Patent Publication Number: US-2021179014-A1

Title: Vehicle control apparatus, vehicle control method, recording medium with program for control recorded, and vehicle control system

Description:
INCORPORATION BY REFERENCE 
     The present application claims priority under 35 U.S.C. § 119 to Japanese Patent Application No. 2019-227115 filed on Dec. 17, 2019. The content of the application is incorporated herein by reference in its entirety. 
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to a vehicle control apparatus, a vehicle control method, a recording medium with a program for control recorded, and a vehicle control system. 
     Description of the Related Art 
     Conventionally, a vehicle control system has been proposed that includes a security device and an interior reader/writer in a vehicle and thus enables operations on the vehicle by using a vehicle key and a mobile terminal such as a smartphone (see Japanese Patent Laid-Open No. 2014-54902, for example). In the vehicle control system, the security device permits locking/unlocking of a door with the vehicle key if authentication of the vehicle key is succeeded within a communication area outside of the vehicle. The security device further permits to start an engine of the vehicle with the vehicle key if the authentication of the vehicle key is succeeded within a communication area within the vehicle. 
     The interior reader/writer permits operations on the vehicle (such as locking/unlocking of a door and start of the engine) with the mobile terminal carried onto the vehicle if authentication via near field communication (NFC) with the mobile terminal is succeeded. 
     Although the operations on a vehicle with a mobile terminal are enabled when the mobile terminal is carried onto the vehicle in the conventional vehicle control system, enabling operations on the vehicle from outside of the vehicle with the mobile terminal like a vehicle key is also desired. With respect to a vehicle key, operations on a vehicle with the vehicle key can be permitted based on a distance between the vehicle and the vehicle key measured with relatively low power consumption achieved by a combination of low-frequency (LF) and ultra-high frequency (UHF). Therefore, also in order to enable operations on a vehicle from outside of the vehicle with a mobile terminal, enabling measurement of a distance between the vehicle and the mobile terminal with reduced power consumption is desirable. 
     The present invention has been made in view of such background, and it is an object of the present invention to provide a vehicle control apparatus, a vehicle control method, a recording medium with a program for control recorded, and a vehicle control system that enable measurement of a distance between a vehicle and a mobile terminal with reduced power consumption. 
     SUMMARY OF THE INVENTION 
     As a first aspect for achieving the object, there is provided a vehicle control apparatus including a vehicle communication control unit performing communication with a mobile terminal used by a user of a vehicle when the mobile terminal positions within an out-vehicle communication area within a predetermined distance from the vehicle, a distance measuring unit measuring a vehicle-terminal distance, the vehicle-terminal distance being a distance between the vehicle and the mobile terminal, and a distance measurement control unit measuring the vehicle-terminal distance by switching, based on a predetermined condition, between a first distance measurement mode repeatedly measuring the vehicle-terminal distance by the distance measuring unit without depending on reception, by the vehicle communication control unit, of measurement instruction information transmitted from the mobile terminal and a second distance measurement mode measuring the vehicle-terminal distance by the distance measuring unit in response to reception, by the vehicle communication control unit, of the measurement instruction information transmitted from the mobile terminal when communication is established between the vehicle communication control unit and the mobile terminal. 
     The vehicle control apparatus may further include a use estimated time period setting unit setting a use estimated time period being a period when it is estimated that the user uses the vehicle. In this case, as the predetermined condition, a first predetermined condition that a current time is within the use estimated time period may be set, and the distance measurement control unit may perform measurement of the vehicle-terminal distance by the first distance measurement mode if the first predetermined condition is satisfied. 
     The vehicle control apparatus may further include a locked/unlocked time recognizing unit recognizing a time when the vehicle is unlocked or locked. In this case, the use estimated time period setting unit may set the use estimated time period based on a time when the vehicle is unlocked or locked recognized by the locked/unlocked time recognizing unit. 
     The vehicle control apparatus may further include a schedule information obtaining unit obtaining schedule information including an action plan of the user. In this case, the use estimated time period setting unit may set the use estimated time period based on the schedule information obtained by the schedule information obtaining unit. 
     The vehicle control apparatus may further include a vehicle use presence/absence recognizing unit recognizing whether the vehicle is in use or not. In this case, the distance measurement control unit may perform measurement of the vehicle-terminal distance by the second distance measurement mode next time in a time period set as the use estimated time period if use of the vehicle is not recognized by the vehicle use presence/absence recognizing unit within the use estimated time period. 
     The vehicle control apparatus may include a vehicle use presence/absence recognizing unit recognizing whether the vehicle is in use or not, and a vehicle use plan information obtaining unit, if use of the vehicle is not recognized by the vehicle use presence/absence recognizing unit within the use estimated time period, transmitting vehicle use inquiry information inquiring about a plan for using the vehicle to the mobile terminal and obtaining, through the vehicle communication control unit, vehicle use answer information transmitted from the mobile terminal in response to reception of the vehicle use inquiry information. In this case, the use estimated time period setting unit may change the use estimated time period based on the vehicle use answer information. 
     In the vehicle control apparatus, the distance measurement control unit may perform measurement of the vehicle-terminal distance or limitation of measurement of the vehicle-terminal distance by switching, based on the predetermined condition, among a third distance measurement mode limiting measurement of the vehicle-terminal distance by the distance measuring unit, the first distance measurement mode and the second distance measurement mode. 
     The vehicle control apparatus may further include a vehicle use presence/absence recognizing unit recognizing whether the vehicle is in use or not. In this case, as the predetermined condition, a second predetermined condition is set, the second predetermined condition being that a state where it is recognized by the vehicle use presence/absence recognizing unit that the vehicle is not used continues for a predetermined period of time or longer, and the distance measurement control unit may limit measurement of the vehicle-terminal distance by switching to the third distance measurement mode if the second predetermined condition is satisfied while measurement of the vehicle-terminal distance is being performed by the first distance measurement mode or the second distance measurement mode. 
     The vehicle control apparatus may include a non-use estimated time period setting unit setting a non-use estimated time period being a time period estimated as that the user does not use the vehicle. In this case, as the predetermined condition, a third predetermined condition that a current time is within the non-use estimated time period may be set, and, if the third predetermined condition is satisfied, the distance measuring unit may limit measurement of the vehicle-terminal distance by the third distance measurement mode. 
