Distance estimation method for precise positioning of wireless power transfer for electric vehicles and distance estimation apparatus using the same

Abstract

Methods and apparatuses for estimating a distance using LF signals when performing precise positioning for electric vehicle (EV) wireless power transfer (WPT) are disclosed. The method includes the steps of: defining a position of a first transmitter of an EV to a point on a first straight line extending towards a center of a primary device of a power supply device; defining a position of a second transmitter of the EV to a point on a second straight line extending towards the center of the primary device; compensating for a distance between the first transmitter and the second transmitter on the first straight line or the second straight line based on a time difference of arrival of LF signals of the first transmitter and the second transmitter to the primary device; and calculating the position of the first transmitter and the position of the second transmitter such that a first distance from a starting point on the first straight line to the first transmitter and a second distance from a starting point on the second straight line to the second transmitter become equal by the compensating step.

Description

Technical Field

[0001] This disclosure relates to a method for distance estimation using low-frequency (LF) signals, and more specifically, to a method and apparatus for position estimation using LF signals in precise positioning for wireless power transmission (WPT) of electric vehicles (EVs). Background Technology

[0002] In magnetic field-based (MF) wireless power transfer (WPT) systems, communication between the Electric Vehicle Communication Controller (EVCC) and the Supply Equipment Communication Controller (SECC) is typically established using the SECC Discovery Protocol (SDP). Signals or messages are transmitted and received via point-to-point (P2PS) signaling using low-frequency (LF) signals, low-power excitations (LPEs), optical markers such as fast-response (QR) codes, etc., without the need for pairing and positioning devices (PPDs).

[0003] In a vehicle-to-grid (V2G) communication session for wireless power transmission, messages between the EVCC and SECC follow a process such as precise positioning setup, precise positioning, and pairing in the described order. Here, precise positioning, or positioning, involves continuously providing alignment information as the EV approaches the supply unit to support the EV's approach within alignment tolerances. Pairing is used to ensure that both the EVCC and SECC can uniquely identify the primary unit located within the EV.

[0004] Simultaneously, the precise positioning request message in the SDP message or precise positioning message includes compatibility information and the Electric Vehicle Identifier (IMD). That is, the precise positioning request message typically includes information about multiple compatible SECCs, while the precise positioning response message includes only information about a specific SECC. In this case, the EV can align the secondary device on the primary device obtained through information shared with the specific SECC during the precise positioning process.

[0005] However, the precise positioning process cannot be performed when the EVCC cannot specify the position of the secondary device's center point or second reference point relative to the primary device's center point or first reference point using data obtained from the SECC connected via a wireless local area network (WLAN).

[0006] Furthermore, when the data transmission rate is low due to the low data transmission capacity of the wireless LAN, it may be difficult to perform accurate positioning normally within a certain time period because the center point of the secondary device cannot be specified in real time.

[0007] Furthermore, because the antenna arrangement of the primary unit is determined by the primary unit manufacturer, primary units with various antenna arrangements may exist. In such an environment, the EV's vehicle controller or EVCC may not be able to obtain information about the antenna arrangement of the primary unit in advance or in real time. In this case, aligning the EV's secondary unit with the primary unit of the EV supply equipment using existing LF-based precise positioning methods may not be easy, and in many cases, practically impossible.

[0008] As mentioned above, there is a need for a robust precision positioning method that addresses the various problems that may arise during the precision positioning process for EVs in different EV-WPT environments. Summary of the Invention

[0009] This disclosure provides a distance estimation method and apparatus for precise positioning, which can effectively align the center of the secondary device of the EV device with the center of the primary device of the supply device using only information about the receiver of the primary device for precise positioning of the EV wireless power transmission (WPT), information about the transmitter of the secondary device, and the LF signal.

[0010] Another object of this disclosure is to provide a distance estimation method and apparatus for precise positioning of EV-WPT, which can effectively align the primary and secondary devices using LF signals without requiring information about the antenna arrangement in the primary device.

[0011] Another object of this disclosure is to provide a distance estimation method and apparatus for precise positioning. Even when information about the location of the transmitter or receiver used for precise positioning cannot be obtained based on data shared via data communication, the distance estimation method and apparatus are able to perform precise positioning based on LF signals based on information about the transmitter and receiver shared between the EVCC and SECC via a wireless LAN.

[0012] According to one aspect of this disclosure, a position estimation method for precise positioning to solve the above-mentioned technical problems is executed by an EV or EV device having an EV communication controller (EVCC) and a secondary device. The EV communication controller (EVCC) is connected to a supply device communication controller (SECC) of a supply device via a network. The secondary device is equipped with at least a first transmitter and a second transmitter, and may include: defining the position of the first transmitter as a point on a first straight line pointing to the center of a primary device of the supply device; defining the position of the second transmitter as a point on a second straight line pointing to the center of the primary device; compensating for the gap between the first transmitter and the second transmitter on the first straight line or the second straight line based on the time difference of the LF signals arriving at the first transmitter and the second transmitter of the primary device; and calculating the positions of the first transmitter and the second transmitter by means of the compensation, such that a first distance from a first starting point on the first straight line to the first transmitter becomes equal to a second distance from a second starting point on the second straight line to the second transmitter.

[0013] In the compensation, the first starting point on the first straight line can be moved a distance on the first straight line by multiplying the time difference by the speed of light, wherein the first starting point is determined based on the time difference between the signal reception time of the first LF signal of the first transmitter at the first receiver and the second receiver of the primary device when the position of the first transmitter is defined.

[0014] The second receiver can be closer to the first transmitter and the second transmitter than the first receiver.

[0015] In the compensation, the second starting point on the second straight line can be moved a distance on the second straight line by multiplying the time difference by the speed of light, wherein the second starting point is determined based on the time difference between the signal reception time of the second LF signal of the second transmitter at the first and second receivers of the primary device when the position of the second transmitter is defined.

[0016] The first receiver can be closer to the first transmitter and the second transmitter than the second receiver.

[0017] The position estimation method may further include: determining the position on the first line and the position on the second line, such that the gap between the first line and the second line is equal to the distance between the first transmitter and the second transmitter, as the position of the first transmitter and the position of the second transmitter, respectively.

[0018] The position estimation method may also include: determining the distance and direction of the center of the secondary device relative to the center of the primary device, based on the positions of the first transmitter and the second transmitter.

[0019] Defining the location of the first transmitter may include: calculating a first time difference between the reception times of the first receiver and the second receiver for the first LF signal; generating a first circle with the second receiver as the center and a radius equal to half the distance obtained by multiplying the first time difference by the speed of light; generating a first tangent line that passes through the first receiver and is tangent to the first circle; generating a first straight line that passes through the first receiver and is orthogonal to the first tangent line; the location of the first transmitter is on the first straight line starting from a second point where the first tangent line intersects the first straight line.

[0020] Defining the location of the second transmitter may include: calculating a second time difference between the reception times of the second LF signal at the first receiver and the second receiver; generating a second circle with the second receiver as the center and a radius equal to half the distance obtained by multiplying the second time difference by the speed of light; generating a second tangent line that passes through the first receiver and is tangent to the second circle; generating a second straight line that passes through the first receiver and is orthogonal to the second tangent line; and the location of the second transmitter is on the second straight line starting from a fourth point where the second tangent line intersects the second straight line.

[0021] According to another aspect of this disclosure, a position estimation method for precise positioning to solve the above-mentioned technical problems is executed by an EV or EV device having an EVCC connected to a supply device's SECC via a network and a secondary device equipped with at least a first transmitter and a second transmitter. This method may include: transmitting a first low-frequency (LF) signal via the first transmitter to a first receiver and a second receiver of a primary device of the supply device; defining the position of the first transmitter on a first straight line extending radially from a reference point of the supply device based on a response received from the SECC in relation to the first LF signal; defining the position of the second transmitter on a second straight line extending radially from the reference point of the supply device based on transmitting a second LF signal via the second transmitter to the first and second receivers; calculating the time difference between the arrival of the first LF signal and the second LF signal at receivers closer to the first and second transmitters; determining a first starting point a obtained by moving the first starting point of the first straight line toward the first transmitter along the first straight line in response to the transmitter being the first transmitter; and determining the position of the first transmitter on the first straight line as a point at the same distance from the first starting point a as the distance between the second starting point of the second straight line and the second transmitter.

[0022] The position estimation method may further include: in response to the transmitter being a second transmitter closer to the primary device, determining a second starting point a obtained by moving the second starting point of the second straight line toward the second transmitter by a time difference; and determining the position of the second transmitter located on the second straight line as a point at a distance from the second starting point a that is the same as the distance between the first starting point of the first straight line and the first transmitter.

[0023] Defining the location of the first transmitter may include: calculating a first time difference between the reception times of the first LF signal at the first receiver and the second receiver; generating a first circle with the second receiver as the center and having a radius of half the distance obtained by multiplying the first time difference by the speed of light; generating a first tangent line that passes through the first receiver and is tangent to the first circle; generating a first normal line that passes through the first receiver and is orthogonal to the first tangent line; the location of the first transmitter is on the first normal line, with the second point where the first tangent line intersects the first normal line as the starting point.

[0024] Defining the location of the second transmitter may include: calculating a second time difference between the reception time at the first receiver and the reception time at the second receiver for the second LF signal; generating a second circle with the second receiver as the center and a radius equal to half the distance obtained by multiplying the second time difference by the speed of light; generating a second tangent line that passes through the first receiver and is tangent to the second circle; and generating a second normal line that passes through the first receiver and is orthogonal to the second tangent line, wherein the location of the second transmitter is on the second normal line originating from a fourth point where the second tangent line and the second normal line intersect.

[0025] The position estimation method may further include: determining the position on the first normal and the position on the second normal such that the gap between the first normal and the second normal is equal to the distance between the first transmitter and the second transmitter, respectively, as the position of the first transmitter and the position of the second transmitter.

