unlock all of the left front door  11 L, the right front door  11 R, the left sliding door  12 L, the right sliding door  12 R, and the tailgate  13 . Accordingly, the driver can get on the vehicle without a problem. 
         [0075]    Next, description is given of automatic door closing control of the left sliding door  12 L, the right sliding door  12 R, and the tailgate  13  by reservation. 
         [0076]    The following case sometimes occurs. The driver gets off the vehicle and opens one of the left sliding door  12 L, the right sliding door  12 R, and the tailgate  13  in order to carry goods loaded on the vehicle to another place and then holds the goods with hands. However, holding the goods in both hands makes the operation on the electronic key  31  difficult, and the one of the doors  12 L,  12 R,  13  which is opened may not be closed. In the embodiment, by storing the automatic door closing command in the door opening-closing control unit  14  in advance before the driver holds the goods in both hands, the one of the doors  12 L,  12 R,  13  which is opened is automatically closed when the driver leaves the vehicle while holding the goods. Accordingly, there is no need to put the goods on the ground and operate the electronic key  31 , and the convenience is improved. 
         [0077]    Specifically, in step T 31  of a flowchart of  FIG. 6 , the driver gets off the vehicle. When the driver is inside the communicable range around one of the left sliding door  12 L, the right sliding door  12 R, and the tailgate  13 , in step T 32 , the authentication between the electronic key authentication ECU  15  of the door opening-closing control unit  14  and the electronic key ECU  37  of the electronic key  31  is established. From this state, in the case of reserving the automatic door closing control in step T 33 , in step T 34 , the driver presses the lock button  32  of the electronic key  31  twice or long to store the automatic door closing command in the electronic key authentication ECU  15  of the door opening-closing control unit  14 , and then leaves the vehicle. In the case where the automatic door closing control of the door  12 L,  12 R,  13  is reserved, in step T 35 , the electronic key authentication ECU  15  of the door opening-closing control unit  14  continues transmitting the request signal at normal time intervals. In this case, the door opening-closing control ECU  17  causes the buzzer  22  to sound to notify the driver that reservation setting of the automatic door closing control is performed. 
         [0078]    In subsequent step T 36 , the driver moves outside the communicable range. The reception levels of the request signal and the response signal thereby fall below the thresholds and, in step T 37 , the intercommunication between the electronic key ECU  37  of the electronic key  31  and the electronic key authentication ECU  15  of the door opening-closing control unit  14  stops. Then, the door opening-closing control ECU  17  drives the door opening-closing actuator  21 , based on the automatic door closing command stored in the electronic key authentication ECU  15  of the door opening-closing control unit  14 , so as to automatically close the left sliding door  12 L, the right sliding door  12 R, or the tailgate  13  which is opened. Moreover, the door lock control ECU  16  drives the door lock actuator  20  to lock all of the left front door  11 L, the right front door  11 R, the left sliding door  12 L, the right sliding door  12 R, and the tailgate  13 . 
         [0079]    The doors  12 L,  12 R,  13  can be thus automatically closed respectively even when the driver holds goods in both hands and cannot operate the electronic key  31 . Accordingly, there is no need to put goods on the ground and operate the electronic key  31 , and the convenience is improved. 
         [0080]    In step T 38 , when the driver returns to the vehicle and enters the communicable range of one of the doors  12 L,  12 R,  13  and the authentication between the door opening-closing control unit  14  and the electronic key  31  is completed, the driver can unlock all of the doors  11 L,  11 R,  12 L,  12 R,  13  by pressing the unlock button  33  of the electronic key  31 . 
         [0081]    Meanwhile, in the case where the automatic door closing control is not reserved in step T 33  described above, the following operations are performed. In step  39 , the driver presses the lock button  32  of the electronic key  31  and leaves the vehicle with all of the left front door  11 L, the right front door  11 R, the left sliding door  12 L, the right sliding door  12 R, and the tailgate  13  being locked. Then, in step T 40 , when the driver moves outside the communicable range and the intercommunication between the door opening-closing control unit  14  and the electronic key  31  stops, the door opening-closing control unit  14  stops transmission of the request signal. This can reduce dark current consumed by the door opening-closing control unit  14  and prevent the battery of the vehicle from being wastefully consumed. 