     As a second aspect for achieving the object, there is provided a vehicle control method to be executed by a vehicle control apparatus performing communication with a mobile terminal used by a user of a vehicle, the method including a vehicle communication control step of performing communication with the mobile terminal when the mobile terminal positions within an out-vehicle communication area within a predetermined distance from the vehicle, a distance measuring step of measuring a vehicle-terminal distance, the vehicle-terminal distance being a distance between the vehicle and the mobile terminal, and a distance measurement control step of measuring the vehicle-terminal distance by switching, based on a predetermined condition, between a first distance measurement mode repeatedly measuring the vehicle-terminal distance by the distance measuring step without depending on reception, by the vehicle communication control step, of measurement instruction information transmitted from the mobile terminal and a second distance measurement mode measuring the vehicle-terminal distance by the distance measuring step in response to reception, by the vehicle communication control step, of the measurement instruction information transmitted from the mobile terminal when communication is established between the vehicle control apparatus and the mobile terminal by the vehicle communication control step. 
     As a third aspect for achieving the object, there is provided a recording medium with a program for control recorded, the recording medium being installed in a vehicle control apparatus performing communication with a mobile terminal used by a user of a vehicle, the program causing the vehicle control apparatus to function as a vehicle communication control unit performing communication with the mobile terminal when the mobile terminal positions within an out-vehicle communication area within a predetermined distance from the vehicle, a distance measuring unit measuring a vehicle-terminal distance, the vehicle-terminal distance being a distance between the vehicle and the mobile terminal, and a distance measurement control unit measuring the vehicle-terminal distance by switching, based on a predetermined condition, between a first distance measurement mode repeatedly measuring the vehicle-terminal distance by the distance measuring unit without depending on reception, by the vehicle communication control unit, of measurement instruction information transmitted from the mobile terminal and a second distance measurement mode measuring the vehicle-terminal distance by the distance measuring unit in response to reception, by the vehicle communication control unit, of the measurement instruction information transmitted from the mobile terminal when communication is established between the vehicle communication control unit and the mobile terminal. 
     As a fourth aspect for achieving the object, there is provided a vehicle control system including a mobile terminal used by a user of a vehicle, and a vehicle control apparatus mounted on the vehicle and having a vehicle communication control unit performing communication with the mobile terminal, and a distance measuring unit measuring a vehicle-terminal distance, the vehicle-terminal distance being a distance between the vehicle and the mobile terminal, wherein the mobile terminal and the vehicle communication control unit establish communication when the mobile terminal positions within an out-vehicle communication area of the vehicle communication control unit within a predetermined distance from the vehicle, the mobile terminal transmits, to the vehicle communication control unit, measurement instruction information instructing to measure the vehicle-terminal distance by the distance measuring unit if a predetermined distance measurement execution condition is satisfied, and the vehicle control apparatus has a distance measurement control unit measuring the vehicle-terminal distance by switching, based on a predetermined condition, between a first distance measurement mode repeatedly measuring the vehicle-terminal distance by the distance measuring unit without depending on reception, by the vehicle communication control unit, of the measurement instruction information transmitted from the mobile terminal and a second distance measurement mode measuring the vehicle-terminal distance by the distance measuring unit in response to reception, by the vehicle communication control unit, of the measurement instruction information transmitted from the mobile terminal when communication is established between the vehicle communication control unit and the mobile terminal. 
     According to the above-described vehicle control apparatus, the first distance measurement mode repeatedly measuring the vehicle-terminal distance by the distance measuring unit without depending on reception, by the vehicle communication control unit, of measurement instruction information transmitted from the mobile terminal and the second distance measurement mode measuring the vehicle-terminal distance by the distance measuring unit in response to reception, by the vehicle communication control unit, of the measurement instruction information transmitted from the mobile terminal are switched by the distance measurement control unit based on a predetermined condition when communication is established between the vehicle communication control unit and the mobile terminal. Thus, power consumption required for measurement of the vehicle-terminal distance can be reduced more than a case where the vehicle-terminal distance is repeatedly measured unconditionally by the first distance measurement mode when communication is established between the vehicle communication control unit and the mobile terminal. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an explanatory diagram of an aspect in which a vehicle control apparatus measures a distance between a vehicle and a mobile terminal; 
         FIG. 2  is an explanatory diagram of a configuration of the mobile terminal; 
         FIG. 3  is an explanatory diagram of a configuration of the vehicle on which the vehicle control apparatus is mounted; 
         FIG. 4  is a flowchart of processing of transmitting measurement instruction information by the mobile terminal; and 
         FIG. 5  is a flowchart of processing of measuring a distance between the vehicle and the mobile terminal by the vehicle control apparatus. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     1. Measurement of Distance Between Vehicle and Mobile Terminal 
     With reference to  FIG. 1 , an aspect is described in which a vehicle-terminal distance M being a distance between a vehicle  100  and a mobile terminal  10  is measured in a vehicle control system  1  including a vehicle control apparatus  110  provided in the vehicle  100  and the mobile terminal  10  used by a user U of the vehicle  100 . The vehicle control apparatus  110  is an electronic control unit (ECU) including a central processing unit (CPU), a memory, an interface circuit, and so on, not shown, and controlling operations of the vehicle  100 . 
     The vehicle control apparatus  110  measures the vehicle-terminal distance M by performing communication with the mobile terminal  10  used by the user U of the vehicle  100 . The mobile terminal  10  is, for example, a smartphone, a mobile phone, a tablet terminal, or a wearable device such as a smart watch and is carried or worn by the user U for use. 
     An electronic key application (app) is installed in the mobile terminal  10 , and the mobile terminal  10  can function as an electronic key including a function that remotely operates the vehicle  100  by executing the electronic key app. The vehicle  100  and the mobile terminal  10  mutually perform communication by communication specifications of Bluetooth Low Energy (BLE where Bluetooth is a registered trademark) and Ultra Wide Band (UWB). In UWB communication, a band of 500 MHz to ten-odd GHz (such as around an 8 GHz band) is used. 
     The vehicle  100  includes a first vehicle communication unit  130  performing communication by BLE, and a second vehicle communication unit  140  performing communication by UWB. The vehicle  100  has a BLE antenna  131  connected to the first vehicle communication unit  130  and UWB antennas  141 ,  142  and  143  connected to the second vehicle communication unit  140 . The BLE antenna  131  is arranged substantially in a center part of the vehicle  100 . The UWB antenna  141  is arranged in a front part of the vehicle  100 , the UWB antenna  142  is arranged in the center part of the vehicle  100 , and the UWB antenna  143  is arranged in a rear part of the vehicle  100 . 
     The vehicle control apparatus  110  performs polling by BLE communication through the first vehicle communication unit  130 , and, when the mobile terminal  10  enters from outside (the state indicated by C 1 ) to inside (the state indicated by C 2 ) of an out-vehicle communication area Ar 1  of BLE communication by the first vehicle communication unit  130 , establishes communication by BLE with the mobile terminal  10 . 