[0026] The position estimation method may also include: determining the distance and direction of the center of the secondary device relative to the center of the primary device, based on the positions of the first transmitter and the second transmitter.

[0027] According to another aspect of this disclosure, a position estimation device for precise positioning to solve the above-mentioned technical problems may include: a processor; and a memory storing instructions executable by the processor, wherein, when executed by the processor, the instructions cause the processor to: define the position of the first transmitter as a point on a first straight line pointing to the center of the primary device of the supply device; define the position of the second transmitter as a point on a second straight line pointing to the center of the primary device; compensate for the gap between the first transmitter and the second transmitter on the first straight line or the second straight line based on the time difference of the LF signals arriving at the first transmitter and the second transmitter of the primary device; and, by means of the compensation, calculate the positions of the first transmitter and the second transmitter such that a first distance from a first starting point on the first straight line to the first transmitter becomes equal to a second distance from a second starting point on the second straight line to the second transmitter.

[0028] This instruction causes the processor to perform the following: in the compensation, to move along the first starting point on the first straight line, which is determined based on the time difference between the signal reception times of the first LF signal of the first transmitter at the first receiver and the second receiver of the primary device when defining the position of the first transmitter, by multiplying the time difference by the speed of light.

[0029] This instruction can cause the processor to perform the following: in the compensation, make the second starting point on the second straight line, which is determined based on the time difference between the signal reception times of the second LF signal of the second transmitter at the first receiver and the second receiver of the primary device when defining the position of the second transmitter, move along the second straight line by a distance obtained by multiplying the time difference by the speed of light.

[0030] The instruction enables the processor to: when defining the location of the first transmitter, calculate a first time difference between the reception times of the first receiver and the second receiver for the first LF signal; generate a first circle with the second receiver as the center and a radius equal to half the distance obtained by multiplying the first time difference by the speed of light; generate a first tangent line passing through the first receiver and tangent to the first circle; generate a first straight line passing through the first receiver and orthogonal to the first tangent line; the location of the first transmitter is on the first straight line originating from a second point where the first tangent line intersects the first straight line.

[0031] The instruction enables the processor to: calculate a second time difference between the reception times of the second LF signal at the first receiver and the second receiver when defining the location of the second transmitter; generate a second circle with the second receiver as the center and a radius equal to half the distance obtained by multiplying the second time difference by the speed of light; generate a second tangent line passing through the first receiver and tangent to the second circle; generate a second straight line passing through the first receiver and orthogonal to the second tangent line; the location of the second transmitter is on the second straight line starting from a fourth point where the second tangent line intersects the second straight line.

[0032] Beneficial effects

[0033] According to this disclosure, in the process of precise positioning of WPT between EV and the power grid, the distance and direction of a predetermined reference point on the secondary device from a predetermined reference point on the primary device can be effectively estimated based on antenna information of the primary and secondary devices and point-to-point (P2PS) signaling based on LF signals, without sharing location information via WLAN.

[0034] Furthermore, according to this disclosure, in environments where antenna position information cannot be delivered or shared via data communication, the EV can effectively calculate the distance and direction required for precise positioning. In this case, the EV can perform precise positioning by controlling its movement while periodically calculating the distance and direction between the second center point of the secondary device and the first center point of the primary device.

[0035] Furthermore, in an EV configured to perform a precise positioning process by delivering or sharing antenna position information via data communication, the following situation may occur: due to an error in at least one of the hardware and software used for precise positioning, the relative position information of the primary and secondary devices cannot be shared, thus preventing the precise positioning process from being performed correctly. According to this disclosure, if only the antenna information of the primary device is shared in the above-described situation, the position of each antenna can be specified using an LF signal based on the previously known antenna information of the primary device and the antenna information of the second device, and thus errors in the precise positioning process can be effectively handled.

[0036] Furthermore, according to this disclosure, during the WPT precise positioning process of an EV, the vehicle's entry direction can be determined in an early stage based on the antenna types of the primary device and the secondary device, and the entry direction or posture of the EV entering the parking area or charging area can be guided accordingly. Therefore, the efficiency of precise positioning can be improved, and user convenience can be enhanced. Attached Figure Description

[0037] Figure 1This is a diagram illustrating the overall configuration of a magnetic field (MF) based WPT system to which a distance estimation method for precise WPT positioning according to an exemplary embodiment of this disclosure can be applied.

[0038] Figure 2 It is used to describe in Figure 1 A diagram illustrating the wireless power flow and communication interface between the supply device (SD) and the EV device (EVD) that can be used in the WPT system.

[0039] Figure 3 This is a diagram illustrating an application environment for a distance estimation method for precise WPT positioning according to an exemplary embodiment of the present disclosure.

[0040] Figures 4A to 4D are diagrams illustrating the arrangement of antennas in the primary device and the secondary device to which the distance estimation method for WPT precise positioning according to an exemplary embodiment of the present disclosure can be applied.

[0041] Figures 5A to 5D are diagrams illustrating the processes performed in a primary device and a second device to which the distance estimation method for WPT precise positioning according to an exemplary embodiment of the present disclosure can be applied.

[0042] Figure 6 and Figure 7 This is a diagram illustrating a state where the distance estimation method for WPT precise positioning according to an exemplary embodiment of the present disclosure can be applied to a primary and secondary device misalignment.

[0043] Figure 8 This shows the application to Figure 6 and Figure 7 The flowchart shows the distance estimation method for WPT accurate positioning in the misaligned state.

[0044] Figures 9 to 17 It is used to describe in more detail Figure 8 An exemplary diagram illustrating the distance estimation method for WPT precise positioning.

[0045] Figure 18 This is a schematic block diagram illustrating the main components of a distance estimation device for precise WPT positioning according to another exemplary embodiment of the present disclosure. Detailed Implementation

[0046] Because this disclosure can be modified in various ways and has multiple forms, specific exemplary embodiments will be shown in the accompanying drawings and described in detail in the specific embodiments. However, it should be understood that this disclosure is not intended to be limited to the specific exemplary embodiments; on the contrary, this disclosure will cover all modifications and substitutions that fall within the spirit and scope of this disclosure.

[0047] Relational terms such as first, second, etc., may be used to describe various elements, but elements should not be limited by the terms. These terms are used only to distinguish one element from another. For example, without departing from the scope of this disclosure, a first component may be named a second component, and a second component may similarly be named a first component. The term "and / or" refers to any one or a combination of a plurality of related and described items.

[0048] When it is mentioned that a component is "coupled" or "connected" to another component, it should be understood that the component is directly "coupled" or "connected" to the other component, or that another component may be arranged in between. Conversely, when it is mentioned that a component is "directly coupled" or "directly connected" to another component, it should be understood that the other component is not arranged in between.

[0049] The terminology used in this disclosure is for the purpose of describing specific exemplary embodiments only and is not intended to limit the disclosure. Singular expressions include plural expressions unless the context clearly specifies otherwise. In this disclosure, terms such as “comprising” or “having” are intended to specify the presence of the features, quantities, steps, operations, components, parts, or combinations thereof described in this specification; however, it should be understood that such terms do not exclude the presence or addition of one or more features, quantities, steps, operations, components, parts, or combinations thereof.

[0050] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. Terms that are commonly used and already in dictionaries should be interpreted as having the meaning appropriate to the context in this art. In this specification, unless explicitly defined, terms are not necessarily to be interpreted as having a formal meaning.

[0051] The additional terms used in this disclosure are defined as follows.

[0052] "Electric vehicle (EV)" can refer to a motor vehicle as defined in Section 49 of Federal Regulations (CFR) 523.3, etc. EVs are designed for use on highways and are powered by electricity supplied from onboard energy storage devices, such as batteries that can be recharged from external power sources. Power sources can include residential, public power services, or generators that use onboard fuel. EVs may be referred to as electric vehicles, electric road vehicles (ERVs), plug-in vehicles (PVs), plug-in electric vehicles (xEVs), etc., and xEVs may be referred to or classified as plug-in fully electric vehicles or battery electric vehicles (BEVs), plug-in electric vehicles (PEVs), hybrid electric vehicles (HEVs), hybrid plug-in electric vehicles (HPEVs), plug-in hybrid electric vehicles (PHEVs), etc.

[0053] "Plug-in electric vehicle (PEV)" can refer to an EV that charges its main battery by connecting to the power grid.

[0054] "Wireless power charging system (WCS)" can refer to a system used for wireless power transfer, alignment and communication between ground components (GA) and vehicle components (VA).

[0055] "Wireless power transfer (WPT)" can refer to the technology of transferring electricity from power sources such as utilities, power grids, energy storage devices, and fuel cell generators, and receiving electricity from EVs via contactless devices such as electromagnetic induction and resonance.

[0056] "Public services": This refers to the supply of electricity and may include a set of systems such as Customer Information Systems (CIS), Advanced Metering Infrastructure (AMI), rate and revenue systems, etc. Utilities can supply energy to EVs based on rate tables and discrete events. Additionally, utilities can provide information on EV certification, gaps in electricity consumption measurement, and rates.

[0057] "Smart charging": A system in which the EVSE and / or PEV communicate with the power grid to optimize the charging or discharging rate of the EV by reflecting the capacity or usage cost of the grid.

[0058] "Interoperability": A state in which components of a system interact with corresponding components of the system to perform operations targeted by the system. Additionally, information interoperability can refer to the ability of two or more networks, systems, devices, applications, or components to effectively share and easily use information without causing inconvenience to users.

[0059] "Inductive charging system": A system that transfers energy from a power source to an EV via a two-part air-gap core transformer, wherein the two halves of the transformer (i.e., the primary coil and the secondary coil) are physically separated from each other. In this invention, the inductive charging system can correspond to an EV power transmission system.

[0060] "Inductive coupling": Magnetic coupling between two coils. In this disclosure, coupling occurs between the GA coil and the VA coil.

