Electronic key verification device, method, and program

Abstract

To provide electronic key verification device, method, and program that can reduce the power consumption required for wireless communication.SOLUTION: An electronic key verification device 100 includes a prediction unit 130 that predicts the direction from which a user is to approach a parked vehicle. The electronic key verification device 100 also includes a drive unit 140 that drives a predicted antenna, which is an antenna among multiple antennas possessed by the vehicle that is oriented toward the predicted approach direction, and stops driving a non-predicted antenna, which is an antenna among the multiple antennas that is different from the predicted antenna.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to an electronic key verification device, method, and program. [Background technology]

[0002] BACKGROUND ART Conventionally, a system is known that uses a plurality of antennas to perform wireless communication with an electronic key (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-070258 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the system of Patent Document 1 has a problem in that it is not possible to suppress the power consumption required for wireless communication because wireless communication is performed using all of the multiple antennas.

[0005] In view of the above, an object of the present invention is to provide an electronic key verification device, method, and program that can reduce the power consumption required for wireless communication. [Means for solving the problem]

[0006] To achieve the above-mentioned object, the electronic key matching device of the present invention is characterized by comprising a prediction unit that predicts the direction of approach from which a user will approach a parked vehicle, and a drive unit that stops the drive of an antenna, among multiple antennas possessed by the vehicle, that is different from the antenna that is pointed in the predicted approach direction. [Effects of the Invention]

[0007] According to the electronic key verification device, method, and program of the present invention, it is possible to reduce the power consumption required for wireless communication. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram illustrating an example of the configuration of a vehicle equipped with a key verification device according to the present invention. [Figure 2] FIG. 2 is a diagram illustrating an example of an area to which an antenna is directed. [Figure 3] FIG. 1 is a diagram illustrating an example of a configuration of a key verification device. [Figure 4] FIG. 2 is a diagram illustrating an example of a learning table stored in the key collating device. [Figure 5] FIG. 2 is a diagram illustrating an example of functions of a key verification device. [Figure 6] FIG. 10 is a diagram illustrating an example of a learning result table stored in the key collating device. [Figure 7] 10 is a flowchart illustrating an example of a learning process executed by the key collating device. [Figure 8] 10 is a flowchart illustrating an example of an unlocking control process executed by the key verification device. [Figure 9] 10 is a flowchart illustrating an example of a direction prediction process executed by the key matching device. [Figure 10] 10 is a flowchart illustrating an example of a locking control process executed by the key verification device. [Figure 11] FIG. 10 is a diagram illustrating an example of the relationship between the approach probability and the antenna drive period. [Figure 12] FIG. 10 is a diagram illustrating an example of the relationship between the approach probability and the antenna output. [Figure 13] FIG. 10 is a diagram illustrating an example of switching of a control mode. DETAILED DESCRIPTION OF THE INVENTION

[0009] <Embodiment> An embodiment of the present invention will now be described with reference to the accompanying drawings. An electronic key verification device (hereinafter simply referred to as verification device) 100 according to this embodiment is, for example, an ECU (Electronic Control Unit) and is mounted on a vehicle V, such as an automobile, as shown in FIG.

[0010] The vehicle V includes antenna units 201 to 204 that wirelessly communicate with the vehicle V's electronic key and a power supply unit 209 that supplies power from a power source, such as a battery, to the antenna units 201 to 204. The antenna unit 201 is, for example, an array antenna and includes an antenna AT1 that periodically emits LF (Low Frequency) waves into space (hereinafter referred to as "polling"). The antenna unit 201 also includes a communication circuit (not shown) that communicates via a communication bus, such as a CAN (Controller Area Network) bus or a LIN (Local Interconnect Network) bus. The communication circuit receives a drive command that commands the driving of the antenna AT1 and specifies the period (hereinafter referred to as the drive period) at which the antenna AT1 is driven and the output power of the antenna AT1. The antenna unit 201 also includes a drive circuit (not shown) that, upon receiving the drive command, drives the antenna AT1 using power supplied from the power supply unit 209 at the drive period and output power specified by the drive command. Driving the antenna AT1 with the output specified by the drive command means emitting LF waves of the field strength or radiation power specified by the drive command from the antenna AT1 into space. In response to this, when the communication circuit of the antenna unit 201 receives a stop command instructing it to stop driving the antenna AT1, the drive circuit stops driving the antenna AT1 from the time of receiving the stop command until the next time the drive command is received.

[0011] The antenna AT1 has directionality and is installed on the vehicle V so as to face an area A1 located in front of the vehicle V, as shown in FIG. 2. For this reason, the direction in which the antenna AT1 faces will hereinafter be simply referred to as the forward direction. The fact that the antenna AT1 faces area A1 means that, when driven at a predetermined output, the antenna AT1 faces in a direction in which the electronic key of the vehicle V can receive the LF waves emitted into space from the antenna AT1 both when the electronic key is present in area A1 and when the electronic key is present inside the passenger compartment of the vehicle V. A suitable value for the predetermined output can be determined by experimentation by one skilled in the art.

[0012] Area A1 is a three-dimensional area in an XYZ coordinate system with the ground surface as the XY plane, and the XYZ coordinate system is a Cartesian coordinate system. The X axis that defines the XYZ coordinate system has its positive direction toward the right of vehicle V, and the Y axis has its positive direction toward the front of vehicle V. The Z axis has its positive direction vertically upward of vehicle V and is an axis that passes through the center point of vehicle V. The ground surface, which is an XY plane, is a horizontal plane that touches the lowest point of vehicle V.

[0013] Area A1 is an area that includes only points that satisfy all of the first, second, and third conditions described below. The first condition is a distance condition that the distance from the center point of vehicle V is equal to or less than a predetermined distance LA, and the second condition is a condition that the Z coordinate value is equal to or greater than a predetermined minimum value and equal to or less than a predetermined maximum value. Suitable values ​​for the predetermined distance LA and the minimum and maximum Z coordinate values ​​can be determined by a person skilled in the art through experimentation. In this embodiment, the minimum Z coordinate value is set to "0," and the maximum Z coordinate value is preset to the vehicle height of vehicle V. Therefore, a point that satisfies the second condition is a point that is located at a height above the ground surface and equal to or less than the vehicle height of vehicle V, and therefore the second condition is also referred to as a height condition. The third condition is that the angle Θ formed by a ray that passes through the foot of a perpendicular line dropped onto the XY plane and starts at the origin, and the positive direction of the X-axis (hereinafter simply referred to as the angle of the ray that passes through the foot of the perpendicular line), is greater than 45 degrees and less than or equal to 135 degrees. The angle Θ formed by the ray and the positive direction of the X-axis means the angle measured counterclockwise from the positive part of the X-axis. In this embodiment, the foot of a perpendicular line that forms an angle Θ with the positive direction of the X-axis that is greater than 45 degrees and less than or equal to 135 degrees, is located forward of the center point of the vehicle V, and therefore, hereinafter, the third condition is also referred to as the directional condition.

[0014] Upon receiving the LF waves transmitted from the antenna AT1, the electronic key transmits a key ID (ID), which is information identifying the electronic key, using RF (Radio Frequency) waves. The electric field strength or radiated power of the RF waves emitted by the electronic key into space is preset to a strength or power that allows two or more of the antennas AT1 to A4 to receive the RF waves transmitted from the electronic key when the electronic key is present in the vehicle cabin. Furthermore, the electric field strength or radiated power of the RF waves emitted by the electronic key is preset to a strength or power that allows the antenna of the antennas AT1 to A4 that is directed toward one of the areas A1 to A4 to receive the RF waves when the electronic key is present in one of the areas A1 to A4. Therefore, for example, when the electronic key is present in area A1, wireless communication between the antenna AT1 and the electronic key is performed as follows: First, the antenna AT1 transmits LF waves into space toward area A1 at a specified frequency. An electronic key present in area A1 receives the LF waves transmitted from the antenna AT1. Next, when the electronic key transmits RF waves into space, the antenna AT1 receives the RF waves. After wireless communication is completed, the drive circuit of the antenna unit 201 outputs the key ID transmitted using the RF waves and the antenna ID of the antenna AT1 to the communication circuit, which then transmits the key ID and antenna ID via the communication bus.

[0015] Antenna units 202 to 204 include antennas AT2 to AT4. The configurations and functions of antenna units 202 to 204 are similar to those of antenna unit 201, but the directions in which antennas AT2 to AT4 are directed are different from the direction in which antenna AT1 is directed. Antennas AT2 to AT4 are directed toward areas A2 to A4 to the right, rear, and left of vehicle V, as shown in FIG. 2. Therefore, the directions in which antennas AT2 to AT4 are directed will hereinafter be simply referred to as the right, rear, and left directions. Areas A2 to A4 are areas that include only points that satisfy all of the following: distance and height conditions that are the same as those of area A1, and directional conditions that are different from those of area A1. The direction condition for area A2 differs from that for area A1 in that the angle Θ of a half line passing through the foot of the perpendicular is greater than 0 degrees and less than or equal to 45 degrees, or greater than 315 degrees and less than or equal to 360 degrees. The direction conditions for areas A3 and A4 differ from that for area A1 in that the angle Θ of a half line passing through the foot of the perpendicular is greater than 225 degrees and less than or equal to 315 degrees, or greater than 135 degrees and less than or equal to 225 degrees.

[0016] As shown in FIG. 3, the collation device 100 is a microcontroller including one or more of a CPU (Central Processing Unit) 101, a RAM (Random Access Memory) 102, a ROM (Read Only Memory) 103, a storage device 104, a communication circuit 105, and an input unit 106. The CPU 101 executes a program stored in the ROM 103 or the storage device 104. The RAM 102 temporarily stores data to be processed when the program is executed. The storage device 104 is, for example, a flash memory, which is a semiconductor memory, and stores various types of data. The communication circuit 105 communicates in accordance with a communication standard such as CAN or LIN. The input unit 106 is, for example, an A / D converter, and converts an analog signal into a digital signal and inputs the digital signal to the CPU 101.

