KR102479336B1 - Method and apparatus for aligning position using low frequency antenna in wireless charging system - Google Patents

Abstract

Connecting to a magnetic field detection device including an antenna located on a transmitting pad using wireless communication, outputting a magnetic field using an antenna located on a receiving pad, and receiving a magnetic field measurement value from the magnetic field detection device and obtaining position difference information between the transmitting pad and the receiving pad by comparing the magnetic field measurement value and a pre-stored reference value. The present invention is a position alignment method performed by a position alignment device including an antenna located in a reception pad for position alignment between a transmission pad and a reception pad performing wireless power transmission, and can maximize or optimize wireless charging efficiency.

Description

Position alignment method and apparatus of wireless charging system using low frequency antenna

The present invention relates to a method and apparatus for aligning a position using a magnetic field signal strength, and more particularly, to a method and apparatus for aligning a position of a wireless charging system using a magnetic field signal strength of a low-frequency antenna.

An electric vehicle (EV), which has been recently developed, drives a motor with battery power, and has fewer air pollutants such as exhaust gas and noise than conventional gasoline engine vehicles, has fewer breakdowns, has a longer lifespan, and operates It has the advantage of simple operation.

Electric vehicles are classified into hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and electric vehicles (EVs) according to driving sources. HEVs have an engine for main power and a motor for auxiliary power. PHEVs have a main powered motor and an engine that is used when the battery is discharged. An EV has a motor, but no engine.

Wireless charging of a battery for driving a motor of an electric vehicle may be performed by coupling a primary coil of a charging station and a secondary coil of the electric vehicle through a magnetic resonance method. In addition, in the self-resonant wireless power transmission system, if the primary coil and the secondary coil are not aligned, the efficiency of wireless power transfer can be greatly reduced. may be requested.

As a conventional alignment method, there is a method of aligning an electric vehicle equipped with a secondary coil with a primary coil of a ground assembly (GA) using a rear camera. In addition, in another conventional alignment method, after an electric vehicle is parked by a bump in a parking area, a movable charging pad is moved, and the primary coil of the charging pad and the second coil of the electric vehicle are moved. There is a way to align the secondary coil.

However, the prior art causes user intervention in coil alignment, alignment and user inconvenience, and large deviations in alignment, which may cause excessive system performance deterioration due to slight coil misalignment. Therefore, if the above-described prior art is used in a self-resonant wireless power transmission system that is sensitive to coil misalignment, it is difficult to realize optimal power transfer efficiency, and stability and reliability of the system may be lowered.

Accordingly, there is a demand for a method of precisely aligning a primary coil of a ground assembly of a charging station and a secondary coil of an electric vehicle to charge a high voltage battery mounted in an electric vehicle in a wireless power transfer system.

An object of the present invention to solve the above problems is to provide a position alignment method using a magnetic field signal strength of a low frequency antenna.

Another object of the present invention to solve the above problems is to provide a position alignment device using a magnetic field signal strength of a low frequency antenna.

In order to achieve the above object, a position alignment method performed by a position alignment device including an antenna located on a receiving pad according to an embodiment of the present invention is a magnetic field including an antenna located on a transmitting pad using wireless communication. Connecting to a detection device, outputting a magnetic field using an antenna located on a receiving pad, receiving a magnetic field measurement value from a magnetic field detection device, and comparing the measured magnetic field value and a pre-stored reference value to the position between the transmitting pad and the receiving pad It may include acquiring difference information.

Here, the step of connecting with a magnetic field detection device including an antenna located in a transmission pad using wireless communication includes the steps of searching for a magnetic field detection device connected to at least one transmission pad within a certain radius using wireless communication, and at least one Among the magnetic field detection devices of Received Signal Strength Indicator (RSSI), Time of Flight (ToF), Time Difference of Flight (TDoF), Time of Arrival (ToA) and The method may include selecting and connecting any one magnetic field detection device based on at least one of the time difference of arrival.

Here, the step of outputting the magnetic field using the antenna located on the receiving pad includes the step of verifying whether the antenna located on the receiving pad is normally driven, and when the antenna is normally driven, driving the antenna to output a unique magnetic field. steps may be included.

Here, the antenna located on the receiving pad and the antenna located on the transmitting pad may be ferrite rod antennas using a low frequency band.

Here, the position difference information is the x-axis separation distance representing the horizontal direction relative to the receiving pad, the y-axis separation distance representing the vertical direction, the z-axis separation distance representing the direction perpendicular to the receiving pad, and the transverse direction and transmission of the receiving pad It may include at least one of degrees of distortion between the horizontal directions of the pad.

Here, the antennas positioned on the receiving pad may include two antennas positioned one by one in a first zone and a second zone divided into left and right halves of the receiving pad.

Here, the antennas located on the transmission pad are four antennas located one by one in the first zone, the second zone, the third zone, and the fourth zone by dividing the transmission pad into four parts into upper left corner, upper right corner, lower left corner, and lower right corner. can include

Here, the magnetic field measurement value may include a magnetic field measurement value obtained by detecting and measuring magnetic fields generated from two antennas located on the receiving pad by each of the four antennas located on the transmitting pad.

Position alignment device according to an embodiment of the present invention for achieving the other object, an antenna located on a receiving pad, at least one processor, and at least one instruction executed through the at least one processor The stored memory, and at least one instruction is executed to connect with a magnetic field detection device including an antenna located on a transmitting pad using wireless communication, and detecting a magnetic field using an antenna located on a receiving pad. It may be executed to output, may be executed to receive a magnetic field measurement from a magnetic field detection device, and may be executed to obtain position difference information between a transmitting pad and a receiving pad by comparing the magnetic field measurement value and a pre-stored reference value.

Here, the at least one command is executed to search for a magnetic field detection device connected to at least one transmission pad within a certain radius using wireless communication, and a received signal strength indicator (RSSI) of the at least one magnetic field detection device. ), time of flight (ToF), time difference of flight (TDoF), time of arrival (ToA), and time difference of arrival (Time Difference of Arrival). It can be executed to select and connect one magnetic field detection device.

Here, at least one command is executed to verify whether the antenna located on the receiving pad is normally driven, and when the antenna located on the receiving pad is normally driven, the antenna located on the receiving pad is driven to output a unique magnetic field. can be executed to

Here, the antenna located on the receiving pad and the antenna located on the transmitting pad may be ferrite rod antennas using a low frequency band.

Here, the position difference information is the x-axis separation distance representing the horizontal direction relative to the receiving pad, the y-axis separation distance representing the vertical direction, the z-axis separation distance representing the direction perpendicular to the receiving pad, and the transverse direction and transmission of the receiving pad It may include at least one of degrees of distortion between the horizontal directions of the pad.

Here, the antennas positioned on the receiving pad may include two antennas positioned one by one in a first zone and a second zone divided into left and right halves of the receiving pad.

Here, the antennas located on the transmission pad are four antennas located one by one in the first zone, the second zone, the third zone, and the fourth zone by dividing the transmission pad into four parts into upper left corner, upper right corner, lower left corner, and lower right corner. can include

Here, the magnetic field measurement value may include a magnetic field measurement value obtained by detecting and measuring magnetic fields generated from two antennas located on the receiving pad by each of the four antennas located on the transmitting pad.

According to the present invention, since the primary coil of the ground assembly and the secondary coil of the electric vehicle can be precisely aligned, wireless charging efficiency can be maximized and optimized.

According to the present invention, the degree of twist between the primary coil of the ground assembly and the secondary coil of the electric vehicle may be output and provided to the user without user intervention.

