WIRELESS COMMUNICATION SYSTEM

Abstract

A wireless communication system comprising: a locking and unlocking device (300) configured to control locking and unlocking of a target, wherein the locking and unlocking device (300) includes a device-side communication module (301) configured to communicate a first signal having a first frequency band, wherein the device-side communication module (301) includes a device-side antenna coil (301a) for communication; and a key unit (100) configured to communicate with the locking and unlocking device (300) and to instruct the locking and unlocking of the target by communicating with the locking and unlocking device (300), wherein the key unit (100) is installed in the target and includes a unit-side communication module (101) that communicates the first signal, wherein the unit-side communication module (101) has a unit-side antenna coil (101a) for communication, wherein the key unit (100) is installed in the target such that a distance between the unit-side communication module (101) and the device-side communication module (301) is within a predetermined distance at which communication between the unit-side communication module (101) and the device-side communication module (301) is possible, and that an axis of the unit-side antenna coil (101a) is parallel to an axis of the device-side antenna coil (301a), characterized in that the locking and unlocking device (300) is installed in a dashboard of a vehicle (10).

Description

BACKGROUND OF THE INVENTION1. Field of the InventionThe invention relates to a system for wireless communication.2. DESCRIPTION OF RELATED ARTThere is known a key management system in which authentication information for unlocking a vehicle is acquired by a portable terminal via a network from a server device, and the portable terminal can be used as an electronic key (Japanese Unexamined Patent Application Publication No. JP 2006-118 122 A). In the system, the vehicle has a tag reading means with an integrated circuit (IC tag), and unlocking is performed using the mobile terminal and the IC tag in which key information is written.In Japanese Unexamined Patent Application Publication No. JP 2004-242 138 A discloses a technology for a navigation device for a vehicle to which a VICS (registered trademark) receiver and a wireless communication device different from the VICS receiver are mounted in which mounting positions of the two wireless communication devices are very close, and radio wave interference of wireless communication is inhibited by the wireless communication devices.DE 10 2014 107 186 A1 discloses a module unit for adapting mobile, portable communication devices to security systems, in particular for keyless activation of an access system for vehicles, having an interface for data exchange with the communication device, and a communication unit for radio connection with the security system, so that communication is realized between the communication unit and the security system.Summary of the InventionVehicles offered for sale include smart key systems. The smart key system is a system that gives a unique identifier (ID) of a portable device (electronic key) that performs wireless communication with a vehicle, and in which a lock-and-unlock device of the vehicle performs door unlock or the like in a case where the ID obtained by the communication matches an ID registered in advance in the vehicle. Locking and unlocking of the vehicle by a portable terminal using the smart key system are studied, and a system that enables locking and unlocking of the vehicle by the portable terminal without redesigning the vehicle is studied.For example, a key unit including a role of the electronic key (this may be referred to as a "key unit" hereinafter for convenience) is installed in the vehicle, and the key unit communicates with the locking and unlocking device of the vehicle on the basis of the result of authentication performed by the mobile terminal such as a smartphone. By executing the above, it is possible to control the locking and unlocking of the vehicle by the portable terminal without redesigning the vehicle.Here, when the key unit is installed in a target such as the vehicle (hereinafter referred to as a "target" for convenience), and in a case where the key unit is installed in a position or an orientation where a communication failure with the locking-and-unlocking device occurs, locking and unlocking of the vehicle by the portable terminal may not be possible.The related art discloses methods for inhibiting radio wave interference, and there is still room for improvement in maintaining good communication between the key unit and the lock-and-unlock device. This is achieved by the subject matter of the independent claims. Further developments are disclosed in the dependent claims.The invention provides a wireless communication system including a locking and unlocking device of a target and a key unit that controls locking and unlocking of the target, in which an intensity of wireless communication between the key unit and the locking and unlocking device is increased as much as possible.The key unit controls locking and unlocking of the target by communicating with a locking and unlocking device. Each of the key unit and the lock-and-unlock device includes a communication module, and thus a wireless communication system in which communication is performed between the communication modules is configured.One aspect of the invention relates to a system for wireless communication. The wireless communication system includes: a locking and unlocking device configured to control locking and unlocking of a target, the locking and unlocking device including a device-side communication module configured to communicate a first signal having a first frequency band; and a key unit configured to communicate with the locking and unlocking device and command locking and unlocking of the target by communicating with the locking and unlocking device, the key unit being installed in the target. The key unit includes a unit-side communication module that communicates the first signal.The device-side communication module includes a device-side antenna coil for communication. The unit-side communication module includes a unit-side antenna coil for communication. The antenna coil has a directivity, and for example, in a case where radio waves are transmitted from the antenna coil, a field intensity in an axial direction of the antenna coil becomes relatively strong. On the other hand, in a case where the radio waves are received by the antenna coil, a reception intensity becomes relatively strong when a direction of the radio waves is parallel to an axis of the antenna coil (in the description, "parallel" includes the replication "substantially parallel").The key unit is installed in the target such that a distance between the unit-side communication module and the device-side communication module is within a predetermined distance at which communication between the unit-side communication module and the device-side communication module is possible, and that an axis of the unit-side antenna coil is parallel to an axis of the device-side antenna coil. According to the configuration, it is possible to increase the intensity of wireless communication between the key unit and the lock-and-unlock device as much as possible. Then, when there