Contactless power transmission system, mobile body, and contactless power transmission method

Abstract

To provide a non-contact power transmission system capable of implementing more appropriate control of power transmission even while a mobile is moving, a mobile, and a non-contact power transmission method.SOLUTION: A non-contact power transmission system supplies power from a power feeding device, which is installed in a movement path of a mobile, to a power receiving device which is installed in the mobile, in a non-contact manner. In the non-contact power transmission system, the power receiving device comprises a control section by which, in a case where a distance or a time corresponding to a position of the mobile and an installation position of the power feeding device becomes less than a threshold, a pairing signal is transmitted from the power receiving device to the power feeding device and in a case where a response from the power feeding device to the pairing signal is obtained, an operation mode of the power receiving device is shifted to a power receiving mode.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present invention relates to a contactless power transfer system, a mobile object, and a contactless power transfer method. [Background technology]

[0002] In recent years, research and development has been conducted on charging and supplying vehicles equipped with secondary batteries that contribute to energy efficiency, in order to ensure that more people have access to affordable, reliable, sustainable, and advanced energy. In this regard, in a contactless power transmission system that supplies power to a vehicle from outside the vehicle, a technology is known in which communication is performed between the power transmitting side and the power receiving side by superimposing a communication signal on a power supply signal transmitted from the power transmitting side to the power receiving side (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-247807 [Patent Document 2] Patent No. 5348325 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in technology related to charging and supplying power to vehicles equipped with secondary batteries, there has been a problem in that when a moving object such as a vehicle is moving, the distance between the transmitting side and the receiving side changes, and therefore appropriate power transmission may not be possible.

[0005] In order to solve the above-mentioned problems, the present application aims to provide a contactless power transfer system, a mobile object, and a contactless power transfer method that can realize more appropriate control of power transfer even when the mobile object is moving, thereby contributing to energy efficiency. [Means for solving the problem]

[0006] The contactless power transfer system, the moving body, and the contactless power transfer method according to the present invention employ the following configurations. (1): A contactless power transmission system according to one embodiment of the present invention is a contactless power transmission system that contactlessly supplies power from a power supply device installed in a path of a moving body to a power receiving device installed in the moving body, wherein the power receiving device includes a control unit that transmits a pairing signal from the power receiving device to the power supply device when a distance or time corresponding to a position of the moving body and an installation position of the power supply device becomes less than a threshold, and that transitions the operating mode of the power receiving device to a power receiving mode when a response to the pairing signal is obtained from the power supply device.

[0007] (2): In the above aspect (1), the present invention further includes a position detection unit that detects the position of the power supply device located in the direction of travel of the moving body based on the position of the moving body and map information, and / or detects the position of the power supply device based on the analysis results of an image captured by a camera mounted on the moving body, and the control unit transmits the pairing signal when the distance to the position corresponding to the installation position of the power supply device detected by the position detection unit becomes less than a predetermined distance.

[0008] (3): In the above aspect (1), the present invention further includes a position detection unit that detects the position of the power supply device located in the direction of travel of the moving body based on the position of the moving body and map information, and / or detects the position of the power supply device based on the analysis results of an image captured by a camera mounted on the moving body, and the control unit transmits the pairing signal when the time until the moving body arrives at the power supply device detected by the position detection unit becomes less than a predetermined time.

[0009] (4): In the above aspect (1), the control unit transmits a pairing signal from the power receiving device to the power supply device when the power receiving device is in a weak coupling state in which the power receiving device and the power supply device are coupled by a weak magnetic field within a predetermined range.

[0010] (5): A mobile body according to one embodiment of the present invention is a mobile body equipped with a power receiving device that receives power contactlessly from a power supply device installed on a path of travel, and is equipped with a control unit that transmits a pairing signal from the power receiving device to the power supply device when a distance or time corresponding to the position of the mobile body and the installation position of the power supply device becomes less than a threshold, and transitions the operating mode of the power receiving device to a power receiving mode when a response to the pairing signal is obtained from the power supply device.

[0011] (6): A contactless power transmission method according to one embodiment of the present invention is a contactless power transmission method for contactlessly supplying power from a power supply device installed in a path of a moving body to a power receiving device installed in the moving body, in which, when the distance or time corresponding to the position of the moving body and the installation position of the power supply device becomes less than a threshold, the power receiving device transmits a pairing signal from the power receiving device to the power supply device, and when a response to the pairing signal is obtained from the power supply device, the operating mode of the power receiving device is transitioned to a power receiving mode. [Effects of the Invention]

[0012] According to the above aspects (1) to (6), more appropriate control of power transmission can be achieved even when the moving body is moving. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a schematic configuration diagram of a contactless power transfer system according to an embodiment. [Figure 2] 1 is a diagram illustrating an example of a configuration of a power supply device 100 according to an embodiment. [Figure 3] 1 is a diagram illustrating an example of the configuration of a vehicle 200 according to an embodiment. [Figure 4] FIG. 10 is a diagram illustrating a transition of an operation mode. [Figure 5] FIG. 10 is a diagram showing the relationship between the bond state and the distance. [Figure 6] FIG. 10 is a diagram illustrating an example of a bit layout of pairing information according to an embodiment. [Figure 7] 10 is a flowchart illustrating an example of a contactless power transmission process according to an embodiment. [Figure 8] FIG. 10 is a diagram for explaining detection of a power supply device 100 installed on a road. [Figure 9] FIG. 2 is a diagram illustrating an arrangement of a plurality of power supply devices 100. [Figure 10] 10 is a flowchart showing another example (part 1) of a contactless power transmission process. [Figure 11] 10 is a flowchart showing another example (part 2) of the contactless power transmission process. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, a contactless power transfer system, a mobile object, and a contactless power transfer method according to an embodiment of the present invention will be described with reference to the drawings.

[0015] [System Configuration] FIG. 1 is a schematic configuration diagram of a contactless power transmission system according to an embodiment. The contactless power transmission system 1 according to the embodiment includes, for example, a power supply device 100, a vehicle 200, which is an example of a mobile object, and an information processing server 300. The power supply device 100 and the information processing server 300 communicate with each other via a network NW. The network NW includes, for example, the Internet, a wide area network (WAN), a local area network (LAN), a cellular network, a public line, a provider device, a wireless base station, and the like. In the contactless power transmission system 1, the vehicle 200 may also communicate with the information processing server 300 via the network NW using an on-board communication device. In the contactless power transmission system 1, the power supply device 100 and the vehicle 200 communicate with each other using other communication means, which will be described later. In the contactless power transmission system 1, the vehicle 200 is, for example, an electric vehicle, a hybrid vehicle, a fuel cell vehicle, or the like. In addition to the vehicle 200, the mobile object according to the embodiment may be an object capable of moving along a path, such as an electric robot. Furthermore, the moving body may or may not have a person on board. Furthermore, the moving body may be configured to be capable of automatic driving as well as manual driving by a passenger (driver). In the following description, the moving body is assumed to be a vehicle.

[0016] The contactless power transfer system 1 supplies power from the power transfer device 100 to the vehicle 200 by contactless power transfer between the power transfer device 100 and the vehicle 200. In the contactless power transfer system 1, the power transfer device 100 supplies power to a plurality of vehicles 200, and the vehicles 200 receive power from a plurality of power transfer devices 100. However, for convenience of explanation, the following description will mainly focus on one-to-one contactless power transfer.