1 is a conceptual diagram for explaining the concept of wireless power transmission for an electric vehicle to which an embodiment of the present invention is applied.
2 is a conceptual diagram illustrating an electric vehicle wireless charging circuit according to an embodiment of the present invention.
3 is a conceptual diagram for explaining a sorting concept in electric vehicle wireless power transmission according to an embodiment of the present invention.
4 is a conceptual diagram of a location alignment method according to an embodiment of the present invention.
5 is a diagram illustrating a loop antenna.
6 is a diagram explaining an equivalent circuit of a loop antenna.
7 is a diagram showing an equivalent circuit of a ferrite rod antenna and a ferrite rod antenna.
8 is a diagram showing radiation resistance according to a core of a loop antenna.
9 is a block diagram of a position alignment device connected to a VA according to an embodiment of the present invention.
10 is a block diagram of a magnetic field detection device connected to a GA according to an embodiment of the present invention.
11 is a detailed block configuration diagram of a position alignment device according to an embodiment of the present invention.
12 is a diagram showing state conversion of the alignment device according to an embodiment of the present invention.
13 is a diagram illustrating a method for a vehicle to search for a parking space according to an embodiment of the present invention.
14 is a diagram illustrating a method for a vehicle to select a parking space according to an embodiment of the present invention.
15 is a diagram showing a magnetic field signal between a GA and a VA at an ideal position according to an embodiment of the present invention.
16 is a diagram showing a magnetic field signal between a GA and a VA at a misaligned position according to an embodiment of the present invention.
17 is a flowchart illustrating a location alignment method according to an embodiment of the present invention.

Since the present invention can make various changes and have various embodiments, specific embodiments will be illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. Like reference numerals have been used for like elements throughout the description of each figure.

Terms such as first, second, A, and B may be used to describe various components, but the components should not be limited by the terms. These terms are only used for the purpose of distinguishing one component from another. For example, a first element may be termed a second element, and similarly, a second element may be termed a first element, without departing from the scope of the present invention. The term “and/or” includes any combination of a plurality of related listed items or any of a plurality of related listed items.

It is understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, but other elements may exist in the middle. It should be. On the other hand, when an element is referred to as “directly connected” or “directly connected” to another element, it should be understood that no other element exists in the middle.

Terms used in this application are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, the terms "include" or "have" are intended to designate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other features It should be understood that the presence or addition of numbers, steps, operations, components, parts, or combinations thereof is not precluded.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related art, and unless explicitly defined in the present application, they should not be interpreted in an ideal or excessively formal meaning. don't

Some terms used in this specification are defined as follows.

An electric vehicle (EV) may refer to an automobile defined in 49 code of federal regulations (CFR) 523.3 or the like. Electric vehicles can be used on highways and driven by electricity supplied from a vehicle-mounted energy storage device such as a rechargeable battery from a power source outside the vehicle. The power supply source may include a residence, a public electric service, or a generator using vehicle-mounted fuel.

An electric vehicle (EV) may be referred to as an electric car, an electric automobile, an electric road vehicle (ERV), a plug-in vehicle (PV), a plug-in vehicle (xEV), and the like. xEV is BEV (plug-in all-electric vehicle or battery electric vehicle), PEV (plug-in electric vehicle), HEV (hybrid electric vehicle), HPEV (hybrid plug-in electric vehicle), PHEV (plug-in hybrid electric vehicle), etc., or may be classified.

A plug-in electric vehicle (PEV) can be referred to as an electric vehicle that recharges an onboard primary battery by connecting to the power grid.

A plug-in vehicle (PV) may be referred to herein as a vehicle that can be recharged through a wireless charging method without using a physical plug and socket from an electric vehicle supply equipment (EVSE).

Heavy duty vehicles (H.D. Vehicles) may refer to any vehicle with four or more wheels as defined in 49 CFR 523.6 or CFR 37.3 (bus).

Light duty plug-in electric vehicles are three or four wheels propelled by an electric motor supplied with current from a rechargeable battery or other energy device, primarily for use on public streets, roads and highways. You can refer to a vehicle with A lightweight plug-in electric vehicle can be specified with a total weight of less than 4.545 kg.

A wireless power charging system (WCS) may refer to a system for wireless power transfer and control between a GA and a VA including alignment and communication.

Wireless power transfer (WPT) may refer to transmission of electrical power through a contactless means from an alternating current (AC) power supply network such as a utility or a grid to an electric vehicle.

Utility is a set of systems that provide electrical energy and usually include Customer Information System (CIS), Advanced Metering Infrastructure (AMI), Rates and Revenue system, etc. can be referred to as Utilities make energy available to plug-in electric vehicles through price tags or discrete events. In addition, utilities can provide information on tariff rates, intervals for metered power consumption, and validation of electric vehicle programs for plug-in electric vehicles.

Smart charging can be described as a system in which the EVSE and/or plug-in electric vehicle communicates the vehicle charge rate or discharge rate with the power grid to optimize the grid capacity or time to cost-of-use ratio.

Automatic charging may be defined as an operation of positioning a vehicle in an appropriate position with respect to a primary charger assembly capable of transmitting power and performing inductive charging. Auto-recharge can be done after obtaining the necessary authentication and authorization.

Interoperability can refer to a state in which components of a system relative to each other can work together to perform the desired operation of the overall system. Information interoperability can refer to the ability of two or more networks, systems, devices, applications or components to share and easily use information safely and effectively with little or no inconvenience to the user. .

An inductive charging system may refer to a system that transfers energy electromagnetically in the forward direction from an electrical supply network to an electric vehicle through a transformer in which two parts are loosely coupled. In this embodiment, the inductive charging system may correspond to an electric vehicle charging system.

An inductive coupler may refer to a transformer formed of a GA coil and a VA coil to transmit power through electrical isolation.

Inductive coupling may refer to magnetic coupling between two coils. The two coils may refer to a ground assembly coil and a vehicle assembly coil.

Ground assembly (GA) may refer to an assembly that is disposed on the ground or infrastructure side, including the GA coil and other suitable components. Other suitable components may include at least one component for controlling impedance and resonant frequency, ferrite and electromagnetic shielding material for enhancing a magnetic path. For example, a GA may include a power/frequency conversion device necessary to function as a power source for a wireless charging system, a GA controller, and wiring from the grid and wiring between each unit and filtering circuits, housing, and the like.

Vehicle assembly (VA) may refer to an assembly that is placed in a vehicle, including a VA coil and other suitable components. Other suitable components may include at least one component for controlling impedance and resonant frequency, ferrite and electromagnetic shielding material for strengthening the magnetic path. For example, the VA may include wiring between each unit and filtering circuits, housing, etc., as well as wiring of the rectifier/power converter and VA controller and vehicle battery necessary to function as a vehicle component of the wireless charging system. .

The aforementioned GA may be referred to as a primary device (PD), a primary device, and the like, and similarly, a VA may be referred to as a secondary device (SD), a secondary device, and the like.

The primary device may be a device that provides contactless coupling to the secondary device, that is, a device external to the electric vehicle. A primary device may be referred to as a primary side device. When an electric vehicle receives power, the primary device can act as a power source that transmits power. A primary device may include a housing and all covers.

The secondary device may be an electric vehicle-mounted device that provides contactless coupling to the primary device. A secondary device may be referred to as a secondary side device. When the electric vehicle receives power, the secondary device may transfer power from the primary device to the electric vehicle. The secondary device may include a housing and all covers.

A ground assembly controller (GA controller) may be part of the GA that adjusts the output power level to the GA coil based on information from the vehicle.

A vehicle assembly controller (VA controller) may be part of the VA that monitors certain vehicle parameters during charging and initiates communication with the GA to control the output power level.

The aforementioned GA controller may be referred to as a primary device communication controller (PDCC), and the VA controller may be referred to as an electric vehicle communication controller (VA controller).

The magnetic gap is the gap between the highest plane of the top of the litz wire or the top of the magnetic material of the GA coil and the bottom of the litz wire or the lowest plane of the magnetic material of the VA coil when they are aligned with each other. It can refer to a vertical distance.

Ambient temperature may refer to the ground level temperature measured in the atmosphere of the subject subsystem not directly illuminated by sunlight.

Vehicle ground clearance may refer to the vertical distance between a road or road pavement and the lowermost portion of a vehicle floor pan.

Vehicle magnetic ground clearance may refer to the vertical distance between the lowest plane of the floor of a Litz wire or the insulating material of a VA coil mounted on a vehicle and a road pavement.

Vehicle assembly (VA) coil surface distance may refer to the vertical distance between the lowest plane of the bottom of the Litz wire or the magnetic material of the VA coil and the lowest outer surface of the VA coil. This distance may include additional items wrapped in protective covers and coil wraps.