is a source of noise around the key unit, a ratio of a signal to a noise ratio can be maintained relatively high, and thus good wireless communication between the key unit and the lock-and-unlock device can be realized. In a case where the key unit is installed at a position spaced from the source of noise, better wireless communication can be realized.According to the aspect of the invention, the aspect can be suitably applied to an embodiment in which the locking and unlocking of the vehicle is controlled by using an existing smart key system.In the wireless communication system according to the aspect of the invention, the device-side communication module may be a device-side transmission module configured to transmit the first signal to the key unit. The unit-side communication module may be a unit-side reception module configured to receive the first signal. Moreover, the key unit may include a unit-side transmission module configured to transmit, to the lock-and-unlock device, a second signal having a second frequency band that is a frequency band higher than the first frequency band. Moreover, the locking and unlocking device may include a device-side receiving module configured to receive the second signal and mounted on a vehicle. The key unit may be configured to transmit the second signal instructing locking and unlocking of the vehicle from the unit-side transmission module when the unit-side reception module receives the first signal. The locking and unlocking device may be configured to control locking and unlocking of the vehicle when the device-side receiving module receives the second signal.As described above, in a case where the target is the vehicle, the locking and unlocking device is specified as the locking and unlocking device of the vehicle, and the key unit is installed in the vehicle. Here, since there may be a plurality of sources of noise in the vehicle (for example, an in-vehicle ETC (registered trademark) device, an air conditioner, a wiper, and a plasma cluster), unless the key unit is installed at an appropriate position or orientation in the vehicle, a communication failure may occur between the key unit and the lock-and-unlock device due to the noise or the noise interference or the radio wave interference. In the aspect in which the key unit is installed in the vehicle, the key unit is installed in the vehicle such that the axis of the unit-side antenna coil is parallel to the axis of the device-side antenna coil. As described above, it is possible to increase the intensity of wireless communication between the key unit and the lock-and-unlock device as much as possible.Here, in the key unit using the intelligent key system, an instruction signal (response signal) is transmitted to the lock-and-unlock device in a manner responding to a calling (checking) signal from a vehicle side. That is, as described above, when the unit-side communication module receives the first signal (the polling signal), the key unit transmits the second signal (response signal) from the unit-side transmission module to instruct the locking and unlocking of the vehicle. Then, when the device-side receiving module receives the second signal (response signal), the locking and unlocking device controls the locking and unlocking of the vehicle.The key unit may include a power supply circuit, and in a case where the key unit including the power supply circuit is installed in the vehicle, the key unit is installed at a position where non-interruptible power supply to the key unit is possible even in a state where system power of the vehicle is turned off. Moreover, the key unit is installed in a position where the key unit can be appropriately set to the vehicle. The key unit is set to the vehicle as described above even when the vehicle travels or another device (for example, an airbag) provided in the vehicle operates, and therefore it is possible to protect occupants of the vehicle and reduce damage to the key unit.In the wireless communication system according to the aspect of the invention, the key unit may be installed in a vehicle cabin of the vehicle. Here, the device-side communication module of the lock-and-unlock device of the vehicle tends to be installed at a position (for example, the center console or the instrument panel) where the first signal (the polling signal) from the device-side communication module can reach an interior of the vehicle cabin. Therefore, by installing the key unit in the vehicle cabin of the vehicle (for example, in a center console, a glove box, under a seat, or a roof), it is possible to increase the intensity of wireless communication between the key unit and the locking and unlocking device as much as possible. Since the people who can access the inside of the vehicle cabin are limited to certain persons, by installing the vehicle unit in the vehicle cabin, it is possible to reduce theft of the key unit and reduce abuse of the key unit.In the wireless communication system according to the aspect of the invention, the unit-side antenna coil may have one axis. According to the configuration described above, since influence of the noise is inhibited as much as possible, better wireless communication can be realized between the key unit and the lock-and-unlock device.In the wireless communication system according to the aspect of the invention, the locking and unlocking device may be installed in an instrument panel of the vehicle.In the wireless communication system according to the aspect of the invention, the key unit and the locking and unlocking device may be installed in a center console of the vehicle.In the wireless communication system according to the aspect of the invention, the key unit and the locking and unlocking device may be installed in an instrument panel of the vehicle.In the wireless communication system according to the aspect of the invention, the first frequency band may be a long-wave band. As described above, the aspect of the invention can be suitably applied to a system that performs the wireless communication by the radio waves in the long band (30 kHz to 300 kHz).The aspect of the invention can be specified as a locking and unlocking system including the wireless communication system. Processing and means can be freely combined and implemented without technical inconsistency.According to the aspect of the invention, it is possible to increase the intensity of wireless communication between the key unit and the lock-and-unlock device as much as possible.Brief Description of the DrawingsFeatures, advantages, and technical and industrial significance of the exemplary embodiments of the invention will be described below with reference to the accompanying drawings, in which like reference numerals designate like elements, and wherein: FIG. 1 is a system design diagram of a lock-and-unlock system according to an embodiment; FIG. 2 is a block diagram schematically showing an example of components of the lock-and-unlock system; FIG. 3 is an example regarding functional modules included in a collating electronic control unit (ECU); FIG. 4 is an example regarding functional modules included in a control unit; FIG. 5 is a device flow diagram of a key unit; FIG. 6 is a flow chart regarding data and processing between the components; FIG. 7 is a diagram showing an attachment example of a low frequency transmitter (LF transmitter); FIG. 