[0061] "Original Equipment Manufacturer (OEM)": EV manufacturer or server operated by EV manufacturer. This may include root certification authorities (CAs) or root certification servers that issue OEM root certificates.

[0062] "V2G Operator": A major participant in V2G communication using the transport protocol, or an entity that initiates automatic authentication for EVs or EV users on a blockchain and creates smart contracts on that blockchain. It may include at least one trusted authentication authority or trusted authentication server.

[0063] "Mobility Operator (MO)": An entity within the PnC architecture that has a contractual relationship with EV owners regarding charging, approval, and payment to enable EV drivers to charge their EV batteries at charging stations. It may include at least one certification authority or certification server that issues and manages its own certificates.

[0064] "Billing Service Provider (CSP)": An entity responsible for managing and authenticating EV user credentials, and performing the role of providing billing and other value-added services to customers. It can correspond to a specific type of MO, and can be implemented in combination with MO.

[0065] “Charging station (CS)”: “A facility or equipment that has one or more EV power supply devices and actually performs the charging of EVs.”

[0066] "Charging Station Operator (CSO)": "An entity that connects to the power grid and manages electricity to supply power requested by EVs. It can be a term with the same concept as a Billing Point Operator (CPO) or an e-Mobility Service Provider (eMSP), or it can be a term included in or encompassing the concepts of a CPO or eMSP. A CSO, CPO, or eMSP may include at least one certification authority that issues or manages its own certificates."

[0067] "e-mobility authentication identifier (eMAID)": A unique identifier that links a contract certificate to the payment account of the owner of an electric vehicle using electricity. In an exemplary embodiment, the mobility authentication identifier may include an identifier of the EV certificate or an identifier that provides the certificate. The term eMAID may be replaced with "e-mobility account identifier" or may be replaced with a contract ID.

[0068] "Clearing House (CH)" is an entity that "handles cooperation matters between MOs, CSPs, and CSOs." It can act as an intermediary to facilitate the approval, billing, and adjustment processes for EV charging services roaming between the parties.

[0069] "Roaming": Information exchange and schemes and regulations between CSPs that allow EV users to access charging services provided by multiple CSPs or CSOs belonging to multiple e-mobility networks by using a single credential and contract.

[0070] "Certificate": A physical or digital asset that represents the identity of an EV or its owner, and may include a password used to verify the identity, a public and private key pair used in a public-key cryptographic algorithm, a public key certificate issued by a certification authority, and information related to a trusted root certification authority.

[0071] "Certificate": An electronic document that binds a public key to an ID through digital signature.

[0072] "Service Session": A collection of services around charging points associated with a specific customer's EV within a specific time frame, each with a unique identifier.

[0073] In the following, exemplary embodiments of the present disclosure will be explained in detail with reference to the accompanying drawings.

[0074] The pairing method between the EVCC and SECC for vehicle-to-grid (V2G) wireless power transmission (WPT) described in this exemplary embodiment can be provided as a new WPT pairing method that simplifies the pairing process by combining the pairing process with a precise positioning process using low-frequency (LF) based point-to-point (P2PS) signaling performed in the V2G communication session, and can effectively prevent or resolve errors that frequently occur during the precise positioning process.

[0075] Figure 1 This is a diagram illustrating the overall configuration of a magnetic field (MF) based WPT system to which a distance estimation method for precise WPT positioning according to an exemplary embodiment of this disclosure can be applied.

[0076] like Figure 1 As shown, the WPT for an electric vehicle (hereinafter referred to as "EV") 10 can be defined as the process of transferring electrical energy from the power grid G1 to the EV device via a magnetic field without a direct current flow connection. That is, the WPT can be used to charge the battery 30 of the EV 10 by transferring power from the charging station 20 to the EV 10.

[0077] EV 10 may include EV power circuit 150, which has a secondary device electromagnetically coupled to a primary device within the power supply circuit 250 of charging station 20. Under the control of EVCC 100 of EV 10, the secondary coil within the secondary device can receive electromagnetic energy from the primary coil of the primary device connected to charging station 20 based on electromagnetic induction or magnetic resonance. The electromagnetic energy transferred to EV 10 can be converted into an induced current, which can be rectified into a DC current and then used to charge battery 30.

[0078] Charging station 20 can receive power from the commercial power grid G1 or the power line, and supply electromagnetic energy to EV 10 through power supply circuit 250 under the control of SECC 200 within charging station 20. Power supply circuit 250 may be a component corresponding to at least a portion of EVSE, and may be located in different places such as the garage or parking lot of the home of the EV 10 owner, a parking area for EV charging at a gas station, or a parking area in a shopping mall or office building.

[0079] Additionally, the charging station 20 can communicate with a power infrastructure management system, infrastructure server, or computing device on the network, which manages the power grid G1 via wired / wireless communication and can perform wireless communication with the EV 10.

[0080] Wireless communication may include Wi-Fi-based or wireless LAN (WLAN)-based communication based on the IEEE 802.11 protocol. Alternatively, wireless communication may include point-to-point (P2PS) signaling using LF signals and / or low-power excitation (LPE) signals. Furthermore, the wireless communication scheme between charging station 20 and EV 10 may include various communication schemes (such as Bluetooth, Zigbee, and cellular) as well as one or more of the aforementioned communication schemes.

[0081] Furthermore, EV 10 and charging station 20 can perform WPT or charging processes by exchanging messages according to a data expression format based on Extensible Markup Language (XML) or Effective XML Exchange (EXI). That is, communication for the charging process can be performed between EVCC 100 and SECC 200 via wireless LAN or the like.

[0082] Furthermore, if the location information used for precise positioning is not shared between the EVCC and SECC via communication such as a wireless LAN, it is not easy for the EV 10 or an EV device equipped with a secondary device to properly perform the LF-based precise positioning process. However, according to this exemplary embodiment, even when the location information used for precise positioning is not shared, information about the distance and direction of the secondary device from the primary device can be provided, enabling precise positioning to be performed normally based on the antenna information of each of the primary and secondary devices and their response to the LF signal.

[0083] Furthermore, during the communication process used for charging, EV 10 can first verify the identity of charging station 20 to identify whether it is a trusted facility or device, and establish a secure channel with charging station 20's SECC 20 to protect communication from unauthorized access. The secure channel can be established using Transport Layer Security (TLS). A TLS session can be performed according to the TLS session establishment process after the Internet Protocol (IP)-based communication connection establishment process.

[0084] Figure 2 It is used to describe in Figure 1 A diagram illustrating the wireless power flow and communication interface between the supply device (SD) and the EV device (EVD) that can be used in the WPT system.

[0085] like Figure 2 As shown, in the wireless power flow between SD and EVD, the power electronics 252 of the power supply circuit 250 can convert commercial power and transmit it to the primary device 251. The primary device 251 can transmit electromagnetic energy to the secondary device 151 of the EV power supply circuit 150 under the control of SECC 200. The power electronics 152 of the EV can convert the induced current generated in the secondary device 151 under the control of EVCC 110 and supply it to the battery, etc.

[0086] Communication between the EVCC 100 and SECC 200 can be performed using a wireless local area network (WLAN) link that supports the physical and data link layers of the wireless communication interface. Furthermore, during communication between the EVCC 100 and SECC 200, compatibility analysis and verification can be performed on both the SECC 200 and EVCC 100 before initiating a WPT session.

[0087] In the aforementioned WPT system, message exchange and communication security requirements can be defined for compatibility analysis and verification to meet compatibility requirements. Message exchange requirements may include communication timing requirements, operation timing requirements, etc.

[0088] Additionally, EVCC 100 and SECC 200 can use EV device P2PS controller 110 and supply device P2PS controller 210 to send and receive signals and data via P2PS signaling. The P2PS may include LF signals. Each of EV device P2PS controller 110 and supply device P2PS controller 210 may have at least one or both of an LF transmitter including at least one antenna and an LF receiver including at least one antenna.

[0089] Multiple LF transmitters connected to the EV device P2PS controller 110 may be arranged around the secondary coil of the secondary device and may be referred to as transmitting antennas or transmitters. Multiple LF receivers connected to the supply device P2PS controller 210 may be arranged around the primary coil of the primary device and may be referred to as receiving antennas or receivers.

[0090] The physical layer for WLAN and P2PS signaling used for WPT communication will be described below.

[0091] A system architecture with a physical layer for WLAN and P2PS signaling may include WLAN between the EVCC and SECC and P2PS signaling between the EV device (EVD) and the supply device (SD). P2PS signaling can be used for LF signals, low-power excitation (LPE) from the primary device, anomaly monitoring via WPT, optical marking, external verification devices, alignment, pairing or other devices to ensure security, power checks, etc.

[0092] Here, the LF signal is a digitally modulated magnetic field operating in a low-frequency radio frequency band, for example, from 30 kHz to 300 kHz. The LF transmitter or receiver can operate at a fixed frequency within the frequency range of 19 kHz to 300 kHz. The system frequency can be selected from 125 kHz, 134 kHz, 145 kHz, 165 kHz, 185 kHz, 205 kHz, etc.

[0093] The maximum radiated power, magnetic field strength, or electric field strength of a specific frequency band used by an LF system shall comply with the technical and operational parameters described in the International Telecommunication Union Radiocommunication Sector (ITU-R) report SM.2153-7, as well as information on national / regional rules regarding spectrum use.

[0094] Different frequencies are required to allow the LF signals to position three EVs in parallel without interference. The magnetic field can be formed by two or more LF transmitters located within the EV or EV unit. Since the location of the LF transmitters depends on the manufacturer, the placement of the LF transmitters within the EV or EV unit may not be specified.

[0095] Information about the antenna's location can be exchanged between the EVCC and SECC via communication. By concentrating or suppressing energy in a specific direction, the antenna can have directivity or orientation in that direction, and the direction of the LF signal from the primary device's transmitter or EV transmitter can be predetermined or configured.