     The vehicle control apparatus  110  confirms that the mobile terminal  10  is registered as an electronic key of the vehicle  100  by performing authentication of the electronic key between the vehicle control apparatus  110  and the mobile terminal  10 . More specifically, the vehicle control apparatus  110  confirms that the mobile terminal  10  is registered as an electronic key of the vehicle  100  by comparing an authentication code transmitted from the mobile terminal  10  and an authentication code saved in the memory of the vehicle control apparatus  110 . 
     The vehicle control apparatus  110  measures the vehicle-terminal distance M in order to permit use of the mobile terminal  10  as an electronic key. The vehicle control apparatus  110  performs UWB communication through the second vehicle communication unit  140  with the mobile terminal  10  and measures a distance X between the UWB antenna  141  and the mobile terminal  10 , a distance Y between the UWB antenna  142  and the mobile terminal  10 , and a distance Z between the UWB antenna  143  and the mobile terminal  10  based on Time of Flight (ToF). Because a position Pa of the UWB antenna  141 , a position Pb of the UWB antenna  142  and a position Pc of the UWB antenna  143  in the vehicle  100  are known, a relative position Pd of the mobile terminal  10  with respect to the vehicle  100  is calculated by trilateration by measuring X, Y and Z, and the vehicle-terminal distance M can thus be measured with high precision. 
     When communication by BLE is established between the first vehicle communication unit  130  and the mobile terminal  10 , the vehicle control apparatus  110  measures the vehicle-terminal distance M by performing UWB communication between the second vehicle communication unit  140  and the mobile terminal  10 . When the vehicle control apparatus  110  recognizes that the mobile terminal  10  has entered a monitoring area Ar 2  near the vehicle  100 , as indicated by C 3 , from the vehicle-terminal distance M measured through UWB communication, the vehicle control apparatus  110  permits use of the mobile terminal  10  as the electronic key. 
     Thus, the user U can unlock and lock a door of the vehicle  100 , open and close an electric door (such as a power slide door, a power hinge door or a power tail gate), start the engine, turn on/off an air conditioner, and cause a buzzer to go off, for example, by operating the mobile terminal  10 . When the vehicle control apparatus  110  recognizes that the mobile terminal  10  has entered the monitoring area Ar 2 , the vehicle control apparatus  110  performs processing for, for example, putting on a welcome light (not shown) included in the vehicle  100 . 
     The mobile terminal  10  transmits, to the vehicle  100 , measurement instruction information Mri instructing measurement of the vehicle-terminal distance M if the mobile terminal  10  has a predetermined state, the details of which are described below. When communication by BLE is established between the vehicle control apparatus  110  and the mobile terminal  10 , the vehicle control apparatus  110  performs processing for reducing power consumption required for measurement of the vehicle-terminal distance M by switching, based on a predetermined condition, among a first distance measurement mode repeatedly measuring the vehicle-terminal distance M every predetermined sampling time without depending on reception of the measurement instruction information Mri, a second distance measurement mode measuring the vehicle-terminal distance M in response to reception of the measurement instruction information Mri, and a third distance measurement mode limiting the measurement of the vehicle-terminal distance M. The limiting of the measurement of the vehicle-terminal distance M is performed by a measure such as inhibiting measurement of the vehicle-terminal distance M or increasing the sampling time for measuring the vehicle-terminal distance M more than that of the first distance measurement mode. 
     2. Configuration of Mobile Terminal 
     With reference to  FIG. 2 , a configuration of the mobile terminal  10  is described. The mobile terminal  10  includes a processor  20 , a memory  50 , a first mobile communication unit  40 , a second mobile communication unit  41 , a touch panel  42 , a button switch  43 , a microphone  44 , a speaker  45 , a motion sensor  46 , and a global positioning system (GPS) sensor  47 . 
     The first mobile communication unit  40  performs BLE communication, and the second mobile communication unit  41  performs UWB communication. The touch panel  42  has a touch sensor on a surface of a flat-type display part such as a liquid crystal panel, and a detection signal from the touch sensor in accordance with an operation by the user U is input to the processor  20 , and screen display by the display part is controlled in accordance with a display control signal from the processor  20 . 
     The button switch  43  inputs an operation signal in accordance with an operation by the user U to the processor  20 . The microphone  44  receives input of sound such as voice of the user U and inputs the sound signal to the processor  20 . The speaker  45  outputs an alarm sound in accordance with a sound output control signal from the processor  20 . The motion sensor  46  includes an acceleration sensor or an angular velocity sensor and detects a displacement of the mobile terminal  10 . The GPS sensor  47  receives a signal transmitted from a GPS satellite and detects a current position of the mobile terminal  10 . 
     In the memory  50 , a program for control  51  for the mobile terminal  10 , a program (electronic-key app program)  52  for the above-described electronic key app, and a program (schedule management app program)  53  for a schedule management app that manages schedule including an action plan of the user U are stored. The processor  20  reads and executes the program for control to function as a mobile communication control unit  21 , a terminal lock control unit  22 , an operation presence/absence recognizing unit  23 , a charging presence/absence recognizing unit  24 , and a displacement presence/absence recognizing unit  25 . 
     The mobile communication control unit  21  performs control over BLE communication through the first mobile communication unit  40  and performs control over UWB communication through the second mobile communication unit  41 . The terminal lock control unit  22  switches the mobile terminal  10  between an unlocked state in which an operation by the user U is received and a locked state in which reception of an operation excluding an unlock operation by the user U is inhibited. The terminal lock control unit  22  switches the mobile terminal  10  to the locked state if a state with no operation on the mobile terminal  10  by the user U continues for a first predetermined period of time or longer. The terminal lock control unit  22  switches from the locked state to the unlocked state if the unlock operation is performed by the user U in the locked state. As the unlock operation, input of a personal identification number (PIN), fingerprint authentication, face authentication or the like is adopted. 
     The operation presence/absence recognizing unit  23  detects whether an operation on the touch panel  42 , an operation on the button switch  43  or an operation by sound input to the microphone  44  is performed by the user U or not. The displacement presence/absence recognizing unit  25  recognizes whether the mobile terminal  10  is displaced or not based on a detection signal from the motion sensor  46 . The charging presence/absence recognizing unit  24  recognizes whether a battery (not shown) provided in the mobile terminal  10  is being charged or not in accordance with, for example, the detection state of charging current to the battery by a current sensor (not shown) provided in the mobile terminal  10 . 
