WO2020060140A1

WO2020060140A1 - Apparatus and method for detecting foreign material in wireless power transmission system

Info

Publication number: WO2020060140A1
Application number: PCT/KR2019/011975
Authority: WO
Inventors: 김진홍
Original assignee: 엘지전자 주식회사
Priority date: 2018-09-21
Filing date: 2019-09-17
Publication date: 2020-03-26

Abstract

An apparatus and a method for detecting foreign material in a wireless power transmission system are provided. Disclosed in the present specification is a wireless power reception device for detecting foreign material by using a first regression equation determined on the basis of at least one parameter that is measurable in a wireless power transmission system, the wireless power reception device comprising: a power pickup unit for receiving wireless power from a wireless power transmission device by means of magnetic coupling with the wireless power transmission device and converting an alternating current signal, generated by the wireless power, into a direct current signal; a communication/control unit for receiving the direct current signal from the power pickup unit and controlling the wireless power; and a load for receiving the direct current signal from the power pickup unit. The accuracy and reliability of foreign material detection can be improved by supporting foreign material detection performed by the wireless power reception device.

Description

Apparatus and method for performing foreign object detection in wireless power transmission system

The present invention relates to a wireless power transmission system, and more particularly, to an apparatus and method for performing foreign object detection in a wireless power transmission system.

Wireless power transmission technology is a technology that wirelessly transfers power between a power source and an electronic device. As an example, the wireless power transmission technology allows a battery of a wireless terminal to be charged simply by placing a wireless terminal such as a smartphone or tablet on the wireless charging pad, and is superior to a wired charging environment using a conventional wired charging connector. It can provide mobility, convenience and safety. Wireless power transmission technology is attracting attention to replace the existing wired power transmission environment in various fields such as consumer electronics, industrial devices, military devices, automobiles, infrastructure, and medical devices.

In the terminal supply method, if the terminal connection is good between the charger and the terminal, there is no possibility that there is an obstacle that prevents charging, such as a foreign object. On the other hand, the wireless power transmission system, due to the characteristic of contactless charging, unnecessary foreign matter may be inserted between the wireless power receiving device and the wireless power transmitting device during charging. If a foreign object such as a metal is caught between the wireless power transmitter and the wireless power receiver, the power transmission may not be smoothly performed due to the foreign matter, and problems such as burnout and explosion of the product due to overload and heat generation of foreign matter may occur. have. In order to solve this, various foreign matter detection methods have been introduced, but as the size of power increases, such as rapid wireless charging, the severity of the foreign matter detection error is getting larger. Therefore, there is a need to further improve the accuracy and reliability of foreign matter detection.

An object of the present invention is to provide an apparatus and method for improving the reliability and accuracy of foreign matter detection in a wireless power transmission system.

Another technical problem of the present invention is to provide a wireless power receiving apparatus and method for performing foreign object detection.

Another technical problem of the present invention is to provide a wireless power transmission apparatus and method for supporting a foreign material detection procedure by a wireless power reception apparatus.

According to an aspect, there is provided an apparatus for receiving wireless power from a wireless power transmitter based on foreign object detection in a wireless power transmitter system. The apparatus is configured to receive wireless power from the wireless power transmitter by magnetic coupling with the wireless power transmitter, and convert the AC signal generated by the wireless power into a DC signal. (power pick-up unit), a communication / control unit configured to receive the DC signal from the power pickup unit and perform control of the wireless power, and a load configured to receive the DC signal from the power pickup unit (load) ).

Here, the communication / control unit may perform foreign matter detection using a first regression equation determined based on at least one parameter measurable in a wireless power transmission system.

In one aspect, the at least one parameter includes the current of the primary coil provided in the wireless power transmitter, the current can be measured before or during the reception of the wireless power.

In another aspect, the at least one parameter includes a quality factor, a rail voltage (Vrail) and a rail current (Irail) of the wireless power transmitter, and a power loss (Ploss) generated in the process of receiving the wireless power, the It may include at least three of the current of the primary coil provided in the wireless power transmission device.