[0096] The primary unit may include at least two LF receivers or transmitters. The manufacturer may arrange the LF transmitters or receivers symmetrically in the X direction around the geometric alignment points of the primary or secondary unit, or mount the LF transmitters or receivers at a sufficient distance from the metallic or ferrite structure of the primary unit to prevent severe interaction or interference.

[0097] The magnetic field strength can be measured by one or more receivers to provide positioning. Furthermore, three or more antennas can be used to optimize antenna arrangement.

[0098] Simultaneously, LF data from LF signals transmitted from EV or EVD devices can be transmitted using an on / off keying (OOK) scheme. In the OOK scheme, "1" can signify the activation of the magnetic field, while "0" can signify the deactivation of the magnetic field.

[0099] The OOK scheme is the simplest form of amplitude shift keying (ASK) modulation, where digital data is represented regardless of the presence of a carrier wave. The formation of the magnetic field is highly dependent on the bandwidth of the coil (i.e., the Q factor). If the Q factor is too narrow, the receiver may not be able to decode the data correctly. Therefore, the Q factor can be adjusted to ensure proper data communication.

[0100] For example, as a result of adjusting the Q factor, the receiver detection threshold can be selected as 70% of the output current required for the transmitter to detect the coil current from 0 to 1, and can be selected as 30% of the output current required to detect 1 to 0.

[0101] Furthermore, Manchester code can be used to encode the modulated signal of the LF data. The data rate of Manchester code can be 3.9 Kbit / s (±300 b / s). Since the LF signal currently uses 6 frequencies as candidates, a data cycle can be highly frequency-dependent. That is, one data cycle for each candidate frequency is shown in Table 1 below.

[0102] [Table 1]

[0103]

[0104] Examples of LF data formats used for precise positioning are shown in Table 2 below.

[0105] [Table 2]

[0106]

[0107] In Table 2, the preamble signal of the preamble block is used by the preamble detection circuit to identify the input signal, preventing unintentional operation of the circuit in noisy environments. The LF telegraph can begin with a preamble to configure the LF data threshold. The preamble can have a 50% duty cycle. Furthermore, the synchronization signal is used by the grounding component (GA) to demodulate the LF modulated signal transmitted from the vehicle component (VA).

[0108] In addition, the first data in a data block can be fixed as "0".

[0109] Furthermore, the Collision Avoidance Code (CAC) can be a temporary identifier for each antenna used to distinguish a signal from signals transmitted from other vehicles. The CAC for each antenna is randomly generated for each session and should be unique for each device. The length of the CAC can be chosen to be 32 bits to keep the probability of collisions between antennas close to zero. For example, assuming there are 6 vehicles and 4 antennas, the maximum number of peripheral antennas can be given as 24. The CAC for each antenna can be delivered as the ANT_ID parameter via the vehicle communication controller and the base communication controller. The data type of ANT_ID can be an 8-character string in the hexadecimal representation of the CAC.

[0110] In addition, a blank (dummy) can be a dummy element that does not contain useful data and has reserved space.

[0111] In addition, Cyclic Redundancy Check (CRC) can refer to a scheme for determining a check value when sending data over a network or other means to verify whether there are errors in the transmitted data, or information about the scheme for determining such a check value.

[0112] Furthermore, when the LF transmitter sends an LF signal to the LF receiver, the LF receiver can continuously receive data. Therefore, guard bits can be used to distinguish between previously transmitted signals and currently transmitted signals.

[0113] Meanwhile, the aforementioned P2PS signaling can be used for precise positioning, pairing, alignment checks, etc. The precise positioning process using LF signals is as follows.

[0114] The precise positioning process of this exemplary embodiment can be initiated by sending a message from the EVCC to the SECC. The SECC can respond to the EVCC by transmitting a message including information about the LF operating frequency. The EV device can transmit an LF signal to the LF receiver of the primary device via a P2PS link at a selected frequency. The SECC can send a message to the EVCC including the RSSI value of the LF signal at the LF receiver of the primary device in the supply device (SD). A positioning algorithm based on feedback of the RSSI value at the LF receiver of the primary device can be implemented in the EV. In this case, by using the distance estimation method according to this exemplary embodiment, the distance between the center point of the EV device or the center point of the secondary device can be estimated based on the center point of the primary device or a predetermined reference point, thereby enabling automatic alignment of the primary and secondary devices within tolerances.

[0115] The following will describe a more specific example of the above-described precise positioning process using LF signals.

[0116] First, the EVCC can request precise positioning using the LF signal. Then, the Supply Device (SD) can prepare an LF receiver to receive the LF signal from the EV device. The SECC can then respond to the EVCC by sending a message including information about the SD's LF operating frequency. The EV device can then prepare to transmit the LF signal to the SD via an LF transmitter. The LF transmitter can then use the information about the SD's LF operating frequency to send the LF signal to the LF receiver.

[0117] When the driver moves the EV to a parking spot or charging point and the secondary device arrives at least 4 meters from the primary device, the LF receiver can detect the LF signal emitted from the EV device.

[0118] The EV device can then send the LF signal for positioning to the SD, and the EVCC can request a message from the SECC that includes pre-calibrated raw data. The SECC can respond to the EVCC with a message that includes pre-calibrated raw data obtained from the LF signal values ​​sensed by the SD.

[0119] The EV device can then dynamically calculate the position of the primary device based on the LF signal value returned from the SECC. In this exemplary embodiment, by moving the EV using the LF signal value (e.g., the maximum value of the LF signal and the arrival time of the LF signal), the secondary device can be aligned with the primary device such that the two distances from the center point of the primary device or two specific reference points on or near the top of the primary device to the two transmit antennas of the secondary device are equal.

[0120] Then, if the secondary device is above the primary device within the alignment tolerance and the primary and secondary devices are well aligned, the EV can stop under the control of the vehicle controller. The EVCC can then request the SECC to complete the precise positioning process, and the SD can respond to the EVCC by deactivating the LF receiver by sending a message indicating that the LF receiver is no longer active.

[0121] Furthermore, the process of exchanging LF parameters using LF signals during the aforementioned precise positioning process will be described below.

[0122] First, at the start of precise positioning based on LF, in order to properly compare the signals detected by the receiving antenna of the primary device, information about the position of the transmitting antenna can be exchanged between the SECC and EVCC via communication.

[0123] Here, the EVCC can send a Precision Positioning Establishment Request message to the SECC, which includes data with preset parameters. Parameters that may be included in the EV's LF Precision Positioning Setup data may include the number of transmitters / receivers of the auxiliary antenna system installed in the EV, the identifiers of each transmitter / receiver, the position and orientation of each transmitter / receiver, the signal frequency, the pulse sequence order, the pulse separation time between pulses within a pulse package, the duration of each individual pulse, and the package separation time between two consecutive pulse packages.

[0124] In addition, the SECC can send a Precision Positioning Establishment Response Message to the EVCC in response to the EVCC's Precision Positioning Establishment Request Message. Parameters that may be included in the SECC's LF Precision Positioning Setup Data may include the number of transmitters / receivers of the precision positioning system installed in the primary equipment of the infrastructure, the identifiers of each transmitter / receiver, the location and orientation of each transmitter / receiver, the signal frequency, the pulse sequence order, the pulse separation time between pulses within a pulse package, the duration of each individual pulse, and the package separation time between two consecutive pulse packages.

[0125] The location of the transmitter or receiver described above can be represented by the transmitter or receiver coordinates (x, y, z), which are based on the coordinates of the primary device relative to the geometric center of the primary coil, given in millimeters (mm). The orientation of the transmitter or receiver can be represented by a unit vector of (x, y, z) for a given measurement direction, and all three values ​​can be set to zero (0) if no orientation is applied. The signal frequency can represent the frequency (Hz) of the signal to be used by the EV device. As an optional parameter, the pulse sequence order can represent an ordered list of antenna identifiers describing the order in which the transmitter or receiver transmits signals as a pulse packet, and the list can define the pulse packets collected in an ordered order at the EV transmitter or receiver.

[0126] After successfully establishing precise LF positioning, a precise positioning request message can be sent via EVCC to initiate the exchange of positioning information between EVCC and SECC. Information regarding whether the positioning process is in progress or complete can be exchanged between EVCC and SECC. In addition, specific parameters used for the LF positioning scheme can also be exchanged.

[0127] Specific parameters may include the number of signal packets included in the message, the packet index of each signal packet, the identifier of each transmitter or receiver, the effective isotropic radiated power (EIRP) of each transmitter, and the transmitter identifier and Received Signal Strength Indicator (RSSI) value of the pulses or signals received at each receiver. The EIRP value representing the signal strength of the transmitted LF signal is used as the transmitting component; otherwise, the corresponding value may be set to zero. The RSSI values ​​may include preprocessed RSSI values ​​of the received pulses, and the order of the RSSI values ​​may correspond to the order of sensor signal encapsulation provided by the EV during precise positioning setup.

[0128] Figure 3 This is a diagram illustrating an application environment for a distance estimation method for precise WPT positioning according to an exemplary embodiment of the present disclosure.

[0129] like Figure 3 As shown, a distance estimation method for precise positioning can be performed via WLAN and LF-based P2PS signaling between EV 10 or EVD and SD. The EVCC of EVD 151 can share antenna-related information and LF signal-related information with the SECC of SD via wireless LAN communication. EVD may include a first communication device 102 connected to EVCC, and the first communication device 102 can be connected via a wireless LAN communication channel to a second communication device 202 installed in the parking area Pa. The second communication device 202 can be connected to the SECC of SD.

[0130] The first transmitter T1 and the second transmitter T2 can be arranged in the secondary device 151 of the EVD, and the secondary device can have an electromagnetic center or a geometric center Cb.

[0131] The primary device 251 may be included in the SD, having a first receiver R1 and a second receiver R2, and having an electromagnetic center or geometric center Ca.