     The processor  20  reads and executes the electronic-key app program  52  to function as an indoor location recognizing unit  26 , a distance measurement necessity determining unit  27 , a distance measurement instructing unit  28 , and a mobile electronic-key control unit  29 . 
     The indoor location recognizing unit  26  determines whether the mobile terminal  10  is located indoors or not based on a current position of the mobile terminal  10  detected by the GPS sensor  47  and map data  54 . The indoor location recognizing unit  26  recognizes that the mobile terminal  10  is located indoors if, for example, the current position of the mobile terminal  10  is within a radius of several meters (such as 5 meters) from a reference position of a building in the map data  54 . Alternatively, the indoor location recognizing unit  26  recognizes that the mobile terminal  10  is located indoors if the current position of the mobile terminal  10  is within an area surrounded by an outer frame of a building in the map data  54 . 
     The distance measurement necessity determining unit  27  determines whether or not the mobile terminal  10  has the following first to fifth predetermined states when the mobile terminal  10  positions within the out-vehicle communication area Ar 1  (see  FIG. 1 ) and BLE communication is established between the mobile terminal  10  and the vehicle  100 . 
     If the mobile terminal  10  has at least one state (distance measurement necessary state) of the following first to third predetermined states, the distance measurement necessity determining unit  27  determines that it is necessary to measure the vehicle-terminal distance M. 
     First predetermined state: The mobile terminal  10  has the locked state. Because the mobile terminal  10  is not operated when the mobile terminal  10  has the locked state, it is estimated that the user U has approached the vehicle  100  for using the vehicle  100 . 
     Second predetermined state: State (no-operation state) in which a state where an operation is not recognized by the operation presence/absence recognizing unit  23  continues for a second predetermined period of time or longer. Because it corresponds to a state where the mobile terminal  10  is not operated, it is estimated that the user U has approached the vehicle  100  for using the vehicle  100 . 
     Third predetermined state: State (electronic-key-app operation state) in which the electronic key app is in operation. If the mobile terminal  10  is in the electronic-key-app operation state, it is estimated that the electronic key app is started for using the vehicle  100  by the user U. 
     If the mobile terminal  10  has at least one state (distance measurement unnecessary state) of the following fourth and fifth predetermined states, the distance measurement necessity determining unit  27  determines that it is not necessary to measure the vehicle-terminal distance M. 
     Fourth predetermined state: State (no-displacement state) in which the displacement presence/absence recognizing unit  25  does not recognize that the mobile terminal  10  is displaced. If the mobile terminal  10  has the no-displacement state, it is estimated that it is not a state where the user U is carrying the mobile terminal  10  and is approaching the vehicle  100  for using the vehicle  100 . 
     Fifth predetermined state: State (indoor charged state) in which the charging presence/absence recognizing unit  24  recognizes that the mobile terminal  10  is being charged and the indoor location recognizing unit  26  recognizes that the mobile terminal  10  is located indoors. If the mobile terminal  10  has the indoor charged state, it is estimated that it is not a state where the mobile terminal  10  is used as the electronic key. For example, such a state is acquired when the vehicle  100  is parked by a house and while the mobile terminal  10  is being charged within the out-vehicle communication area Ar 1  of the first vehicle communication unit  130  within the house. 
     If the charging presence/absence recognizing unit  24  recognizes that the mobile terminal  10  is being charged, there is a high possibility that the mobile terminal  10  is being charged indoors, and it is presumed that it is not a state where the user U uses the mobile terminal  10  as the electronic key. Thus, the indoor location recognizing unit  26  may be omitted, and if the charging presence/absence recognizing unit  24  recognizes that the mobile terminal  10  is being charged (charging presence state), the distance measurement necessity determining unit  27  may determine that it is not necessary to measure a relative position Pd of the mobile terminal  10  with respect to the vehicle  100 . 
     If the distance measurement necessity determining unit  27  determines that it is necessary to measure the vehicle-terminal distance M, the distance measurement instructing unit  28  transmits the measurement instruction information Mri that instructs to measure the vehicle-terminal distance M to the vehicle  100 . The mobile electronic-key control unit  29  transmits remote operation instruction information that instructs a remote operation on the vehicle  100  to the first vehicle communication unit  130 . 
     The processor  20  reads and executes the schedule management app program  53  stored in the memory  50  to function as a schedule managing unit  30 . The schedule managing unit  30  stores, in the memory  50 , schedule information indicating schedule of the user U set by an input operation or the like on the touch panel  42  by the user U. The schedule information includes an action plan using the vehicle  100  by the user U. The schedule managing unit  30  transmits the schedule information to the vehicle  100  through the first mobile terminal communication unit  40  in response to a request from the vehicle  100 . The schedule information is stored in the memory  50 . The schedule information may be stored in a management server (not shown) connected to the mobile terminal  10  over a communication network. 
     3. Configuration of Vehicle 
     With reference to  FIG. 3 , a configuration of the vehicle  100  on which the vehicle control apparatus  110  is mounted is described. The vehicle  100  includes, in addition to the vehicle control apparatus  110 , the first vehicle communication unit  130  and the second vehicle communication unit  140  described above, a door lock mechanism  150 , a power window  151 , an electric door  152  (such as a power slide door, a power hinge door or a power tail gate), an air conditioner  153 , an engine starting unit  154 , a speaker  155 , a timer circuit  156 , and a battery  160 . 
     The timer circuit  156  counts pulse signals output from a transmitter, not shown, and inputs the count signal to the vehicle control apparatus  110 . The battery  160  provides power supply to the vehicle control apparatus  110 , the first vehicle communication unit  130 , the second vehicle communication unit  140 , and so on. The battery  160  has a voltage sensor  161  that detects inter-terminal voltage in the battery  160  and a current sensor  162  that detects input and output currents of the battery  160 . 
     The CPU (not shown) provided in the vehicle control apparatus  110  reads and executes a program for control  126  for the vehicle  100  stored in a memory  125 (recording medium) to function as a vehicle communication control unit  111 , a distance measuring unit  112 , a locked/unlocked time recognizing unit  113 , a vehicle use presence/absence recognizing unit  114 , a schedule information obtaining unit  115 , a use estimated time period setting unit  116 , a non-use estimated time period setting unit  117 , a current time recognizing unit  118 , a distance measurement control unit  119 , and a vehicle electronic-key control unit  120 . The program for control  126  may be recorded in an external recording medium (flash memory, magnetic disk, optical disk or the like), and transferred from the external recording medium to the memory  125 . 
     Processing to be executed by the vehicle communication control unit  111  corresponds to a vehicle communication control step in a vehicle control method of the present invention, and processing to be executed by the distance measuring unit  112  corresponds to a distance measuring step in the vehicle control method of the present invention. Processing to be executed by the distance measurement control unit  119  corresponds to a distance measurement control step in the vehicle control method of the present invention. 