8 is a diagram schematically showing radio waves transmitted from an LF transmission antenna coil; FIG. 9 is a first diagram showing an example of an installation aspect of an LF reception antenna coil; and FIG. 10 is a second diagram showing an example of the installation aspect of the LF reception antenna coil.Detailed Description of EmbodimentsFirst EmbodimentDesign of a Lock-and-Unlock SystemA design of a lock-and-unlock system according to the embodiment will be described with reference to FIG. 1. The locking and unlocking system according to the first embodiment is configured to include a key unit 100 and a locking and unlocking device 300 mounted on a vehicle 10, a portable terminal 200, and a server device 400. In the locking and unlocking system according to the first embodiment, the key unit 100 has the same wireless interface as an electronic key (portable device) of a smart key, and it is possible to control locking and unlocking of the vehicle without using a physical key by communicating with the existing locking and unlocking device 300. The key unit 100 performs short-range wireless communication with the portable terminal 200, and determines whether or not the key unit 100 plays a role of an electronic key of the vehicle 10 based on the result of authentication of the portable terminal 200. That is, a user can control the locking and unlocking of the vehicle by manipulating the portable terminal 200 from the outside of the vehicle 10.Configuration of a Lock-and-Unlock SystemComponents of the lock and unlock system will be described in detail. FIG. 2 is a block diagram schematically showing an example of the configuration of the key unit 100, the portable terminal 200, the locking and unlocking device 300, and the server device 400 shown in FIG. 1. Among the components of the lock-and-unlock system, the key unit 100 and the lock-and-unlock device 300 are mounted on the vehicle 10 which is a target of locking and unlocking (which is to be locked and unlocked).The locking and unlocking device 300 is a device that locks and unlocks a door of the vehicle 10, and is an existing device that forms a part of a smart key system. Specifically, the door of the vehicle 10 is locked and unlocked according to a lock signal and an unlock signal transmitted from a portable device, which is the electronic key of the vehicle (in the related art, the portable device is owned by the user of the vehicle), via radio waves in a high frequency band (radio frequency band, hereinafter referred to as RF band). A function of transmitting the radio waves in a low frequency band (hereinafter referred to as an LF band) for checking the portable device is included.In the first embodiment, the key unit 100 mounted on the vehicle 10 transmits and receives the radio waves in the RF band and the LF band instead of the portable device owned by the user to control the locking and unlocking of the door of the vehicle. Hereinafter, unless otherwise specified, description will be made with a communication destination of the locking and unlocking device 300 limited to the key unit 100.The lock-and-unlock device 300 is configured to include an LF transmitter 301, an RF receiver 302, a collation ECU 303, a body ECU 304, and a door lock motor 305. The lock-and-unlock device 300 operates by power supplied from an auxiliary battery (not shown) mounted on the vehicle 10. The LF transmitter 301 functions as a device-side communication module or a device-side transmission module. The RF receiver 302 functions as a device-side receiving module.In the LF transmitter 301, a means for transmitting the radio waves in the low frequency band (functions as a first frequency band, for example, 100 kHz to 300 kHz) is provided for checking (retrieving) the key unit 100.The RF receiver 302 is a means for receiving the radio waves in the high frequency band (functions as a second frequency band, for example, 100 MHz to 1 GHz) transmitted from the key unit 100. The RF receiver 302 is installed at any location in the vehicle cabin.The collation ECU 303 is a computer that performs control for locking and unlocking the door of the vehicle 10 based on the signal (lock signal or unlock signal) transmitted from the key unit 100 via the radio waves in the RF band. The collation ECU 303 is configured by, for example, a microcomputer. In the following description, the lock signal and the unlock signal are collectively referred to as the lock and unlock signals. The term "lock-and-unlock signals" represents at least one of the lock signal and the unlock signal.FIG. 3 shows functional modules included in a collation ECU 303. Each of the functional modules shown in FIG. 3 may be realized by executing a program stored in a storage means (such as a read only memory (ROM)) by a central processing unit (CPU) (of which entities are not shown).An LF transmission processing unit 3031 performs control to transmit a polling signal (function as the first signal) as the radio waves in the LF band to inside and outside the vehicle cabin via the LF transmitter 301. An RF reception processing unit 3032 performs control to receive the lock-and-unlock signals (function as the second signal) transmitted from the key unit 100 as the radio waves in the RF band via the RF receiver 302. An authentication unit 3033 authenticates whether or not the lock-and-unlock signals transmitted from the key unit 100 are transmitted from a legitimate device. Specifically, a determination is made as to whether or not a key ID included in the lock-and-unlock signals matches a key ID stored in advance in the storage means (not shown) of the collation ECU 303. Detailed details will be described later.A key control device 3034 transmits an unlock instruction or a lock instruction to the body ECU 304, which will be described later, on the basis of the result of the authentication performed by the authentication unit 3033. The signal is transmitted via an in-vehicle network, such as a controller area network (CAN).The body ECU 304 is a computer that controls the body of the vehicle. The body ECU 304 has a function of unlocking and locking the door of the vehicle by a door lock motor 305 described later on the basis of the received unlock command or lock command. The body ECU 304 may further have a function of controlling components associated with the vehicle body, such as a window regulator controller, a seat adjuster, an anti-theft device, a seat belt controller, and a headlight controller.The door lock motor 305 is an actuator that locks and unlocks the door of the vehicle 10 (including a trunk room and a door for getting in and out and a rear inlet). The door lock motor 305 operates based on a signal transmitted from the body ECU 304.The key control device 3034 may only transmit the information that the authentication is successful to the body ECU 304 instead of the unlock command or the lock command. According to such a configuration, it is possible to cause the locking operation or unlocking operation to be performed with the action of the user (for example, pushing an unlocking button or touching a door button) as a trigger.The key unit 100 will be described. The key unit 100 is a device installed in the vehicle 10, and has a function of authenticating the portable terminal 200 by performing short-range wireless communication with the portable terminal 200, and a function of