[0132] Meanwhile, unlike the first receiver R1 and the second receiver R2 fixed in the primary device 251 mounted on the ground, the first transmitter T1 and the second transmitter T2 of the secondary device 151 of the EVD mounted on the moving EV 10 can have various arrangements depending on the position of the EV 10 relative to the two receivers. Furthermore, without information about the arrangement of the primary device or the LF antenna of the primary device, it may not be easy to properly perform LF signal processing for precise positioning in an misaligned state.

[0133] Therefore, in this exemplary embodiment, a distance estimation method is provided for accurate positioning with environmental tolerance characteristics even when the positions of the first transmitter T1 and the second transmitter T2 mounted on the mobile EV 10 change, and the method does not require information about the arrangement of the primary device or the LF antenna of the primary device.

[0134] Figures 4A to 4D are diagrams illustrating the arrangement of antennas in the primary device and the secondary device to which the distance estimation method for WPT precise positioning according to an exemplary embodiment of the present disclosure can be applied.

[0135] In this exemplary embodiment, the LF antenna (LFA) may include an LF transmitting antenna or transmitter for transmitting LF signals, or it may include an LF receiving antenna or receiver for receiving LF signals. The LF antenna can operate as a transmitter when transmitting LF signals and as a receiver when receiving LF signals.

[0136] As shown in Figures 4A to 4D, at least three LF antennas on the EV device side can be mounted in a secondary device including a receiving coil or a secondary coil. These at least three LF antennas can be mounted around the secondary coil as auxiliary antennas. For example, when the secondary coil has a shape with four sides in a plane, the at least three LF antennas can be arranged outside the middle of each side of the secondary coil, such that the longitudinal direction of their centers is parallel to the respective side where the corresponding LF antenna is located.

[0137] Furthermore, at least three LF antennas on the supply device side can be mounted in a primary device including a transmitting coil or a primary coil. The at least three LF antennas can be mounted as auxiliary antennas around the primary coil. For example, when the primary coil has a shape with four sides in a plane, the at least three LF antennas can be arranged outside the middle of each side of the primary coil, such that the longitudinal direction of their centers is parallel to the respective side where the corresponding LF antenna is located.

[0138] More specifically, in the first arrangement shown in Figure 4A, when three receivers are arranged in the primary device, the first receiver (i.e., LFA 1A) may be arranged symmetrically with the second receiver (i.e., LFA 1B), and the third receiver (i.e., LFA 1C) may be arranged in a (-x) direction that is parallel to the surface of the paper and points towards the upper side of the paper, in a direction orthogonal to the straight line passing through the center of the first receiver (i.e., LFA 1A) and the second receiver (i.e., LFA 1B).

[0139] Similarly, when three transmitters are arranged in the secondary device, the first transmitter (i.e., LFA2A) can be arranged symmetrically with the second transmitter (i.e., LFA2B), and the third transmitter (i.e., LAF2C) can be arranged in a (-x) direction that is parallel to the surface of the paper and points towards the upper side of the paper, in a direction orthogonal to the straight line passing through the center of the first transmitter (i.e., LFA2A) and the second transmitter (i.e., LFA2B).

[0140] Furthermore, in the second arrangement shown in Figure 4B, in the primary device, the first receiver (i.e., LFA 1A) may be arranged symmetrically with the second receiver (i.e., LFA 1B), and the third receiver (i.e., LAF 1C) may be arranged in the (-x) direction. In the secondary device, the first transmitter (i.e., LFA 2A) may be arranged symmetrically with the second transmitter (i.e., LFA 2B), and the third transmitter (i.e., LAF 2C) may be arranged in the x direction. The x direction may be opposite to the (-x) direction.

[0141] Furthermore, in the third arrangement shown in Figure 4C, in the primary device, the first receiver (i.e., LFA 1A) can be arranged symmetrically with the second receiver (i.e., LFA 1B), and the third receiver (i.e., LAF 1C) can be arranged in the x-direction. In the secondary device, the first transmitter (i.e., LFA 2A) can be arranged symmetrically with the second transmitter (i.e., LFA 2B), and the third transmitter (i.e., LAF 2C) can be arranged in the (-x) direction.

[0142] Furthermore, in the fourth arrangement shown in Figure 4D, in the primary device, the first receiver (i.e., LFA 1A) may be arranged symmetrically with the second receiver (i.e., LFA 1B), and the third receiver (i.e., LAF 1C) may be arranged along the x-direction. In the secondary device, the first transmitter (i.e., LFA 2A) may be arranged symmetrically with the second transmitter (i.e., LFA 2B), and the third transmitter (i.e., LAF 2C) may be arranged in the x-direction.

[0143] Here, an LF antenna comprising one or more transmitters and one or more receivers can be arranged to form each magnetic field in the directions of 0 degrees, 90 degrees, 180 degrees, or 270 degrees.

[0144] Meanwhile, among various positioning technologies, RSSI-based methods can be mentioned as a representative positioning technology that can be used for precise positioning based on LF signals in EV WPT.

[0145] The distance estimation based on RSSI can be expressed according to Equation 1 below.

[0146] [Equation 1]

[0147] or

[0148] Here, d can represent distance, n can represent signal propagation constant, Ar can represent RSSI value per meter, λ can represent wavelength of radio wave, c can represent speed of radio wave, f can represent frequency of radio wave, and L can represent propagation path loss, that is, the value obtained by subtracting the strength of received signal from the strength of transmitted signal.

[0149] To identify 3D coordinates using an RSSI-based scheme, at least three signals need to be identified. At least three LF transmitters can be arranged in the receiving coil, and at least three LF receivers can be arranged in the transmitting coil.

[0150] In this exemplary embodiment, two of the at least three or more transmitters of the EV device and two of the at least three or more receivers of the primary device can be used, and precise positioning can be performed by estimating the distance and direction of the center point of the secondary device relative to the center point of the primary device using the LF signal.

[0151] Figures 5A to 5D are diagrams illustrating the processes performed in a primary device and a second device to which the distance estimation method for WPT precise positioning according to an exemplary embodiment of the present disclosure can be applied.

[0152] As shown in Figures 5A to 5D, when the primary device and the secondary device are in an aligned or partially aligned state, a distance estimation method for precise positioning can be executed by the EV or EV device, a distance estimation device coupled thereto, a vehicle controller, or a vehicle computing device. The partially aligned state can include the following state: where the center point Cb of the secondary device 151, which combines the first transmitter T1 and the second transmitter T2, is aligned with the center point Ca of the primary device 251, which combines the first receiver R1 and the second receiver R2, within an acceptable range on a straight line.

[0153] First, as shown in Figure 5A, in the distance estimation method for precise positioning, a signal can be transmitted from a first transmitter T1 positioned around the secondary device 151 of the vehicle to two receivers R1 and R2. Based on the difference in reception time of the LF signal received at the two receivers R1 and R2, a first distance between the first transmitter T1 and the first receiver R1 and a second distance between the first transmitter T1 and the second receiver R2 can be calculated respectively.

[0154] As shown in Figure 5B, in the distance estimation method for precise positioning, a first circle can be formed with the second receiver R2 as its center. This first circle has a radius equal to half the difference between the calculated first and second distances (distance difference). A first tangent line can also be formed that passes through the center of the first receiver R1 and intersects with the first circle. The second receiver R2 can be the receiver that is relatively farther from the first transmitter T1 among the two receivers.

[0155] As shown in Figure 5C, in the distance estimation method for precise positioning, a first normal line passing through the center of the first transmitter T1 can be formed on the first tangent component between the point where the first circle intersects the first tangent and the center of the first receiver R1. The first normal line may have a first starting point on the first tangent component.

[0156] As shown in Figure 5D, in the distance estimation method for precise positioning, similar to the case of the first transmitter T1, a second circle with a radius equal to half the second distance difference corresponding to the signal difference of the second LF signal can be formed with the first receiver R1 as the center, relative to the second transmitter T2. A second tangent line can be formed that passes through the center of the second receiver R2 and intersects the second circle. A second normal line passing through the center of the second transmitter T2 can be formed on the second tangent component between the point where the second circle intersects the second tangent line and the center of the second receiver R2. The second normal line can have a second starting point on the second tangent component.

[0157] Then, when the positions of the two receivers are known, the distance estimation device that performs the distance estimation method for precise positioning can use geometry to specify the coordinates where each normal and each circle meet.

[0158] Furthermore, since the two emitters should be located at the same distance from the two starting points, it can be seen that the vertices of the isosceles triangle with the two points as its base are the positions of the emitters. The vertices of the isosceles triangle can move along a line segment perpendicular to the center of the base. Therefore, if a line is drawn perpendicular to the center of the line segment connecting the two points, the emitters should be located on that line segment.

[0159] Then, assuming the distance between the first transmitter T1 and the second transmitter T2 is known, the distance estimation device can calculate the distance to the first transmitter T1 by configuring the distance between the first starting point and the first transmitter T1 on the first normal to be the same as the distance between the second starting point and the second transmitter T2 on the second normal.

[0160] According to this exemplary embodiment, when the distance between the first normal and the second normal is equal to the distance between the two transmitters, the position of the center of the secondary device 151 that combines the two transmitters can be determined from the coordinates of the two transmitters, and the distance to the center point of the primary device can be calculated.

[0161] Figure 6 and Figure 7 This is a diagram illustrating a state where the distance estimation method for WPT precise positioning according to an exemplary embodiment of the present disclosure can be applied to a primary and secondary device misalignment.