[0017] The power supply devices 100 are installed (buried) at predetermined intervals on the road surface of a predetermined power supply lane (e.g., lane L1) among lanes L1 and L2 (examples of travel paths) on which the vehicle 200 can travel (e.g., power supply devices 100-1, 100-2, 100-3, etc. shown in FIG. 1 ). The predetermined intervals are intervals at which the magnetic field coupling regions of the power supply devices 100 do not overlap. The predetermined intervals may be set according to the type of road (e.g., an ordinary road or an expressway) or according to traffic regulations such as the speed limit of the road. The power supply device 100 communicates with the vehicle 200 approaching within a predetermined distance, and supplies power in response to a power supply request from the vehicle 200. The power supply device 100 also performs processing related to power control and power protection functions (e.g., FSA (Fail Safe Action)) in response to the request.

[0018] Vehicle 200 is equipped with a power receiving device 210. Power receiving device 210 is installed at the bottom of vehicle 200 so as to easily receive power from a power supply device installed on the road surface, but the installation location is not limited to this. Power receiving device 210 performs processes related to, for example, vehicle energy management and power protection functions (e.g., FSA). Vehicle 200 also uses power stored in a power storage unit such as a battery to travel and supplies power to other in-vehicle devices. Vehicle 200 also communicates with power supply devices 100-1 to 100-3 while traveling in a power supply lane (lane L1) and charges the power storage unit installed in vehicle 200 using power supplied in response to requests. In wireless power transfer system 1, a communication system required between power supply device 100 and vehicle 200 is a system that can at least individually identify vehicle 200 and can communicate when vehicle 200 is traveling at a speed V1 of approximately 0 to 100 km / h. The functional configurations of the power supply device 100 and the vehicle 200 will be described in detail later.

[0019] The information processing server 300 may be, for example, a server device or a PC (Personal Computer), or may be a cloud server configured by cloud computing including one or more information processing devices. The information processing server 300 communicates with the power supply device 100, the vehicle 200, and the like, and performs various processes related to power. The information processing server 300 may be, for example, a billing system for contactless power supply, a power input system, or a system linked to these systems. The billing system is, for example, a system that individually recognizes the vehicle 200 and collects fees according to the power charged. The power bidding system is, for example, a system that performs various controls and management to conduct low-cost power bidding based on demand forecasts. The information processing server 300 also manages the status of the power supply device 100, calculates the power supplied to the vehicle 200 from each of the power supply devices 100-1 to 100-3, and calculates and manages the actual power transmitted to each vehicle 200.

[0020] [Power supply device] 2 is a diagram illustrating an example of the configuration of a power supply device 100 according to an embodiment. The power supply device 100 includes, for example, a power transmitting device 110 and a power supply-side communication unit 130. The power transmitting device 110 includes, for example, a power supply unit 112, a power transmission power conversion unit 114, a power transmitting unit 116, a power transmitting-side control unit (an example of a power supply-side control unit) 118, and a communication control unit 120. The power transmitting-side control unit 118 includes a voltage detection unit 118A. Some or all of the power transmitting-side control unit 118 and the communication control unit 120 are realized by, for example, a hardware processor such as a CPU (Central Processing Unit) executing a program (software). Some or all of these components may be realized by hardware (including circuitry) such as a large-scale integration (LSI), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), a graphics processing unit (GPU), or a system on chip (SOC), or may be realized by a combination of software and hardware. The program may be stored in advance in a storage device (a storage device having a non-transitory storage medium) such as a hard disk drive (HDD) or flash memory of the power supply device 100, or may be stored in a removable storage medium such as a DVD or CD-ROM, and installed in the HDD or flash memory of the power supply device 100 by inserting the storage medium (non-transitory storage medium) into a drive device.

[0021] The power supply unit 112 of the power transmitting device 110 is connected to the transmission power conversion unit 114. The power supply unit 112 includes, for example, an AC power supply such as a commercial power supply, an AC-DC converter that converts the AC power into DC power, and a capacitor for smoothing power. The power supply unit 112 converts, for example, AC power supplied from the AC power supply into DC power using the AC-DC converter. Furthermore, the power supply unit 112 performs a power smoothing process using a capacitor during power conversion.

[0022] The transmission power conversion unit 114 is connected to the power transmission unit 116. The transmission power conversion unit 114 includes, for example, an inverter that converts DC power into AC power. The inverter includes, for example, a bridge circuit formed by a plurality of switching elements and rectifier elements that are bridge-connected in two phases, and a resonance capacitor for adjusting the resonance of the coil. The circuit configuration of the transmission power conversion unit 114 will be described in detail later.

[0023] The power transmitting unit 116 transmits power to the outside (for example, the power receiving device 210 of the vehicle 200) by changing a high-frequency magnetic field, for example, by magnetic field coupling due to magnetic field resonance. In magnetic field resonance, for example, when a current flows through a power transmitting coil, a magnetic field oscillation occurs, and this is transmitted to a resonant circuit on the power receiving side that resonates at the same frequency, causing a current to flow. In addition to magnetic field resonance, known coupling methods such as electromagnetic induction may also be used for magnetic field coupling. In electromagnetic induction, for example, power is transmitted by utilizing an induced magnetic flux generated between the power transmitting side and the power receiving side.

[0024] The power transmitting-side control unit 118 comprehensively controls each function of the power transmitting device 110 or the entire power supply device 100. For example, the power transmitting-side control unit 118 controls pairing, power transmission, and the like based on information (e.g., a pairing signal or a power receiving-side operation mode) obtained by the power supply-side communication unit 130 communicating with the vehicle-side communication unit 230 of the vehicle 200. The pairing signal includes, for example, a power receiving device ID, which is identification information for identifying the power receiving device 210, or a vehicle ID, which is identification information for identifying the vehicle 200, parameter information such as required power, battery voltage, and the like. For example, the power transmitting-side control unit 118 identifies the power receiving device 210 or the vehicle 200 based on the power receiving device ID or the vehicle ID and establishes (completes) pairing. Furthermore, the power transmitting-side control unit 118 may refer to user information, etc., registered in advance based on the power receiving device ID or the vehicle ID, and establish pairing if the vehicle (or user) is capable of receiving power (capable of using the power supply service). The power transmission side control unit 118 controls the power transmission so that power is supplied to the vehicle 200 with which pairing has been established.

[0025] The power receiving side operation mode is an operation mode of the power receiving device 210 (described later) mounted on the vehicle 200, and includes, for example, a short mode, a parameter transmission mode, a standby mode, and a power receiving mode. The short mode is a mode that prevents unexpected power reception and is used, for example, in FSA and the like. The parameter transmission mode is a mode that transmits parameter information. The standby mode is, for example, a mode that waits for communication with the power supply side. The power receiving mode is a mode in which pairing is established and the power receiving unit 211 and the power receiving power conversion unit 212 are operating and waits for power reception, or is in a state where power can be received or is currently being received based on a predetermined frequency (a required frequency for resonance).

[0026] Furthermore, the power transmitting side control unit 118 controls the operation mode (power transmitting side operation mode) of the power transmitting device 110 depending on the situation. Examples include an off mode, a search mode, a standby mode, and a power transmission mode. The off mode among the power transmitting side operation modes is a mode in which there is no vehicle providing service within the power transmission service section (electric road) and the power transmitting device is not operating. The search mode is a mode in which pairing with the vehicle 200 is established, the coupling coefficient increases, and a situation is detected in which power transmission efficiency can be ensured, and power transmission is suspended. The standby mode is, for example, a mode in which communication with the power receiving side is on standby. The power transmission mode is, for example, a state in which power can be transmitted based on a requested frequency or a state in which power is being transmitted (power transmission state).