[0017] When the communication circuit 105 of the verification device 100 receives a key ID from one of the antenna units 201 to 204, the CPU 101 verifies the received key ID against one or more IDs pre-stored in the storage device 104 to determine whether the received key ID matches any of the one or more IDs. If the CPU 101 determines that the received key ID does not match any of the one or more pre-stored IDs, it determines that the electronic key that transmitted the key ID is not an electronic key for the vehicle V (hereinafter referred to as verification failure). The CPU 101 then outputs a verification failure notification to the communication circuit 105 notifying that verification has failed, and the communication circuit 105 transmits the verification failure notification via the communication bus.

[0018] In response to this, if the CPU 101 of the verification device 100 determines that the received key ID matches any of the multiple IDs, it determines that the electronic key is an electronic key for vehicle V (hereinafter referred to as verification success), and determines that the user who owns the electronic key is approaching vehicle V. The user being approaching vehicle V means that the distance between the user and vehicle V is less than or equal to distance LA that defines areas A1 to A4. Thereafter, the CPU 101 outputs a verification success notification notifying that verification has been successful, along with the key ID used for verification, to the communication circuit 105, and the communication circuit 105 transmits the verification success notification and the key ID via the communication bus.

[0019] 1 includes a sensor 211 that detects a door lock approach operation, which is an operation for locking or unlocking the doors of the vehicle V and is, for example, an operation performed on a button installed on a door lever of the vehicle V. The vehicle V also includes a door lock control device 212, which is, for example, an ECU, and has the same hardware configuration as the verification device 100. A CPU (not shown) of the door lock control device 212 controls locking or unlocking the doors when a communication circuit (not shown) receives a verification success notification from the verification device 100 before a predetermined time has elapsed since an input unit (not shown) inputs a signal indicating that a door lock approach operation has been detected from the sensor 211.

[0020] After the doors are locked or unlocked, the CPU of the door lock control device 212 determines that it cannot detect a direction based on the vehicle V in which the user left the parked vehicle V before locking (hereinafter referred to as the leaving direction). The CPU also determines that it cannot detect a direction based on the vehicle V in which the user approaches the parked vehicle V after unlocking (hereinafter referred to as the approaching direction). The user leaving the vehicle V means that the user moves away from the vehicle V while the distance between the user and the vehicle V is equal to or less than a predetermined distance LA. The user approaching the vehicle V means that the user approaches the vehicle V while the distance between the user and the vehicle V is equal to or less than the distance LA. The CPU determines that it cannot detect the leaving direction because, for example, the user who operated the door lever button has not yet started to leave the vehicle V. In addition, the CPU determines that it cannot detect the direction of approach because, based on the signal input by sensor 211, the CPU can only detect the position of a user who has already approached vehicle V, for example, as the position of the door lever.

[0021] Thereafter, the CPU of the door lock control device 212 acquires, for example, information indicating the system date and time from a hardware clock as information indicating the date and time when the door was locked or unlocked. Next, the CPU generates information indicating the door lock opening and closing history (hereinafter referred to as opening and closing history information) by associating the acquired date and time information with locking information or unlocking information indicating that the door has been locked or unlocked, and non-detection information indicating that the direction of departure or approach could not be detected, and stores the generated opening and closing history information in a storage device (not shown). Thereafter, the CPU outputs a locking notification indicating that the door has been locked or an unlocking notification indicating that the door has been unlocked, non-detection information indicating that the direction of departure or approach of the user who performed the operation to lock or unlock the door could not be detected, and the key ID of the electronic key carried by the user to a communication circuit (not shown). The communication circuit transmits the output information via a communication bus.

[0022] In response to this, when a door lock remote operation is performed, which is an operation to lock or unlock the doors of vehicle V and is a remote operation performed on the electronic key, the electronic key transmits a lock command to lock or unlock the doors and the key ID of the electronic key using RF waves. A remote operation is usually an operation performed at a location away from vehicle V, but it may also be an operation performed at the location of vehicle V. Furthermore, an operation performed at a location away from vehicle V includes, for example, not only an operation performed at a location away from vehicle V that is longer than the predetermined distance LA that defines areas A1 to A4, but also an operation performed at a location that is less than or equal to the distance LA.

[0023] When the RF waves transmitted by the electronic key are received, for example, by the antenna AT1, the drive circuit of the antenna unit 201 outputs a lock or unlock command and a key ID to the communication circuit. Next, the communication circuit of the antenna unit 201 transmits the key ID, the lock or unlock command, and the antenna ID of the antenna AT1 via the communication bus. Upon receiving the key ID, the verification device 100 transmits a verification success or failure notification based on the key ID. Upon receiving the lock or unlock command and the antenna ID and the verification success notification, the door lock control device 212 locks or unlocks the door.

[0024] Thereafter, the CPU of the door lock control device 212 detects, based on the antenna ID, the direction in which the user carrying the electronic key left the vehicle V or the direction in which the user is approaching the vehicle V. To detect the direction of departure or approach based on the antenna ID, the CPU determines whether the received antenna ID was received together with a locking command or an unlocking command. If the CPU determines that the antenna ID was received together with a locking command, it determines that the direction in which the antenna identified by the antenna ID among antennas AT1 to AT4 is pointed is the direction in which the user left the vehicle V. The CPU detects the direction of departure in this way because it determines that the user left the vehicle V along a half line that passes through one of areas A1 to A4 in the direction in which the antenna is pointed and that begins at the center of the vehicle V and passes through the operation point where the door lock remote operation was performed. The CPU then generates door lock opening / closing history information by associating information indicating the date and time the door was locked, locking information indicating that the door was locked, and exit direction information indicating the detected exit direction, and stores the generated door lock opening / closing history information in a storage device.The CPU then outputs the locking notification, exit direction information, and key ID to a communication circuit, and the communication circuit transmits the output information via a communication bus.

[0025] In response to this, when the CPU of the door lock control device 212 determines that the antenna ID has been received together with an unlock command rather than a lock command, it detects that the direction in which the antenna identified by the antenna ID is pointed is the user's approaching direction. The CPU detects the approaching direction in this manner because it determines that the user is approaching the vehicle V from the operation point along a half-line that passes through one of areas A1 to A4 in the direction in which the antenna is pointed and that starts at the center of the vehicle V and passes through the operation point. The CPU then generates door lock opening / closing history information by associating information indicating the date and time the door was unlocked, the unlocking information, and approach direction information indicating the detected approach direction (hereinafter referred to as the detected approach direction). Next, the CPU stores the generated door lock opening / closing history information in a storage device. The CPU of the door lock control device 212 then identifies, from the opening / closing history information, information indicating the most recent date and time among the information associated with the locking information. As a result, the CPU identifies information indicating the date and time the door was last locked. Next, the CPU acquires departure direction information or non-detection information associated with the identified information. The CPU then outputs the unlock notification, the removal direction information or non-detection information, the approach direction information, and the key ID to the communication circuit, and the communication circuit transmits the output information via the communication bus.

[0026] In response to these, even if the door lock control device 212 receives a lock command or unlock command and an antenna ID, if it receives a verification failure notification, it will not lock or unlock the door and will not detect the departure direction or approach direction.

[0027] The vehicle V in Fig. 1 includes a position measurement unit 221 having, for example, a GPS (Global Positioning System) antenna and an ECU (not shown). The position measurement unit 221 receives GPS signals emitted from GPS satellites at a predetermined cycle using the GPS antenna, and measures the latitude and longitude representing the position of the vehicle V based on the received GPS signals. Next, the position measurement unit 221 transmits information representing the position of the vehicle V (hereinafter referred to as position information) using the measured latitude and longitude via a communication bus at a predetermined cycle. A suitable value for the predetermined cycle can be determined by experimentation by a person skilled in the art.

[0028] The vehicle V also includes a sensor 231, such as a sonar, and a situation detection device 232 that detects the situation around the vehicle V (hereinafter referred to as the surrounding situation) based on a signal input from the sensor 231. The surroundings of the vehicle V refer to a three-dimensional area that includes only points that are located at a distance from the vehicle V that is equal to or less than a predetermined distance LO. In this embodiment, the distance LO is equal to or less than the distance LA that defines the areas A1 to A4, but is not limited to this. A suitable value for the distance LO can be determined by a person skilled in the art through experimentation. Furthermore, detecting the surrounding situation includes detecting objects present around the vehicle. Detected objects include, for example, walls, pillars, utility poles, guardrails, and trees present around the vehicle V, as well as vehicles and motorcycles parked around the vehicle V. Vehicles parked around the vehicle V refer to vehicles other than the vehicle V that are parked around the vehicle V, and do not refer to the vehicle V itself.

[0029] The sensor 231 includes four sensors (not shown). The first sensor is installed on the vehicle V and faces an area A1 located forward of the vehicle V. Therefore, the direction in which the first sensor faces will hereinafter be simply referred to as the forward direction. The fact that the first sensor faces the area A1 means that it can emit sound waves throughout the entire area A1 and, if an object is present in the area A1, can receive sound waves reflected by the object. When the first sensor receives a reflected wave, it measures the distance from the object to the first sensor based on, for example, the difference between the time the sound wave was emitted into the area A1 and the time the reflected wave was received, and the speed of sound, and outputs a signal representing the measured distance. In contrast, if the first sensor does not receive a reflected wave, it stops outputting a signal. The second to fourth sensors have the same configurations and functions as the first sensor. However, the second to fourth sensors are facing areas A2 to A4 located to the right, rear, and left, respectively. For these reasons, the directions in which the second to fourth sensors are pointed will hereinafter be simply referred to as the right direction, the rear direction, and the left direction.