The aforementioned VA coil may be referred to as a secondary coil, a vehicle coil, a receiver coil, and the like, and similarly, a ground assembly coil (GA coil) may be referred to as a primary coil. It may be referred to as a primary coil, a transmit coil, and the like.

An exposed conductive component may refer to a conductive component of an electrical device (eg, an electric vehicle) that can be contacted by a person and does not normally flow electricity, but electricity may flow in the event of a failure.

Hazardous live component may refer to a live component capable of giving a hazardous electric shock under certain conditions.

A live component can refer to any conductor or conductive component that is electrically energized in its primary use.

Direct contact may refer to contact of a living being, a person.

Indirect contact may refer to a person contacting an exposed, conductive, live active component due to an insulation failure (see IEC 61140).

Alignment may refer to a procedure for finding a relative location of a secondary device with respect to a primary device and/or a procedure for finding a relative location of a primary device with respect to a secondary device for prescribed efficient power transmission. In this specification, alignment may refer to positional alignment of a wireless power transmission system, but is not limited thereto.

Pairing may refer to a procedure in which a vehicle (electric vehicle) is associated with a single dedicated ground assembly (primary device) arranged to be capable of transmitting power. In this specification, pairing may include a procedure for associating a charging spot or a specific ground assembly with a vehicle assembly controller. Correlation/Association may include a procedure for establishing a relationship between two peer communication entities.

Command and control communication may refer to communication between an electric vehicle power supply and an electric vehicle that exchanges information necessary for initiating, controlling, and terminating a wireless power transfer process.

High level communication can handle all information beyond that covered by command and control communication. A data link of high level communication may use power line communication (PLC), but is not limited thereto.

Low power excitation may refer to, but is not limited to, activating an electric vehicle to detect a primary device to perform precise positioning and pairing, and vice versa.

SSID (Service set identifier) is a unique identifier consisting of 32 characters attached to the header of a packet transmitted over a wireless LAN. The SSID distinguishes a basic service set (BSS) that a wireless device is trying to access. SSID basically distinguishes several wireless LANs from each other. Therefore, all access points (APs) and all terminal/station equipment that want to use a specific wireless LAN can use the same SSID. Devices that do not use a unique SSID cannot join the BSS. Since the SSID is shown in plain text, it may not provide any security features to the network.

ESSID (Extended service set identifier) is the name of the network to be connected. It is similar to SSID, but may be a more extended concept.

A basic service set identifier (BSSID) is usually 48 bits and is used to identify a specific basic service set (BSS). In the case of an infrastructure BSS network, the BSSID may be a medium access control (MAC) of an AP device. In the case of an independent BSS or ad hoc network, the BSSID can be generated with an arbitrary value.

A charging station may include one or more ground assemblies and one or more ground assembly controllers that manage the one or more ground assemblies. The ground assembly may include at least one wireless communicator. A charging station may refer to a place having at least one ground assembly installed in a home, office, public place, road, parking lot, or the like.

Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a conceptual diagram for explaining the concept of wireless power transmission for an electric vehicle to which an embodiment of the present invention is applied.

Referring to FIG. 1 , wireless power transmission may be performed by at least one component of an electric vehicle (10) and a charging station (20), and to wirelessly transmit power to the electric vehicle (10). can be used for

Here, the electric vehicle 10 may generally be defined as a vehicle that supplies current induced from a rechargeable energy storage device such as the battery 12 as an energy source for an electric motor, which is a power unit.

However, the electric vehicle 10 according to the present invention may include a hybrid vehicle having an electric motor and a general internal combustion engine together, and may be used not only in automobiles but also in motorcycles, carts, may include scooters and electric bicycles.

In addition, the electric vehicle 10 may include a receiving pad 11 including a receiving coil to charge the battery 12 wirelessly, and may include a plug connector to charge the battery 12 by wire. may be In this case, the electric vehicle 10 capable of charging the battery 12 by wire may be referred to as a plug-in electric vehicle (PEV).

Here, the charging station 20 may be connected to a power grid 30 or a power backbone, and an alternating current (AC) is supplied to the transmission pad 21 including the transmission coil through a power link. Alternatively, direct current (DC) power may be provided.

In addition, the charging station 20 can communicate with a power grid 30 or an infrastructure management system or infrastructure server that manages the power grid through wired or wireless communication, and performs wireless communication with the electric vehicle 10 can do.

Here, wireless communication may include Bluetooth, zigbee, cellular, wireless local area network, and the like.

Also, for example, the charging station 20 may be located in various places, such as a parking lot attached to the house of the owner of the electric vehicle 10, a parking area for charging an electric vehicle at a gas station, a shopping center or a parking area at a workplace.

Here, in the process of wirelessly charging the battery 12 of the electric vehicle 10, first, the receiving pad 11 of the electric vehicle 10 is located in the energy field by the transmitting pad 21, and the transmitting pad 21 It can be performed by interaction or coupling between the transmission coil of the transmission coil and the reception coil of the reception pad 11 . As a result of the interaction or coupling, electromotive force is induced in the receiving pad 11, and the battery 12 may be charged by the induced electromotive force.

In addition, all or part of the charging station 20 and the transmitting pad 21 may be referred to as a Ground Assembly (GA), and the meaning defined above may be referred to as the ground assembly.

In addition, all or part of the receiving pad 11 of the electric vehicle 10 and other internal components of the electric vehicle may be referred to as a vehicle assembly (VA), where the meaning defined above may be referred to as the vehicle assembly.

Here, the transmission pad or the reception pad may be non-polarized or polarized.

At this time, if the pad is non-polar, one pole may be present in the center of the pad, and the opposite pole may be located on the outer periphery of the pad. Here, the flux may be formed to exit at the center of the pad and return at all outer edges of the pad.

Also, if the pad is polar, it may have a respective pole at either end of the pad. Here, the magnetic flux may be formed based on the orientation of the pad.

2 is a conceptual diagram illustrating an electric vehicle wireless charging circuit according to an embodiment of the present invention.

Referring to FIG. 2, a schematic configuration of a circuit in which charging is performed in an electric vehicle wireless charging system can be seen.

Here, the circuit on the left side of FIG. 2 can be interpreted as representing all or part of the configurations of the power source (Vsrc) supplied from the power grid, the charging station 20, and the transmission pad 21 in FIG. 1, and the right side of FIG. 2 The circuit can be interpreted as expressing part or all of an electric vehicle including a receiving pad and a battery.

First, the circuit on the left of FIG. 2 provides the output power (P _src ) corresponding to the power supply (V _src ) supplied from the power grid to the wireless charging power converter, and the wireless charging power converter generates the desired resonance in the transmission coil (L ₁ ) In order to emit an electromagnetic field at a frequency, the frequency of the supplied power (P _src ) and AC/DC converted power (P ₁ ) may be output.

Specifically, the wireless charging power converter includes an AC/DC converter for converting AC power when the power (P _src ) supplied from the power grid is AC power, and a low-frequency converter for converting DC power into power of a resonant frequency suitable for wireless charging (or LF converter). The resonant frequency may be determined to be located between 80 and 90 kHz, for example.

The power (P ₁ ) output from the wireless charging power converter may be supplied again to a circuit composed of a transmission coil (L ₁ ), a first capacitor (C ₁ ), and a first resistor (R ₁ ), where the first capacitor ( C ₁ ) may be determined to have a device value to have a resonant frequency suitable for charging together with the transmission coil (L ₁ ). Also, here, the first resistance (R ₁ ) may mean power loss generated by the transmission coil (L ₁ ) and the first capacitor (C ₁ ).

Here, the transmission coil (L ₁ ) and the reception coil (L ₂ ) Electromagnetic coupling defined by the coupling coefficient k is made so that power is transmitted, or power may be induced to the reception coil (L ₂ ). Therefore, in the present invention, the meaning that power is transmitted may be used interchangeably with the meaning that power is induced.

Here, the power (P ₂ ) induced or transmitted to the receiving coil may be provided to the electric vehicle power converter. In this case, the second capacitor (C ₂ ) may be determined as an element value that has a resonant frequency suitable for charging together with the receiving coil (L ₂ ), and the second resistor (R ₂ ) is the receiving coil (L ₂ ) and the second capacitor (L 2 ). It may refer to power loss caused by the capacitor C ₂ .