[0027] For example, when pairing with the vehicle 200 is established, the power transmitting side control unit 118 transitions the operation mode of the power transmitting device 110 from the off mode to the reception (standby) mode. Furthermore, upon receiving information from the power receiving device 210, such as a requested frequency for power transmission from the vehicle 200, via the communication control unit 120, the power transmitting side control unit 118 transitions the operation mode from the reception mode to the search mode. Furthermore, when a state in which power transmission efficiency can be ensured in the search mode is reached, the power transmitting side control unit 118 transitions to the power transmission mode. Note that, in the power transmission state of the power transmission mode, the power transmitting side control unit 118 may transmit power at a preset drive frequency instead of the requested frequency. The power transmitting side control unit 118 transmits power to the power receiving device 210 of the vehicle 200 by controlling the on (conduction) and off (cutoff) switching of each switching element of the power transmitting power conversion unit 114 according to the requested frequency. Furthermore, for example, when power transmission to the vehicle 200 side or communication becomes impossible, the power transmitting side control unit 118 ends pairing and causes the power transmitting device 110 to transition to the off mode.

[0028] Furthermore, the power transmitting-side control unit 118 may control billing and settlement according to the amount of power used [kWh] after system use on the vehicle 200 side. Furthermore, a voltage detection unit 118A of the power transmitting-side control unit 118 detects the voltage at the power transmitting power conversion unit 114. The power transmitting-side control unit 118 acquires information (e.g., bit string information) from the vehicle side based on the waveform of the detected voltage (e.g., a rectangular wave). This process will be described in detail later. The power transmitting-side control unit 118 performs the various controls described above based on various information obtained through communication between the power supply-side communication unit 130 and the vehicle-side communication unit 230 or information obtained based on the voltage waveform.

[0029] The communication control unit 120 controls the operation of the power supply-side communication unit 130. For example, if the power supply device 100 has a plurality of power supply-side communication units 130, the communication control unit 120 controls the operation of all of the power supply-side communication units 130. For example, the communication control unit 120 attempts to acquire predetermined information (e.g., a pairing signal or information related to power transmission (e.g., a required frequency, information required for billing and settlement after system use, etc.)) through communication between the power supply-side communication unit 130 and the vehicle-side communication unit 230 of the surrounding vehicle 200 at a timing such as a predetermined cycle. The communication control unit 120 outputs the acquired information to the power transmission-side control unit 118, and transmits information acquired from the power transmission-side control unit 118 (pairing establishment information, information required for starting power transmission), etc. to the vehicle-side communication unit 230 via the power supply-side communication unit 130.

[0030] The power supply-side communication unit 130 includes an antenna for wireless communication and communicates wirelessly with external devices (for example, the information processing server 300 and the vehicle 200). The power supply-side communication unit 130 also transmits and receives information relating to, for example, power transmission from the power transmitting device 110 to the vehicle 200. Specifically, the power supply-side communication unit 130 transmits and receives information for pairing with the vehicle 200 so that power is supplied to a specific vehicle 200 under the control of the power transmitting-side control unit 118 and the communication control unit 120, and transmits and receives information for adjusting the amount of power to be transmitted. The power supply-side communication unit 130 may also acquire information from other external devices via the network NW.

[0031] [vehicle] 3 is a diagram illustrating an example of the configuration of a vehicle 200 according to an embodiment. The vehicle 200 includes, for example, a power receiving device 210, a rotating electric machine 220, a vehicle-side communication unit 230, a detection device 240, a vehicle sensor 250, and a driving control unit 260. Although not shown in FIG. 1 , the vehicle 200 includes, in addition to the above-described on-board devices, various on-board devices (examples of loads and auxiliary devices) such as various devices (such as a driving control device) for traveling on roads by manual driving by a driver or automatic driving, a car navigation device, and an audio device. The power receiving device 210 includes, for example, a power receiving unit 211, a received power conversion unit 212, a power conversion unit 213, a power storage unit 214, a power receiving-side control unit 215, a communication control unit 216, and a position detection unit 217. The power receiving-side control unit 215 includes, for example, a voltage detection unit 215A. Some or all of the power receiving-side control unit 215, the communication control unit 216, and the position detection unit 217 are realized, for example, by a hardware processor such as a CPU executing a program (software). Some or all of these components may be realized by hardware (including circuitry) such as an LSI, ASIC, FPGA, or GPU, or may be realized by a combination of software and hardware. The program may be stored in advance in a storage device (storage device having a non-transitory storage medium) such as a HDD or flash memory of the vehicle 200 or the power receiving device 210, or may be stored in a removable storage medium such as a DVD or CD-ROM and installed in the HDD or flash memory of the vehicle 200 or the power receiving device 210 by attaching the storage medium (non-transitory storage medium) to a drive device.

[0032] The power receiving unit 211 of the power receiving device 210 is connected to the received power conversion unit 212. The power receiving unit 211 receives power by changes in the high-frequency magnetic field transmitted from the power transmitting unit 116 due to magnetic field coupling such as magnetic resonance or electromagnetic induction.

[0033] The received power conversion unit 212 is connected to the power conversion unit 213. The received power conversion unit 212 includes, for example, an inverter that converts AC power into DC power and smooths and divides the voltage. The inverter includes, for example, a bridge circuit formed by a plurality of switching elements and rectifier elements that are bridge-connected in two phases, and a capacitor for smoothing the voltage. The circuit configuration of the received power conversion unit 212 will be described in detail later.

[0034] For example, a power receiving device 210 having a power receiving unit 211 and a power receiving power conversion unit 212 receives power transmitted from the power transmitting device 110 by controlling the power receiving side control unit 215 to switch on (conducting) and off (cutting) each switching element of the power receiving power conversion unit 212 in accordance with information on the frequency of power transmission by the power transmitting device 110.

[0035] The power conversion unit 213 is connected to the rotating electric machine 220. The power conversion unit 213 includes, for example, a power converter that converts between DC power and AC power. The power converter includes, for example, an element module and a capacitor for voltage smoothing. Details of the circuit configuration of the power conversion unit 213 will be described later.

[0036] The rotating electric machine 220 is, for example, a three-phase AC brushless DC motor provided for driving a vehicle. The rotating electric machine 220 includes a rotor having a permanent magnet for a field and a stator having a three-phase stator winding that generates a rotating magnetic field that rotates the rotor. The three-phase stator winding is connected to three-phase AC terminals of the power conversion unit 213. The rotating electric machine 220 generates a rotational driving force by performing a power running operation using electric power supplied from the power conversion unit 213. For example, if the rotating electric machine 220 can be connected to the wheels of the vehicle 200, the rotating electric machine 220 generates a driving force for driving the vehicle by performing a power running operation using electric power supplied from the power conversion unit 213. The rotating electric machine 220 may generate electric power by performing a regenerative operation using rotational power input from the wheels of the vehicle 200. If the rotating electric machine 220 can be connected to an internal combustion engine of the vehicle 200, the rotating electric machine 220 may generate electric power using the power of the internal combustion engine.