In another aspect, the first regression equation includes the quality factor, the rail voltage (Vrail) and the rail current (Irail) of the wireless power transmitter, and the power loss (Ploss) generated in the process of receiving the wireless power. , It may be determined based on at least two or more parameters of the current of the primary coil provided in the wireless power transmission device.

In another aspect, the first regression equation includes the quality factor, the rail voltage (Vrail) and the rail current (Irail) of the wireless power transmitter, and the power loss (Ploss) generated in the process of receiving the wireless power. , It may be determined based on additional parameters calculated by performing arithmetic operations on at least two or more parameters of the current of the primary coil provided in the wireless power transmission apparatus.

In another aspect, the foreign matter detection procedure includes: the communication / control unit measuring the at least one parameter to obtain a measurement value, and substituting the measurement value into the first regression equation to obtain a result value A step and a step of determining whether a foreign substance is detected may be performed based on whether the result value falls within a range treated as a foreign substance.

In another aspect, the first regression equation may be individually defined for each type of foreign material.

In another aspect, the first regression equation may be individually defined for each section when the measured value of the at least one parameter is divided into a plurality of sections.

In another aspect, the at least one parameter may be a resistance value (= rail voltage / rail current) measured by the wireless power transmission device.

In another aspect, the communication / control unit may detect the position alignment of the wireless power receiver using the second regression equation determined based on at least one parameter measurable in the wireless power transmission system.

The accuracy and reliability of foreign matter detection can be improved by supporting the performance of foreign matter detection by the wireless power receiver.

1 is a block diagram of a wireless power system 10 according to an embodiment.

2 is a block diagram of a wireless power system 10 according to another embodiment.

3A shows an embodiment of various electronic devices in which a wireless power transmission system is introduced.

3B shows an example of a WPC NDEF in a wireless power transmission system.

4A is a block diagram of a wireless power transmission system according to another embodiment.

4B is a diagram illustrating an example of a Bluetooth communication architecture to which the present invention can be applied.

4C is a block diagram illustrating a wireless power transmission system using BLE communication according to an example.

4D is a block diagram illustrating a wireless power transmission system using BLE communication according to another example.

5 is a state transition diagram for explaining a wireless power transmission procedure.

6 illustrates a power control control method according to an embodiment.

7 is a block diagram of a wireless power transmission apparatus according to another embodiment.

8 shows a wireless power receiving apparatus according to another embodiment.

9 shows a communication frame structure according to an embodiment.

10 is a structure of a sink pattern according to an embodiment.

11 illustrates an operation state of a wireless power transmitter and a wireless power receiver in a shared mode according to an embodiment.

12 is a flowchart illustrating a method of performing foreign object detection according to an embodiment.

13 shows a histogram of a wireless power receiving device and a wireless power receiving device + foreign matter according to another example.

14 illustrates a histogram of a wireless power receiving device and a wireless power receiving device + foreign matter according to another example.

15 illustrates a histogram of a wireless power receiver and a wireless power receiver + foreign matter according to another example.

16 illustrates a histogram of a wireless power receiving device and a wireless power receiving device + foreign matter according to another example.

17 is the current of the primary coil measured before the start of wireless power transmission, and FIG. 18 is the primary coil current measured during the wireless power transmission.

19 is a diagram illustrating a process of deriving various variables and regression equations to be applied to a regression analysis according to an example.

20 is a histogram simulating the performance of a foreign material detection algorithm derived based on a regression analysis according to an example.

21 is a diagram illustrating a process of deriving various variables and regression equations to be applied to regression analysis according to another example.

22 is a histogram simulating the performance of a foreign object detection algorithm derived based on regression analysis according to another example.

23 is a diagram illustrating a process of deriving various variables and regression equations to be applied to regression analysis according to another example.

24 is a histogram simulating the performance of a foreign material detection algorithm derived based on a regression analysis according to another example.