[0030] The situation detection device 232 is, for example, an ECU and has the same hardware configuration as the verification device 100. When an input unit (not shown) of the situation detection device 232 receives a signal from a first sensor and the distance represented by the received signal is equal to or shorter than a predetermined distance LO, a CPU (not shown) detects the presence of an object in the vicinity of the vehicle V included in the area A1. Since the area A1 is located forward of the vehicle V, the direction of the object detected to be present in the area A1 (hereinafter referred to as the object direction) is referred to as the forward direction. The object direction is the direction of the object relative to the vehicle V. In contrast, when no signal is received from the first sensor or when the distance represented by the received signal is longer than the distance LO, the CPU detects that no object is present in the vicinity of the vehicle V included in the area A1. Similar to the signal from the first sensor, the CPU of the situation detection device 232 detects whether or not an object is present in the vicinity of the vehicle V included in the areas A2 to A4 based on the signals from the second to fourth sensors. Since areas A2 to A4 are located to the right, rear, and left of vehicle V, the object directions of objects detected to be present in areas A2 to A4 are referred to as the right, rear, and left directions.

[0031] Furthermore, when the CPU of the situation detection device 232 detects an object whose object direction is forward, it generates information representing the detection result for the forward direction (hereinafter referred to as detection result information) by associating information representing the forward direction with information representing that the object has been detected (hereinafter referred to as object detection information). On the other hand, when such an object is not detected, the CPU generates detection result information for the forward direction by associating information representing the forward direction with information representing that the object has not been detected. Similar to the detection result information for the forward direction, the CPU generates detection result information for the right direction, the rearward direction, and the left front direction. Next, the CPU generates information including the detection result information for the forward direction, the right direction, the rearward direction, and the left direction (hereinafter referred to as the four directions) as situation information representing the surrounding situation of the vehicle V. Thereafter, the CPU outputs the situation information to a communication circuit (not shown), and the communication circuit transmits the output situation information via a communication bus.

[0032] The vehicle V in FIG. 1 includes an antenna unit 241 having a configuration similar to that of the antenna unit 201. The antenna unit 241 receives information representing a remote parking / stopping operation by wirelessly communicating with a terminal device carried by a user according to a communication protocol including, for example, Bluetooth (registered trademark). The remote parking / stopping operation includes a movement operation of moving the vehicle V to a space where the vehicle is to be parked (hereinafter referred to as a parking / stopping space), and a parking / stopping operation of parking the vehicle V after moving the vehicle V. The movement operation and parking / stopping operation of the remote parking / stopping operation are remote operations performed on the user's terminal device and are operations performed by the user after getting off the vehicle V. The vehicle V also includes a parking / stopping control device 242 that, upon receiving information representing the remote parking / stopping operation from the antenna unit 241, moves the vehicle V to the parking / stopping space and then parks the vehicle V. The parking / stopping control device 242 is, for example, an ECU and has the same hardware configuration as the verification device 100. When parking and stopping the vehicle V, a CPU (not shown) of the parking and stopping control device 242 acquires, for example, from a hardware clock, information indicating the system date and time as information indicating the date and time when the remote parking and stopping operation was performed. Next, the CPU generates information indicating the operation history of the remote parking and stopping operation (hereinafter referred to as operation information) by associating the acquired information indicating the date and time with information indicating that the remote parking and stopping operation was performed, and saves the generated operation information in a storage device (not shown).

[0033] The vehicle V also includes a sensor 251, which is, for example, a speed sensor, that detects the rotational speed, which is the number of tire rotations per unit time, and outputs a signal representing the detected rotational speed, and a stop / start detection device 252 that detects parking, stopping, and departure of the vehicle V based on the signal output from the sensor 251. The stop / start detection device 252 is, for example, an ECU, and has the same hardware configuration as the verification device 100. A CPU (not shown) of the stop / start detection device 252 detects parking, stopping, and departure based on a signal input from the sensor 251 to an input unit (not shown). The CPU also detects that the vehicle V is parked, stopping, and starting from the time after detecting parking and stopping until detecting departure, and detects that the vehicle V is traveling from the time after detecting departure until detecting parking and stopping. When the CPU detects parking and stopping, it obtains information representing the system date and time from, for example, a hardware clock, as information representing the date and time when the parking and stopping was detected. Next, the CPU generates information representing the parking history (hereinafter referred to as parking history information) by associating information representing the acquired date and time with information representing that parking and stopping has been detected, and stores the generated parking and stopping history information in a storage device not shown.

[0034] When the communication circuit 105 of the verification device 100 receives an unlock notification and approach direction information indicating the detected approach direction from the door lock control device 212, the CPU 101 executes a storage process (not shown) to store information used for learning the detected approach direction (hereinafter referred to as learning information) in a learning table such as that shown in FIG. 4. The learning information includes date and time information indicating the date and time, position information of the vehicle V, a key ID, departure direction information or non-detection information, and approach direction information. The date and time information included in the learning information is information indicating the date and time when the approach direction was detected, and the position information in the learning information is information indicating the location where the vehicle V was parked or stopped on that date and time. The key ID in the learning information is information identifying the electronic key of a user who approached the vehicle V on that date and time. The departure direction information in the learning information is information indicating the departure direction in which the user last left the vehicle V before that date and time, and the non-detection information is information indicating that such a departure direction could not be detected. The approach direction information of the learning information is information that indicates the detected approach direction of the user detected at the relevant date and time. By executing a storage process for saving the learning information, the CPU 101 functions as an acquisition unit 110 shown in FIG. 5 that acquires the learning information from the communication circuit 105, and as a learning unit 120 that saves the acquired learning information in a learning table. In addition, the storage device 104 functions as an information storage unit 190 that stores the learning table.

[0035] When the execution of the storage process is started, the acquisition unit 110 of the verification device 100 acquires from the communication circuit 105 the key ID, the departure direction information or non-detection information, and the approach direction information received from the door lock control device 212 along with the unlock notification. Next, the acquisition unit 110 acquires date and time information representing the system date and time, for example, from a hardware clock. Thereafter, when the communication circuit 105 receives the position information of the vehicle V from the position measurement unit 221, the acquisition unit 110 acquires the position information from the communication circuit 105. Thereafter, the learning unit 120 generates learning information by associating the acquired date and time information, the position information, the key ID, the departure direction information or non-detection information, and the approach direction information. Next, the learning unit 120 adds a record to the learning table of FIG. 4, saves the generated learning information in the added record, and then terminates the execution of the storage process.

[0036] When a predetermined time arrives, the CPU 101 of the verification device 100 uses the learning information to learn the detected approach direction and stores information representing the learning result (hereinafter referred to as learning result information) in a learning result table such as that shown in FIG. 6, thereby executing a learning process such as that shown in FIG. 7. A suitable value for the predetermined time can be determined through experimentation by a person skilled in the art. The learning result information includes time period information representing a time period, position information of the vehicle V, a key ID, departure direction information or non-detection information, approach count information representing the number of approaches, and approach probability information representing the approach probability. The time period information included in the learning result information represents a predetermined time period, and the position information in the learning result information represents the location where the vehicle V was parked or stopped during that time period. A suitable length of the predetermined time period can be determined through experimentation by a person skilled in the art. Furthermore, the key ID in the learning result information is information identifying the electronic key of the user who approached the vehicle V parked at that location during that time period. Furthermore, the departure direction information in the learning result information is information that indicates the departure direction in which the user last left vehicle V before the time the user approached, and the non-detection information is information that indicates that such departure direction could not be detected.

[0037] The approach count information includes information representing the number of approaches in the front direction. The number of approaches in the front direction is the number of times that the front direction was detected as the direction of approach of the user to the vehicle V parked at the location in the relevant time period. The approach count information further includes information representing the number of times that the right direction, the rear direction, and the left direction were detected as such approach directions.

[0038] The approach probability information includes information representing the approach probability in the forward direction. The approach probability in the forward direction is the probability that the user will approach the vehicle V parked at the location in the relevant time period from the forward direction. The approach probability information further includes information representing the approach probabilities in the right, backward, and left directions, which are the probabilities that such an approach direction will be from the right, backward, and left.

[0039] When the learning process of Fig. 7 starts, the learning unit 120 of the collation device 100 deletes all records to initialize the learning result table of Fig. 6 (step S01). Next, the acquisition unit 110 acquires multiple pieces of time zone information pre-stored in the information storage unit 190 (step S02). In this embodiment, the information storage unit 190 stores 24 pieces of time zone information representing time zones of different one-hour lengths, but the length of the time zone represented by the time zone information and the number of pieces of time zone information pre-stored in the information storage unit 190 are not limited to one hour and 24.

[0040] Next, the learning unit 120 of the verification device 100 executes a process of determining whether or not there is a record (hereinafter referred to as an unprocessed record) that has not been processed among one or more records stored in the learning table of FIG. 4. At this time, if it is determined that there is an unprocessed record, the acquisition unit 110 processes one of the one or more unprocessed records and acquires learning information from the record that has been processed (step S03). Thereafter, the learning unit 120 identifies which of the time periods represented by the acquired multiple time period information includes the time represented by the acquired learning information, thereby identifying the time period in which the approach direction was detected (step S04). Next, the learning unit 120 searches the learning result table of FIG. 6 for a record that stores information representing the identified time period (hereinafter referred to as specific time period information) and the location information, key ID, and departure direction information or non-detection information included in the acquired learning information. At this time, if the learning unit 120 does not find such a record by searching, it adds to the learning table a record that stores specific time period information, location information, key ID, departure direction information or non-detection information, and approach count information indicating "0". The approach count information indicating "0" is information that indicates that the number of approaches in all four directions is "0".