[0162] refer to Figure 6 In (a) and (b), the secondary device 151 of the EV device can be located to the left of the primary device 251. Furthermore, at the first moment, the front of the EV equipped with the secondary device 151 can be positioned facing the direction where the primary device 251 is located (see...). Figure 6 (a)), and at the second time, it can be positioned far to the left of the primary device 251, such that the primary device 251 is positioned to the right of the EV (see [reference]). Figure 6 (b)

[0163] refer to Figure 7 In (a) and (b), the secondary device 151 of the EV device can be located to the right of the primary device 251. Furthermore, the front side of the EV equipped with the secondary device 151 can be positioned at a third time to be offset far to the right of the primary device 251, such that the primary device 251 (see...) Figure 7 (a) is located to the left of EV, and in the fourth time, it can be positioned facing the direction of the primary device 251 (see Figure 7 (b)

[0164] As described above, in the distance estimation method for precise positioning according to this exemplary embodiment, even when there is no information about the antenna arrangement of the primary device 251, the distance and direction of each of the two transmitters relative to the two receivers can be effectively estimated using the LF signal, and thus the center Cb of the secondary device 151 can be aligned with the center Ca of the primary device 251.

[0165] Figure 8 This shows the application to Figure 6 and Figure 7 The flowchart shows the distance estimation method for WPT accurate positioning in the misaligned state.

[0166] like Figure 8 As shown, the distance estimation method for precise positioning can be executed by an EV or an EVD, which has an EVCC connected to the SECC of the SD via WLAN and a secondary device equipped with a first transmitter and a second transmitter.

[0167] In the distance estimation method for precise positioning, firstly, a first LF signal can be sent from a first transmitter to a first receiver and a second receiver of a primary device of the SD, and the position of the first transmitter can be defined on a first straight line extending radially from a reference point on the SD based on the response received by the SECC in relation to the first LF signal.

[0168] Furthermore, in the distance estimation method for precise positioning, a second LF signal can be transmitted from a second transmitter to a first receiver and a second receiver, and the position of the second transmitter can be defined on a second straight line extending radially from a reference point on the SD based on the response received by the SECC in relation to the second LF signal.

[0169] Each of the first and second straight lines is a straight line having a starting point at one end, and each extending from the starting point can be configured to pass through the center point of the primary device. The center point of the primary device can be the center point among a plurality of LF receivers installed in the primary device or the geometric center point of the primary device. Of course, in this disclosure, the center point of the primary device is not limited to the above configuration, and can be any position calculated from at least one LF receiver or any specific position arbitrarily specified on the primary device. Therefore, the center point of the primary device can be used as a reference point for the distance estimation method of this exemplary embodiment, and in this sense can be referred to as a "reference point".

[0170] The starting point of the first straight line can be the midpoint of the first tangent component, and it can be formed at the point where it intersects the normal to the first transmitter. Similarly, the starting point of the second straight line can be the midpoint of the second tangent component, and it can be formed at the point where it intersects the second normal passing through the center of the second transmitter. The starting point, tangent component, and normal will be described in detail below.

[0171] Then, the EV or EVD can calculate the time difference between the first LF signal and the second LF signal arriving at a specific receiver closer to the first and second transmitters (S83). The time difference between the first LF signal and the second LF signal can be converted into a distance difference by multiplying the speed of light by the distance difference between the first LF signal and the second LF signal. Here, the EV or EVD may include a distance estimation device or a vehicle controller including means or components that perform the same function as the distance estimation device.

[0172] Then, EV or EVD can move the starting point of a straight line passing through the center of a particular transmitter located closer to the primary device toward that particular transmitter, either corresponding to the time difference or by the distance difference calculated based on the time difference (S84).

[0173] Based on the movement of the aforementioned starting points, the distance from the center of each of the two transmitters to the corresponding starting point can be set to be the same. One of the corresponding starting points can be the starting point from which the aforementioned distance difference is moved.

[0174] Then, when the transmitter closer to the primary device is the first transmitter, the EV or EVD can determine the first a starting point obtained by moving the first starting point of the first straight line toward the first transmitter according to the time difference on the first straight line, and determine the position of the first transmitter, which is positioned on the first straight line at a distance from the first a starting point such that this distance is the same as the distance between the second starting point and the second transmitter on the second straight line (refer to S85).

[0175] Additionally, when the transmitter closer to the primary device is the second transmitter, the EV or EVD can determine the second a starting point obtained by moving the second starting point of the second straight line toward the second transmitter according to the time difference on the second straight line, and determine the position of the second transmitter, which is positioned on the second straight line at a distance from the second a starting point, such that this distance is the same as the distance between the first starting point and the first transmitter on the first straight line (refer to S85).

[0176] Then, the EV or EV device can estimate the distance and direction of the center or center point of the secondary device relative to the center or center point of the primary device based on the determined positions of the two transmitters (S86), and can perform LF-based precise positioning based thereon. The center or center point of the secondary device can be, but is not limited to, the midpoint of the straight line component connecting the center of the first transmitter and the center of the second transmitter.

[0177] According to this exemplary embodiment, two of the at least three LF antennas disposed in the primary device can be used as a first receiver and a second receiver, and two of the at least three LF antennas disposed in the secondary device can be used as a first transmitter and a second transmitter.

[0178] Here, the first and second receivers can be arranged on a straight line passing through the center point of the primary device, on a straight line parallel to one side of the primary device, or in any position, without needing to be arranged in a point-symmetric or line-symmetric manner relative to the center point of the primary device. Similarly, the first and second transmitters can also be arranged on a straight line passing through the center point of the secondary device, on a straight line parallel to one side of the secondary device, or in any position, without needing to be arranged in a point-symmetric or line-symmetric manner relative to the center point of the secondary device.

[0179] Figures 9 to 17 It is used to describe in more detail Figure 8 An exemplary diagram illustrating the distance estimation method for WPT precise positioning.

[0180] In the distance estimation method for precise positioning in this exemplary embodiment, information about LF receiving antennas (Rx LFAs) installed in the main device (PD) or SD of the GA installed in the EVSE can be obtained via WLAN communication (such as WiFi communication between the EVCC and SECC). The information about the Rx LFAs may include the location of two of three or more antennas installed on the SD, and information about the locations of the two Rx LFAs can be exchanged between the EVCC and SECC via communication.

[0181] like Figure 9 As shown, one of the multiple first transmit LF antennas (Tx LFAs) (hereinafter referred to as "first transmitters") installed in the VA of the EV or EVD can transmit LF signals to the first Rx LFA (hereinafter referred to as "first receiver") and the second Rx LFA (hereinafter referred to as "second receiver") installed in the PD.

[0182] Here, the first transmitter may include one of three or more antennas mounted on the EVD. The at least one pair of three or more antennas mounted on the EVD may be arranged in a point-symmetric or line-symmetric manner, but the arrangement of three or more antennas in this disclosure is not limited thereto, and may include three or more transmitting antennas arranged in any location.

[0183] Additionally, the first receiver and the second receiver may include two of three or more antennas mounted on the SD. At least one of the three or more antennas mounted on the SD may be arranged in a point-symmetric or line-symmetric manner, but the arrangement of the three or more antennas in this disclosure is not limited thereto, and may include three or more receiving antennas arranged in any location.

[0184] For ease of illustration and description, this exemplary embodiment will be described based on the configuration in which only two antennas are arranged in each of the primary and secondary devices. Here, each antenna may be a dedicated receiver for receiving LF signals or a dedicated transmitter for transmitting LF signals. Furthermore, each antenna may be configured to operate as at least part of an LF transmitter when transmitting LF signals and as at least part of an LF receiver when receiving LF signals. In this exemplary embodiment, each of the two antennas in the primary device may be a receiver or may operate as a receiver, and each of the two antennas in the secondary device may be a transmitter or may operate as a transmitter.

[0185] In this exemplary embodiment, the position of the first transmitter T1 can be represented as (x1, y1), the position of the second transmitter T2 can be represented as (x2, y2), the position of the first receiver R1 can be represented as (a, b), and the position of the second receiver R2 can be represented as (c, d). Here, the variables a, b, c, and d related to the positions of the first receiver R1 and the second receiver R2 can be obtained from the manufacturer, etc.

[0186] Because the first distance between the first receiver R1 and the first transmitter T1 is different from the second distance between the second receiver R2 and the first transmitter T1, the signals received at the first receiver R1 and the second receiver R2 can have a first time difference Δt1. An example of the time difference Δt1 is as follows: Figure 10 As shown.

[0187] Since the time difference corresponds to the difference between the propagation time of the electromagnetic wave and the distance traveled by the signal transmission, the first distance difference r1 between the first distance and the second distance can be calculated by multiplying the time difference by the speed of light. With the first receiver R1 as the center, a circle with a radius of half the first distance difference can be drawn.

[0188] like Figure 11As shown, a first circle with a first radius can be formed with a first receiver R1 positioned relatively far from the first transmitter T1 as its center. The first radius can correspond to half of a first distance difference r1. That is, the diameter of the first circle can correspond to the first distance difference.

[0189] like Figure 12 As shown, a receiver located relatively close to the first transmitter T1 can be formed (i.e., Figure 12 The first tangent L1 is located at the center of the second receiver R2 and intersects the first circle. The position of the first point P1 on the first circle where the first tangent L1 intersects the first circle can be represented as (e, f). The first tangent L1 can be the line closer to EVD among the two tangents that pass through the center of the second receiver R2 and intersect the first circle.

[0190] The center of the aforementioned receiver or transmitter can be the geometric center of the antenna. However, it is not limited to this; it can be any location configured on the antenna.

[0191] Then, a first normal L2 can be defined, which is a straight line passing through the center of the first transmitter T1 and meeting the first tangent L1 as a normal. The second point P2 where the first normal L2 meets the first tangent L1 can be the center point of the first tangent component connecting the first point P1 and the second receiver R2. The first normal L2 can be a straight line starting from the second point. The position of the second point P2 can be represented as (g, h).

[0192] The above relationship can be represented by Equations 2 and 3 below.

[0193] [Equation 2]

[0194] (ea) 2 +(fb) 2 =r1 2

[0195] [Equation 3]

[0196] (ea)(ca)+(fb)(db)=r1 2

[0197] In Equations 2 and 3, the position (e, f) of the first point represents the coordinates of the first point on the first tangent line L1, and r1 represents the first distance difference.