25 is a diagram illustrating a process of deriving various variables and regression equations to be applied to regression analysis according to another example.

FIG. 26 is a histogram simulating the performance of a foreign material detection algorithm derived based on a regression analysis using 9 FOD parameters according to FIG. 25.

27 is a diagram illustrating a process of deriving various variables and regression equations to be applied to regression analysis according to another example.

FIG. 28 is a histogram simulating the performance of a foreign material detection algorithm derived based on regression analysis applying 13 FOD parameters according to FIG. 27.

29A and 29B are diagrams illustrating a process of deriving various variables and regression equations to be applied to regression analysis according to another example.

FIG. 30 is a histogram simulating the performance of a foreign material detection algorithm derived based on regression analysis using 22 FOD parameters according to FIGS. 29A and 29B.

31A and 31B are diagrams illustrating a process of deriving various variables and regression equations to be applied to regression analysis according to another example.

FIG. 32 is a histogram simulating the performance of a foreign material detection algorithm derived based on regression analysis using 14 FOD parameters according to FIGS. 31A and 31B.

33A and 33B are diagrams illustrating a process of deriving various variables and regression equations to be applied to regression analysis according to another example.

FIG. 34 is a histogram simulating the performance of a foreign material detection algorithm derived based on a regression analysis using 13 FOD parameters according to FIGS. 33A and 33B.

35A and 35B are diagrams illustrating a process of deriving various variables and regression equations to be applied to regression analysis according to another example.

FIG. 36 is a histogram simulating the performance of a foreign material detection algorithm derived based on a regression analysis using 15 FOD parameters according to FIGS. 35A and 35B.

37 is a diagram illustrating a process of deriving various variables and regression equations to be applied to regression analysis according to another example.

38 is a histogram simulating the performance of the foreign material detection algorithm derived based on regression analysis applying 13 FOD parameters according to FIG. 37.

39 is a diagram illustrating a process of deriving various variables and regression equations to be applied to regression analysis according to another example.

FIG. 40 is a histogram simulating the performance of a foreign material detection algorithm derived based on a regression analysis using nine FOD parameters according to FIG. 39.

41A and 41B are diagrams illustrating a process of deriving various variables and regression equations to be applied to regression analysis according to another example.

FIG. 42 is a histogram simulating the performance of a foreign material detection algorithm derived based on a regression analysis using 13 FOD parameters according to FIGS. 41A and 41B.

43A and 43B are diagrams illustrating a process of deriving various variables and regression equations to be applied to regression analysis according to another example.

FIG. 44 is a histogram simulating the performance of a foreign material detection algorithm derived based on a regression analysis using 11 FOD parameters according to FIGS. 43A and 43B.

45A and 45B are diagrams illustrating a process of deriving various variables and regression equations to be applied to regression analysis according to another example.

FIG. 46 is a histogram simulating the performance of a foreign material detection algorithm derived based on a regression analysis using 11 FOD parameters according to FIGS. 45A and 45B.

47A and 47B are tables showing various FOD parameters to be applied to a regression analysis according to another example.

48A to 48C are histograms simulating the performance of a foreign material detection algorithm derived based on regression analysis using 19 FOD parameters according to FIGS. 47A and 47B.

49 is a flowchart illustrating a method of detecting a foreign object according to an embodiment.

50 is a flowchart illustrating a method of detecting a foreign material according to another embodiment.

FIG. 51 shows a histogram when the wireless power receiver and the foreign material are aligned with the center and when they are not aligned.

52A and 52B illustrate an experimental process for determining an optimal FOD parameter for regression analysis for each section.

53 is a flowchart illustrating a method of detecting a foreign material according to another embodiment.

54A to 54C are experimental results showing the presence / absence of a foreign material as a histogram when regression analysis is performed by dividing the resistance R into 1, 2, 4, 7, 13, and 27 sections.

55 is a graph showing a correspondence relationship between the number of sections and the z value for the R measurement value.