The electric vehicle power converter may include a LF/DC converter that converts the provided electric power (P ₂ ) of a specific resonant frequency back into DC power having a voltage level suitable for the battery (V _HV ) of the electric vehicle.

When the EV power converter outputs power (P _HV ) obtained by converting the supplied power (P ₂ ), the output power (P _HV ) can be used to charge the battery (V _HV ) built into the EV.

Here, the circuit on the right side of FIG. 2 may further include a switch for selectively connecting or disconnecting the receiving coil L ₂ from the battery V _HV .

Here, the resonance frequency of the transmitting coil (L ₁ ) and the receiving coil (L ₂ ) may be configured to be similar or identical to each other, and the receiving coil (L ₂ ) is applied to the electromagnetic field generated by the transmitting coil (L ₁ ). It can be configured to be located at this short distance.

Here, the circuit of FIG. 2 should be understood as an exemplary circuit for power transmission in an electric vehicle wireless charging system usable for the embodiments of the present invention, and should not be construed as being limited to the circuit in FIG. 2 .

On the other hand, since power loss may increase as the transmitting coil (L ₁ ) and the receiving coil (L ₂ ) are located farther away, setting the positions of both may be an important factor.

In this case, the transmitting coil L ₁ may be included in the transmitting pad 21 in FIG. 1 , and the receiving coil L ₂ may be included in the receiving pad 11 in FIG. 1 . Also, the transmitting coil may be referred to as a GA coil (Ground Assembly coil), and the receiving coil may be referred to as a VA coil (Vehicle Assembly coil). Accordingly, positioning between the transmitting pad and the receiving pad or positioning between the electric vehicle and the transmitting pad will be described with reference to the drawings below.

3 is a conceptual diagram for explaining a sorting concept in electric vehicle wireless power transmission according to an embodiment of the present invention.

Referring to FIG. 3 , a position alignment method between the transmitting pad 21 in FIG. 1 and the receiving pad 11 built in the electric vehicle 10 can be described. Here, positional alignment may correspond to alignment, which is a term previously described, and thus may be defined as positional alignment between GA and VA, and interpreted as limited to positional alignment between the transmission pad 21 and the reception pad 11. It doesn't work.

Here, the transmission pad 21 is shown as being located below the ground surface in FIG. 3, but may be located above the ground surface, or may be located below the ground surface so that the upper surface of the transmission pad 21 is exposed.

In addition, the receiving pad 11 of the electric vehicle can be defined in different categories according to the height (defined in the z direction) measured with respect to the ground surface. For example, the height of the receiving pad 11 from the ground surface is 100-150 (mm) can be set as class 1, 140-210 (mm) as class 2, and 170-250 (mm) as class 3. At this time, depending on the receiving pad 11, partial support such as supporting only class 1 or supporting classes 1 and 2 may be possible.

Here, the height measured based on the ground surface may correspond to the vehicle magnetic ground clearance, which is the term previously described.

In addition, the position of the transmitting pad 21 in the height direction (defined in the z direction) can be determined to be located between the maximum class and the minimum class supported by the receiving pad 11. For example, the receiving pad 11 If only classes 1 and 2 are supported, the transmission pad may be determined to be located between 100 and 210 (mm) with respect to the reception pad 11.

In addition, the gap between the center of the transmitting pad 21 and the center of the receiving pad 11 may be determined to be located within limit values in horizontal and vertical directions (defined as x and y directions). For example, it may be determined to be located within ±75 (mm) in the horizontal direction (defined in the x direction) and within ±100 (mm) in the vertical direction (defined in the y direction).

Here, the relative positions of the transmitting pad 21 and the receiving pad 11 may have different limit values according to experimental results, and it should be understood that the above numerical values are exemplary.

In addition, the transmission pad 21 and the reception pad 11 have been described as alignment between the pads on the premise that each includes a coil, but more specifically, transmission built into the transmission pad 21 and the reception pad 11, respectively. It can also be defined as the alignment between the coil (or GA coil) and the receiving coil (or VA coil).

4 is a conceptual diagram of a location alignment method according to an embodiment of the present invention.

Referring to FIG. 4 , a position alignment method according to an embodiment of the present invention maximizes wireless charging efficiency by aligning the positions of the primary coil of the ground assembly (GA) and the secondary coil of the vehicle assembly (VA) and/or As a method for optimization, it may be performed based on magnetic field measurements between four antennas (ANT1, ANT2, ANT3, and ANT4) on the GA side and two antennas (ANTa and ANTb) on the VA side.

More specifically, the VA may include two antennas, and the two antennas may be located one by one in the left zone and the right zone of the VA, and the left zone and the right zone are the zones dividing the VA into left and right halves. It may mean, and may mean a zone symmetrically divided left and right. When the VA has a quadrangular structure, the two antennas may be located at the center of the left side and the center of the right side of the quadrangle, respectively, but since the structure may be changed according to design, it is not limited to the quadrangle.

In addition, the two antennas may be connected to the VA and located in a specific part of the vehicle, and in this case, one may be located in the left zone and the right zone of the specific part of the vehicle. The left zone and the right zone of the specific part of the vehicle may refer to a zone in which the specific part of the vehicle is symmetrically divided left and right.

The aforementioned VA and the left and right zones of a specific part of the vehicle may also be a front zone and a rear zone, but are not limited thereto, and may mean two zones symmetrically divided. Hereinafter, it will be described assuming that it is located in VA.

The VA or vehicle assembly controller may control the antenna and may include a position alignment device capable of calculating position difference information between the VA and the GA.

The GA may include four antennas, and each of the four antennas may be located in the first area, the second area, the third area, and the fourth area of the GA, one for the first area, the second area, and the third area. And the fourth zone may mean, but is not limited to, the upper left zone, the upper right zone, the lower left zone, and the lower right zone of the GA, respectively, and the GA is divided into 4 parts to have the same size. there is. When the GA has a quadrangular structure, the four antennas may be positioned at each corner of the oblique shape, but the structure may be changed according to the design, so it is not limited to a quadrangular structure. In addition, the GA or ground assembly controller may include a magnetic field detection device capable of calculating a magnetic field measurement value based on the magnetic field information detected by the four antennas and transmitting the magnetic field measurement value to a position alignment device. there is.

Here, the antenna included in VA and/or GA may mean a loop antenna or a ferrite rod antenna, but is not limited thereto.

A ferrite rod antenna may refer to an antenna using a low frequency. Here, the low frequency may mean an LF band using a 30 to 300 kHz band among frequency domains classified into 12 steps by the International Telecommunication Union (ITU). The frequency domain divided into 12 levels by the ITU is shown in Table 1.

Before describing the alignment device according to an embodiment of the present invention, a loop antenna and/or a ferrite rod antenna used in the alignment device will be described together with FIGS. 5 to 8 .

5 is a diagram illustrating a loop antenna.

Referring to FIG. 5, (a) of FIG. 5 is a diagram illustrating a loop antenna having one winding number, and FIG. 5 (b) is a diagram illustrating a loop antenna having a plurality of winding numbers.

A loop antenna may mean an antenna including a closed-circuit. The loop antenna has the advantage of being simple in structure, low cost, and easy to change the shape of the antenna, so that it can be manufactured into various types of antennas. Here, the various shapes may include, but are not limited to, circular, triangular, rectangular, and elliptical shapes. In addition, loop antennas can generally be classified as electrically small loop antennas when the length of the circumference or circumference is smaller than 0.1 times the wavelength, and otherwise can be classified as electrically large loop antennas.

5(a) is a loop antenna having a winding number of 1, and since the length of the circumference or circumference is less than 0.085 times the wavelength, it may be an electrically small loop antenna. Also, the loop antenna of FIG. 5(a) may have very small radiation resistance. In other words, the radiation resistance can be less than 1 ohm, but the radiation resistance can be improved by increasing the number of turns.

The loop antenna of FIG. 5(a) may have a narrowband with a small loop, and may have a bandwidth of less than 1% typically. A loop antenna may have a far field pattern similar to a small electric dipole perpendicular to the loop plane and may be equivalent to a magnetic dipole. In addition, the loop antenna may further improve radiation resistance by inserting a ferromagnetic core.