transmitting the lock-and-unlock signals using the radio waves in the RF band on the basis of the result of authentication of the portable terminal 200. The key unit 100 is configured to include an LF receiver 101, an RF receiver 102, a short-range communication unit 103, and a controller 104. The LF receiver 101 functions as a unit-side communication module or a unit-side reception module. The RF transmitter 102 functions as a unit-side transmission module.The LF receiver 101 is a means for receiving the polling signal transmitted from the locking and unlocking device 300 via the radio waves in the LF band. The LF receiver 101 includes an antenna coil that receives the radio waves in the LF band.The RF transmitter 102 is a means for transmitting the lock-and-unlock signals to the key unit 100 via the radio waves in the RF band.The short-range communication unit 103 is a means for communicating with the portable terminal 200 owned by the user. The short-range communication unit 103 performs communication in a short range (to the extent that communication can be performed inside and outside the vehicle cabin) using a predetermined wireless communication standard.In the first embodiment, the short-range communication unit 103 performs data communication by a Bluetooth low power standard (Bluetooth is a registered trademark) (hereinafter, referred to as a BLE). The BLE is a low-power communication standard based on Bluetooth, and can immediately start communication by detecting a partner without requiring pairing between the devices. In the first embodiment, the BLE is exemplified, but other wireless communication standards may also be used. For example, near-field communication (NFC), ultra-wide band (UWB), or WiFi (registered trademark) may be used.The controller 104 is a computer that performs short-range wireless communication with the portable terminal 200 via the short-range communication unit 103, performs control for authenticating the portable terminal 200, and performs control for transmitting the lock-and-unlock signals on the basis of the authentication result. The controller 104 is configured by, for example, a microcomputer.The functional modules contained in the control device 104 are shown in FIG. 4. Each of the functional modules shown in FIG. 4 may be realized by executing the program stored in the storage means (the ROM or the like) by the CPU (of which entities none is shown).An LF reception processing unit 1041 performs control to receive the polling signal transmitted as the radio waves in the LF band from the locking and unlocking device 300 via the LF receiver 101. An RF transmission processing unit 1042 performs control to transmit the lock-and-unlock signals as the radio waves in the RF band via the RF transmitter 102. The lock-and-unlock signals are generated by a communication processing unit 1043 described later in a case where an authentication unit 104 described later successfully authenticates the portable terminal 200.The communication processing unit 1043 processes the communication with the portable terminal 200 via the short-range communication unit 103. Specifically, the communication processing unit 1043 receives a lock request or an unlock request (hereinafter, collectively referred to as lock and unlock requests) from the portable terminal 200, and generates the lock and unlock signals according to the received request. The generated lock-and-unlock signals are temporarily stored, and are output at a time when the authentication unit 1044 described later successfully authenticates the portable terminal.The authentication unit 1044 authenticates the portable terminal 200 on the basis of authentication information included in the lock and unlock requests transmitted from the portable terminal 200. Specifically, the authentication information stored in the storage means (not shown) is compared with the authentication information transmitted from the portable terminal 200, and in a case where both pieces of the authentication information match, the determination is made that the authentication is successful. In a case where both pieces of authentication information do not match, the determination is made that the authentication has failed. In a case where the authentication unit 1044 successfully authenticates the portable terminal 200, the lock-and-unlock signals generated by the communication processing unit 1043 are output to the RF transmission processing unit 1042, and wirelessly transmitted to the lock-and-unlock device 300. An authentication method performed by the authentication unit 1044 may be a method of easily comparing the pieces of authentication information for authenticating the identity or a method using asymmetric encryption. Hereinafter, the authentication information stored in the key unit 100 is referred to as device authentication information, and the authentication information transmitted from the portable terminal 200 is referred to as terminal authentication information as necessary for description.In the first embodiment, the authentication unit 1044 is set to generate a transmission trigger of the lock-and-unlock signals; however, the authentication unit 1044 may control power supply of the key unit 100 on the basis of the authentication status. For example, in a situation where authentication of the portable terminal 200 is not performed, all the components other than the communication processing unit 1043 and the authentication unit 1044 are set to be in a suspended state, and in a case where the authentication is successful, all the components are in a powered state in a predetermined period (for example, until the response from the lock-and-unlock device 300 to the transmitted lock-and-unlock signals is made). As long as the lock-and-unlock signals can be transmitted only in a case where the authentication succeeds, the method for realizing the authentication is not limited.The key unit 100 simultaneously transmits the lock-and-unlock signals and the ID of the electronic key (hereinafter referred to as a key ID) to the lock-and-unlock device 300. The key ID may be stored in advance in the key unit 100 in a plain text state, or may be stored in a state encrypted by a cryptogram unique to the portable terminal 200. In the case where the key ID is encrypted and stored, the encrypted key ID may be decrypted by the authentication information transmitted from the portable terminal to obtain the original key ID.The portable terminal 200 will be described. The portable terminal 200 is a small computer such as a smartphone, a mobile phone, a tablet terminal, a personal information terminal, and a wearable (a smart watch or the like). The portable terminal 200 is configured to include a short-range communication unit 201, a communication unit 202, a control device 203, and an input and output unit 204.The short-range communication unit 201 is a means for communicating with the key unit 100 according to the same communication standard as the short-range communication unit 103. The communication unit 202 is a communication means for connecting the portable terminal 200 to a network. In the first embodiment, it is possible to communicate with the other device (for example, the server device 400) via the network by using a mobile communication service such as Third Generation (3G) and Long Term Evolution (LTE).The controller 203 is a computer