[0041] After adding a record or finding such a record, the learning unit 120 of the matching device 100 increases the approach count represented by the added or found record by the value "1" based on the detected approach direction represented by the acquired learning information. Increasing the approach count by the value "1" based on the detected approach direction means, for example, if the detected approach direction is forward, increasing the forward approach count by the value "1." Next, the learning unit 120 changes the approach count information stored in the added or found record to approach count information representing the increased approach count. Updating the approach count information stored in the record with approach count information representing the increased count means, for example, if the forward approach count is increased, changing the information representing the forward approach count in the record to information representing the increased forward approach count. In this way, the learning unit 120 counts the number of approaches for each combination of the time period when the approach direction was detected, the location where the vehicle V was parked, the electronic key held by the user, the departure direction in which the user left the vehicle V, and the detected approach direction (step S05). Thereafter, the learning unit 120 of the verification device 100 repeats the above process, starting with the process of determining whether or not there are any unprocessed records in the learning table of FIG. 4.

[0042] At this time, if it is determined that no unprocessed records exist in the learning table, the learning unit 120 of the collation device 100 executes a process of determining whether or not there exists an unprocessed record for which the process of saving approach probability information has not been executed among one or more records stored in the learning result table of Fig. 6. At this time, if it is determined that an unprocessed record exists, the acquisition unit 110 selects one of the one or more unprocessed records as a processing target. Next, the learning unit 120 calculates the approach probability based on the approach count indicated by the approach count information stored in the record selected as the processing target (hereinafter referred to as the approach count information to be processed) (step S06).

[0043] To calculate the approach probability, the learning unit 120 of the matching device 100 calculates the sum of the approach counts in the four directions represented by the approach count information to be processed. Next, the learning unit 120 calculates the approach probability in the forward direction by dividing the approach count in the forward direction by the calculated sum. The learning unit 120 also calculates the approach probabilities in the rightward direction, backward direction, and leftward direction by dividing the approach counts in the rightward direction, backward direction, and leftward direction by the sum of the approach counts. Thereafter, the learning unit 120 saves approach probability information representing the calculated approach probabilities in the four directions in the record to be processed (step S07). Thereafter, the learning unit 120 repeats the above process, starting with the process of determining whether or not an unprocessed record exists in the learning result table. At this time, if it is determined that an unprocessed record does not exist in the learning result table, the learning unit 120 ends the execution of the learning process.

[0044] When the communication circuit 105 of the verification device 100 receives the unlock notification, the CPU 101 of the verification device 100 starts executing an unlocking control process as shown in FIG. 8, which switches the control state (hereinafter referred to as the control mode) of the antennas AT1 to AT4 while the door is unlocked. This causes the CPU 101 to function as a drive unit 140 as shown in FIG. 5, which drives the antennas AT1 to AT4. When the unlocking control process starts, the acquisition unit 110 of the verification device 100 acquires, from the information storage unit 190, set cycle information indicating a cycle F1 predetermined as a drive cycle for the antennas AT1 to AT4, and set output information indicating a predetermined output E1 for the antennas AT1 to AT4. Suitable values ​​for the cycle F1 and the output E1 can be determined experimentally by a person skilled in the art. Next, the driver 140 determines the drive period of the antennas AT1 to AT4 to be the period F1 represented by the acquired set period information, and determines the output of the antennas AT1 to AT4 to be the output E1 represented by the set output information (step S11). Next, the driver 140 generates a drive command that commands driving and specifies the determined period F1 and output E1. Thereafter, the driver 140 outputs the generated drive command to the communication circuit 105, addressed to the antenna units 201 to 204, to drive all of the antennas AT1 to AT4 at the specified period and output (step S12).

[0045] Thereafter, the communication circuit 105 of the verification device 100 transmits a drive command to the antenna units 201 to 204, and upon receiving the drive command, the antenna units 201 to 204 drive the outputs of the antennas AT1 to AT4 as output E1 at a cycle F1. In this way, the drive unit 140 switches the control mode of the antennas AT1 to AT4, whose drive has been stopped, to a normal mode (also referred to as an all-around polling mode) in which control is performed to drive all of the antennas AT1 to AT4. Thereafter, the drive unit 140 changes the value of the variable representing the current control mode (hereinafter referred to as the current mode), which is stored in the information storage unit 190, to a value representing the normal mode (step S13).

[0046] Next, the drive unit 140 of the verification device 100 determines whether the doors are locked based on whether the communication circuit 105 has received a locking notification after the execution of the unlocking control process has started (step S14). At this time, if the drive unit 140 determines that the doors are not locked because the locking notification has not been received (step S14; No), the drive unit 140 sleeps for a predetermined time and then repeats the process of step S14. On the other hand, if the drive unit 140 determines that the doors are locked because the locking notification has been received (step S14; Yes), the drive unit 140 determines whether start conditions for starting the direction prediction process shown in FIG. 9 and the locking control process shown in FIG. 10 have been satisfied (step S15). The direction prediction process is a process for predicting the approach direction from which a user who has performed an operation to lock the doors and left the vehicle V will approach the vehicle V. The locking control process is a process for switching the control states of the antennas AT1 to AT4 while the doors are locked. The conditions for starting the direction prediction process and the locking control process are that the doors are locked when the vehicle V is parked or stopped and the electronic key is located outside the vehicle.

[0047] In order to determine whether the start condition is satisfied, the drive unit 140 of the verification device 100 outputs a request for transmission of information representing the driving state of the vehicle V to the communication circuit 105, addressed to the stop / start detection device 252, and the communication circuit 105 transmits the request. When the communication circuit (not shown) of the stop / start detection device 252 receives the request, the CPU (not shown) outputs driving information representing that the vehicle V is driving or parked / stopped information representing that the vehicle V is parked to the communication circuit (not shown) as information representing the driving state of the vehicle V. Next, the communication circuit replies with the output information representing the driving state via the communication bus.

[0048] When the communication circuit 105 of the verification device 100 receives information indicating the driving state, the acquisition unit 110 acquires the received information. At this time, if the acquired information is parked / stopped information, the drive unit 140 determines that the vehicle V is parked / stopped. In contrast, if the acquired information is not parked / stopped information, the drive unit 140 determines that the vehicle V is not parked / stopped. Furthermore, if the drive unit 140 receives two or more antenna IDs from antennas AT1 to AT4 along with a key ID determined to be successfully verified during the post-locking period from when the locking notification is received until a predetermined time has elapsed, the drive unit 140 determines that the electronic key is present inside the vehicle. In contrast, if only one antenna ID or no antenna ID is received during the post-locking period, the drive unit 140 determines that the electronic key is present outside the vehicle.

[0049] In this way, when the drive unit 140 of the verification device 100 determines that the vehicle V is not parked or stopped, or that the electronic key is present in the vehicle interior, it determines that the conditions for starting the direction prediction process and the locking control process are not satisfied (step S15; No). Next, the drive unit 140 outputs a stop command to the communication circuit 105 addressed to all of the antenna units 201 to 204 to stop driving the antennas AT1 to AT4 (step S16). Thereafter, the communication circuit 105 transmits the stop command to the antenna units 201 to 204, and upon receiving the stop command, the antenna units 201 to 204 stop driving the antennas AT1 to AT4. In this way, the drive unit 140 switches the control mode to a stop mode (also referred to as a complete stop mode) in which control is performed to stop driving all of the antennas AT1 to AT4. Thereafter, the drive unit 140 changes the value of the variable representing the current mode to a value representing the stop mode (step S17) and then ends the execution of the unlocking control process.

[0050] In step S15, if the drive unit 140 of the verification device 100 determines that the vehicle V is parked or stopped and that the electronic key for the vehicle V is present outside the vehicle compartment, it determines that the conditions for starting the direction prediction process and the locking time control process are satisfied (step S15; Yes). Next, the CPU 101 of the verification device 100 starts executing the direction prediction process of Fig. 9 using the leaving direction information or non-detection information received together with the locking notification and the key ID as arguments (step S18). In addition, the CPU 101 starts executing the locking time control process in parallel with the direction prediction process (step S19), and then ends the execution of the unlocking time control process without waiting for the execution of the direction prediction process and the locking time control process to end.

[0051] The CPU 101 of the verification device 100 executes a direction prediction process to predict the approach direction, and functions as a prediction unit 130 as shown in FIG. 5 . When the execution of the direction prediction process starts, the prediction unit 130 acquires departure direction information or non-detection information and a key ID from arguments (step S21). Next, the prediction unit 130 outputs a request for transmission of operation information for the remote parking / stopping operation to the communication circuit 105, addressed to the parking / stopping control device 242, and the communication circuit 105 transmits the request. When the communication circuit of the parking / stopping control device 242 receives the request, the CPU of the parking / stopping control device 242 acquires the operation information from the storage device. Next, the CPU of the parking / stopping control device 242 outputs the acquired operation information to the communication circuit, and the communication circuit returns the operation information.

[0052] When the communication circuit 105 of the verification device 100 receives the operation information, the acquisition unit 110 acquires the operation information from the communication circuit 105 (step S22). Next, the prediction unit 130 outputs a request for transmission of parking and stopping history information to the communication circuit 105, addressed to the stop and start detection device 252, and the communication circuit 105 transmits the request. When the communication circuit of the stop and start detection device 252 receives the request, the CPU acquires the parking and stopping history information from the storage device. Next, the CPU of the stop and start detection device 252 outputs the acquired parking and stopping history information to the communication circuit, and the communication circuit replies with the parking and stopping history information. When the communication circuit 105 of the verification device 100 receives the parking and stopping history information, the acquisition unit 110 of the verification device 100 acquires the parking and stopping history information from the communication circuit 105.