[0037] The power storage unit 214 includes, for example, a battery (an example of a secondary battery) such as a lithium ion battery, a current sensor that detects the current of the battery, a voltage sensor that detects the voltage of the battery, and a temperature sensor that measures the temperature of the battery. In the vehicle 200, the power storage unit 214 is connected to the power conversion unit 213 and the received power conversion unit 212, which will be described later. Under the control of the power receiving side control unit 215, for example, the power storage unit 214 stores power from the power feeding device 100 or the rotating electric machine 220 and supplies the stored power to the rotating electric machine 220 and various other on-board devices (loads, auxiliaries).

[0038] The power receiving-side control unit 215, for example, comprehensively controls each function of the power receiving device 210 or the entire vehicle 200. For example, the power receiving-side control unit 215 generates control signals indicating the timing to drive each switching element on (conducting) and off (cutting), and generates gate signals for actually driving each switching element on and off based on the control signals. For example, the power receiving-side control unit 215 controls the switching of each switching element of the power receiving device 210, thereby rectifying the AC power received from the power transmitting device 110 into DC power and improving the power factor of the input voltage and input current.

[0039] Furthermore, the power receiving-side control unit 215 generates predetermined information (e.g., a pairing signal or information related to power transmission) for transmitting power from the power supply device 100 and transmits the generated signal from the vehicle-side communication unit 230 to the outside. The power receiving-side control unit 215 may transmit the pairing signal at a predetermined cycle or at another predetermined timing. When the power receiving-side control unit 215 acquires permission information (pairing completion information) indicating that power supply device 100 is able to supply power or information necessary to start power transmission from the vehicle-side communication unit 230, the power receiving-side control unit 215 acquires target power by performing a synchronous rectification operation that synchronously drives multiple switching elements of the power receiving device 210 to turn on and off, and a short-circuit operation that short-circuits the secondary-side coil, which will be described later. The power receiving-side control unit 215 also controls the current of the power transmission device 110 to perform independent power control, such as stopping power transmission, on the power receiving device 210 side.

[0040] The information related to power transmission includes, for example, the required power and required frequency of power transmission, a target output (power consumption) for fail-safe purposes, and information related to various abnormalities. The required power of power transmission is a target value of power that the power receiving device 210 receives from the power transmitting device 110, and is set, for example, in accordance with the target driving force of the vehicle 200 or the rotating electric machine 220, the power consumption of various auxiliaries connected to the power storage unit 214, and the power state (SOC: State of Charge) of the power storage unit 214. The power state includes, for example, the remaining capacity and charging rate of the power storage unit 214. The required frequency of power transmission is a frequency required for power transmission from the power transmitting device 110 and is set in accordance with the required power. The required frequency is set, for example, based on the minimum ground clearance of the vehicle 200 and the installation layout of the power receiving device 210 on the vehicle 200, so as to suppress a decrease in the efficiency of power transmission and the output (power). The required frequency may be set, for example, in accordance with the state of power transmission between the power transmitting device 110 and the power receiving device 210. Furthermore, the information regarding power transmission may include information necessary for billing and settlement after use of the system.

[0041] Furthermore, the power receiving-side control unit 215 controls the operation mode of the power receiving device 210 depending on the situation of the vehicle 200. The operation modes include the short mode, parameter transmission mode, standby mode, and power receiving mode, as described above. For example, the power receiving-side control unit 215 transmits a pairing signal at a predetermined cycle of approximately several tens of microseconds to several milliseconds, and upon receiving a response signal to the pairing signal from the power supply device 100, the power receiving-side control unit 215 transitions the operation mode of the power receiving device 210 from the off mode to the short mode and transmits information such as a requested frequency. Furthermore, the power receiving-side control unit 215 transitions from the short mode to the power receiving mode and starts power reception control for power transmission from the power supply device 100 in the power transmission section. Furthermore, when power reception is completed, the power receiving-side control unit 215 transitions the operation mode of the power receiving device 210 from the power receiving mode to the off mode.

[0042] Furthermore, the voltage detection unit 215A of the power receiving side control unit 215 detects the voltage of the received power conversion unit 212. Furthermore, predetermined information is acquired from the power feeding device 100 based on the waveform (for example, a rectangular wave) of the detected voltage.

[0043] The communication control unit 216 controls the operation of the vehicle-side communication unit 230. For example, the communication control unit 216 causes the vehicle-side communication unit 230 to transmit predetermined information (for example, parameter information such as a pairing signal) at a timing such as a predetermined cycle. Furthermore, the communication control unit 216 may cause the vehicle-side communication unit 230 to transmit the predetermined information when the position of the vehicle 200 is within a predetermined distance from the installation position (power supply section) of the power supply device 100 based on the position of the power supply device 100 detected by the position detection unit 217. Then, when pairing is established, the communication control unit 216 causes the vehicle-side communication unit 230 to transmit information related to power transmission (for example, a required frequency and information necessary for billing and settlement after using the system).

[0044] The position detection unit 217 detects the position of the power supply device 100 based on the surrounding conditions of the vehicle 200 detected by the detection device 240, information about the vehicle 200 detected by the vehicle sensor 250, and the like.

[0045] The vehicle-side communication unit 230 includes an antenna for wireless communication and communicates wirelessly with external devices (for example, the information processing server 300 and the power supply device 100). The vehicle-side communication unit 230 also transmits and receives information related to power transmission from the power supply device 100, for example. Specifically, the vehicle-side communication unit 230 transmits and receives information for pairing with the power supply device 100 side so that power is supplied from a specific power supply device 100 under the control of the power receiving-side control unit 215, and transmits and receives information for adjusting the amount of power to be transmitted. The vehicle-side communication unit 230 may also acquire information from other external devices via the network NW.

[0046] The detection device 240 is a device that detects the surrounding conditions of the vehicle 200 (within a predetermined distance from the vehicle 200). The detection device 240 includes, for example, a camera, a radar device, a LIDAR (Light Detection and Ranging), a sensor fusion device, and the like. The detection device 240 recognizes the type, shape, position (relative position), speed (relative speed), and the like of objects present in the vicinity based on the detection results. The objects include, for example, traffic participants such as other vehicles and pedestrians, as well as the lane in which the vehicle 200 is traveling, road dividing lines that divide the lane, and other road structures (road signs, medians, curbs, traffic lights), and the like. The detection device 240 may also refer to map information and the like stored in a memory unit (not shown) in the vehicle 200 based on the position information of the vehicle 200 detected by the vehicle sensor 250, and recognize the shape of the surrounding roads (for example, the positions of road dividing lines), the power supply lane, the position of the power supply device 100, and the like from the position of the vehicle 200. The map information is, for example, information that represents the shape of a travel path by links that indicate the travel path, such as a road, associated with location information (e.g., latitude and longitude), and nodes connected by the links. The map information may also include the curvature and gradient of the travel path, and POI (Point of Interest) information associated with the location information. The map information may also include information about the location and installation section of the power supply device 100 or the power transmission device 110 installed in a predetermined area such as a road (travel path) or a parking lot, identification information (power supply device ID) of the power supply device 100, and identification information (power supply section ID) of the installation section.