that controls the portable terminal 200. The controller 203 performs, for example, processing of generating the lock and unlock requests, processing of acquiring the terminal authentication information, and processing of transmitting the lock and unlock requests and the terminal authentication information to the key unit 100. The controller 203 is configured by, for example, a microcomputer. The controller 203 may realize the functions such as processing by executing the program stored in the storage means (ROM or the like) by the CPU (neither of which is shown).The controller 203 interacts with the user via the input and output unit 204. The input and output unit 204 is a means for receiving an input manipulation performed by the user and presenting information to the user. The input and output unit is configured by a touch panel, a control means of the touch panel, a liquid crystal display, and a control means of the liquid crystal display. In the first embodiment, the touch panel and the liquid crystal display are configured to be a single touch panel display.The controller 203 displays a manipulation screen on the input and output unit 204, and generates the unlock request or the lock request on the basis of the manipulation performed by the user. For example, the controller 203 outputs a symbol image for unlocking and a symbol image for locking to the touch panel display, and generates the unlocking request or the locking request on the basis of the manipulation performed by the user. The manipulation performed by the user is not limited to the one through the touch panel display. For example, the manipulation may be a manipulation via a hardware switch.The controller 203 performs processing of acquiring the terminal authentication information. In the first embodiment, the terminal authentication information is generated in the server device 400 and transmitted to the portable terminal 200 via the communication unit 202. In a case where the portable terminal 200 does not have the terminal authentication information, the locking manipulation and the unlocking manipulation from the manipulation screen are not possible.The terminal authentication information acquired by the portable terminal 200 may be for a fixed key or a one-time key. In either case, the device authentication information corresponding to the terminal authentication information is stored in the key unit 100 in advance.Design of a Lock-and-Unlock DeviceBefore describing the operation of the lock-and-unlock system in detail, the outline of the operation performed by the lock-and-unlock device 300 will be described. The locking and unlocking device 300 is a device that forms a normal smart key system, and in the first embodiment, communicates with the key unit 100 to detect that the key unit 100 is located inside the vehicle cabin.More specifically, the collation ECU 303 transmits the polling signal to the inside and outside of the vehicle via the LF transmitter 301 at a certain period, and receives a return signal transmitted by the key unit 100 in response to the polling signal. The key ID unique to the key unit 100 is included in the return signal, and the registered key ID of the key unit 100 is stored in the collation ECU 303. The collation ECU 303 performs the authentication processing of the key unit 100 by using the received key ID and the stored key ID. In a case where the key unit 100 is successfully authenticated, the body ECU 304 is notified that the authentication is successful, and it is possible to cause the vehicle to perform the above-described operation (for example, the door unlocking and the ending of the immobilizer) as described above.Here, the work of registering the key ID of the key unit 100 in the locking and unlocking device 300 will be described. The work is performed by a manufacturer or owner of the vehicle. Here, the flow of work will be described with reference to FIG. 5.First, in a step S 1, the lock-and-unlock device 300 shifts to a mode for registering a new key ID. At this time, the lock-and-unlock device 300 may request communication with the previously registered portable device (i.e., a portable device having the previously stored key ID). As described above, it is possible to confirm that the person performing the registration work is a legitimate owner of the vehicle.In a step S 2, the user brings the key unit 100 close to or substantially in contact with the locking and unlocking device 300. As described above, the key unit 100 is supplied with a signal for registration from the lock-and-unlock device 300, and the key unit 100 that acquires the signal transmits the key ID to the lock-and-unlock device 300 (step S 3). The operation is known for registering the key ID on a vehicle side in a smart key system for an automobile (generally referred to as transponder communication). The transmitted key ID is received by the lock-and-unlock device 300 and is registered as a valid key ID (step S 4). That is, the lock-and-unlock device and the key unit are linked.The communication and processing performed between the lock-and-unlock device 300 and the key unit 100 have been described above.Operation of Lock-and-Unlock SystemThe operation of the lock-and-unlock system according to the first embodiment will be described with reference to FIG. 6. FIG. 6 is a flowchart for describing the data transmitted and received between the components and the processing performed by each of the components.First, in a step S 11, the portable terminal 200 requests the server device 400 to output terminal authentication information. The terminal authentication information described herein is not information for the locking and unlocking device 300 for authenticating the key unit 100, but is information for the key unit 100 for authenticating the portable terminal 200. When the portable terminal 200 transmits the terminal identifying information to the server device 400, the server device 400 acquires the terminal authentication information unique to the portable terminal 200 (step S 12), and transmits the acquired terminal authentication information to the portable terminal 200 (step S 13). As described above, it is possible to perform the manipulation of unlocking the vehicle 10 by the portable terminal 200. Since the processing in steps S 11 to S 13 is preparation processing for controlling locking and unlocking, the processing is not particularly limited, and it is preferable to perform the processing in advance.Steps S 21 to S 24 are processing for unlocking the vehicle 10 using the portable terminal 200. When the user of the portable terminal 200 performs the manipulation for unlocking the vehicle 10 via the input and output unit 204, the portable terminal 200 transmits the unlocking request and the terminal authentication information to the server device 400 in step S 21. In a step S 22, the key unit 100 compares the terminal authentication information transmitted from the portable terminal 200 with the device authentication information stored in advance, and performs the authentication processing.In a case where the authentication succeeds, the key unit 100 transmits the unlock signal and the key ID to the lock-and-unlock device 300 in step S 23. Then, in a step S 24, the lock-and-unlock device 300 performs the authentication processing based on the received key ID. As a result, in a case where the