     The vehicle communication control unit  111  performs control over BLE communication through the first vehicle communication unit  130  and performs control over UWB communication through the second vehicle communication unit  140 . The distance measuring unit  112  measures the vehicle-terminal distance M by performing UWB communication with the mobile terminal  10  through the second vehicle communication unit  140  and the vehicle communication control unit  111  as described above with reference to  FIG. 1 . 
     Pairing by BLE communication between the vehicle control apparatus  110  and the mobile terminal  10  is performed by transmitting a polling signal to the mobile terminal  10  by the vehicle communication control unit  111  and receiving, by the vehicle communication control unit  111 , a response signal transmitted from the mobile terminal  10  having received the polling signal. In the mobile terminal  10 , the mobile communication control unit  21  receives the polling signal from the vehicle  100  through the first mobile communication unit  40  and transmits a response signal to the vehicle  100  through the first mobile communication unit  40 . As the procedure of the pairing, the pairing between the vehicle  100  and the mobile terminal  10  may be performed by transmitting a polling signal from the mobile terminal  10  and receiving, by the mobile terminal  10 , a response signal transmitted from the vehicle  100  having received the polling signal. 
     The locked/unlocked time recognizing unit  113  recognizes an unlocked time and a locked time of a door of the vehicle  100  based on detection signals of locking and unlocking of the door lock mechanism  150  output from a door lock sensor  150   a.  Then, the locked/unlocked time recognizing unit  113  records the information on the recognized unlocked time and locked time in vehicle use reference data  127  stored in the memory  125 . 
     The vehicle use presence/absence recognizing unit  114  recognizes whether the vehicle  100  is in use or not based on, for example, an ON/OFF state of an ignition switch (not shown) of the vehicle  100 . The schedule information obtaining unit  115  obtains schedule information from the mobile terminal  10  by performing BLE communication with the mobile terminal  10  through the vehicle communication control unit  111  and the first vehicle communication unit  130  and records the schedule information in the vehicle use reference data  127 . 
     A use estimated time period setting unit  116  sets a use estimated time period, which is a time period estimated as having a high possibility that the user U uses the vehicle  100 , with reference to the information on the unlocked time and locked time of the door of the vehicle  100  and the schedule information recorded in the vehicle use reference data  127 . The non-use estimated time period setting unit  117  sets a non-use estimated time period, which is a time period estimated as having a low possibility that the user U uses the vehicle  100 , with reference to the information on the unlocked time and locked time of the door of the vehicle  100  and the schedule information recorded in the vehicle use reference data  127 . 
     For example, in a case where the user U uses the vehicle  100  for driving to and from work, the use estimated time period setting unit  116  recognizes a time period from 8:00 AM to 9:00 AM and a time period from 5:00 PM to 6:00 PM that are commuting time periods on weekdays from the schedule information and sets them as use estimated time periods. The non-use estimated time period setting unit  117  recognizes a time period from 9:00 AM to 5:00 PM that is working hours on weekdays from the schedule information and sets it as a non-use estimated time period. 
     The current time recognizing unit  118  recognizes a current time based on a count signal output from the timer circuit  156 . The distance measurement control unit  119  performs measurement of the vehicle-terminal distance M and the limitation of the measurement by switching among the first distance measurement mode, the second distance measurement mode, and the third distance measurement mode based on the use estimated time period set by the use estimated time period setting unit  116 , the non-use estimated time period set by the non-use estimated time period setting unit  117 , and a use state of the vehicle  100  recognized by the vehicle use presence/absence recognizing unit  114 . 
     The vehicle electronic-key control unit  120  permits a remote operation on the vehicle  100  with the mobile terminal  10  by performing the electronic-key authentication processing described above between the vehicle electronic-key control unit  120  and the mobile electronic-key control unit  29  in the mobile terminal  10 . Then, when receiving remote operation instruction information transmitted from the mobile terminal  10 , the vehicle electronic-key control unit  120  controls an operation of the vehicle  100  in accordance with details of the instruction based on the remote operation instruction information. The remote operation instruction information instructs an operation of the door lock mechanism  150 , the power window  151 , the electric door  152 , the air conditioner  153 , the engine starting unit  154 , and the speaker  155 , for example. 
     A vehicle use plan information obtaining unit  121  transmits vehicle use inquiry information that inquires about a use plan of the vehicle  100  to the mobile terminal  10  if the use of the vehicle  100  is not recognized within the use estimated time periods by the vehicle use presence/absence recognizing unit  114 . Then, the vehicle use plan information obtaining unit  121  obtains vehicle use answer information transmitted from the mobile terminal  10  in response to the reception of the vehicle use inquiry information. The use estimated time period setting unit  116  changes the use estimated time period based on the use plan of the vehicle  100  by the user U recognized from the vehicle use answer information. 
     4. Distance Measurement Processing between Vehicle and Mobile Terminal 
     With reference to flowcharts shown in  FIGS. 4 and 5 , distance measurement processing between the vehicle  100  and the mobile terminal  10  is described. The mobile terminal  10  transmits measurement instruction information Mri that instructs to measure the vehicle-terminal distance M to the vehicle  100  by executing the processing based on the flowchart shown in  FIG. 4 . 
     In step S 1  in  FIG. 4 , the mobile communication control unit  21  performs the pairing by BLE communication by transmitting a response signal to the vehicle control apparatus  110  through the first mobile communication unit  40  in response to reception, through the first mobile communication unit  40 , of a polling signal transmitted from the vehicle control apparatus  110 . When BLE communication with the vehicle  100  is established by the pairing in the subsequent step S 2 , the mobile communication control unit  21  advances the processing to step S 3 . 
     In step S 3 , the distance measurement necessity determining unit  27  recognizes whether the mobile terminal  10  has the first to fifth predetermined states or not. In the next step S 4 , the distance measurement necessity determining unit  27  determines whether the mobile terminal  10  has the distance measurement unnecessary state (at least one state of the fourth and fifth predetermined states) or not. 
     If the mobile terminal  10  has the distance measurement unnecessary state, the distance measurement necessity determining unit  27  advances the processing to step S 7 . In this case, the measurement instruction information Mri is not transmitted to the vehicle  100 . On the other hand, if the mobile terminal  10  does not have the distance measurement unnecessary state, the distance measurement necessity determining unit  27  advances the processing to step S 5  where whether the mobile terminal  10  has the distance measurement necessary state (at least one state of the first to third predetermined states) or not is determined. If the mobile terminal  10  has the distance measurement necessary state, the distance measurement necessity determining unit  27  advances the processing to step S 6 . 