5(b) is a loop antenna having a plurality of windings, and radiation resistance may be improved, but efficiency may be very low. Most loop antennas with multiple windings can be used as receive antennas, and loss may not be significant.

A small loop antenna may have a high radiation resistance by having a plurality of windings and inserting a ferrite core, but may have high loss and low radiation efficiency. However, the small loop antenna has a simple structure, and also has the advantage of having a small size and weight.

6 is a diagram explaining an equivalent circuit of a loop antenna.

Referring to FIG. 6, (a) of FIG. 6 is a diagram illustrating an equivalent circuit of the loop antenna, and (b) of FIG. 6 is a diagram for explaining loss resistance in the equivalent circuit of the loop antenna.

In the equivalent circuit of FIG. 6(a), C _r may represent resonance capacitance, R _l may represent loss resistance of the loop antenna, and R _r may represent radiation resistance. ) can be expressed. Also, L _A may represent the inductance of the loop, and X _A may represent the reactance of L _A . L _i may represent the inductance of the loop conductor (wire), and X _i may represent the reactance of L _i . In addition, Z _in may represent input impedance, and Z' _in may represent impedance in a conjugate matching relationship with Z _in .

Input impedance Z _in , impedance Z' _in of conjugate matching relationship with Z _in , admittance Y _in equivalent to input impedance Z _in , and resonant capacitance C _r may be calculated as in Equation 1.

는 주파수를 나타낼 수 있으며, G_in 및 B_in은 각각 어드미턴스 Y_in의 컨덕턴스(conductance) 및 서셉턴스(susceptance)를 나타낼 수 있다.In Equation 1,

may represent a frequency, and G _in and B _in may represent conductance and susceptance of the admittance Y _in , respectively.

6(b) is a diagram for explaining the value of the loss resistance R _l . In FIG. 6(a), 2a may indicate a diameter of a loop, 2b may indicate a diameter of a wire, 2c may represent the spacing between each winding.

Referring to FIG. 6 , R _l may be calculated as in Equation 2 in consideration of loop and proximity effects.

In Equation 2, R _S may represent surface resistance, R _P may represent ohm resistance per unit length according to a proximity effect, and R _O may represent a skin effect according to It can represent resistance in ohms per unit length. N may represent the number of windings, and the surface resistance R _S may be determined according to the characteristics of the wire.

In addition, in a loop antenna having a winding number of 1, the loop inductance of a circular loop antenna, the loop inductance of a rectangular loop antenna, and the loop internal reactance can be calculated as in Equation 3.

는 투자율(permeability)를 나타낼 수 있다. 또한, 수학식 3의 사격형 루프 안테나 인덕턴스 L_A1 ^sq에서 a는 한 변의 길이를 나타낼 수 있으며, b는 와이어의 반경을 나타낼 수 있고,

는 투자율(permeability)를 나타낼 수 있다. 수학식 3의 루프 내부 리액턴스 L_i에서 a는 루프의 반경을 나타낼 수 있으며, b는 와이어의 반경을 나타낼 수 있고,

는 각주파수를 나타낼 수 있다. 또한,

는 와이어의 전기전도도(conductivity)를 나타낼 수 있고,

는 자유공간에서의 투자율을 나타낼 수 있다.In the circular loop antenna inductance L _A1 ^circ of Equation 3, a may represent the radius of the loop, b may represent the radius of the wire,

may represent permeability. In addition, in the inductance L _A1 ^sq of the shooting loop antenna of Equation 3, a may represent the length of one side, b may represent the radius of the wire,

may represent permeability. In the loop internal reactance L _i of Equation 3, a may represent the radius of the loop, b may represent the radius of the wire,

may represent an angular frequency. Also,

can represent the electrical conductivity of the wire,

can represent the permeability in free space.

7 is a diagram showing an equivalent circuit of a ferrite rod antenna and a ferrite rod antenna.

Referring to FIG. 7, (a) of FIG. 7 is a diagram illustrating a ferrite rod antenna, and (b) of FIG. 7 is a diagram illustrating an equivalent circuit of the ferrite rod antenna.

A small magnetic wave loop antenna may improve radiation resistance and radiation efficiency by inserting a ferrite core having high magnetic permeability. In addition, a small magnetic field loop antenna may have a large magnetic flux due to a high magnetic permeability and may have a high induced voltage. Magnetic properties may be determined according to magnetic permeability and geometry. Also, magnetic flux can be expressed by effective relative permeability.

The ferrite rod antenna in which the ferrite core of FIG. 7 (a) is inserted may have an equivalent relationship with the circuit of FIG. 7 (b).

, 페라이트 코어 코일의 인덕턴스

및 큐 인자(Quality factor) Q는 수학식 4와 같이 산출될 수 있다.Referring to (b) of FIG. 7 , the RLC resonant frequency of the equivalent circuit can be adjusted by adjusting the capacitance of the capacitor. Resonant frequency in (b) of FIG.

, the inductance of the ferrite core coil

And the quality factor Q can be calculated as in Equation 4.

는 자유 공간에서의 투자율을 나타낼 수 있고,

는 페라이트 로드의 길이, 반경, 크기 및 고일의 위치에 따른 상대 투자율(relative permeability)을 나타낼 수 있고, N은 권선 수를 나타낼 수 있다. 또한, l_f는 페라이트 로드의 길이를 나타낼 수 있으며, rf는 페라이트 로드의 반경을 나타낼 수 있고,

는 half-power half-bandwidth의 주파수를 나타낼 수 있다.In Equation 4, C may represent the capacitance of the capacitor,

can represent the permeability in free space,

May represent relative permeability according to the length, radius, size and position of the ferrite rod, and N may represent the number of windings. In addition, l _f may represent the length of the ferrite rod, rf may represent the radius of the ferrite rod,

may represent the frequency of half-power half-bandwidth.

8 is a diagram showing radiation resistance according to a core of a loop antenna.

Referring to FIG. 8 , it can be confirmed that the loop antenna having a ferrite core has improved radiation resistance than that of the loop antenna having an air core, which is a free space.

Ferrite rod antennas can be used in vehicles, portable radios and aircraft, etc. due to their reduced size, have almost no reflection, and can achieve good range control with a gentle decrease in field strength. In addition, the ferrite rod antenna may have a high penetration rate, may require a low quiescent current according to a resonant frequency input step, and may be less sensitive to detuning than a high frequency antenna. However, since the ferrite rod antenna has a very high Q factor, it is possible to filter out part of the required signal modulation.

Hereinafter, a position alignment device according to an embodiment of the present invention in which the above-described ferrite core antenna can be used will be described.

9 is a block diagram of a position alignment device connected to a VA according to an embodiment of the present invention.

Referring to FIG. 9 , the alignment device 100 connected to the VA 11 according to an embodiment of the present invention may include a communication unit 110, a processing unit 120, and an LF transmission unit 130. In addition, when the VA has a rectangular structure, the LF transmitter 130 of the alignment device 100 has one antenna ANT a (151) in the center of the left side of the rectangle and one antenna ANT b (152) in the center of the right side of the rectangle. ), but since the structure of the VA can be changed according to design, it is not limited to a rectangle, and the location of the antenna can be changed accordingly. Here, the configuration of the alignment device 100 is not limited to a name and may be defined by a function. In addition, one component may perform a plurality of functions, and a plurality of components may perform one function.

The communication unit 110 may include a communication module capable of communicating with the magnetic field detection device 200 to be described later. Here, the communication module may include a communication module capable of performing WIFI communication, and may also include a communication module capable of performing 3G communication and 4G communication, but is not limited thereto. The communication unit 110 may search for a parking space where the GA is located through the communication module, and may establish a communication connection with the magnetic field detection device 200 connected to the corresponding GA for position alignment of the GA and VA, and the magnetic field detection device A magnetic field measurement may be received from (200). In addition, the communication unit 110 uses a Received Signal Strength Indicator (RSSI), Time of Flight (ToF), Time Difference of Flight (TDoF) arrival time (RSSI) to select a parking space. At least one value of Time of Arrival (ToA) and Time Difference of Arrival may be measured. Operations related to searching for and selecting a parking space will be described later in detail with reference to FIGS. 13 and 14 .