[0053] Next, the prediction unit 130 of the verification device 100 determines the latest date and time among the dates and times represented in the parking and stopping history information as the date and time when parking and stopping by the vehicle V started (hereinafter referred to as the parking and stopping start date and time). Furthermore, the prediction unit 130 determines the latest date and time among the dates and times represented in the operation information as the date and time when the last remote parking and stopping operation was performed on the vehicle V. Next, the prediction unit 130 of the verification device 100 calculates the time from the date and time when the last remote parking and stopping operation was performed to the parking and stopping start date and time, and determines whether the calculated length of time is equal to or shorter than a predetermined length. As a result, the prediction unit 130 determines whether the parking and stopping that the vehicle V started at the parking and stopping start date and time is the parking and stopping performed by the vehicle V in accordance with the remote parking and stopping operation (step S23). A suitable value for the predetermined length can be determined by experimentation by a person skilled in the art.

[0054] In step S23, if the prediction unit 130 of the verification device 100 determines that the calculated length of time is longer than a predetermined length, it determines that the parking that started at the parking start date and time was not performed in accordance with a remote parking operation (step S23; No). Next, the prediction unit 130 determines that after the user leaves vehicle V, it is possible or easy to approach the vehicle that continues to be parked (step S24). The reason for this determination is that remote parking operations are more often performed when, for example, the parking space in which vehicle V is parked is so narrow or there is an object around vehicle V that it is impossible or difficult for the user to get off and leave vehicle V. In other words, the prediction unit 130 determines that, since a remote parking / stopping operation was not performed, the parking space in which the vehicle V is parked is large enough that the user can get off and leave the vehicle V, or that it is easy for the user to leave, and that there are no objects around the vehicle V, or that there are only objects around the vehicle V to that extent.

[0055] Next, when the communication circuit 105 of the verification device 100 receives the position information of the vehicle V from the position measurement unit 221, the acquisition unit 110 of the verification device 100 acquires the position information from the communication circuit 105 (step S25). The acquisition unit 110 also acquires information representing the system time, for example, from a hardware clock (step S26). Next, the prediction unit 130 identifies a time period including the system time (hereinafter referred to as the system time period) from among the time periods represented by one or more pieces of learning result information stored in the learning result table of FIG. 6. Thereafter, the acquisition unit 110 attempts to acquire, from the learning result table of FIG. 6, approach probability information associated with the information representing the identified system time period, the position information of the vehicle V acquired in step S25, and the key ID and departure direction information or non-detection information acquired in step S21. At this time, when the approach probability information is acquired (step S27), the acquisition unit 110 acquires information representing a predetermined probability Pm from the information storage unit 190. A suitable value for the probability Pm can be determined by a person skilled in the art through experiments. Then, if any of the four directions has an approach probability represented by the acquired approach probability information that is equal to or greater than Pm, the prediction unit 130 predicts that such a direction is the approach direction. Furthermore, if any of the four directions has an approach probability lower than Pm, the prediction unit 130 predicts that such a direction is a direction (hereinafter referred to as a non-approach direction) different from the predicted approach direction (hereinafter referred to as a predicted approach direction) (step S28). On the other hand, if no approach probability information is acquired, the prediction unit 130 predicts that all of the four directions are non-approach directions.

[0056] Next, the prediction unit 130 of the verification device 100 outputs a request for transmission of situation information indicating the surrounding situation of the vehicle V to the communication circuit 105, addressed to the situation detection device 232, and the communication circuit 105 transmits the request. When the communication circuit of the situation detection device 232 receives the request, the CPU outputs the latest situation information to the communication circuit, and the communication circuit replies with the output situation information. When the communication circuit 105 of the verification device 100 receives the situation information, the acquisition unit 110 of the verification device 100 acquires the situation information from the communication circuit 105 (step S29). Next, the prediction unit 130 determines whether or not an object present in the vicinity of the vehicle V has been detected by determining whether or not object detection information is included in the acquired situation information (step S30).

[0057] At this time, if the prediction unit 130 of the verification device 100 determines that the object detection information is included, it determines that an object has been detected (step S30; Yes). Next, the acquisition unit 110 acquires information indicating the object direction, which is associated with the object detection information, from the situation information. Thereafter, if a direction that is predicted as the approach direction in step S28 and is the same as the object direction exists, the prediction unit 130 changes its prediction to indicate that such a direction is not the approach direction but a non-approach direction (step S31). That is, for example, when the forward direction is predicted to be the approach direction, if the object direction represented by the acquired information is the forward direction, the prediction unit 130 changes its prediction to indicate that the forward direction is a non-approach direction. The prediction unit 130 changes its prediction in this manner because it predicts that an object present around the vehicle will prevent the user from approaching the vehicle V from the object direction.

[0058] If it is determined in step S30 that an object has not been detected (step S30; No), or after step S31 has been executed, the prediction unit 130 of the matching device 100 generates information representing the prediction result and stores the generated information in the information storage unit 190 (step S32). The information representing the prediction result includes information representing the predicted approach direction and information representing the approach probability of the predicted approach direction if an approach direction is predicted, and does not include this information if an approach direction is not predicted. Furthermore, the information representing the prediction result includes information representing the predicted non-approach direction (hereinafter referred to as the predicted non-approach direction) if a non-approach direction is predicted, and does not include information representing the predicted non-approach direction if a non-approach direction is not predicted.

[0059] Next, the prediction unit 130 of the verification device 100 determines whether the doors of the vehicle V are unlocked based on whether the communication circuit 105 has received an unlocking notification after the direction prediction process has started (step S33). At this time, if the prediction unit 130 determines that the doors are not unlocked because an unlocking notification has not been received (step S33; No), it repeats the above process from step S25. This allows the approach direction to be predicted again. On the other hand, if the prediction unit 130 determines that the doors are unlocked because an unlocking notification has been received (step S33; Yes), it ends the direction prediction process.

[0060] In step S23, if the prediction unit 130 of the verification device 100 determines that the calculated length of time is equal to or shorter than a predetermined length, it determines that the parking / stopping that started at the parking / stopping start date and time was performed in accordance with a remote parking / stopping operation (step S23; Yes). Next, the prediction unit 130 determines that the user cannot approach the vehicle V or that it is difficult for the user to approach the vehicle V (step S34). Next, the prediction unit 130 predicts that all four directions are non-approach directions (step S35). Thereafter, the prediction unit 130 generates information representing the prediction result including information representing the predicted non-approach direction, stores the generated information in the information storage unit 190 (step S36), and then terminates the execution of the direction prediction process.

[0061] When parallel execution of the direction prediction process and the locking control process shown in FIG. 10 is started, the acquisition unit 110 of the verification device 100 acquires a variable representing the current mode from the information storage unit 190 (step S41). Next, the acquisition unit 110 acquires information representing the predicted result saved in step S32 or S36 of FIG. 9 from the information storage unit 190 (step S42). Thereafter, if the acquired information representing the predicted result includes information representing the predicted approach direction, the drive unit 140 identifies, among the antennas AT1 to AT4, an antenna (hereinafter referred to as a predicted antenna) that is oriented in the predicted approach direction represented by the acquired information. Furthermore, if the acquired information representing the predicted result includes information representing the predicted non-approach direction, the drive unit 140 identifies, among the antennas AT1 to AT4, an antenna (hereinafter referred to as a non-predicted antenna) that is oriented in the predicted non-approach direction represented by the acquired information.

[0062] Next, the driver 140 of the verification device 100 determines whether all of the antennas AT1 to AT4 have been identified as predicted antennas (step S43). If the driver 140 determines that all of the antennas have been identified as predicted antennas (step S43; Yes), it determines to control the antennas AT1 to AT4 in a normal mode in which control is performed to drive all of the antennas AT1 to AT4. Next, the driver 140 changes the value of a variable representing the post-switching control mode (hereinafter referred to as the new mode) to a value representing the normal mode (step S44). Thereafter, the driver 140 determines whether to switch the control mode by determining whether the value of the variable representing the new mode is the same as the value of the variable representing the current mode (step S45).

[0063] At this time, if the driver 140 of the verification device 100 determines that the value of the variable representing the new mode and the value of the variable representing the current mode are not the same (step S45; No), it decides to switch the control mode. Next, the acquisition unit 110 acquires the setting cycle information and setting output information from the information representing the prediction result, and acquires information representing the approach probability from the information representing the prediction result. Thereafter, the driver 140 determines the drive cycles and outputs of the prediction antennas AT1 to AT4 based on the acquired setting cycle information and setting output information and the information representing the approach probability (step S46). In this embodiment, the driver 140 determines the drive cycle Ff of the prediction antenna AT1 directed in the forward direction as the sum of a predetermined cycle F1 and a value obtained by multiplying the absolute value of the difference between the forward approach probability Pf and the value "1" by a predetermined positive constant α, as shown in FIG. 11. Furthermore, the driver 140 determines the drive period of the predicted antennas AT2 to AT4 oriented in the rightward, backward, and leftward directions as the sum of the period F1 and a value obtained by multiplying the absolute value of the approach probability in the rightward, backward, and leftward directions and the value "1" by a constant α. That is, for example, as shown in FIG. 11, if the approach probability Pr in the rightward direction is lower than the approach probability Pf in the forward direction, the driver 140 determines the drive period Fr of the predicted antenna AT2 oriented in the rightward direction to be longer than the drive period Ff of the predicted antenna AT1 oriented in the forward direction. However, the method for determining the drive period is not limited to this, and any method may be used as long as the drive period is equal to or longer than the predetermined drive period F1 and the lower the approach probability, the longer the drive period.