     The distance measurement instructing unit  28  transmits the measurement instruction information Mri to the vehicle  100  in step S 6  and advances the processing to step S 7 . In step S 7 , the distance measurement necessity determining unit  27  determines whether the communication by BLE with the vehicle  100  is established or not. If the communication by BLE with the vehicle  100  is established, the distance measurement necessity determining unit  27  advances the processing to step S 3  and executes the processing in step S 3  and subsequent steps again. On the other hand, if the communication by BLE between the vehicle  100  and the mobile terminal  10  is disconnected, the distance measurement necessity determining unit  27  advances the processing to step S 8  and exits the processing by the flowchart in  FIG. 4 . 
     Next, the vehicle control apparatus  110  provided in the vehicle  100  measures the vehicle-terminal distance M by executing the processing by the flowchart shown in  FIG. 5 . In step S 30  in  FIG. 5 , the use estimated time period setting unit  116  sets a use estimated time period based on the information on the locked time and unlocked time recorded in the vehicle use reference data  127  by the locked/unlocked time recognizing unit  113  and the schedule information recorded in the vehicle use reference data  127  by the schedule information obtaining unit  115 . 
     In the subsequent step S 31 , the non-use estimated time period setting unit  117  sets a non-use estimated time period based on the information on the locked time and unlocked time recorded in the vehicle use reference data  127  by the locked/unlocked time recognizing unit  113  and the schedule information recorded in the vehicle use reference data  127  by the schedule information obtaining unit  115 . 
     If BLE communication with the mobile terminal  10  is established by the pairing in the next step S 32 , the vehicle communication control unit  111  advances the processing to the step S 33 . In the subsequent steps S 33  to S 36 , S 40  and S 50 , processing by the distance measurement control unit  119  is performed. In step S 33 , the distance measurement control unit  119  determines whether the current time recognized by the current time recognizing unit  118  is within the use estimated time period or not. The condition that the current time is within the use estimated time period corresponds to a first predetermined condition of the present invention. 
     If the current time is within the use estimated time period, the distance measurement control unit  119  advances the processing to step S 40  where the measurement of the vehicle-terminal distance M is performed by the first distance measurement mode and then advances the processing to step S 36 . On the other hand, if the current time is not within the use estimated time period, the distance measurement control unit  119  advances the processing to step S 34 . 
     In step S 34 , the distance measurement control unit  119  determines whether the current time recognized by the current time recognizing unit  118  is within the non-use estimated time period or not. If the current time is within the non-use estimated time period, the distance measurement control unit  119  advances the processing to step S 50  where the limitation of the measurement of the vehicle-terminal distance M by the third distance measurement mode is performed and then advances the processing to step S 36 . The condition that the current time is within the non-use estimated time period corresponds to a third predetermined condition of the present invention. On the other hand, if the current time is not within the non-use estimated time period, the distance measurement control unit  119  advances the processing to step S 35 . 
     In step S 35 , the distance measurement control unit  119  performs the measurement of the vehicle-terminal distance M by the second distance measurement mode. The distance measurement control unit  119  in the subsequent step S 36 , determines whether communication by BLE between the vehicle  100  and the mobile terminal  10  is established or not, and, if the communication is established, advances the processing to step S 33  and, if the communication is disconnected, advances the processing to step S 37 . 
     In this manner, the distance measurement control unit  119  inhibits the measurement of the vehicle-terminal distance M by the distance measuring unit  112  as the third distance measurement mode in the non-use estimated time period that is estimated as having a low possibility that the user U uses the vehicle  100 . The distance measurement control unit  119  measures the vehicle-terminal distance M limitedly if receiving the measurement instruction information Mri from the mobile terminal  10  as the second distance measurement mode in a time period, excluding the use estimated time period and non-use estimated time period, when the possibility that the user U uses the vehicle  100  is not clear. By performing the measurement of the vehicle-terminal distance M and the measurement limitation by the second and third distance measurement modes, power consumption by the measurement of the vehicle-terminal distance M can be reduced more than a case where the measurement of the vehicle-terminal distance M by the first distance measurement mode is performed at all times. 
     The distance measurement control unit  119  performs the measurement of the vehicle-terminal distance M by the distance measuring unit  112  as the first distance measurement mode in the use estimate time period estimated as having a high possibility that the user U uses the vehicle  100 . Thus, in the use estimated time period, the vehicle-terminal distance M is quickly measured, and the use of the mobile terminal as the electronic key by the user U is quickly enabled so that the convenience to the user U can be enhanced. 
     If the use of the vehicle  100  is not recognized by the vehicle use presence/absence recognizing unit  114  within the use estimated time period, the vehicle use plan information obtaining unit  121  transmits vehicle use inquiry information that inquires about a use plan of the vehicle  100  to the mobile terminal  10 . Then, the vehicle use plan information obtaining unit  121  obtains vehicle use answer information transmitted from the mobile terminal  10  in response to reception of the vehicle use inquiry information. The use estimated time period setting unit  116  changes the use estimated time period based on the use plan of the vehicle  100  by the user U, which is recognized from the vehicle use answer information. 
     5. Other Embodiments 
     In the above-described embodiment, the non-use estimated time period setting unit  117  is provided, and the distance measurement control unit  119  performs the measurement of the vehicle-terminal distance M by the distance measuring unit  112  and the measurement limitation by switching among the first to third distance measurement modes. As another configuration, the non-use estimated time period setting unit  117  may be omitted, and the distance measurement control unit  119  may perform the measurement of the vehicle-terminal distance M by the distance measuring unit  112  by switching between the first distance measurement mode and the second distance measurement mode. In this case, the measurement of the vehicle-terminal distance M by the second distance measurement mode is performed in a time period excluding the use estimated time period. 
     In the above-described embodiment, the use estimated time period setting unit  116  sets a use estimated time period based on the locked time and unlocked time recognized by the locked/unlocked time recognizing unit  113  and the schedule information obtained by the schedule information obtaining unit  115 . As another embodiment, the use estimated time period setting unit  116  may set a use estimated time period based on any one or two of the locked time, the unlocked time and the schedule information. The non-use estimated time period setting unit  117  may set a non-use estimated time period based on any one or two of the locked time, the unlocked time and the schedule information. 
     In the above-described embodiment, if it is not recognized within the use estimated time period by the vehicle use presence/absence recognizing unit  114  that the vehicle  100  is used, the distance measurement control unit  119  may perform the measurement of the vehicle-terminal distance M by the second distance measurement mode next time in the time period set as the use estimated time period. 