The processing unit 120 may verify that the antenna connected to the LF transmission unit 130 described below is normally driven, may drive the antenna, and use the magnetic field measurement value received by the communication unit 110 to compare with a pre-stored reference value. and positional difference information between GA and VA can be calculated based on the comparison result.

The LF transmission unit 130 may verify whether the connected antenna is normally driven according to the operation of the processing unit 120, and may drive the antenna.

Operations of the communication unit 110, the processing unit 120, and the LF transmission unit 130 according to an embodiment of the present invention will be described later in detail with reference to FIG.

Position alignment device 100 according to an embodiment of the present invention may include at least one processor and a memory storing at least one command for executing the above-described operation through the processor. Here, the processor may execute program commands stored in memory, and a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor in which the methods according to the present invention are performed. can mean a processor. The memory may include a volatile storage medium and/or a non-volatile storage medium, and may include a read only memory (ROM) and/or a random access memory (RAM).

10 is a block diagram of a magnetic field detection device connected to a GA according to an embodiment of the present invention.

Referring to FIG. 10 , the magnetic field detection device 200 connected to the GA 21 according to an embodiment of the present invention may include a communication unit 210, a processing unit 220, and an LF receiving unit 230. In addition, when the GA has a rectangular structure, the LF receiving unit 230 of the magnetic field detection device 200 has four antennas ANT 1 (251), ANT 2 (252), ANT 3 (253) and ANT 3 (253) at each corner of the rectangle. It may be connected to ANT 4 254, but since the structure of the GA can be changed according to design, it is not limited to a rectangle, and the position of the antenna can be changed accordingly. Here, the configuration of the magnetic field detection device 200 is not limited to a name and may be defined by a function. In addition, one component may perform a plurality of functions, and a plurality of components may perform one function.

The communication unit 210 may include a communication module capable of communicating with the alignment device 100 . Here, the communication module may include a communication module capable of performing WIFI communication, and may also include a communication module capable of performing 3G communication and 4G communication, but is not limited thereto. The communication unit 210 may transmit parking space information to the VA through the communication module. An operation of providing parking space information will be described later in detail with reference to FIGS. 13 and 14 .

In addition, the communication unit 210 may be connected to the alignment device 100 to align the positions of the GA and VA, and may transmit the magnetic field measurements measured by the processing unit 220 to the alignment device 100.

The processing unit 220 may measure a magnetic field measurement based on magnetic field information detected from the LF receiving unit 230 to be described later. Here, since the magnetic field information may exist for each antenna, the four antennas (ANT 1, ANT 2, ANT 3, and ANT 4) detect the magnetic fields of the two antennas (ANT a and ANT b) connected to the alignment device 100 , and accordingly, 8 pieces of magnetic field information may exist. In addition, the processing unit 220 may measure four magnetic field measurement values for each of the four antennas ANT 1 , ANT 2 , ANT 3 , and ANT 4 based on the eight magnetic field information. The measurement of the magnetic field will be described later in detail together with FIGS. 15 and 16 . Processing unit 220 may provide four magnetic field measurements to communication unit 210 .

The LF receiver 230 may be connected to four antennas (ANT 1, ANT 2, ANT 3, and ANT 4) located in GA, and two antennas of the alignment device 100 detected by the four antennas ( Information on magnetic fields output by ANT a and ANT b) may be obtained. The LF receiving unit 230 may provide information about the obtained magnetic field to the processing unit 220 .

The magnetic field detection device 200 according to an embodiment of the present invention may include at least one processor and a memory storing at least one command for executing the above-described operation through the processor. Here, the processor may execute program commands stored in memory, and a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor in which the methods according to the present invention are performed. can mean a processor. The memory may include a volatile storage medium and/or a non-volatile storage medium, and may include a read only memory (ROM) and/or a random access memory (RAM).

11 is a detailed block configuration diagram of a position alignment device according to an embodiment of the present invention.

Referring to FIG. 11 , the processing unit 120 of the alignment device 100 according to an embodiment of the present invention may include a calculation unit 121 and a serial interface 122, and the LF transmission unit 130 may include an antenna control unit 131, a serial interface 132, and an antenna driver 133. Also, the antenna driver 133 may be connected to at least one antenna. Here, configurations of the processing unit 120 and the LF transmission unit 130 are not limited to names and may be defined by function. In addition, one component may perform a plurality of functions, and a plurality of components may perform one function.

When connected to the magnetic field detection device 200 connected to a specific GA by the communication unit 110, the calculation unit 121 may provide LF data to the antenna control unit 131 to be described later so as to drive the antenna. However, before the LF data is provided by the calculation unit 121, it is possible to verify whether the antenna of the serial interface 122 to be described later is normally driven. Here, the LF data may include preamble, synchronization, and wake up ID.

In addition, the calculation unit 121 may calculate position difference information between the GA and VA using the four magnetic field measurement values received by the communication unit 110 . In other words, the calculation unit 121 may calculate position difference information based on a difference between each of the four magnetic field measurement values and a pre-stored reference value. Here, the pre-stored reference value may mean a magnetic field measurement value when the position between GA and VA is an ideal position, and the pre-stored reference value may include four values corresponding to each of the four received magnetic field measurement values.

The position difference information calculated by the calculation unit 121 may include the distance between GA and VA based on the x-axis, the distance based on the y-axis, and the distance based on the z-axis, and the distance based on the x-axis and the y-axis It may also include the standard separation distance and angle (degree of distortion). Here, the x-axis may indicate a horizontal direction relative to the receiving pad, the y-axis may indicate a vertical direction, and the z-axis may indicate a direction perpendicular to the receiving pad. Also, the angle (degree of distortion) may represent the degree of distortion between the horizontal direction of the receiving pad and the horizontal direction of the transmitting pad. However, it is not limited thereto, and when a specific criterion is set, it may be defined according to a specific criterion.

The calculation unit 121 may provide the calculated location difference information to the user, and the user may determine the parking location of the vehicle so that the locations between the GA and VA are aligned with reference to the location difference information. In addition, the calculation unit 121 may generate an image or video based on the calculated position difference information and provide it to the user, but the method of providing the position difference information to the user is not limited thereto.

The serial interface 122 of the processing unit 120 may verify whether at least one antenna is normally driven before providing LF data for driving the antenna of the calculating unit 121 described above. The serial interface 122 of the processor 120 may perform serial peripheral interface (SPI) communication with the serial interface 132 of the LF transmitter 130 for verification. In other words, the serial interface 122 of the processor 120 may transmit SPI data to the serial interface 132 of the LF transmitter 130, and receive the SPI data from the serial interface 132 of the LF transmitter 130 and it is possible to verify whether the antenna is normally driven based on the received SPI data. When the antenna is normally driven, LF data for driving the antenna may be provided by the calculation unit 121, but when the antenna is not normally driven, the serial interface 122 of the processing unit 120 provides feedback. Internal diagnostics can be performed through In other words, the SPI data may be an enable signal for verifying whether the antenna is normally driven.

When receiving LF data from the calculation unit 121, the antenna control unit 131 may control driving of at least one antenna through the antenna driver 133. In addition, the antenna control unit 131 may control the driving of the antenna through the antenna driver 133 to verify whether the antenna is normally driven according to the request of the serial interface 132 of the LF transmission unit 130.

When the serial interface 132 of the LF transmission unit 130 receives SPI data from the serial interface 122 of the processing unit 120, the antenna control unit 131 and/or the antenna driver 133 determine whether the antenna is normally driven. can be verified through In addition, the serial interface 132 of the LF transmission unit 130 may transmit the verification result as SPI data to the serial interface 122 of the processing unit 120.

The antenna driver 133 may be connected to at least one antenna, and may drive at least one antenna according to a signal from the antenna controller 131 . Here, at least one antenna may be a ferrite rod antenna outputting a magnetic field having a low frequency band between 100 kHz and 150 kHz, and may have a radius of about 5 m, but is not limited thereto. In addition, at least one antenna may output a unique magnetic field.