[0047] Vehicle sensor 250 includes, for example, a speed sensor that detects speed V1 of vehicle 200, an acceleration sensor that detects acceleration, a yaw rate sensor that detects yaw rate (angular velocity), an orientation sensor that detects the orientation of the vehicle 200 in the forward direction, and an operation amount detection sensor attached to a driving operator. Driving operators include, for example, an operator (e.g., an accelerator pedal or a brake pedal) for instructing acceleration or deceleration, and an operator (e.g., a steering wheel) for instructing steering. In this case, vehicle sensor 250 may include an accelerator opening sensor, a brake depression amount sensor, a steering torque sensor, etc. Vehicle sensor 250 may also be provided with a position sensor that detects the position of vehicle 200. The position sensor is, for example, a sensor that acquires position information (longitude and latitude information) from a GPS (Global Positioning System) device. The position sensor may also be a sensor that acquires position information using a GNSS (Global Navigation Satellite System) receiver.

[0048] The above-described position detection unit 217 detects the positions of the power supply lane and the power supply device based on the detection results of the detection device 240. For example, the position detection unit 217 analyzes an image of the surroundings of the vehicle 200 captured by a camera using a known image analysis process, and detects the positions of the power supply lane and the power supply device 100 from road signs and characters and marks drawn on the road. Furthermore, when the position detection unit 217 acquires the position information of the vehicle 200 using a position sensor or the like mounted on the vehicle 200, the position detection unit 217 acquires the installation position of the power supply device 100 (or power supply section information) by referring to map information stored in advance in a storage unit or the like.

[0049] The driving control unit 260 controls at least one of the steering and speed of the vehicle 200 based on the surrounding conditions detected by the detection device 240, information detected by the vehicle sensor 250, etc., to perform driving control. The driving control includes, for example, LKAS (Lane Keeping Assistance System) control (lane maintenance control) that performs steering control so that the vehicle 200 travels in the center of the driving lane (travel path) (in other words, so that the vehicle does not deviate from the road dividing lines that divide the driving lane). The driving control also includes ACC (Adaptive Cruise Control) that causes the vehicle 200 to travel at a constant speed set in advance and, when approaching a preceding vehicle, measures the distance and speed difference with the preceding vehicle and automatically accelerates or decelerates the vehicle, and ALC (Auto Lane Changing) control that, when an instruction to change lanes by the driver's operation of a turn signal switch is received, performs lane change (steering control) in the instructed direction.

[0050] [Transition of operation modes in contactless power transfer] Next, transitions of the operation modes of the power transmitting device 110 and the power receiving device 210 in contactless power feeding will be described with reference to the drawings. FIG. 4 is a diagram for explaining transitions of the operation modes. In the example of FIG. 4, the horizontal axis represents time, and the vertical axis represents the operation of the vehicle 200, the operation mode of the power receiving device 210 (VA operation), and the operation mode of the power feeding device 100 (GA operation). Note that the operation transitions in FIG. 4 illustrate, as an example, a case where contactless power transmission is performed between the power feeding device 100 and the power receiving device 210 while the vehicle 200 is traveling at a predetermined speed (for example, approximately 80 km / h). The operation transitions over time will be described below. Note that in the example of FIG. 4, in contactless power feeding, FSA (Fail Safe Action) is always executed on the power receiving device 210 side and the power feeding device 100 side, and FSA is executed to control to the safe side when an abnormality is detected (VA-side FSA, GA-side FSA).

[0051] At time T1, the power receiving-side control unit 215 of the vehicle 200 communicates with the information processing server 300 or the like via the vehicle-side communication unit 230, for example, and performs billing processing for contactless power feeding or preliminary processing for billing corresponding to the amount of power to be fed (in-vehicle device billing). Note that, prior to time T1, the operation mode of the power receiving device 210 is in standby mode. Also, during the billing processing, the operation mode of the power feeding device is in off mode.

[0052] At time T2, after the billing process is completed, the power receiving device 210 aligns the vehicle 200 so that it passes over the power supply device 100 installed on the road surface (e.g., a power supply lane). In this case, the alignment may be performed by the driving control unit 260 based on information detected by the position detection unit 217. Alternatively, an image showing the position of the power supply device 100 (or the position of the power supply lane) and the current position of the vehicle 200 may be displayed on a display unit (not shown) or the like mounted on the vehicle 200, and the driver may manually align the vehicle 200 while viewing the image displayed on the display unit. For example, when the LKAS control is being executed by the driving control unit 260, the vehicle 200 is controlled to travel in the center of the lane. Therefore, by performing the LKAS control and traveling on the power supply lane, the vehicle 200 can be aligned. Note that from time T2 to time T3, the power receiving device 210 remains short-circuited, and the power supply device 100 transitions from the off mode to the standby (standby) mode.

[0053] At time T3, when the distance between the power receiving device 210 and the power supply device 100 becomes within a predetermined distance (a distance at which communication is possible) due to the travel of the vehicle 200, the power receiving-side control unit 215 of the vehicle 200 starts pairing through communication (VA-GA communication) between the power receiving device 210 and the power supply device 100. Between times T3 and T4, the power receiving-side control unit 215 alternates between a transmission mode in which parameter information (ID, requested power, battery voltage, etc.) is transmitted and a standby mode until the efficiency of power transmission becomes greater than a predetermined value (for example, greater than 0[%]). Meanwhile, the power transmitting-side control unit 118 of the power supply device 100 alternates between a reception mode and a search mode. In the search mode, for example, the power transmission efficiency is obtained from the correspondence information of the power (transmission power) and efficiency of the power transmission corresponding to the horizontal distance (the relative movement amount between the primary coil and the secondary coil in the direction parallel to the road surface) in the contactless power transmission system 1 of the embodiment, which is preset. The power transmission side control unit 118 also determines the efficiency based on the ratio of the voltage to the current. If the efficiency is below a predetermined value, the power transmission side control unit 118 outputs information to that effect to the power receiving device 210, causing the power receiving device 210 to execute a retry operation. That is, in this embodiment, if the transmission efficiency is not suitable for power supply, the above-described pairing-related communication can be performed. For example, when the vehicle 200 is traveling at a speed of 80 km / h, the expected period from time T3 to T4 (expected communication completion time) is approximately 22.5 msec.

[0054] At time T4, the efficiency of power transmission exceeds a predetermined value, and therefore power transmission control is executed. For example, the power supply device 100 performs power control (GA power control) to transmit power corresponding to the required power specified by the parameters to the outside. The power receiving device 210 performs power control (VA charging (power reception) control) to receive the power transmitted from the power supply device 100 and store the power in the power storage unit 214 mounted on the vehicle 200. That is, the power supply device 100 performs communication (pairing communication) with the power receiving device 210 when the efficiency of power transmission with the power receiving device 210 is equal to or lower than a predetermined value, and performs power supply control to the power receiving device 210 when the efficiency exceeds the predetermined value. This allows the pairing communication to be completed when the power transmission efficiency is low, and allows power to be supplied more efficiently when the power transmission efficiency is high.

[0055] At time T5, the efficiency of power transmission becomes equal to or less than a predetermined value, and therefore the power supply operation is terminated at this time. This enables power supply control using efficient power transmission. For example, when vehicle 200 is traveling at 80 km / h, the expected period from time T4 to T5 (expected power transmission time) is approximately 18 msec. Note that, since a plurality of power supply devices 100 are installed at predetermined intervals on the power supply lane, vehicle 200 can be charged up to the requested power by each power supply device 100 performing the control shown in FIG. 4. Furthermore, when power supply is completed, the amount of power supplied up to that point is accumulated, and billing processing (billing processing) for that amount is executed.