authentication succeeds, the door of the vehicle 10 is unlocked. At this time, a response or the like may be performed.Steps S 31 to S 36 are processing for locking the vehicle 10 using the portable terminal 200. When the user of the portable terminal 200 performs the manipulation of locking the vehicle 10 via the touch panel screen, the portable terminal 200 transmits the locking request and the terminal authentication information to the server device 400 in a step S 31. Then, in step S 32, the key unit 100 compares the terminal authentication information transmitted from the portable terminal 200 with the device authentication information stored in advance, and performs the authentication processing.In a case where the authentication succeeds, the key unit 100 transmits the lock signal and a key ID to the lock-and-unlock device 300 in step S 33. Then, in a step S 34, the lock-and-unlock device 300 performs the authentication processing based on the received key ID. As a result, in a case where the authentication succeeds, the door of the vehicle 10 is locked.After transmitting the lock signal, the key unit 100 transmits a notification (lock notification) that locking is completed to the portable terminal 200 (step S 35). As described above, a notification that locking is completed is output to the touch panel screen of the portable terminal 200. In a case where the authentication information concerns a one-time key, the one-time key may be invalidated at the time of step S 35. The portable terminal 200 generates a notification that the use of the system is finished, and transmits this notification to the server device 400 (step S 36).System for Wireless CommunicationA system for wireless communication according to the first embodiment will be described. The wireless communication system according to the first embodiment is defined as a system of wireless communication performed between the locking and unlocking device 300 and the key unit 100 via the LF transmitter 301 and the LF receiver 101.As described above, the LF transmission processing unit 3031 included in the collation ECU 303 of the lock-and-unlock device 300 transmits the polling signal at a certain cycle via the LF transmitter 301. Then, the key unit 100 receives the polling signal via the LF receiver 101. Here, the polling signal, which is the radio wave in the LF band, tends to be sensitive to noise. In addition, a plurality of sources of noise (for example, an in-vehicle ETC (registered trademark) device, an air conditioner, a wiper, and a plasma cluster) may be present in the vehicle 10. Therefore, as long as the key unit 100 is not installed in an appropriate position or orientation in the vehicle 10, there is a possibility that the LF receiver 101 cannot adequately receive the polling signal due to the noise interference or radio wave interference.As shown in FIG. 7, the LF transmitter 301 of the locking and unlocking device 300 is installed in a center console or dash panel of the vehicle 10. Here, the LF transmitter 301 includes an LF transmission antenna coil 301 athat transmits the radio waves in the LF band. The radio waves transmitted from the LF transmission antenna coil 301 ahave directivity, and a field intensity in the axial direction of the antenna coil becomes relatively strong. FIG. 8 is a diagram schematically showing the radio waves transmitted from the LF transmission antenna coil 301 ain a case where the LF transmitter 301 is built in the center console. As shown in FIG. 8, a radiation characteristic of the radio waves transmitted from the LF transmission antenna coil 301 ais radiation in a doughnut shape around the antenna coil. Therefore, as described above, the field intensity in the axial direction of the antenna coil becomes relatively strong.In the wireless communication system according to the first embodiment, the key unit 100 is installed in the vehicle 10 such that a distance between the LF receiver 101 of the key unit 100 and the LF transmitter 301 of the locking and unlocking device 300 is within a predetermined distance at which communication between the LF receiver 101 and the LF transmitter 301 is possible, and that an axis of an LF reception antenna coil 101 aof the LT receiver 101 is parallel to an axis of the LF transmission antenna coil 301 a. In the first embodiment, the key unit 100 is installed in the vehicle cabin. This is because the polling signal transmitted from the LF transmission antenna coil 301 abends to reach the entire area inside the vehicle cabin, and when the key unit 100 is installed in the vehicle cabin, good communication between the LF receiver 101 and the LF transmitter 301 becomes possible.Moreover, by installing the key unit 100 in the vehicle cabin, it is possible to reduce theft of the key unit 100 and reduce abuse with respect to the key unit 100. This is because people who can get inside the vehicle cabin are limited to certain people.On the other hand, in the wireless communication system according to the first embodiment of the present invention, there is no intention to restrict the installation of the key unit 100 in the vehicle cabin as described above, as long as the key unit 100 is installed in the vehicle 10 such that the distance between the LF receiver 101 and the LF transmitter 301 is within the predetermined distance and that the axis of an LF reception antenna coil 101 ais parallel to the axis of the LF transmission antenna coil 301 a. As described later, the installation target of the key unit 100 is not limited to the vehicle 10, and the key unit 100 may be installed in a predetermined facility. In this case, the locking and unlocking device 300 functions as a locking and unlocking device of the predetermined device.The aspect according to which the key unit 100 is installed in the vehicle cabin such that the axis of the LF reception antenna coil 101 ais parallel to the axis of the LF transmission antenna coil 301 awill be described. FIG. 9 is a diagram showing an example of an installation aspect of an LF reception antenna coil 101 ain a case where the LF transmitter 301 is installed in the center console, and the axis of the LF transmission antenna coil 301 ais oriented in a traveling direction of the vehicle 10 (hereinafter, this direction may be referred to as a "longitudinal direction of the vehicle 10"). According to the installation aspect shown in FIG. 9, the key unit 100 is installed in the center console such that the axis of the LF reception antenna coil 101 ais in an orientation substantially coincident with the axis of the LF transmission antenna coil 301 a. In the installation aspect described above shown in FIG. 9, the radio waves transmitted from the LF transmission antenna coil 301 aappear on the axis of the LF reception antenna coil 101 awith ease. As described above, the field intensity of the radio waves incident on the axis of the LF reception antenna coil 101 afrom the LF transmission antenna coil 301 ais relatively strong. That is, the reception intensity of the polling signal in the LF reception antenna coil 101 ais increased as much as possible.FIG. 10 is a diagram showing an example of the installation aspect of the LF reception antenna coil 101 ain a case where the LF transmitter 301 is installed in the dash panel and the axis of the LF transmission antenna coil 301 ais oriented in a width direction of the vehicle 10. Also