12 is a diagram showing state conversion of the alignment device according to an embodiment of the present invention.

Referring to FIG. 12 , the position alignment device 100 according to an embodiment of the present invention may basically maintain a standby state. When the position alignment device 100 in a standby state performs a connection with the magnetic field detection device 200, it is determined that an event (LF event) to output a magnetic field using an antenna has occurred, and the serial processing unit 120 internally Serial (SPI) communication between the interface 122 and the serial interface 132 of the LF transmitter 130 may be performed. When an error occurs in SPI communication, the alignment device 100 may return to a standby state. However, the position alignment device 100 may not return to a standby state when a problem is solved through internal diagnosis and/or feedback and SPI communication is completed. When the SPI communication is completed, the alignment device 100 may be in an LF output state for outputting a low-frequency magnetic field through an antenna, and may return to a standby state when a magnetic field measurement value is received from the magnetic field detection device 200. there is. However, the event of returning to the standby state from the LF output state is not limited thereto, and may be defined according to time or number of repetitions.

13 is a diagram illustrating a method for a vehicle to search for a parking space according to an embodiment of the present invention.

Referring to FIG. 13 , a search for a parking space for a vehicle according to an embodiment of the present invention may be performed by the communication unit 110 of the alignment device 100 . However, when the VA includes another communication module, it may be performed by another communication module.

As described above, the communication unit 110 of the alignment device 100 may include a communication module capable of performing at least one of WIFI, 3G and 4G communication, but in this specification, for convenience of explanation, it is limited to WIFI. would.

The location alignment device 100 may search for a parking space at the current location of the vehicle through WIFI communication, and may select one parking space from among at least one searched parking space. A description of the selection of a parking space will be described later along with FIG. 14 . Here, a method for the position alignment device 100 to search for a parking space may be initiated by a driver or may be automatically searched, but is not limited thereto. Also, the parking space search can be performed within a range of 100 m.

Each parking space may include a GA, and each GA may include one magnetic field detection device 200 . Accordingly, each parking space may have a WIFI area capable of providing parking space information through the communication unit 210 of the magnetic field detection device 200. Here, the WIFI area may be generated by the communication unit 210 of the magnetic field detection device 200, but may be performed by another communication module when the GA includes another communication module.

The communication unit 210 or other communication module of the magnetic field detection device 200 may provide the communication unit 210 or other communication module of the alignment device 100 whether or not a vehicle currently exists in the parking space, and When a vehicle exists, communication is not performed and communication may be performed only when a vehicle does not exist. However, a method of providing whether a vehicle exists is not limited thereto.

14 is a diagram illustrating a method for a vehicle to select a parking space according to an embodiment of the present invention.

According to an embodiment of the present invention, when a vehicle searches for a plurality of parking spaces, a method for selecting one parking space includes a Received Signal Strength Indicator (RSSI), Time of Flight (ToF) , time difference of flight (TDoF), time of arrival (ToA), and time difference of arrival (Time Difference of Arrival). Here, RSSI may mean a value obtained by measuring power present in a received radio signal, ToF may mean a signal propagation time, and TDoF may mean a difference in signal propagation time. In addition, ToA may mean a time at which a signal arrives, and TDoA may mean a time difference at which a signal arrives.

Hereinafter, it is assumed that RSSI is used to select one parking space, and even when ToF and TdoF are used, one parking space can be selected similarly to the case of using RSSI.

Referring to FIG. 14 , when searching for a parking space, the vehicle may receive a result indicating that there are two parking spaces (GA 2 and GA 3 ). In this case, the communication unit 110 of the positioning alignment device 100 may measure RSSI for the two signals for the two parking spaces, and may select a parking space transmitting a signal having a higher RSSI. In other words, since RSSI 2 for the signal of GA 2 is greater than RSSI 3 for the signal of GA 3, the position aligning apparatus 100 may determine that GA 2 is closer to the vehicle and select GA 2. When there are two or more parking spaces, the position aligning apparatus 100 may select a GA having the largest RSSI.

Thereafter, the position alignment device 100 may connect to the magnetic field detection device 200 connected to GA 2 to drive a low-frequency antenna, receive a magnetic field measurement from the magnetic field detection device 200, and obtain position difference information between the GA and VA. can be printed out.

15 is a diagram showing a magnetic field signal between a GA and a VA at an ideal position according to an embodiment of the present invention.

Referring to FIG. 15, when GA and VA are in ideal positions, four antennas (ANT 1, ANT 2, ANT 3, and ANT 4) connected to the magnetic field detection device 200 and two antennas connected to the position alignment device 100 The magnetic field between the antennas ANT a and ANT b is described as follows.

The antenna ANT 1 (251) of the magnetic field detection device 200 can detect Flux 1 based on the magnetic field output by the antenna ANT a (151) and the magnetic field output by the ANT b (152) of the alignment device 100 there is.

The antenna ANT 2 (252) of the magnetic field detection device 200 can detect Flux 2 based on the magnetic field output by the antenna ANT a (151) and the magnetic field output by the ANT b (152) of the alignment device 100 there is.

Similarly, the antenna ANT 3 (253) of the magnetic field detection device 200 can detect Flux 3, and the ANT 4s (254) can detect Flux 4.

In other words, Flux 1 to 4 can be calculated as in Equation 5.

Since the position alignment device 100 according to an embodiment of the present invention can calculate position difference information between GA and VA based on a reference value that is a magnetic field measurement value of an ideal position stored in advance, the above-described Flux 1 to 4 are pre-stored It can be used as a reference value.

16 is a diagram showing a magnetic field signal between a GA and a VA at a misaligned position according to an embodiment of the present invention.

Referring to FIG. 16, when GA and VA are misaligned, four antennas (ANT 1, ANT 2, ANT 3, and ANT 4) connected to the magnetic field detection device 200 and 2 antennas connected to the position alignment device 100 The magnetic field between the two antennas ANT a and ANT b is described as follows.

The antenna ANT 1 (251) of the magnetic field detection device 200 detects Flux 1' based on the magnetic field output by the antenna ANT a (151) and the magnetic field output by the ANT b (152) of the position alignment device 100. can

The antenna ANT 2 (252) of the magnetic field detection device 200 detects Flux 2' based on the magnetic field output by the antenna ANT a (151) and the magnetic field output by the ANT b (152) of the position alignment device 100. can

Similarly, the antenna ANT 3 (253) of the magnetic field detection device 200 can detect Flux 3', and the ANT 4s (254) can detect Flux 4'.

In other words, Flux 1' to 4' can be calculated as in Equation 6.

The magnetic field detection device 200 according to an embodiment of the present invention may transmit the above-described flux 1' to 4' values according to the misaligned position to the alignment device 100, and the alignment device 100 may transmit the flux Positional difference information may be calculated by comparing the values 1' to 4' and Flux 1 to 4 values.

In other words, the arithmetic unit 121 of the position alignment device 100 may calculate position difference information by performing a specific algorithm based on Flux 1' to 4' values and Flux 1 to 4 values, and Flux 1 and Flux 1 Positional difference information may be calculated based on the difference between 'the difference between Flux 2 and Flux 2', the difference between Flux 3 and Flux 3', and the difference between Flux 4 and Flux 4'.

In addition, the position alignment device 100 according to an embodiment of the present invention may be set based on a position separated by a predetermined distance between the GA and VA, and calculate position difference information based on the reference value and the current magnetic field measurement value. may be

17 is a flowchart illustrating a location alignment method according to an embodiment of the present invention.

Referring to FIG. 17 , in the alignment method according to an embodiment of the present invention, first, the alignment device 100 may search for magnetic field detection devices connected to at least one GA, and select a specific one of the searched magnetic field detection devices. It can be connected with (S1710). Here, the position alignment device 100 is any one magnetic field detection device based on at least one of a received electric field strength indicator (RSSI), a time of flight (ToF), and a time difference (TdoF) of at least one magnetic field detection device retrieved. You can connect by selecting Thereafter, the alignment device 100 may verify whether the antenna is normally driven through SPI communication (S1720), and when the antenna is normally driven, the alignment device 100 may output a magnetic field by driving the antenna. Yes (S1730). Here, the antenna may be a low frequency antenna (LF antenna). In addition, the position alignment device 100 may receive the magnetic field measurement from the magnetic field detection device 200 (S1740), and perform a position estimation algorithm based on the received magnetic field measurement value and a pre-stored reference value (S1750), GA And position difference information between the VA may be calculated and output (S1760). Here, the magnetic field measurement values may include four magnetic field measurement values calculated based on magnetic field information detected by four antennas connected to the magnetic field detection device 200 .