[0056] In the above process, the vehicle 200 is shown traveling at a high speed (for example, 80 km / h), but similar control may be applied when traveling at a low speed or when the vehicle is stopped. That is, the process of this embodiment is widely applicable, for example, when the speed V1 of the vehicle 200 is 0 to 100 km / h. When the vehicle is stopped, power supply is controlled in consideration of a time rating, such as 1, 3, or 10 seconds, that is set in advance.

[0057] [About pairing via VA-GA communication] Next, the pairing by the above-mentioned VA-GA communication will be specifically described. In the embodiment, for example, in a state of weak magnetic field coupling (hereinafter referred to as a weak coupling state), the vehicle 200 transmits a pairing signal (parameters) to the power supply device 100, and when a response indicating that power transmission from the power supply device 100 will start (for example, the efficiency of power transmission is greater than a predetermined value) is obtained, the power receiving device 210 is shifted from the standby mode to the power receiving mode.

[0058] In the embodiment, when the vehicle 200 is in a weakly coupled state before reaching the power supply device 100, the communication control unit 216 transmits pairing information (a pairing signal) from the power receiving device 210 side. Fig. 5 is a diagram showing the relationship between the coupling state and the distance. In the example of Fig. 5, the horizontal axis indicates the distance between the power transmitting device 110 and the power receiving device 210, and the vertical axis indicates the coupling coefficient between the power transmitting side and the power receiving side (an index value indicating the coupling state, such as the strength of the magnetic field coupling).

[0059] 5, the closer the distance between the power supply side and the power receiving side, the larger the coupling coefficient on the curve. Also, even in a weakly coupled state where the power supply side and the power receiving side are far apart (for example, the coupling coefficient is about 0.1), it is possible to induce a current from the power receiving device 210 to the power transmitting device 110. Therefore, before the vehicle 200 arrives at the power supply device 100, when the weakly coupled state falls within a predetermined range (for example, the coupling coefficient is about 0.1 to 0.3), the communication control unit 216 transmits pairing information to the power supply device 100.

[0060] In this case, the communication control unit 216 superimposes the pairing information on the carrier wave by, for example, switching a signal (carrier wave) for contactlessly transmitting power to the power transmitting device 110 at a predetermined ratio to generate a two-level digital signal, so-called dominant and recessive. This carrier wave is, for example, a time-series waveform of a current measured (induced) on the power supply side. The communication control unit 216 can transmit the pairing information by amplitude modulation of the carrier wave by changing the switching ratio.

[0061] The power transmission side control unit 118 of the power supply device 100 in the embodiment demodulates the current (the above-mentioned carrier wave) received by the power transmission unit 116 to obtain the contents of the pairing information.

[0062] In a weakly coupled state, the coupled state may not be able to continue due to some factor, such as the surrounding environment, so it is necessary to shorten the time until pairing is completed. For example, if the communication completion time in a weakly coupled state is set to 10 [msec], the current at the time of resonance to the power transmitting device 110 side is used as a signal, so transmission is required at approximately 85 [kHz], and the transferable signal in this case is approximately 85 [kbps]. Therefore, the amount of data that can be transmitted in 10 [msec] is 850 [bits] in one direction. Considering bidirectional transmission and multiple transmissions (e.g., approximately three times), it is desirable to set the upper limit to approximately 8 [bytes]. Therefore, in this embodiment, the pairing information data is controlled to be within 8 bytes.

[0063] Fig. 6 is a diagram showing an example of a bit layout of pairing information in an embodiment. In the example of Fig. 6, the horizontal direction indicates a bit string for each byte, and the vertical direction indicates the position of each byte 1 to 8. The pairing information in an embodiment may include not only a power receiving device ID and a vehicle ID, but also other information related to power transmission.

[0064] The pairing information shown in FIG. 6 stores, for example, between a start flag (SOF) and an end flag (EOF) of the data, information such as a Data Length Code (DLC), a power supply section ID that is identification information for the power receiving section, a power receiving device ID or a vehicle ID, a vehicle classification (e.g., passenger car, truck, bus, etc.), a vehicle state (e.g., whether or not the vehicle is in a state where power can be received (or a state where power reception is required)), an allowable charging power (e.g., target power, required power), and a resonant frequency (required frequency). The "reservation" area shown in FIG. 6 may be information stored on the power supply device 100 side or may be a spare area. The pairing information may also include information about the battery voltage. The type, order, and number of bits stored as the pairing signal are not limited to the example shown in FIG. 6. For example, if the amount of data is to be further reduced from that shown in FIG. 6, this can be achieved by reducing the number of bits of a predetermined item (e.g., power supply section ID) or by reducing the number of items such as "reservation." In this way, by storing the information necessary for contactless power supply within 8 bytes, it is possible to transmit more appropriate information for pairing in a weakly coupled state.

[0065] [Processing flow] FIG. 7 is a flowchart showing an example of a contactless power transmission process in an embodiment. Among various processes executed in the contactless power transmission process, the process in FIG. 7 mainly relates to a process of transmitting pairing information and performing power reception control after pairing. The process in FIG. 7 may be repeatedly executed at a predetermined timing. In the example in FIG. 7, the communication control unit 216 monitors the magnetic field coupling state with the power supply device 100 and determines whether the coupling degree is within a predetermined range and is in a weak coupling state (step S200). If it is determined that the coupling state is weak, the communication control unit 216 transmits a signal (carrier wave) including pairing information from the power receiving device 210 to the coupled power supply device 100 (step S210). Next, the communication control unit 216 determines whether a predetermined response to the pairing signal (information indicating that power transmission will start) has been received from the power supply device 100 (step S220). If it is determined that a response has been received, the communication control unit 216 transitions the power receiving device 210 from the sleep mode to the power receiving mode to enable power reception (step S230), and executes power reception control (step S230). This ends the process of this flowchart. If it is determined in the process of step S200 that the power receiving device 210 is not in a weakly coupled state, or if it is determined in the process of step S220 that a response has not been received from the power supply device 100, the process of this flowchart ends.

[0066] Thus, according to the embodiment, there is provided a contactless power transmission system 1 that contactlessly supplies power from a power supplying device 100 installed on the path of a vehicle 200 (an example of a moving body) to a power receiving device 210 installed on the vehicle 200, and the power receiving device 210 is provided with a communication control unit 216 that transmits pairing information from the power receiving device 210 to the power supplying device 100 when the power receiving device 210 is in a weakly coupled state with the power supplying device 100, and transitions the operation mode of the power receiving device 210 to a power receiving mode when a response is obtained from the power supplying device 100, thereby enabling more appropriate control of power transmission even when the vehicle 200 is moving.

[0067] Furthermore, according to the embodiment, pairing can be performed more quickly and reliably. Furthermore, according to the embodiment, by utilizing weak magnetic field coupling between the VA (power receiving device 210) and the GA (power supply device 100), pairing information can be transmitted from the VA side using a power transmission frequency. Furthermore, according to the embodiment, for example, the power transmission side coil on the power supply device 100 side can be used as a communication function for transmitting pairing information, thereby making it possible to eliminate the need for functions such as the communication control unit 120, the power supply side communication unit 130, and the vehicle side communication unit 230. This allows for cost reduction of the power supply device 100A and the vehicle 200A.