in the above-described installation aspect, the radio waves of the relatively high intensity transmitted from the LF transmission antenna coil 301 afall on the axis of the LF reception antenna coil 101 awith ease. Therefore, the reception intensity of the polling signal of the LF reception antenna coil 101 ais increased as much as possible.In FIGS. 9 and 10, the key unit 100 is installed so that the axis of the LF reception antenna coil 101 ais in an orientation substantially coincident with the axis of the LF transmission antenna coil 301 a, and there is no intention to restrict the installation of the key unit 100. It may be that any installation of the key unit 100 is employed in which the axis of the LF reception antenna coil 101 ais in an orientation parallel to the axis of the LF transmission antenna coil 301 a. Therefore, even in a case where the LF transmitter 301 is installed in the center console, in the orientation in which the axis of the LF reception antenna coil 101 ais parallel to the axis of the LF transmission antenna coil 301 a, the key unit 100 can be installed in a glove box, under a seat, on a roof, or the like.By installing the key unit 100 as described above, the intensity of wireless communication between the key unit 100 and the lock-and-unlock device 300, particularly, the intensity of wireless communication between the LF receiver 101 of the key unit 100 and the LF transmitter 301 of the lock-and-unlock device 300 can be increased as much as possible. Also, in a case where the key unit 100 is installed in the vicinity of sources of noise such as the in-vehicle ETC device (registered trademark), the air conditioner, the wiper, and the plasma cluster, good wireless communication can be realized between the LF receiver 101 and the LF transmitter 301 when a signal-to-noise ratio can be maintained relatively high when the LF receiver 101 receives the polling signal.In a case where the key unit 100 is installed at a position spaced from the source of noise, better wireless communication can be realized. In this case, the key unit 100 is installed in the glove box, for example.In the LF reception antenna coil 101 ashown in FIGS. 9 and 10, the antenna coil has an axis. Since the influence of the noise is inhibited as much as possible as described above, the better wireless communication between the LF receiver 101 and the LF transmitter 301 can be realized.On the other hand, in the wireless communication system according to the first embodiment of the invention, there is no intention to limit the number of axes of the LF reception antenna coil 101 ato one, and the LF reception antenna coil 101 amay have three axes. Also, in a case where the LF reception antenna coil 101 ahas three axes, the intensity of wireless communication between the LF receiver 101 and the LF transmitter 301 will be increased as much as possible by installing the key unit 100 such that one of the axes of the antenna coil is parallel to the axis of the LF transmission antenna coil 301 a.The key unit 100 includes a power supply circuit (not shown). The power supply circuit supplies power of a predetermined voltage to the LF receiver 101, the RF transmitter 102, the short-range communication unit 103, and the controller 104. Here, even when system power of the vehicle 10 is turned off, the key unit 100 is installed in a position where non-interruptible power supply to the key unit 100 is possible. Even when the system power of the vehicle 10 is turned off, power is supplied from an auxiliary battery (not shown) mounted in the vehicle 10 to the key unit 100.The key unit 100 is installed in a position (for example, in a glove box) where the key unit 100 may be fixed to the vehicle 10 in an appropriate manner. As described above, the key unit 100 is fixed to the vehicle 10 even when the vehicle 10 travels or when another device (e.g., an airbag) provided in the vehicle 10 operates, and therefore it is possible to protect occupants of the vehicle 10 and reduce damage to the key unit 100.In the description of the embodiment, the example in which the key unit 100 only performs the locking and unlocking of the vehicle 10 is shown; however, the key unit 100 may be caused to perform an operation other than the locking and unlocking. For example, the key unit 100 may communicate with a control device that manages a combustor to enable a start of the vehicle. According to such a configuration, an existing portable device (electronic key) owned by the user can be replaced with the portable terminal.In the description of the first embodiment, the description is made that the key unit 100 receives the polling signal transmitted via the radio waves in the LF band; however, the lock and unlock signals may not necessarily be transmitted in response to the polling signal. By transmitting the key ID in response to the polling signal, it is possible to cause the lock-and-unlock device 300 to recognize that the valid electronic key is present inside the vehicle; however, the lock-and-unlock signals may be transmitted only via the radio waves in the RF band.Second EmbodimentThe first embodiment is an example in which the key unit 100 is installed in the vehicle. In contrast to the above description, in the second embodiment, the key unit 100 is installed in a predetermined facility. At this time, the locking and unlocking device 300 functions as a locking and unlocking device of the predetermined device, and the key unit 100 communicates with the locking and unlocking device 300 to instruct locking and unlocking of the predetermined device.Also in the second embodiment, the wireless communication system may be defined as a system of wireless communication performed between the locking and unlocking device 300 and the key unit 100 via the LF transmitter 301 and the LF receiver 101. Also, in the wireless communication system as described above, the key unit 100 is installed in the predetermined device such that the distance between the LF receiver 101 and the LF transmitter 301 is within a predetermined distance and that the axis of the LF reception antenna coil 101 ais parallel to the axis of the LF transmission antenna coil 301 a. As described above, it is possible to increase the intensity of wireless communication between the LF receiver 101 and the LF transmitter 301 as much as possible.The wireless communication system according to the second embodiment is not limited thereto, and may be defined as a system of wireless communication performed between the locking and unlocking device 300 and the key unit 100 via the RF transmitter 102 and the RF receiver 302. In the wireless communication system as described above, the key unit 100 is installed in the predetermined device such that the distance between the RF transmitter 102 and the RF receiver 302 is within a predetermined distance, and that an axis of an antenna coil of the RF transmitter 102 is parallel to an axis of an antenna coil of the RF receiver 302. As described above, it is possible to increase the intensity of wireless communication between the RF transmitter 102 and the RF receiver 302 as much as possible.The embodiment is merely an example of implementing the invention. Therefore, the invention is not limited thereto, and may be appropriately modified and implemented within a range that does not depart from the gist of the invention described in the claims.