     In the above-described embodiment, if a state where it is recognized by the vehicle use presence/absence recognizing unit  114  that the vehicle  100  is not used continues for a predetermined period of time or longer while the distance measurement control unit  119  is performing the measurement of the vehicle-terminal distance M by the first or second distance measurement mode, the measurement of the vehicle-terminal distance M by the third distance measurement mode may be performed. The condition that the state where it is recognized by the vehicle use presence/absence recognizing unit  114  that the vehicle  100  is not used continues for a predetermined period of time or longer corresponds to a second predetermined condition of the present invention. 
       FIGS. 1 to 3  are schematic diagrams showing the configurations of the mobile terminal  10  and the vehicle control apparatus  110  by dividing them based on main processing details for easy understanding of the present invention of the subject application, but the mobile terminal  10  and the vehicle control apparatus  110  may be configured based on other divisions. Processing by the constituent elements may be executed by one hardware unit or may be executed by a plurality of hardware units. The processing by the constituent elements shown in  FIGS. 4 and 5  may be executed by one program or may be executed by a plurality of programs. 
     6. Configuration Supported by Embodiments Above 
     The embodiments above are specific examples of the following configuration. 
     (1) A vehicle control apparatus including a vehicle communication control unit performing communication with a mobile terminal used by a user of a vehicle when the mobile terminal positions within an out-vehicle communication area within a predetermined distance from the vehicle, a distance measuring unit measuring a vehicle-terminal distance, the vehicle-terminal distance being a distance between the vehicle and the mobile terminal, and a distance measurement control unit measuring the vehicle-terminal distance by switching, based on a predetermined condition, between a first distance measurement mode repeatedly measuring the vehicle-terminal distance by the distance measuring unit without depending on reception, by the vehicle communication control unit, of measurement instruction information transmitted from the mobile terminal and a second distance measurement mode measuring the vehicle-terminal distance by the distance measuring unit in response to reception, by the vehicle communication control unit, of the measurement instruction information transmitted from the mobile terminal when communication is established between the vehicle communication control unit and the mobile terminal. 
     According to the vehicle control apparatus under (1), the first distance measurement mode repeatedly measuring the vehicle-terminal distance by the distance measuring unit without depending on reception, by the vehicle communication control unit, of measurement instruction information transmitted from the mobile terminal and the second distance measurement mode measuring the vehicle-terminal distance by the distance measuring unit in response to reception, by the vehicle communication control unit, of the measurement instruction information transmitted from the mobile terminal are switched by the distance measurement control unit based on a predetermined condition when communication is established between the vehicle communication control unit and the mobile terminal. Thus, power consumption required for measurement of the vehicle-terminal distance can be reduced more than a case where the vehicle-terminal distance is repeatedly measured unconditionally by the first distance measurement mode when communication is established between the vehicle communication control unit and the mobile terminal. 
     (2) The vehicle control apparatus under (1), further including a use estimated time period setting unit setting a use estimated time period being a period when it is estimated that the user uses the vehicle, wherein, as the predetermined condition, a first predetermined condition that a current time is within the use estimated time period is set, and the distance measurement control unit performs measurement of the vehicle-terminal distance by the first distance measurement mode if the first predetermined condition is satisfied. 
     According to the vehicle control apparatus under (2), the vehicle-terminal distance is repeatedly measured by the first distance measurement mode in a use estimated time period having a high possibility that the user uses the vehicle so that processing based on the vehicle-terminal distance can be quickly performed when the user uses the vehicle. 
     (3) The vehicle control apparatus under (2), further including a locked/unlocked time recognizing unit recognizing a time when the vehicle is unlocked or locked, wherein the use estimated time period setting unit sets the use estimated time period based on a time when the vehicle is unlocked or locked recognized by the locked/unlocked time recognizing unit. 
     According to the vehicle control apparatus under (3), the use estimated time period can be set by recognizing a time when the user starts or finishes use of the vehicle based on a locked time or unlocked time of the vehicle. 
     (4) The vehicle control apparatus under (2) or (3), further including a schedule information obtaining unit obtaining schedule information including an action plan of the user, wherein the use estimated time period setting unit sets the use estimated time period based on the schedule information obtained by the schedule information obtaining unit. 
     According to the vehicle control apparatus under (4), the use estimated time period can be set by recognizing a use plan of the vehicle by the user from the schedule information. 
     (5) The vehicle control apparatus under any one of (2) to (4), further including a vehicle use presence/absence recognizing unit recognizing whether the vehicle is in use or not, wherein the distance measurement control unit performs measurement of the vehicle-terminal distance by the second distance measurement mode next time in a time period set as the use estimated time period if use of the vehicle is not recognized by the vehicle use presence/absence recognizing unit within the use estimated time period. 
     According to the vehicle control apparatus under (5), power consumption required for measurement of the vehicle-terminal distance can be reduced in accordance with a change of a use pattern of the vehicle by the user by performing next measurement of the vehicle-terminal distance by the second distance measurement mode in a time period set as the use estimated time period in accordance with the actual use state of the vehicle in the use estimated time period. 
     (6) The vehicle control apparatus under any one of (2) to (5), further including a vehicle use presence/absence recognizing unit recognizing whether the vehicle is in use or not, and a vehicle use plan information obtaining unit, if use of the vehicle is not recognized by the vehicle use presence/absence recognizing unit within the use estimated time period, transmitting vehicle use inquiry information inquiring about a plan for using the vehicle to the mobile terminal and obtaining, through the vehicle communication control unit, vehicle use answer information transmitted from the mobile terminal in response to reception of the vehicle use inquiry information, wherein the use estimated time period setting unit changes the use estimated time period based on the vehicle use answer information. 
     According to the vehicle control apparatus under (6), the use estimated time period can be changed by reflecting a use plan of the vehicle by the user based on the vehicle use answer information transmitted from the mobile terminal in response to reception of the vehicle use inquiry information. 
     (7) The vehicle control apparatus under any one of (1) to (6), wherein the distance measurement control unit performs measurement of the vehicle-terminal distance or limitation of measurement of the vehicle-terminal distance by switching, based on the predetermined condition, among a third distance measurement mode limiting measurement of the vehicle-terminal distance by the distance measuring unit, the first distance measurement mode and the second distance measurement mode. 
     According to the vehicle control apparatus under (7), power consumption required for measurement of the vehicle-terminal distance can further be reduced by setting the third distance measurement mode limiting the measurement of the vehicle-terminal distance. The limiting of the measurement of the vehicle-terminal distance includes measures such as inhibiting the measurement of the vehicle-terminal distance or reducing the frequency of measurement of the vehicle-terminal distance more than that of the first distance measurement mode. 