         [0082]    In step T 41 , even when the driver returns to the vehicle and enters the communicable range near the door  12 L,  12 R or  13 , the intercommunication does not automatically start because the door opening-closing control unit  14  has stopped transmission of the request signal. However, in step T 42 , when the driver presses the unlock button  33  of the electronic key  31 , the door unlock command signal including the ID code is transmitted. Then, when the electronic key authentication ECU  15  of the door opening-closing control unit having received the door unlock command signal completes the authentication, the door lock control ECU  16  drives the door lock actuator  20  to unlock all of the left front door  11 L, the right front door  11 R, the left sliding door  12 L, the right sliding door  12 R, and the tailgate  13 . Accordingly, the driver can get on the vehicle without a problem. 
         [0083]    In the embodiment, since the automatic door closing command and the automatic door opening command can be stored in the electronic key  31  by utilizing the existing lock button  32  and unlock button  33 , increase in cost can be suppressed to the minimum. 
       Third Embodiment 
       [0084]    As illustrated in  FIG. 7 , an electronic key  31  in a third embodiment further includes a slide switch  39 . The slide switch  39  can be switched between an ON position and an OFF position. When the slide switch  39  is operated to be set at the ON position, automatic opening-closing functions of doors by reservation are enabled. When the slide switch  39  is operated to be set at the OFF position, the automatic opening-closing functions of the doors by reservation are disabled. In the embodiment, whether the automatic opening-closing functions of the doors  12 L,  12 R,  13  by reservation are enabled or disabled can be checked in a glance by visually observing the position of the slide switch  39 . 
         [0085]    Moreover, as a modified example of the aforementioned embodiment, the automatic door closing function by reservation may be enabled by pressing a lock button  32  with the slide switch  39  operated to be set at the ON position, and the automatic door opening function by reservation may be enabled by pressing an unlock button  33  with the slide switch  39  operated to be set at the ON position. In this modified example, since only one of the automatic door closing function by reservation and the automatic door opening function by reservation can be enabled, the convenience is further improved. 
       Fourth Embodiment 
       [0086]    As illustrated in  FIG. 8 , an electronic key  31  in a fourth embodiment includes a slide switch  39  different from the slide switch  39  in the third embodiment. This slide switch  39  can be switched among an OFF position, an open position, and a close position. When the slide switch  39  is operated to be set at the OFF position, automatic opening-closing functions of doors by reservation are disabled. When the slide switch  39  is operated to be set at the open position, the automatic door opening function by reservation is enabled. When the slide switch  39  is operated to be set at the close position, the automatic door closing function by reservation is enabled. In this embodiment, whether the automatic door opening function or the automatic door closing function of the doors  12 L,  12 R,  13  by reservation is enabled or disabled can be checked in a glance by visually observing the position of the slide switch  39 . 
         [0087]    The embodiments of the present invention are described above. However, various design changes can be made within the scope not departing from the gist of the present invention. 
         [0088]    For example, the door in the present invention is not limited to the left sliding door  12 L, the right sliding door  12 R, and the tailgate  13  in the embodiments and may be a trunk lid. 
         [0089]    Moreover, the automatic opening-closing functions of the doors in the embodiments include the locking and unlocking of the doors by the door lock actuator  20  and the opening and closing of the doors by the door opening-closing actuator  21 . However, it is possible to eliminate the opening and closing of the doors by the door opening-closing actuator  21  and include only the locking and unlocking of the doors by the door lock actuator  20 . 
         [0090]    Moreover, the reason why the intercommunication between the electronic key  31  and the door opening-closing control unit  14  stops is not limited to that the reception level of the signal transmitted from the electronic key  31  falls below the threshold, and may be that the door opening-closing control unit  14  does not receive any response signal from the electronic key  31  in response to the request signal transmitted from the door opening-closing control unit  14  multiple times. 
         [0091]    Furthermore, the automatic door opening control or the automatic door closing control in the present invention is effective not only in the case where both hands of the driver are occupied, but also in the case where the driver wears thick gloves and therefore it is difficult to operate the electronic key  31 .

Summary:
A portable device includes a reservation setting device which stores an automatic door opening command for automatically opening a door, and in a case where the portable device is moved close to a vehicle and authentication is established between the portable device and a door opening-closing control unit, the door opening-closing control unit automatically opens the door when receiving the automatic door opening command stored in the reservation setting device from the portable device. Accordingly, for example, in a case where a driver leaves the vehicle and then needs to return to the vehicle while holding an unexpectedly large amount of goods, the driver operates the portable device and reserves the automatic door opening command before returning to the vehicle so as to be able to automatically open the door when returning to the vehicle, and convenience is thereby improved.