[0068] [Pairing transmission timing] Next, the timing of transmitting the pairing information by the above-mentioned VA-GA communication will be specifically described. In the embodiment, when the distance or time depending on the position of the vehicle 200 and the installation position of the power supply device 100 becomes less than a threshold, the power receiving device 210 transmits a pairing signal to the power supply device 100, and when a response to the pairing signal is obtained from the power supply device 100, the operation mode of the power receiving device 210 is shifted to the power receiving mode.

[0069] FIG. 8 is a diagram illustrating the detection of a power supply device 100 installed on a road. In the example of FIG. 8, a power transmission device 110 is buried under a road RD1, and a position identification member 150 is installed above (on the ground side of) the power transmission device 110 to identify the position of the power supply device 100 in the road area from the outside. The position identification member 150 is, for example, a member that passes (does not block) signals (radio waves) from the power supply device 100 and signals to the power supply device 100, and is also a cover member (lid portion) that reduces impacts (loads) on the power supply device 100. In addition, at least the upper surface of the position identification member 150 is formed in a color different from the color of the road surface (or is painted a different color) so that the position of the power supply device 100 can be identified from the analysis results of a camera image captured by the camera of the detection device 240. The shape and size of the position identification member 150 are not limited to those of the example of FIG. 8.

[0070] For example, the position detection unit 217 refers to map information based on the position information acquired by the vehicle sensor 250 and detects a position corresponding to the power supply device 100 (or the power transmission device 110) in the vicinity of the vehicle 200 (within a predetermined distance). The position corresponding to the power supply device 100 may be, for example, a center position P1 of the power supply device 100 or a position at the closest end as viewed from the vehicle 200. The position corresponding to the power supply device 100 may also be a position P2 at which communication by the power supply-side communication unit 130 or power supply from the power supply device 100 is predicted to be possible. The position P2 is a position before the position P1 as viewed from the vehicle 200. The position P2 is, for example, a position at which the coupling coefficient (coupling degree) in magnetic field coupling is equal to or greater than a threshold value (for example, a coupling coefficient of approximately 0.003), but is not limited thereto, and may be a position a predetermined distance D1 before the position P1 (on the vehicle 200 side).

[0071] The communication control unit 216 acquires a distance D2 between the vehicle 200 and a position P1 corresponding to the power supply device 100 present in the traveling direction, based on the position and traveling direction of the vehicle 200, and transmits a pairing signal when the acquired distance D2 is less than a predetermined distance. Alternatively, the communication control unit 216 may acquire a distance D3 between the position P2 and the vehicle 200B instead of the position P1, and transmit a pairing signal when the vehicle 200 reaches the distance D3. This allows the pairing signal to be transmitted at an appropriate timing when there is a high possibility of receiving a response to the pairing signal from the power supply device 100, thereby enabling more efficient communication with the power supply device 100.

[0072] Furthermore, the communication control unit 216 may control the timing of transmitting the pairing signal based on time information instead of the distance information (distances D2 and D3). In this case, the communication control unit 216 calculates the time required for the vehicle 200 to reach a position (for example, position P1) associated with the power supply device 100 based on the current position and speed V1 of the vehicle 200, and transmits the pairing signal when the calculated time is less than a predetermined time. The predetermined time may be the time required for the vehicle 200 to reach position P2, assuming that the speed V1 of the vehicle 200 is constant, or may be a fixed time. Furthermore, the communication control unit 216 may calculate the time required for the vehicle 200 to reach position P2 associated with the power supply device 100, and transmit the pairing signal when the calculated time has elapsed.

[0073] Furthermore, instead of (or in addition to) calculating the distance to the power supply device 100 using the position of the vehicle 200 and map information as described above, the position detection unit 217 may perform known image analysis processing (e.g., edge extraction processing, feature extraction, pattern matching processing, etc.) on a camera image captured by the camera, and acquire the position corresponding to the power supply device 100 present in the traveling direction of the vehicle 200 based on the analysis result. In this case, the detection device 240 detects the position of the power supply device 100 from the position of the position identification member 150 obtained from the analysis result of the camera image captured by the camera, road signs, letters and marks drawn on the road, etc. The position detection unit 217 can acquire the position of the power supply device 100 more accurately by both acquiring the position of the power supply device 100 based on map information and acquiring the position of the power supply device 100 based on the analysis result of the camera image from the camera, and therefore can transmit a pairing signal at a more appropriate time, thereby achieving more efficient communication.

[0074] For example, when the speed V1 of the vehicle 200 is less than a predetermined speed, the position detection unit 217 detects the position of the power supply device 100 using both the map information and the camera image because the time required for the vehicle 200 to reach the power supply device 100 can be secured, and when the speed is equal to or greater than the predetermined speed, the position detection unit 217 detects the position of the power supply device 100 using either the map information or the camera image. Furthermore, the position detection unit 217 may detect the position of the power supply device 100 using only the map information when it is expected that it will be difficult to detect the position identification member 150 using the camera image due to rain or the like, based on the weather and illuminance around the vehicle 200. In this way, the position of the power supply device 100 can be detected more appropriately depending on the situation of the vehicle 200.

[0075] Furthermore, when a plurality of power supply devices 100 are installed, the position detection unit 217 may detect the section. FIG. 9 is a diagram illustrating an arrangement of a plurality of power supply devices 100. In the example of FIG. 9, a vehicle 200 travels in a traveling direction (X-axis direction in the figure) at a speed V1 on a road RD1 divided by road dividing lines LN1 and LN2. On the road RD1, a plurality of position identification members 150-1 to 150-3 are arranged at a predetermined interval D4 along the extension direction of the road RD1. Power supply devices 100-1 to 100-3 are buried beneath the plurality of position identification members 150-1 to 150-3, respectively.

[0076] For example, if the predetermined interval D4 is less than the predetermined interval, the position detection unit 217 detects the power supply devices 100-1 to 100-3 as one power supply device. Based on the detection result, the communication control unit 216 controls the timing to start transmitting the pairing signal in the power supply section based on the position of the closest power supply device 100-1 among the power supply devices 100-1 to 100-3. This makes it possible to transmit the pairing signal at a more appropriate timing.

[0077] [Processing flow] FIG. 10 is a flowchart showing another example (part 1) of a contactless power transmission process. The process in FIG. 10 relates to another example of a process of transmitting pairing information shown in FIG. 7 and performing power reception control after pairing. The processes in FIG. 10 and FIG. 11 described later may be repeatedly executed at predetermined timing. In the example in FIG. 10, the position detection unit 217 detects the position of the power supply device 100 present in the traveling direction of the vehicle 200 (step S300). Next, the position detection unit 217 acquires the distance from the current position of the vehicle 200 to the position associated with the power supply device 100 (step S310). Next, the communication control unit 216 determines whether the acquired distance is less than a predetermined distance (step S320). If it is determined that the acquired distance is less than the predetermined distance, the communication control unit 216 causes the vehicle-side communication unit 230 of the vehicle 200B to transmit a pairing signal (step S330). Next, the communication control unit 216 determines whether a response to the pairing signal has been obtained from the power supply device 100 (step S340). If it is determined that a response has been received, the communication control unit 216 transitions the operation mode of the power receiving device 210 from the standby mode to the power receiving mode (step S350) and executes control for receiving power (charging control) (step S360). This ends the process of this flowchart. If it is determined in the process of step S320 that the distance is not less than the predetermined distance, or if no response is received from the power supply device 100 even after a predetermined time has elapsed in the process of step S340, the process of this flowchart ends.