[0198] Based on the above configuration, an equation can be obtained relative to the straight line L2 of the first normal line connecting the first transmitter T1 and the second point P2. The first normal line L2 may have the second point P2 as the starting point of the straight line, and the position of the first transmitter T1 on the first straight line L2 is defined. The first normal line L2 may be referred to as the "first straight line".

[0199] The equation of the line perpendicular to the first normal line L2 passing through the first tangent L1 of the second point P2 and the second receiver R2 can be expressed as Equation 4 below.

[0200] [Equation 4]

[0201]

[0202] The position of the first transmitter T1 can be a point on the line represented by Equation 4. That is, the distance between the point on the first normal line L2, which is perpendicular to the first normal line L1 originating from the second point P2, can be obtained by using the equation.

[0203] like Figure 13 As shown, the same program as the program of the first transmitter T1 can be executed, so that a second circle with a second radius r2 centered on the second transmitter T2 can be formed, a second tangent L3 can be formed that meets the second circle at a third point P3 and passes through the second receiver R2, and a second normal L4 perpendicular to the second tangent L3 can be formed.

[0204] The equation of the line that is perpendicular to the second tangent L3 and intersects the fourth point P4 on the second tangent L3 can be calculated. The fourth point P4 can be the center point of the second linear component between the second receiver R2 and the third point P3, and the position of the fourth point P4 can be represented as (k, l).

[0205] The equation for the line relative to the second normal L4 can be expressed as Equation 5.

[0206] [Equation 5]

[0207]

[0208] The position of the second transmitter T2 can be a point on the equation of the straight line represented by Equation 5. That is, the distance between the point existing on the second normal line L4 and the fourth point P4 can be obtained by using the equation of the second normal line L4 perpendicular to the second tangent line L2, with the fourth point P4 as the starting point.

[0209] At the same time, in order to solve the two straight line equations for each normal simultaneously, that is, to obtain the allowable distance estimation solution for precise positioning of the antenna arrangement structure, the distance between the remaining transmitters and the starting point can be adjusted according to the distance between the transmitter with a relatively short distance and the starting point.

[0210] like Figure 14 As shown, the second time difference Δt2 can be calculated based on the third time of arrival of the LF signal from the first transmitter T1 to the second receiver R2 and the fourth time of arrival of the LF signal from the second transmitter T2 to the second receiver R2. Figure 15An example of the second time difference Δt2 is shown in the figure.

[0211] The second receiver R2 can be a receiver that is closer to the first transmitter T1 and the second transmitter T2, but is not limited to this.

[0212] In this configuration, the LF signals transmitted from the first transmitter T1 and the second transmitter T2 can be synchronized with each other. For example, the first transmitter T1 and the second transmitter T2 can transmit LF signals simultaneously or transmit LF signals separately with a preset time difference. Information about the time difference between the transmission times of the signals transmitted from the first transmitter T1 and the second transmitter T2 can be detected or stored in the EVD.

[0213] Furthermore, since the aforementioned second time difference Δt2 corresponds to the time difference of the distance traveled by the electromagnetic wave propagation signal, the second distance difference can be calculated by multiplying the second time difference by the speed of light.

[0214] like Figure 16 As shown, a virtual tangent L5 can be formed by moving the previously formed first tangent L1 along the first normal L2 by a distance corresponding to the second distance difference. The position of the fifth point P5, which is the orthogonal point between the virtual tangent L5 and the first normal L2, can be configured as (m, n).

[0215] The coordinates of point P5 can be obtained by solving equations 6 and 7 below.

[0216] [Equation 6]

[0217]

[0218] [Equation 7]

[0219] (ng) 2 +(mh) 2 =r3 2

[0220] In Equation 7, r3 can be represented by the second distance difference based on the second time difference.

[0221] In this exemplary embodiment, the virtual tangent L5 is obtained by moving the first tangent L1 parallel to the first normal by a second distance difference r3, but this disclosure is not limited thereto.

[0222] That is, the virtual tangent L5 can vary according to the direction or posture of the EV toward the SD at the current position; in other words, it can vary according to the relative positions of T1 and T2 mounted on the EV. The virtual tangent L5 can correspond to the parallel displacement of the tangent that encounters a circle with a small radius.

[0223] Using the aforementioned virtual tangent L5, the position of the first transmitter T1 can be determined so that the distance between the first transmitter T1 and the fifth point P5 (hereinafter referred to as the "second reference distance") is configured to be the same as the distance between the second transmitter T2 and the fourth point P4 (hereinafter referred to as the "first reference distance").

[0224] That is, since the difference in distance between the first transmitter T1 and the second transmitter T2 is corrected, position estimation can be performed to satisfy the condition that the second transmitter T2 and the first transmitter T1 are located at the same distance from the two starting points P4 and P5.

[0225] Using the first reference distance and the second reference distance, the coordinates of the first transmitter T1 can be easily calculated even when the position of the starting point of the straight line (normal) component changes with time in the equations for each straight line calculated above.

[0226] like Figure 17 As shown, any point located on the first normal L2 and having a predetermined distance d3 from the fifth point P5 (i.e., the position (x1, y1) of the first transmitter T1) can be obtained through the following equations 8 and 9.

[0227] [Equation 8]

[0228]

[0229] [Equation 9]

[0230] (x1-m) 2 +(y1-n) 2 =d3 2

[0231] Furthermore, any point located on the second normal L4 and having a predetermined distance d3 from the fourth point P4 (i.e., the position (x2, y2) of the second transmitter T2) can be obtained through the following equations 10 and 11.

[0232] [Equation 10]

[0233]

[0234] [Equation 11]

[0235] (x1-m) 2 +(y1-n) 2 =d3 2

[0236] Here, when the distance between the first transmitter T1 and the second transmitter T2 is d2, the following equation 12 should be satisfied.

[0237] [Equation 12]

[0238] (x2-x1) 2 +(y1-y2) 2 =d2 2

[0239] We can obtain x1, y1, x2, and y2 that satisfy equations 8 to 12.

[0240] As described above, according to this typical embodiment, the distance and angle between the center of the receiving board or the secondary device of the EV device mounted on the EV and the center of the transmitting board or the primary device of the supply device can be calculated using the known coordinates of the first receiver R1 and the second receiver R2, as well as the coordinates of the first transmitter T1 and the second transmitter T2 calculated above.

[0241] Furthermore, the distance between the coordinates of the starting points of two straight lines can be calculated to become the distance between the two transmitters, and since all positions can be represented by coordinates, the approach angle and tilt angle of the vehicle can be easily calculated.

[0242] Since the distance estimation method according to this exemplary embodiment does not require the condition of symmetrically arranging multiple transmitters or multiple receivers, the positions of multiple transmitters installed on the secondary device of the EV can be determined even when multiple receivers are randomly arranged, regardless of the position of the receivers on the primary device, thus enabling reliable and accurate positioning.

[0243] Figure 18 This is a schematic block diagram illustrating the main components of a distance estimation device for precise WPT positioning according to another exemplary embodiment of the present disclosure.

[0244] like Figure 18 As shown, the distance estimation device 300 may be a device installed as part of an EVCC or SECC, a device integrated within an EVCC or SECC, or a functional unit performing functions corresponding to those of the device, and may include at least one processor 310 and a memory 320. Furthermore, the distance estimation device 300 for precise positioning may further include an input interface 330, an output interface 340, and a storage device 350. Additionally, the distance estimation device 300 for precise positioning may include a communication interface 360. The communication interface 360 ​​may correspond to a transmitting / receiving device for network access.

[0245] The processor 310 can execute program instructions stored in the memory 320 and / or storage device 350. The processor 310 may be implemented as at least one central processing unit (CPU) or graphics processing unit (GPU), or as other processors capable of performing the methods according to the invention.

[0246] Memory 320 may include, for example, volatile memory (such as read-only memory (ROM)) and non-volatile memory (such as random access memory (RAM)). Memory 320 may load program instructions stored in storage device 350 and provide the loaded program instructions to processor 310.

[0247] Storage device 350 is a recording medium suitable for storing program instructions and data, such as magnetic media such as hard disks, floppy disks and magnetic tapes, optical media such as compact disc read-only memory (CD-ROM) and digital universal disc (DVD), magneto-optical media such as floppy disc, or semiconductor memory such as flash memory, erasable programmable ROM (EPROM), or solid-state drives (SSDs) based thereon.

[0248] Storage device 350 may store program instructions. The program instructions may include instructions for implementing the distance estimation method for WPT precise positioning according to this disclosure. The program instructions may be implemented to cause processor 310, in a state loaded into processor 310 when executed by processor 310, to perform the above-mentioned references. Figure 8 The distance estimation process for precise positioning is described above. For example, program instructions may include instructions for transmitting LF signals, instructions for receiving LF signal correlation responses, instructions for calculating time differences, instructions for calculating distance differences, instructions for forming circles, instructions for forming tangents, instructions for calculating center points, instructions for forming normals, instructions for forming equations, instructions for solving simultaneous equations, instructions for calculating positions, instructions for calculating distances, instructions for calculating angles, etc.

[0249] Meanwhile, the functions or configurations of the input interface 330, output interface 340, and communication interface 360 ​​are obvious to those skilled in the art to which this disclosure pertains, and therefore their detailed description is omitted.

[0250] Furthermore, the location estimation method for precise positioning described in the exemplary embodiments above can be implemented as a computer-readable program or code on a computer-readable recording medium. The computer-readable recording medium may include all types of storage devices in which data readable by a computer system is stored. In addition, the computer-readable recording medium may be distributed to computer systems connected via a network, thereby storing and executing the computer-readable program or code in a distributed manner.

[0251] Computer-readable recording media may include hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, and flash memory. Program instructions may include high-level language code executable by a computer using an interpreter or similar means, as well as machine code generated by a compiler.