The operation of the method according to the embodiment of the present invention can be implemented as a computer readable program or code on a computer readable recording medium. A computer-readable recording medium includes all types of recording devices in which data that can be read by a computer system is stored. In addition, computer-readable recording media may be distributed to computer systems connected through a network to store and execute computer-readable programs or codes in a distributed manner.

In addition, the computer-readable recording medium may include hardware devices specially configured to store and execute program instructions, such as ROM, RAM, and flash memory. The program command may include high-level language codes that can be executed by a computer using an interpreter or the like as well as machine code generated by a compiler.

Although some aspects of the present invention have been described in the context of an apparatus, it may also represent a description according to a corresponding method, where a block or apparatus corresponds to a method step or feature of a method step. Similarly, aspects described in the context of a method may also be represented by a corresponding block or item or a corresponding feature of a device. Some or all of the method steps may be performed by (or using) a hardware device such as, for example, a microprocessor, programmable computer, or electronic circuitry. In some embodiments, one or more of the most important method steps may be performed by such an apparatus.

In embodiments, a programmable logic device (eg, a field programmable gate array) may be used to perform some or all of the functions of the methods described herein. In embodiments, a field programmable gate array may operate in conjunction with a microprocessor to perform one of the methods described herein. Generally, methods are preferably performed by some hardware device.

Although the above has been described with reference to preferred embodiments of the present invention, those skilled in the art can variously modify and change the present invention without departing from the spirit and scope of the present invention described in the claims below. You will understand that you can.

10: electric car 11: receiving pad
12: battery 20: charging station
21: transmission pad 30: power grid
100: position alignment device 200: magnetic field detection device

Claims (16)

A position alignment method performed by a position alignment device including an antenna positioned at a receiving pad for position alignment between a transmitting pad and a receiving pad performing wireless power transmission, the method comprising:
connecting to a magnetic field detection device including an antenna located on the transmission pad using wireless communication;
outputting a magnetic field using an antenna positioned on the receiving pad;
receiving a magnetic field measurement from the magnetic field detection device; and
Comparing the magnetic field measurement values and pre-stored reference values to obtain position difference information between the transmitting pad and the receiving pad,
The antenna located on the receiving pad includes two antennas, each located in a first zone and a second zone divided into left and right halves of the receiving pad,
The antennas located on the transmission pad include four antennas located in the upper left area, the upper right area, the lower left area, and the lower right area of the transmission pad,
The upper left region, the upper right region, the lower left region, and the lower right region have the same size;
The magnetic field measurements are
A first of the four antennas located on the transmitting pad based on a magnetic field generated from a first of the two antennas located on the receiving pad and a second antenna of the two antennas located on the receiving pad a measured value of the first magnetic flux detected by the antenna;
Of the four antennas located on the transmission pad based on the magnetic field generated from the first antenna among the two antennas located on the receiving pad and the second antenna among the two antennas located on the receiving pad a measured value of the second magnetic flux detected by the second antenna;
Among the four antennas located on the transmission pad based on the magnetic field generated from the first antenna among the two antennas located on the receiving pad and the second antenna among the two antennas located on the receiving pad a measured value of the third magnetic flux detected by the third antenna;
Among the four antennas located on the transmission pad based on the magnetic field generated from the first antenna among the two antennas located on the receiving pad and the second antenna among the two antennas located on the receiving pad a measured value of the fourth magnetic flux detected by the fourth antenna;
Including, position alignment method. The method of claim 1,
The step of connecting with a magnetic field detection device including an antenna located on the transmission pad using the wireless communication,
Searching for at least one magnetic field detection device within a predetermined radius using the wireless communication; and
Among the at least one magnetic field detection device, a received signal strength indicator (RSSI), time of flight (ToF), time difference of flight (TDoF), time of arrival (Time of Arrival, A position alignment method comprising selecting and connecting any one magnetic field detection device based on at least one of ToA) and time difference of arrival. The method of claim 1,
The step of outputting a magnetic field using an antenna located on the receiving pad,
verifying whether an antenna positioned on the receiving pad is normally driven; and
and outputting a unique magnetic field by driving the antenna when the antenna is normally driven. The method of claim 1,
An antenna located on the receiving pad and an antenna located on the transmitting pad,
A position alignment method, which is a ferrite rod antenna using a low frequency band. The method of claim 1,
The position difference information,
A separation distance on the x-axis representing the horizontal direction with respect to the receiving pad, a separation distance on the y-axis representing the vertical direction, a separation distance on the z-axis representing a direction perpendicular to the receiving pad, and the horizontal direction of the receiving pad and the horizontal direction of the transmitting pad A position alignment method comprising at least one of the degree of distortion between directions. A position alignment device for position alignment between a transmission pad and a reception pad performing wireless power transmission,
an antenna located on the receiving pad;
at least one processor; and
A memory in which at least one instruction executed by the at least one processor is stored;
The at least one command,
It is executed to connect with a magnetic field detection device including an antenna located in the transmission pad using wireless communication,
It is executed to output a magnetic field using an antenna located on the receiving pad,
be configured to receive magnetic field measurements from the magnetic field detection device;
Comparing the magnetic field measurement values with pre-stored reference values to obtain position difference information between the transmitting pad and the receiving pad;
The antenna located on the receiving pad includes two antennas, each located in a first zone and a second zone divided into left and right halves of the receiving pad,
The antennas located on the transmission pad include four antennas located in the upper left area, the upper right area, the lower left area, and the lower right area of the transmission pad,
the upper left region, the upper right region, the lower left region, and the lower right region have the same size;
The magnetic field measurements are
A first of the four antennas located on the transmitting pad based on a magnetic field generated from a first of the two antennas located on the receiving pad and a second antenna of the two antennas located on the receiving pad a measured value of the first magnetic flux detected by the antenna;
Of the four antennas located on the transmission pad based on the magnetic field generated from the first antenna among the two antennas located on the receiving pad and the second antenna among the two antennas located on the receiving pad a measured value of the second magnetic flux detected by the second antenna;
Among the four antennas located on the transmission pad based on the magnetic field generated from the first antenna among the two antennas located on the receiving pad and the second antenna among the two antennas located on the receiving pad a measured value of the third magnetic flux detected by the third antenna;
Among the four antennas located on the transmission pad based on the magnetic field generated from the first antenna among the two antennas located on the receiving pad and the second antenna among the two antennas located on the receiving pad a measured value of the fourth magnetic flux detected by the fourth antenna;
Including, position alignment device. The method of claim 6,
The at least one command,
Searching for at least one magnetic field detection device within a certain radius using the wireless communication,
Among the at least one magnetic field detection device, a received signal strength indicator (RSSI), a time of flight (ToF), a time difference of flight (TDoF), a time of arrival (time of arrival, A position alignment device that is executed to select and connect which one magnetic field detection device based on at least one of a ToA and a Time Difference of Arrival. The method of claim 6,
The at least one command,
It is executed to verify whether the antenna located on the receiving pad is normally driven,
When the antenna located on the receiving pad is normally driven, the alignment device is executed to output a unique magnetic field by driving the antenna located on the receiving pad. The method of claim 6,
An antenna located on the receiving pad and an antenna located on the transmitting pad,
A position alignment device that is a ferrite rod antenna using a low frequency band. The method of claim 6,
The position difference information,
A separation distance on the x-axis representing the horizontal direction with respect to the receiving pad, a separation distance on the y-axis representing the vertical direction, a separation distance on the z-axis representing a direction perpendicular to the receiving pad, and the horizontal direction of the receiving pad and the horizontal direction of the transmitting pad Position alignment device comprising at least one of the degree of misalignment between directions. delete delete delete delete delete delete

Images