[0078] Fig. 11 is a flowchart showing another example (part 2) of the contactless power transmission process. Compared to the process of steps S300 to S360 shown in Fig. 10, the process of Fig. 11 includes processes of steps S312 and S322 instead of the processes of steps S310 and S320. Therefore, the following description will mainly focus on the processes of steps S312 and S322.

[0079] 11 , after the process of step S310, the position detection unit 217 acquires the arrival time from the vehicle 200 to the position corresponding to the power supply device 100 based on the current position and speed V1 of the vehicle 200 (step S312). Next, the position detection unit 217 determines whether the recognized time is less than a predetermined time (step S322). If it is determined that the recognized time is less than the predetermined time, the communication control unit 216 causes the vehicle-side communication unit 230 of the vehicle 200 to transmit a pairing signal (step S330) and executes the subsequent processes. If it is determined in the process of step S322 that the recognized time is not less than the predetermined time, or if no response is obtained from the power supply device 100 even after the predetermined time has elapsed, the process of this flowchart ends.

[0080] According to the embodiment described above, there is provided a contactless power transmission system in which power is supplied contactlessly from a power supplying device 100 installed on the path of a vehicle 200 (an example of a moving body) to a power receiving device 210 installed on the vehicle 200, and the power receiving device 210 is provided with a communication control unit 216 that transmits a pairing signal from the power receiving device 210 to the power supplying device when a distance or time depending on the position of the vehicle 200 and the installation position of the power supplying device 100 becomes less than a threshold, and that switches the operation mode of the power receiving device 210 to a power receiving mode when a response to the pairing signal is obtained from the power supplying device 100, thereby enabling more appropriate power transmission even when the vehicle 200 is moving.

[0081] Furthermore, according to the embodiment, pairing can be performed more quickly and reliably. Furthermore, according to the embodiment, by adjusting the timing of transmission of the pairing signal from the power receiving device 210, power consumption related to the transmission of the pairing signal can be reduced. When using weak magnetic field coupling, the timing of transmission from the VA side is important. For example, if the distance between the power receiving device 210 and the power supply device 100 is too far, coupling is not established, which not only prevents information transmission but also leads to wasteful power consumption. Furthermore, if the distance is too close, the VA side enters the power transmission range before pairing is completed, resulting in a loss of charging opportunities. Therefore, in the embodiment, the position of the GA side is detected more accurately using a camera or the like, and the transmission timing is calculated to transmit the pairing signal from the VA side, thereby reducing power consumption and realizing efficient pairing communication.

[0082] [Variations] For example, as a modified example of the embodiment, when the power receiving device 210 of the vehicle 200 is in a weakly coupled state coupled to the power supply device 100 by a weak magnetic field within a predetermined range and when the distance or time depending on the position of the vehicle 200 and the position corresponding to the installation position of the power supply device 100 becomes less than a threshold, the power receiving device 210 (vehicle 200) may transmit pairing information to the power supply device 100. Also, as a modified example of the embodiment, for example, the vehicle 200 may not be provided with the vehicle-side communication unit 230. In this case, the communication control unit 216 transmits pairing information from the power receiving device 210 to the power supply device 100 when the distance or time depending on the position of the vehicle 200 and the installation position of the power supply device 100 becomes less than a threshold and when the power receiving device 210 is in a weakly coupled state coupled to the power supply device 100 by a weak magnetic field within a predetermined range.

[0083] The embodiments of the present invention are presented as examples and are not intended to limit the scope of the invention. These embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are intended to be included within the scope and spirit of the invention, as well as within the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0084] 1...contactless power transmission system, 100...power supply device, 110...power transmission device, 112...power supply unit, 114...transmission power conversion unit, 116...power transmission unit, 118...power transmission side control unit, 120...communication control unit, 130...power supply side communication unit, 150...position identification member, 200...vehicle, 210...power receiving device, 211...power receiving unit, 212...receiving power conversion unit, 213...power conversion unit, 214...power storage unit, 215...power receiving side control unit, 216...communication control unit, 217...position detection unit, 220...rotating electric machine, 230...vehicle side communication unit, 240...detection device, 250...vehicle sensor, 260...driving control unit

Claims

1. A contactless power transmission system that supplies power contactlessly from a power supply device installed on a path of a moving object to a power receiving device installed on the moving object, The power receiving device is a control unit configured to, when a distance or time depending on a position of the moving body and an installation position of the power supply device becomes less than a threshold while the moving body is moving, repeatedly switch between a transmission mode in which the power receiving device transmits a pairing signal to the power supply device and a standby mode in which the power supply device waits for a response from the power receiving device until an efficiency of power transmission between the power receiving device and the power supply device becomes greater than a predetermined value, and to transition an operation mode of the power receiving device from the standby mode to a power receiving mode when it is determined from the response from the power supply device to the pairing signal that the efficiency of power transmission has become greater than the predetermined value; Contactless power transmission system.

2. a position detection unit that detects the position of the power supply device that is present in the traveling direction of the moving body based on the position of the moving body and map information, and / or detects the position of the power supply device based on an analysis result of an image captured by a camera mounted on the moving body, the control unit transmits the pairing signal when a distance to a position corresponding to an installation position of the power supply device detected by the position detection unit becomes less than a predetermined distance. The contactless power transfer system according to claim 1 .

3. a position detection unit that detects the position of the power supply device that is present in the traveling direction of the moving body based on the position of the moving body and map information, and / or detects the position of the power supply device based on an analysis result of an image captured by a camera mounted on the moving body, the control unit transmits the pairing signal when a time until the moving object arrives at the power supply device detected by the position detection unit becomes less than a predetermined time. The contactless power transfer system according to claim 1 .

4. the control unit transmits a pairing signal from the power receiving device to the power feeding device when the power receiving device is in a weakly coupled state in which the power receiving device and the power feeding device are coupled by a weak magnetic field within a predetermined range. The contactless power transfer system according to claim 1 .

5. A mobile body equipped with a power receiving device that receives power contactlessly from a power supply device installed on a moving path, a control unit configured to, when a distance or time depending on a position of the moving body and an installation position of the power supply device becomes less than a threshold while the moving body is moving, repeatedly switch between a transmission mode in which the power receiving device transmits a pairing signal to the power supply device and a standby mode in which the power supply device waits for a response from the power receiving device until an efficiency of power transmission between the power receiving device and the power supply device becomes greater than a predetermined value, and to transition an operation mode of the power receiving device from the standby mode to a power receiving mode when it is determined from the response from the power supply device to the pairing signal that the efficiency of power transmission has become greater than the predetermined value; Mobile object.

6. A contactless power transmission method for contactlessly supplying power from a power supply device installed on a path of a moving body to a power receiving device installed on the moving body, comprising: The power receiving device, When a distance or time depending on a position of the moving body and an installation position of the power supply device becomes less than a threshold value while the moving body is moving, a transmission mode in which a pairing signal is transmitted from the power receiving device to the power supply device and a standby mode in which a response from the power supply device is awaited are repeatedly performed until an efficiency of power transmission between the power receiving device and the power supply device becomes greater than a predetermined value; transitioning the operation mode of the power receiving device from the standby mode to a power receiving mode when it is determined from a response from the power supply device to the pairing signal that the efficiency of the power transmission has become greater than a predetermined value; Contactless power transmission method.

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