     (8) The vehicle control apparatus under (7), further including a vehicle use presence/absence recognizing unit recognizing whether the vehicle is in use or not, wherein, as the predetermined condition, a second predetermined condition is set, the second predetermined condition being that a state where it is recognized by the vehicle use presence/absence recognizing unit that the vehicle is not used continues for a predetermined period of time or longer, and the distance measurement control unit limits measurement of the vehicle-terminal distance by switching to the third distance measurement mode if the second predetermined condition is satisfied while measurement of the vehicle-terminal distance is being performed by the first distance measurement mode or the second distance measurement mode. 
     According to the vehicle control apparatus under (8), the power consumption required for measurement of the vehicle-terminal distance can further be reduced by switching to the third distance measurement mode if a state where the vehicle is not used continues in the first distance measurement mode or the second distance measurement mode. 
     (9) The vehicle control apparatus under (7) or (8), further including a non-use estimated time period setting unit setting a non-use estimated time period being a time period estimated as that the user does not use the vehicle, wherein, as the predetermined condition, a third predetermined condition that a current time is within the non-use estimated time period is set, and, if the third predetermined condition is satisfied, the distance measuring unit limits measurement of the vehicle-terminal distance by the third distance measurement mode. 
     According to the vehicle control apparatus under (9), the power consumption required for measurement of the vehicle-terminal distance can further be reduced by setting a non-use estimated time period in advance and limiting the measurement of the vehicle-terminal distance by the third distance measurement mode. 
     (10) A vehicle control method to be executed by a vehicle control apparatus performing communication with a mobile terminal used by a user of a vehicle, the method including a vehicle communication control step of performing communication with the mobile terminal when the mobile terminal positions within an out-vehicle communication area within a predetermined distance from the vehicle, a distance measuring step of measuring a vehicle-terminal distance, the vehicle-terminal distance being a distance between the vehicle and the mobile terminal, and a distance measurement control step of measuring the vehicle-terminal distance by switching, based on a predetermined condition, between a first distance measurement mode repeatedly measuring the vehicle-terminal distance by the distance measuring step without depending on reception, by the vehicle communication control step, of measurement instruction information transmitted from the mobile terminal and a second distance measurement mode measuring the vehicle-terminal distance by the distance measuring step in response to reception, by the vehicle communication control step, of the measurement instruction information transmitted from the mobile terminal when communication is established between the vehicle control apparatus and the mobile terminal by the vehicle communication control step. 
     The configuration of the vehicle control apparatus under (1) above can be implemented by executing the vehicle control method under (10) by the vehicle control apparatus. 
     (11) A recording medium with a program for control recorded, the recording medium being installed in a vehicle control apparatus performing communication with a mobile terminal used by a user of a vehicle, the program causing the vehicle control apparatus to function as a vehicle communication control unit performing communication with the mobile terminal when the mobile terminal positions within an out-vehicle communication area within a predetermined distance from the vehicle, a distance measuring unit measuring a vehicle-terminal distance, the vehicle-terminal distance being a distance between the vehicle and the mobile terminal, and a distance measurement control unit measuring the vehicle-terminal distance by switching, based on a predetermined condition, between a first distance measurement mode repeatedly measuring the vehicle-terminal distance by the distance measuring unit without depending on reception, by the vehicle communication control unit, of measurement instruction information transmitted from the mobile terminal and a second distance measurement mode measuring the vehicle-terminal distance by the distance measuring unit in response to reception, by the vehicle communication control unit, of the measurement instruction information transmitted from the mobile terminal when communication is established between the vehicle communication control unit and the mobile terminal. 
     The configuration of the vehicle control apparatus under (1) above can be implemented by executing the program for control under (11) by the vehicle control apparatus. 
     (12) A vehicle control system including a mobile terminal used by a user of a vehicle, and a vehicle control apparatus mounted on the vehicle and having a vehicle communication control unit performing communication with the mobile terminal, and a distance measuring unit measuring a vehicle-terminal distance, the vehicle-terminal distance being a distance between the vehicle and the mobile terminal, wherein the mobile terminal and the vehicle communication control unit establish communication when the mobile terminal positions within an out-vehicle communication area of the vehicle communication control unit within a predetermined distance from the vehicle, the mobile terminal transmits, to the vehicle communication control unit, measurement instruction information instructing to measure the vehicle-terminal distance by the distance measuring unit if a predetermined distance measurement execution condition is satisfied, and the vehicle control apparatus has a distance measurement control unit measuring the vehicle-terminal distance by switching, based on a predetermined condition, between a first distance measurement mode repeatedly measuring the vehicle-terminal distance by the distance measuring unit without depending on reception, by the vehicle communication control unit, of the measurement instruction information transmitted from the mobile terminal and a second distance measurement mode measuring the vehicle-terminal distance by the distance measuring unit in response to reception, by the vehicle communication control unit, of the measurement instruction information transmitted from the mobile terminal when communication is established between the vehicle communication control unit and the mobile terminal. 
     According to the vehicle control system under (12), the first distance measurement mode repeatedly measuring the vehicle-terminal distance by the distance measuring unit without depending on reception, by the vehicle communication control unit, of measurement instruction information transmitted from the mobile terminal and the second distance measurement mode measuring the vehicle-terminal distance by the distance measuring unit in response to reception, by the vehicle communication control unit, of the measurement instruction information transmitted from the mobile terminal are switched by the distance measurement control unit based on a predetermined condition when communication is established between the vehicle communication control unit and the mobile terminal. Thus, power consumption required for measurement of the vehicle-terminal distance can be reduced more than a case where the vehicle-terminal distance is repeatedly measured unconditionally by the first distance measurement mode when communication is established between the vehicle communication control unit and the mobile terminal. 
     REFERENCE SIGNS LIST 
       1 : vehicle control system,  10 : mobile terminal,  100 : vehicle,  110 : vehicle control apparatus,  111 : vehicle communication control unit,  112 : distance measuring unit,  113 : locked/unlocked time recognizing unit,  114 : vehicle use presence/absence recognizing unit,  115 : schedule information obtaining unit,  116 : use estimated time period setting unit,  117 : non-use estimated time period setting unit,  118 : current time recognizing unit,  119 : distance measurement control unit,  120 : vehicle electronic-key control unit,  121 : vehicle use plan information obtaining unit,  125 : memory,  126 : program for control,  127 : vehicle use reference data,  130 : first vehicle communication unit,  131 : BLE antenna,  140 : second vehicle communication unit,  141 ,  142 ,  143 : UWB antenna, U: user