[0252] Some aspects of this disclosure have been described above in the context of devices, but some aspects of this disclosure can be described using corresponding methods. Here, a block or device corresponds to an operation of a method or a characteristic of the operation of a method. Similarly, the aspects of the invention described above in the context of methods can be described using corresponding blocks or items or characteristics of corresponding devices. Some or all of the operation of the method can be performed, for example, by (or using) hardware devices (such as microprocessors, programmable computers, or electronic circuits). In some embodiments, at least one of the most important operations of the method can be performed by such a device.

[0253] In exemplary embodiments, a programmable logic device (e.g., a field-programmable gate array) may be used to perform some or all of the functions of the methods described herein. In embodiments, the field-programmable gate array may be operated by a microprocessor to perform one of the methods described herein. Typically, the method is preferably performed by a hardware device.

[0254] Although the present disclosure has been described above with reference to embodiments thereof, those skilled in the art will understand that various changes and modifications may be made without departing from the concept and scope of the present disclosure as defined in the appended claims.

Claims

1. A position estimation method for precise positioning, executed by an electric vehicle (EV) or EV device, the EV or EV device having an EV communication controller (EVCC) and a secondary device, the EV communication controller being connected via a network to a supply device communication controller (SECC) of a supply device, the secondary device being equipped with at least a first transmitter and a second transmitter, the position estimation method comprising: The position of the first transmitter is defined as a point on a first straight line pointing to the geometric center of the primary device of the supply device; wherein the first straight line is determined based on the time difference between the signal reception time of the first low-frequency signal of the first transmitter at the first receiver and the second receiver of the primary device; The position of the second transmitter is defined as a point on a second straight line pointing to the geometric center of the primary device; wherein the second straight line is determined based on the time difference between the signal reception time of the second low-frequency signal of the second transmitter at the first receiver and the second receiver of the primary device. Based on the time difference between the arrival of the low-frequency signal from the first transmitter to the primary device and the arrival of the low-frequency signal from the second transmitter to the primary device, a first starting point on the first straight line is moved along the first straight line by a distance obtained by multiplying the time difference by the speed of light; or a second starting point on the second straight line is moved along the second straight line by a distance obtained by multiplying the time difference by the speed of light; and Through the movement, the positions of the first transmitter and the second transmitter are calculated such that a first distance from a first starting point on the first straight line to the first transmitter becomes equal to a second distance from a second starting point on the second straight line to the second transmitter. This includes calculating a first time difference between the reception times of the first low-frequency signal at the first receiver and at the second receiver; generating a first circle with the second receiver as its center and a radius half the distance obtained by multiplying the first time difference by the speed of light; generating a first tangent line passing through the first receiver and tangent to the first circle; and generating a first straight line passing through the first receiver and orthogonal to the first tangent line, with the second point where the first tangent line intersects the first straight line being the first starting point. Specifically, a second time difference is calculated between the reception times of the second low-frequency signal at the first receiver and the second receiver; a second circle is generated with the second receiver as the center, and the radius is half the distance obtained by multiplying the second time difference by the speed of light; a second tangent line is generated that passes through the first receiver and is tangent to the second circle; and a second straight line is generated that passes through the first receiver and is orthogonal to the second tangent line, with the fourth point where the second tangent line intersects the second straight line being the second starting point.

2. The location estimation method according to claim 1, wherein, The second receiver is positioned closer to the first transmitter and the second transmitter than the first receiver.

3. The location estimation method according to claim 1, wherein, The first receiver is positioned closer to the first transmitter and the second transmitter than the second receiver.

4. The location estimation method according to claim 1, further comprising: The positions on the first and second lines, where the gap between the first and second lines is equal to the distance between the first and second transmitters, are respectively defined as the positions of the first and second transmitters.

5. The location estimation method according to claim 4, further comprising: The distance and direction of the geometric center of the secondary device relative to the geometric center of the primary device are determined, and the geometric center of the secondary device is obtained based on the positions of the first transmitter and the second transmitter.

6. The location estimation method according to claim 1, wherein, The location of the first transmitter is defined as follows: The first transmitter is located on the first straight line with the first starting point.

7. The location estimation method according to claim 1, wherein, Defining the location of the second transmitter includes: The second transmitter is located on the second straight line with the second starting point.

8. A position estimation method for precise positioning, performed by an electric vehicle (EV) or EV device, the EV or EV device having an EV communication controller (EVCC) and a secondary device, the EV communication controller being connected via a network to a supply device communication controller (SECC) of a supply device, the secondary device being equipped with at least a first transmitter and a second transmitter, the position estimation method comprising: The first transmitter transmits a first low-frequency signal to a first receiver and a second receiver of the primary device of the supply device, and based on the response received from the SECC related to the first low-frequency signal, the position of the first transmitter is defined on a first straight line extending outward from the geometric center of the primary device of the supply device; wherein the first straight line is determined based on the time difference between the signal reception time of the first low-frequency signal from the first transmitter at the first receiver and the second receiver of the primary device. Based on the transmission of a second low-frequency signal to the first and second receivers via the second transmitter, the position of the second transmitter is defined on a second straight line extending outward from the geometric center of the primary device of the supply device; wherein the second straight line is determined based on the time difference between the signal reception time of the second low-frequency signal from the second transmitter at the first and second receivers of the primary device; Calculate the time difference between the arrival of the first low-frequency signal and the second low-frequency signal at the receivers closer to the first transmitter and the second transmitter; In response to the transmitter being closer to the primary device being the first transmitter, a first starting point 'a' is determined by moving the first starting point of the first straight line toward the first transmitter according to the time difference; wherein, a first time difference is calculated between the reception times of the first low-frequency signal at the first receiver and at the second receiver; a first circle is generated with the second receiver as the center, and the radius is half the distance obtained by multiplying the first time difference by the speed of light; a first tangent line is generated passing through the first receiver and tangent to the first circle; and a first normal line is generated passing through the first receiver and orthogonal to the first tangent line, the second point where the first tangent line intersects the first normal line being the first starting point; The position of the first transmitter located on the first straight line is determined as a point such that the distance from the first starting point a is the same as the distance between the second starting point of the second straight line and the second transmitter; wherein, a second time difference is calculated between the reception time of the second low-frequency signal at the first receiver and the second receiver; a second circle is generated with the second receiver as the center and the radius is half the distance obtained by multiplying the second time difference by the speed of light; a second tangent line is generated that passes through the first receiver and is tangent to the second circle; and a second normal line is generated that passes through the first receiver and is orthogonal to the second tangent line, the fourth point where the second tangent line intersects the second normal line is the second starting point.

9. The location estimation method according to claim 8, further comprising: In response to the fact that the transmitter closer to the primary device is the second transmitter, a second starting point a is determined by moving the second starting point of the second straight line toward the second transmitter according to the time difference; and The position of the second transmitter located on the second straight line is determined as a point whose distance from the starting point of the second a is the same as the distance between the first starting point of the first straight line and the first transmitter.

10. The location estimation method according to claim 8, wherein, The location of the first transmitter is defined as follows: The first transmitter is located on the first normal line having the first starting point.

11. The location estimation method according to claim 8, wherein, Defining the location of the second transmitter includes: The second transmitter is located on the second normal line having the second starting point.

12. The location estimation method according to claim 8, further comprising: The positions on the first normal and the second normal, where the gap between the first normal and the second normal is equal to the distance between the first transmitter and the second transmitter, are respectively defined as the positions of the first transmitter and the second transmitter.

13. The location estimation method according to claim 12, further comprising: The distance and direction of the geometric center of the secondary device relative to the geometric center of the primary device are determined, and the geometric center of the secondary device is obtained based on the positions of the first transmitter and the second transmitter.

14. A position estimation device for precise positioning, executed by an electric vehicle (EV) or EV device, the EV or EV device having an EV communication controller (EVCC) and a secondary device, the EV communication controller being connected via a network to a supply device communication controller (SECC) of a supply device, the secondary device being equipped with at least a first transmitter and a second transmitter, the position estimation device comprising: processor; as well as The memory stores instructions that the processor can execute. Wherein, when the instruction is executed by the processor, it causes the processor to perform: The position of the first transmitter is defined as a point on a first straight line pointing to the geometric center of the primary device of the supply device; wherein the first straight line is determined based on the time difference between the signal reception time of the first low-frequency signal of the first transmitter at the first receiver and the second receiver of the primary device; The position of the second transmitter is defined as a point on a second straight line pointing to the geometric center of the primary device; wherein the second straight line is determined based on the time difference between the signal reception time of the second low-frequency signal of the second transmitter at the first receiver and the second receiver of the primary device. Based on the time difference between the arrival of the low-frequency signal from the first transmitter to the primary device and the arrival of the low-frequency signal from the second transmitter to the primary device, a first starting point on the first straight line is moved along the first straight line by a distance obtained by multiplying the time difference by the speed of light; or a second starting point on the second straight line is moved along the second straight line by a distance obtained by multiplying the time difference by the speed of light; and Through the movement, the positions of the first transmitter and the second transmitter are calculated such that a first distance from a first starting point on the first straight line to the first transmitter becomes equal to a second distance from a second starting point on the second straight line to the second transmitter. This includes calculating a first time difference between the reception times of the first low-frequency signal at the first receiver and at the second receiver; generating a first circle with the second receiver as its center and a radius half the distance obtained by multiplying the first time difference by the speed of light; generating a first tangent line passing through the first receiver and tangent to the first circle; and generating a first straight line passing through the first receiver and orthogonal to the first tangent line, with the second point where the first tangent line intersects the first straight line being the first starting point. Specifically, a second time difference is calculated between the reception times of the second low-frequency signal at the first receiver and the second receiver; a second circle is generated with the second receiver as the center, and the radius is half the distance obtained by multiplying the second time difference by the speed of light; a second tangent line is generated that passes through the first receiver and is tangent to the second circle; and a second straight line is generated that passes through the first receiver and is orthogonal to the second tangent line, with the fourth point where the second tangent line intersects the second straight line being the second starting point.

Images