[0064] Thereafter, the driver 140 of the verification device 100 determines the outputs of the prediction antennas AT1 to AT4 based on the predetermined output E1 represented by the acquired setting output information and the approach probability represented by the information representing the prediction result. In this embodiment, as shown in FIG. 12, the driver 140 determines the output Ef of the prediction antenna AT1 directed in the forward direction to be an output obtained by multiplying the approach probability Pf in the forward direction by the predetermined output E1. The driver 140 also determines the outputs of the prediction antennas AT2 to AT4 directed in the rightward, backward, and leftward directions to be outputs obtained by multiplying the approach probabilities in the rightward, backward, and leftward directions by the output E1. That is, for example, as shown in FIG. 12, if the approach probability Pr in the rightward direction is lower than the approach probability Pf in the forward direction, the driver 140 determines the output Er of the prediction antenna AT2 directed in the rightward direction to be an output weaker than the output Ef of the prediction antenna AT1 directed in the forward direction. However, the method of determining the output is not limited to this, and any method may be used as long as the output is determined to be equal to or less than a predetermined output E1 and the lower the approach probability, the weaker the output.

[0065] Thereafter, the driver 140 of the verification device 100 generates a drive command specifying the determined cycle and output. Next, the driver 140 outputs the generated drive command to the communication circuit 105, addressed to all of the antenna units 201 to 204, to drive all of the predicted antennas AT1 to AT4 at the specified cycle and output (step S47). The communication circuit 105 then transmits the drive command to the antenna units 201 to 204. Upon receiving the drive command, the antenna unit 201 sets the output of the antenna AT1 to the output specified by the drive command and drives the antenna AT1 at the cycle specified by the drive command. Similarly to the antenna unit 201, upon receiving a drive command, the antenna units 202 to 204 set the output of the antennas AT2 to AT4 to the specified output and drive the antennas AT2 to AT4 at the specified cycle. In this way, after switching the control mode of antennas AT1 to AT4 to the normal mode, the driver 140 of the verification device 100 changes the value of the variable representing the current mode to a value representing the normal mode (step S48).

[0066] In step S43, if the driver 140 of the verification device 100 determines that not all of the antennas AT1 to AT4 have been identified as expected antennas (step S43; No), it determines whether a portion of the antennas have been identified as expected antennas (step S49). The term "a portion of the antennas" refers to at least one but not more than three of the antennas AT1 to AT4. If the driver 140 determines that a portion of the antennas have been identified as expected antennas (step S49; Yes), the driver 140 determines to control the antennas AT1 to AT4 in a partial mode (also referred to as a partial polling mode) in which a portion of the antennas AT1 to AT4 are driven and the remaining portion of the antennas are stopped. The remaining portion of the antennas refers to antennas among the antennas AT1 to AT4 that are different from the portion of the antennas. Next, the driver 140 changes the value of the variable representing the new mode to a value representing the partial mode (step S50).

[0067] Thereafter, by performing a process similar to step S45, the verification device 100 determines that the value of the variable representing the new mode is not the same as the value of the variable representing the current mode (step S51; No), and then determines the drive cycle and output of a portion of the predicted antennas (step S52). The portion of predicted antennas refers to the portion of antennas identified as predicted antennas. Next, the verification device 100 performs a process similar to step S46 to determine the cycle and output based on the approach probability. Then, to drive the portion of antennas at the determined cycle and output (step S53), the verification device 100 outputs a drive command to the communication circuit 105, addressed to the portion of antenna units. The portion of antenna units refers to one or more but not more than three antenna units among the antenna units 201 to 204 that have predicted antennas. Furthermore, to stop driving the other portion of antennas (step S54), the verification device 100 outputs a stop command to the communication circuit 105, addressed to the other portion of antenna units, to stop driving. The antenna units of the other portion refer to antenna units among the antenna units 201 to 204 that are different from the antenna units of the part. Then, the communication circuit 105 transmits the output drive command to the antenna units of the part and transmits a stop command to the antenna units of the other portion. When the antenna units of the part receive the drive command, they set the output of the antennas of the part to the output specified by the drive command and drive the antennas of the part at the cycle specified by the drive command. Furthermore, when the antenna units of the other portion receive the stop command, they stop driving the antennas of the other portion. In this way, after switching the control mode to the partial mode, the driver 140 changes the value of the variable representing the current mode to a value representing the partial mode (step S55).

[0068] In step S49, if the driver 140 of the verification device 100 determines that none of the antennas AT1 to AT4 are identified as predicted antennas (step S49; No), it determines that none of the antennas AT1 to AT4 are predicted antennas. Next, the driver 140 determines to control the antennas AT1 to AT4 in the stop mode. Thereafter, the driver 140 changes the value of the variable representing the new mode to a value representing the stop mode (step S56). Thereafter, if the driver 140 determines that the value of the variable representing the new mode and the value of the variable representing the current mode are not the same by performing a process similar to that of step S45 (step S57; No), it performs a process similar to steps S16 and S17 of FIG. 8. As a result, the driver 140 stops driving the antennas AT1 to AT4 (step S58), switches the control mode to the stop mode, and then changes the value of the variable representing the current mode to a value representing the stop mode (step S59).

[0069] In step S45, S51, or S57, if the drive unit 140 of the verification device 100 determines that the value of the variable representing the new mode is the same as the value of the variable representing the current mode (step S45; Yes, S51; Yes, or S57; Yes), it determines not to switch the control mode. After determining not to switch the control mode or after executing the processing of step S48, S55, or S59, the drive unit 140 executes processing similar to step S33 in FIG. 9 to determine whether the doors of the vehicle V are unlocked (step S60). At this time, if the drive unit 140 determines that the doors are not unlocked (step S60; No), it repeats the above processing from step S42. On the other hand, if the drive unit 140 determines that the doors are unlocked (step S60; Yes), it ends the execution of the locking control processing.

[0070] In this way, the verification device 100 controls the antennas AT1 to AT4 in a normal mode in which all of the antennas AT1 to AT4 are driven by executing steps S11 to S13 of the unlocking control process of Fig. 8. Next, for example, when the verification device 100 executes steps S14, S15, S18, and S19, it starts parallel execution of the direction prediction process of Fig. 9 and the locking control process of Fig. 10. Thereafter, for example, when the verification device 100 executes steps S21 to S28 of the direction prediction process of Fig. 9 and predicts that all four directions are non-approach directions, it executes steps S41 to S43, S49, and S56 to S59 of the locking control process of Fig. 10. As a result, the verification device 100 performs switch 1, which transitions the control mode of the antennas AT1 to AT4 from the normal mode to the stop mode, as shown in Fig. 13. After a certain time has elapsed, the verification device 100 executes steps S21 to S32 in Fig. 9 again, and if it again predicts that all four directions are approach directions, for example, it executes steps S42 to S48 in Fig. 10. As a result, the verification device 100 performs switch 4, which transitions the control mode from the stop mode to the normal mode in which all of the antennas AT1 to AT4 are driven.

[0071] Further, after a period of time has elapsed, if the verification device 100 predicts, for example, that a portion of the directions is an approaching direction and another portion of the directions is a non-approaching direction, it executes steps S42, S43, and S49 to S55 of FIG. 10. As a result, the verification device 100 performs switch 6 of FIG. 13, which transitions the control mode from normal mode to partial mode, in which a portion of the antennas is driven and another portion of the antennas is stopped. The partial direction refers to at least one but not more than three of the four directions, and the other partial direction refers to a direction that is different from the portion of the four directions. Further, after a period of time has elapsed, if the verification device 100 predicts, for example, that all four directions are non-approaching directions, it performs switch 7, which transitions the control mode from partial mode to stop mode. Further thereafter, after a lapse of time, if the verification device 100 again predicts that, for example, one direction is an approaching direction and another direction is a non-approaching direction, it performs switch 9, which transitions the control mode from the stop mode to the partial mode.Further thereafter, after a lapse of time, if the verification device 100 again predicts that, for example, all four directions are approaching directions, it performs switch 10, which transitions the control mode from the partial mode to the normal mode.

[0072] Furthermore, for example, when a user performs a remote parking / stopping operation, the verification device 100 sets the control mode to the normal mode by executing steps S11 to S13 of the unlocking control process shown in Fig. 8. Thereafter, when executing steps S14, S15, S18, and S19, for example, the verification device 100 starts parallel execution of the direction prediction process shown in Fig. 9 and the locking control process shown in Fig. 10. Next, the verification device 100 predicts that all four directions are non-approach directions by executing steps S21 to S23, S34, and S35 of the direction prediction process shown in Fig. 9, and executes steps S41 to S43, S49, and S56 to S58 of the locking control process shown in Fig. 10. As a result, the verification device 100 performs switch 2, which transitions the control modes of the antennas AT1 to AT4 from the normal mode to the stop mode as shown in Fig. 13. Furthermore, if the user performs an operation to unlock the door while the control mode is the stop mode or the partial mode, the verification device 100 ends the direction prediction process of Fig. 9 and the locking control process of Fig. 10, and executes steps S11 to S13 of the unlocking control process of Fig. 8. As a result, the verification device 100 performs switch 5 or 11 to transition the control mode from the stop mode or the partial mode to the normal mode.

[0073] In the present embodiment, the prediction unit 130 of the verification device 100 executes steps S27 and S28, S30 and S31, and S34 and S35 of FIG. 9 to predict the approach direction based on all of the learning result information, the situation information, and the operation information of the remote parking / stopping operation. However, the prediction unit 130 may also predict the approach direction based on one or two of the learning result information, the operation information, and the situation information. For example, when the prediction unit 130 predicts the approach direction based on the situation information and the learning result information but not the operation information, it does not need to execute steps S23, S34, and S35, which are processes based on the operation information. Furthermore, when the prediction unit 130 predicts the approach direction based on the situation information and the operation information but not the learning result information, it may execute a process of predicting that all four directions are approach directions instead of executing steps S27 and S28, which are processes based on the learning result information. Furthermore, for example, when the prediction unit 130 predicts the approach direction based on the learning result information and operation information but not on the situation information, it is not necessary to perform the processes of steps S30 and S31 based on the situation information.