Claims

A system for wireless communication, comprising: a locking and unlocking device (300) configured to control locking and unlocking of a target, wherein the locking and unlocking device (300) includes a device-side communication module (301) configured to communicate a first signal having a first frequency band, wherein the device-side communication module (301) includes a device-side antenna coil (301a) for communication; and a key unit (100) configured to communicate with the locking and unlocking device (300), and instruct locking and unlocking of the target by communicating with the locking and unlocking device (300), wherein the key unit (100) is installed in the target, and includes a unit-side communication module (101) communicating the first signal, wherein the unit-side communication module (101) has a unit-side antenna coil (101a) for communication, the key unit (100) is installed in the target such that a distance between the unit-side communication module (101) and the device-side communication module (301) is within a predetermined distance at which communication between the unit-side communication module (101) and the device-side communication module (301) is possible, and that an axis of the unit-side antenna coil (101a) is parallel to an axis of the device-side antenna coil (301a), characterized in that the lock-and-unlock device (300) is installed in a dash panel of a vehicle (10).A system for wireless communication, comprising: a locking and unlocking device (300) configured to control locking and unlocking of a target, wherein the locking and unlocking device (300) includes a device-side communication module (301) configured to communicate a first signal having a first frequency band, wherein the device-side communication module (301) includes a device-side antenna coil (301a) for communication; and a key unit (100) configured to communicate with the locking and unlocking device (300), and instruct locking and unlocking of the target by communicating with the locking and unlocking device (300), wherein the key unit (100) is installed in the target, and includes a unit-side communication module (101) communicating the first signal, wherein the unit-side communication module (101) has a unit-side antenna coil (101a) for communication, the key unit (100) is installed in the target such that a distance between the unit-side communication module (101) and the device-side communication module (301) is within a predetermined distance at which communication between the unit-side communication module (101) and the device-side communication module (301) is possible, and that an axis of the unit-side antenna coil (101a) is parallel to an axis of the device-side antenna coil (301a), characterized in that the key unit (100) and the locking-and-unlocking device (300) are installed in a center console of a vehicle (10).A system for wireless communication, comprising: a locking and unlocking device (300) configured to control locking and unlocking of a target, wherein the locking and unlocking device (300) includes a device-side communication module (301) configured to communicate a first signal having a first frequency band, wherein the device-side communication module (301) includes a device-side antenna coil (301a) for communication; and a key unit (100) configured to communicate with the locking and unlocking device (300), and instruct locking and unlocking of the target by communicating with the locking and unlocking device (300), wherein the key unit (100) is installed in the target, and includes a unit-side communication module (101) communicating the first signal, wherein the unit-side communication module (101) has a unit-side antenna coil (101a) for communication, the key unit (100) is installed in the target such that a distance between the unit-side communication module (101) and the device-side communication module (301) is within a predetermined distance at which communication between the unit-side communication module (101) and the device-side communication module (301) is possible, and that an axis of the unit-side antenna coil (101a) is parallel to an axis of the device-side antenna coil (301a), characterized in that the key unit (100) and the locking-and-unlocking device (300) are installed in a dash panel of one of the vehicle (10).The wireless communication system according to any one of claims 1 to 3, wherein: the device-side communication module (301) is a device-side transmission module (301) configured to transmit the first signal to the key unit (100); the unit-side communication module (101) is a unit-side reception module (101) configured to receive the first signal; the key unit (100) further includes a unit-side transmission module (102) configured to transmit a second signal having a second frequency band that is a frequency band higher than the first frequency band to the locking and unlocking device (300); the locking and unlocking device (300) further includes a device-side reception module (302) configured to receive the second signal and that is mounted on the vehicle (10); the key unit (100) is configured to transmit the second signal instructing locking and unlocking of the vehicle (10) from the unit-side transmission module (102) when the unit-side reception module (101) receives the first signal; and the locking and unlocking device (300) is configured to control locking and unlocking of the vehicle (10) when the device-side reception module (302) receives the second signal.The wireless communication system according to claim 4, wherein the key unit (100) is installed in a vehicle cabin of the vehicle (10).The wireless communication system according to any one of claims 1 to 5, wherein the unit-side antenna coil (101a) has an axis.The wireless communication system according to any one of claims 1 to 6, wherein the first frequency band is a long-wave band.

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