[0074] In the present embodiment, the prediction unit 130 of the verification device 100 predicts, for example, the forward direction and the rightward direction as approach directions (hereinafter also referred to as the first approach direction and the second approach direction), and the approach probability Pr of the second approach direction is lower than the approach probability Pf of the first approach direction. Furthermore, in the present embodiment, in the case where the approach probability Pr is lower than the approach probability Pf, the drive unit 140 executes the processes of steps S46 and S47, as well as S52 and S53 of FIG. 10, which control the driving of the antenna AT1 (hereinafter also referred to as the first antenna) directed toward the first approach direction and the antenna AT2 (hereinafter also referred to as the second antenna) directed toward the second approach direction. Through this process, the drive unit 140 drives the second antenna with an output weaker than the output of the first antenna and with a longer period than the period of the first antenna. However, in this case, the driver 140 may drive the second antenna at an output weaker than the output of the first antenna, but may not drive the second antenna at a cycle longer than the cycle of the first antenna. To this end, the driver 140 may command the driving of the second antenna, output a drive command specifying an output Er weaker than the output Ef of the first antenna and specifying a predetermined cycle F1, and may command the driving of the first antenna, output a drive command specifying the output Ef and the cycle F1. Furthermore, in this case, the driver 140 may not drive the second antenna at an output weaker than the output of the first antenna, but may drive the second antenna at a cycle longer than the cycle of the first antenna. For this purpose, the driving unit 140 may output a driving command to drive the second antenna, specify a driving period Fr longer than the driving period Ff of the first antenna, and specify a predetermined output E1, and may also output a driving command to drive the first antenna, specify a driving period Ff and output E1.

[0075] Furthermore, in this embodiment, the driver 140 of the verification device 100 has been described as stopping the driving of the non-prediction antennas in steps S54 and S58 of FIG. 10 , but the driving of the non-prediction antennas does not have to be stopped. If the driving of the non-prediction antennas is not stopped, the driver 140 may perform at least one of driving the non-prediction antennas at a longer cycle than the predicted antennas and driving them at a weaker output than the predicted antennas. For this purpose, the driver 140 may output a drive command to drive the non-prediction antennas and to specify at least one of a longer drive cycle than the predicted antennas and a weaker output than the predicted antennas.

[0076] Furthermore, in this embodiment, it has been explained that the learning unit 120 of the verification device 100 learns the detected approach direction for each combination of four factors: the location where the vehicle V was parked, the electronic key used to lock the vehicle V, the direction in which the user left the vehicle V, and the time period in which the user approached the vehicle V. However, the learning unit 120 may also learn the detected approach direction for each of the four factors, or for each combination of two or three of the four factors.

[0077] According to these configurations, the verification device 100 includes a prediction unit 130 that predicts the direction of approach from which the user will approach the parked vehicle V, based on at least one of the learning results of the detected approach direction detected as the direction from which the user will approach the parked vehicle V, the user's remote parking / stopping operation performed to park the vehicle V, and the status of the parked vehicle V. The verification device 100 also includes a drive unit 140 that drives a predicted antenna, which is an antenna among the multiple antennas AT1 to AT4 possessed by the vehicle V and is oriented toward the predicted approach direction, and stops driving a non-predicted antenna, which is an antenna among the multiple antennas AT1 to AT4 that is different from the predicted antenna. This allows the verification device 100 to reduce power consumption required for wireless communication.

[0078] Furthermore, with these configurations, the prediction unit 130 of the verification device 100 predicts a first approach direction and a second approach direction from which a user will approach a parked vehicle V. The prediction unit 130 also calculates a first approach probability Pf that the user will approach the vehicle V from the predicted first approach direction and a second approach probability Pr that the user will approach the vehicle V from the predicted second approach direction. Furthermore, when the calculated second approach probability Pr is lower than the first approach probability Pf, the drive unit 140 performs at least one of the following: driving a second antenna, which is an antenna oriented in the second approach direction among the multiple antennas AT1 to AT4, with a drive period longer than the drive period of the first antenna, which is an antenna oriented in the first approach direction; and driving the second antenna with an output Er weaker than the output Ef of the first antenna. Therefore, the verification device 100 can reduce the amount of power consumed by driving the second antenna while suppressing a decrease in the probability (hereinafter referred to as the reception probability) that the LF waves emitted from the first antenna or the second antenna can be received by the electronic key of a user approaching the vehicle V.

[0079] Furthermore, with these configurations, when all of the multiple antennas AT1 to AT4 are predicted antennas, the driver 140 of the verification device 100 switches the control mode of the multiple antennas AT1 to AT4 to a normal mode in which all of the multiple antennas AT1 to AT4 are driven. Furthermore, when some of the multiple antennas AT1 to AT4 are predicted antennas and other antennas are non-predicted antennas, the driver 140 switches the control mode to a partial mode in which some of the antennas are driven and other antennas are stopped. Furthermore, when all of the multiple antennas AT1 to AT4 are non-predicted antennas, the driver 140 switches the control mode to a stop mode in which all of the multiple antennas AT1 to AT4 are stopped. Therefore, the verification device 100 can reduce the power consumption required for wireless communication while suppressing a decrease in the receivable probability.

[0080] Furthermore, with these configurations, the situation of the vehicle V includes a situation in which an object is present at a position away from the vehicle V by a distance equal to or less than a predetermined distance LO. The verification device 100 further includes an acquisition unit 110 that acquires information indicating an object direction, which is a direction from the vehicle V toward the object. Furthermore, the prediction unit 130 of the verification device 100 predicts the object direction as a non-approach direction different from the approach direction, and the drive unit 140 stops driving the non-prediction antenna pointed toward the predicted non-approach direction. The verification device 100 makes such a prediction because an object located at a distance equal to or less than the predetermined distance LO from the vehicle V may prevent the user from approaching the vehicle V. Therefore, the verification device 100 can improve the prediction accuracy of the non-approach direction, thereby reducing power consumption by stopping the driving of the non-prediction antenna while suppressing a decrease in the probability of reception.

[0081] Furthermore, according to these configurations, the user's operation includes a remote parking / stopping operation, which is an operation to move the vehicle V to a parking space where the vehicle will be parked and stopped, an operation performed on the user's terminal device, and an operation performed after the user gets out of the vehicle. The verification device 100 also includes an acquisition unit 110 that acquires operation information indicating that a remote parking / stopping operation has been performed. Furthermore, upon acquiring the operation information, the prediction unit 130 of the verification device 100 predicts that all of the directions toward which the multiple antennas AT1 to AT4 are pointed are non-approach directions different from the approach directions, and the drive unit 140 stops driving all of the multiple antennas AT1 to AT4. The verification device 100 makes such a prediction because a remote parking / stopping operation is more likely to be performed when, for example, the parking space where the vehicle V is parked is so narrow or there is an object near the vehicle V that it is impossible or difficult for the user to get out of the vehicle V and leave. Therefore, the verification device 100 can improve the prediction accuracy of the non-approach direction, and can reduce power consumption by stopping the driving of the non-prediction antenna while suppressing a decrease in user convenience.

[0082] According to these configurations, the verification device 100 further includes a learning unit 120 that learns the detected approach direction for each of the location where the vehicle V was parked, the departure direction in which the user left the parked vehicle V, the electronic key operated to lock the vehicle V, and the time period in which the user approached the vehicle V, or for each combination of at least two of the location, the departure direction, the electronic key, and the time. The verification device 100 also includes an acquisition unit 110 that acquires at least one of location information indicating the location where the vehicle V was parked, departure direction information indicating the departure direction in which the user left the parked vehicle V, a key ID that identifies the electronic key operated to lock the vehicle V, and information indicating the system time. The prediction unit 130 of the verification device 100 predicts the approach direction based on the at least one piece of acquired information and the learning result by the learning unit 120, and the drive unit 140 drives a predicted antenna pointed toward the predicted approach direction and stops driving a non-predicted antenna. Therefore, the verification device 100 can improve the accuracy of predicting the approach direction, and can suppress a decrease in the probability of receiving signals while suppressing power consumption.

[0083] Furthermore, with these configurations, the prediction unit 130 of the verification device 100 stops driving some or all of the multiple antennas AT1 to AT4, and then again predicts the direction of approach from which the user will approach the parked vehicle V. Furthermore, the drive unit 140 again drives the antennas that are pointed toward the predicted approach direction among some or all of the antennas whose driving has been stopped. Therefore, even if the predicted approach direction changes over time, the verification device 100 can continue to drive the antennas pointed toward the direction from which the user is predicted to approach, thereby continuously suppressing a decrease in the probability of reception.

[0084] In the present embodiment, the verification device 100 executes the direction prediction process shown in FIG. 9 to predict the direction of approach from which a user will approach a parked vehicle V based on learning result information representing the learning results of the detected approach direction, situation information representing the surrounding conditions of the vehicle V, and operation information for the remote parking / stopping operation. Also, in the present embodiment, the verification device 100 executes the locking control process shown in FIG. 10 to switch the control mode based on the predicted approach direction. However, the basis for switching the control mode is not limited to the predicted approach direction. The drive unit 140 of the verification device 100 may perform switches 3 and 8 shown in FIG. 13 to transition the control mode from the normal mode or partial mode to the stop mode when the length of time elapsed since execution of the locking control process begins is equal to or greater than a predetermined time length. A suitable value for the predetermined time can be determined by experimentation by those skilled in the art.

[0085] In order to switch the control mode based on the elapsed time from the start of execution of the locking control process, the drive unit 140 of the verification device 100 starts counting a predetermined time using a hardware timer or software timer when execution of the locking control process is started. Thereafter, when an interrupt is generated notifying that the predetermined time has elapsed, the drive unit 140 executes the processes of steps S58 and S59 in Fig. 10 to transition the control mode to the stop mode and then terminate execution of the locking control process. With this configuration, the verification device 100 can reduce power consumption required for wireless communication, thereby suppressing a decrease in the amount of stored power in the battery.

[0086] In this embodiment, the vehicle V is described as having four antennas AT1 to AT4. However, the vehicle V may have two, three, or more than four antennas. When the vehicle V has two antennas, one of the two antennas may be directed forward and the other may be directed backward. The area to which one antenna is directed may be the area A1 shown in FIG. 2 or an area A1' (not shown) that includes the area A1. The area A1' that includes the area A1 may be an area that includes only points that satisfy the same distance and height conditions as the area A1, and a direction condition that the angle Θ of a half line passing through the foot of the perpendicular is greater than 0 degrees and less than or equal to 180 degrees. The area to which the other antenna is directed may be the area A3 shown in FIG. 2 or an area A3' (not shown) that includes the area A3. Area A3' including area A3 may be an area that includes only points that satisfy all of the following: the same distance and height conditions as area A3; and a direction condition that the angle Θ of a half line passing through the foot of the perpendicular is greater than 180 degrees and less than or equal to 360 degrees. In this embodiment, for example, sensor 231, which is a sonar, is described as including four sensors (not shown). However, it may include two, three, or four or more sensors. When sensor 231 includes two sensors, one of the two sensors may be directed forward and the other may be directed backward. The area toward which one sensor is directed may be area A1 in FIG. 2 or area A1' (not shown). The area toward which the other sensor is directed may be area A3 in FIG. 2 or area A3' (not shown).

[0087] Furthermore, if vehicle V is equipped with two antennas, one of the two antennas may be directed to the right and the other to the left. The area to which one antenna is directed may be area A2 shown in FIG. 2 or area A2' (not shown) including area A2. Area A2' including area A2 may be an area that includes only points that satisfy all of the following distance and height conditions: the same distance and height conditions as area A2; and the directional condition that the angle Θ of a half line passing through the foot of the perpendicular is greater than 0 degrees and less than or equal to 90 degrees, or greater than 270 degrees and less than or equal to 360 degrees. The area to which the other antenna is directed may be area A4 shown in FIG. 2 or area A4' (not shown) including area A4. Area A4' including area A4 may be an area that includes only points that satisfy all of the following: the same distance and height conditions as area A4, and a direction condition that the angle Θ of a half line passing through the foot of the perpendicular is greater than 90 degrees and less than or equal to 270 degrees. Furthermore, if sensor 231 includes two sensors, one of the two sensors may be oriented to the right and the other to the left. The area toward which one sensor faces may be area A2 in FIG. 2 or area A2' (not shown), and the area toward which the other sensor faces may be area A4 in FIG. 2 or area A4' (not shown).

[0088] Furthermore, although the antennas AT1 to AT4 have been described as emitting LF waves into space, they may emit any electromagnetic waves, including RF waves. Furthermore, although the antennas AT1 to AT4 have been described as receiving RF waves propagating through space, they may receive any electromagnetic waves, including LF waves. Furthermore, instead of the antenna units 201 to 204, the vehicle V may be equipped with multiple communication units that communicate with the electronic key using light, and each of the multiple communication units may include a light-emitting element, such as an LED (Light-Emitting Diode), that emits light into space, and a light-receiving element, such as a photodiode, that receives the light propagating through space. Although the sensor 231 has been described as a sonar, it may also be, for example, a digital camera or radar. Although the vehicle has been described as an automobile, it may also be any vehicle, including, for example, a motorcycle or a railroad car.

[0089] The verification device 100 can be provided as a system having a configuration for realizing the functions of the present embodiment. It can also be provided as a system consisting of multiple devices, with the entire system having a configuration for realizing the functions of the verification device 100 of the present embodiment. Furthermore, the verification device 100 may further include some or all of the functions of the door lock control device 212, the situation detection device 232, the parking / stopping control device 242, and the stop / start detection device 252. Furthermore, an existing microcomputer can execute a program for realizing each functional configuration of the verification device 100 exemplified in this embodiment to function as the verification device 100 of the present embodiment. Such a program can be distributed in any manner. For example, the program can be stored on a non-transitory recording medium such as a memory card, a CD (Compact Disc)-ROM, or a DVD (Digital Versatile Disk)-ROM and distributed via a communication medium such as the Internet. Furthermore, the method of the present invention can be implemented using the verification device 100 of the present embodiment. While the preferred embodiments of the present invention have been described above in detail, the present invention is not limited to these specific embodiments, and various modifications and variations are possible within the scope of the present invention as defined by the claims. [Explanation of symbols]

[0090] 100: Collation device 101: CPU 102: RAM 103: ROM 104: Storage device 105: Communication circuit 106: Input unit 110: Acquisition unit 120: Learning unit 130: Prediction unit 140: Drive unit 190: Information storage unit 201 to 204 and 241: Antenna unit 209: Power supply unit 211, 231 and 251: Sensor 212: Door lock control device 221: Position measurement unit 232: Situation detection device 242: Parking / stopping control device 252: Stop / start detection device A1 to A4: Area AT1 to AT4: Antenna V: Vehicle

Claims

1. a prediction unit that predicts the direction of approach from which the user will approach the parked vehicle based on at least one of a learning result of a detected approach direction detected as the direction from which the user will approach the parked vehicle, an operation performed by the user to park the vehicle, and a situation of the parked vehicle; a driving unit that drives a predicted antenna, which is an antenna directed toward the predicted approach direction among a plurality of antennas possessed by the vehicle, and stops driving a non-predicted antenna, which is an antenna different from the predicted antenna, among the plurality of antennas; An electronic key verification device comprising:

2. The prediction unit predicting a first approach direction and a second approach direction from which the user will approach the parked vehicle; calculating a first approach probability that the user will approach the vehicle from the predicted first approach direction and a second approach probability that the user will approach the vehicle from the predicted second approach direction; When the calculated second approach probability is lower than the first approach probability, the driving unit performs at least one of driving a second antenna, which is an antenna oriented in the second approach direction, among the plurality of antennas at a period longer than a period of a first antenna, which is an antenna oriented in the first approach direction, and driving the second antenna with an output weaker than the output of the first antenna.

2. The electronic key verification device according to claim 1.

3. The drive unit is If all of the plurality of antennas are the predicted antennas, switching the control mode of the plurality of antennas to a normal mode in which all of the plurality of antennas are driven; When a portion of the antennas among the plurality of antennas is the predicted antennas and another portion of the antennas is the non-predicted antennas, the control mode is switched to a partial mode in which the portion of the antennas is driven and the other portion of the antennas is stopped from being driven; and switching the control mode to a stop mode in which driving of all of the plurality of antennas is stopped when all of the plurality of antennas are the non-prediction antennas; 3. The electronic key verification device according to claim 1 or 2.

4. the situation of the vehicle includes a situation in which an object is present at a position away from the vehicle by a distance equal to or less than a predetermined distance; an acquisition unit that acquires information indicating an object direction, which is a direction from the vehicle toward the object; the prediction unit predicts that the object direction represented by the information is a non-approach direction different from the approach direction, the driving unit stops driving the non-predicted antenna directed in the predicted non-approach direction; 3. The electronic key verification device according to claim 1 or 2.

5. The operation of the user includes a remote operation that is an operation to move the vehicle to a space where the vehicle is parked and stopped, an operation that is performed on a terminal device of the user, and an operation that is performed after the user gets off the vehicle, an acquisition unit that acquires operation information indicating that the remote operation has been performed, when the operation information is acquired, the prediction unit predicts that all of the directions in which the plurality of antennas are pointed are non-approach directions different from the approach direction; The driving unit stops driving all of the plurality of antennas.

3. The electronic key verification device according to claim 1 or 2.

6. a learning unit configured to learn the detected approach direction for each of a location where the vehicle was parked, a direction in which the user left the parked vehicle, an electronic key used to lock the vehicle, and a time period in which the user approached the vehicle, or for each combination of at least two of the location, the direction in which the user left the parked vehicle, the electronic key, and the time period; an acquisition unit that acquires at least one of information indicating a location where the vehicle is parked, information indicating a direction in which the user left the parked vehicle, information identifying an electronic key that has been operated to lock the vehicle, and information indicating a system time; the prediction unit predicts the approach direction based on at least one of the acquired information and a result of learning by the learning unit; the driving unit drives the predicted antennas directed toward the predicted approach direction, and stops driving the non-predicted antennas; 3. The electronic key verification device according to claim 1 or 2.

7. the prediction unit predicts again the approach direction in which the user will approach the parked vehicle after driving of some or all of the antennas among the plurality of antennas has been stopped, the driving unit drives an antenna that is directed again in the predicted approach direction among the part of the antennas or all of the antennas whose driving has been stopped, 3. The electronic key verification device according to claim 1 or 2.

8. A method performed by an electronic key verification device, comprising: predicting the direction of approach from which the user will approach the parked vehicle based on at least one of a learning result of a detected approach direction detected as the direction from which the user will approach the parked vehicle, an operation performed by the user to park the vehicle, and a situation of the parked vehicle; stopping the driving of a non-predicted antenna, which is an antenna directed in a non-approach direction different from the predicted approach direction, among a plurality of antennas possessed by the vehicle; A method comprising:

9. Computer, a prediction unit that predicts the direction of approach from which the user will approach the parked vehicle based on at least one of a learning result of a detected approach direction detected as the direction from which the user will approach the parked vehicle, an operation performed by the user to park the vehicle, and a situation of the parked vehicle; and a drive unit that outputs a drive command to drive a predicted antenna, which is an antenna pointed in the predicted approach direction among a plurality of antennas possessed by the vehicle, and outputs a stop command to stop driving a non-predicted antenna, which is an antenna different from the predicted antenna, among the plurality of antennas; A program characterized by functioning as

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