56A and 56B are simulation results showing a histogram of a wireless power receiving device (phone) located at the center of a wireless power transmitting device and a wireless power receiving device 5 to 7 mm away from the center based on regression analysis according to an example.

57A and 57B show histograms of multiple wireless power receivers located at the center of the wireless power transmitter and multiple wireless power receivers 0 mm, 5 mm, and 7 mm off the center based on regression analysis according to another example. It is a simulation result.

58 is a flowchart illustrating a method of detecting a position or misalignment according to an embodiment.

59 is a flowchart illustrating a method for detecting a location according to another embodiment.

The term " wireless power " used hereinafter is any form related to an electric field, magnetic field, electromagnetic field, etc. transmitted from a wireless power transmitter to a wireless power receiver without the use of physical electromagnetic conductors. It is used to mean the energy of. The wireless power may also be called a wireless power signal, and may mean an oscillating magnetic flux enclosed by the primary coil and the secondary coil. For example, power conversion in a system is described herein to wirelessly charge devices including mobile phones, cordless phones, iPods, MP3 players, headsets, and the like. In general, the basic principles of wireless power transmission include, for example, a method of delivering power through magnetic coupling, a method of delivering power through radio frequency (RF), and microwaves. ), A method of transmitting power, and a method of transmitting power through ultrasound.

1 is a block diagram of a wireless power system 10 according to an embodiment.

Referring to FIG. 1, the wireless power system 10 includes a wireless power transmission device 100 and a wireless power reception device 200.

The wireless power transmission apparatus 100 receives power from an external power source S to generate a magnetic field. The wireless power receiving device 200 generates electric current using the generated magnetic field to receive power wirelessly.

In addition, in the wireless power system 10, the wireless power transmission device 100 and the wireless power reception device 200 may transmit and receive various information necessary for wireless power transmission. Here, the communication between the wireless power transmission device 100 and the wireless power reception device 200 is in-band communication using a magnetic field used for wireless power transmission or out-band communication using a separate communication carrier. It can be performed according to any one of (out-band communication). Out-band communication may also be referred to as out-of-band communication. Hereinafter, terms are uniformly described through out-band communication. Examples of the out-band communication may include NFC, Bluetooth (Bluetooth), Bluetooth low energy (BLE).

Here, the wireless power transmission apparatus 100 may be provided as a fixed or mobile type. Examples of the fixed type include a type embedded in furniture such as an indoor ceiling or a wall or a table, an outdoor parking lot, a type installed in an implantation form at a bus stop or subway station, or a type installed in a vehicle or train. There is this. The portable wireless power transmission device 100 may be implemented as a part of another device, such as a portable device having a movable weight or size or a cover of a notebook computer.

In addition, the wireless power receiving device 200 should be interpreted as a comprehensive concept including various electronic devices having a battery and various household appliances that are powered by wireless power instead of power cables. Typical examples of the wireless power receiving device 200 include a portable terminal, a cellular phone, a smart phone, a personal digital assistant (PDA), and a portable media player (PMP: Portable Media Player), Wibro terminal, tablet, phablet, notebook, digital camera, navigation terminal, television, and electric vehicle (EV).

In the wireless power system 10, the wireless power receiving apparatus 200 may be one or more. In FIG. 1, the wireless power transmission device 100 and the wireless power reception device 200 are represented as exchanging power on a one-to-one basis, but as illustrated in FIG. 2, one wireless power transmission device 100 includes a plurality of wireless power reception devices It is also possible to transfer power to (200-1, 200-2, ..., 200-M). In particular, in the case of performing wireless power transmission in a self-resonance method, one wireless power transmission device 100 applies a simultaneous transmission method or a time division transmission method to simultaneously apply multiple wireless power reception devices 200-1, 200-2, ..., 200-M).

In addition, although FIG. 1 shows a state in which the wireless power transmission device 100 directly transmits power to the wireless power reception device 200, wireless communication between the wireless power transmission device 100 and the wireless power reception device 200 is shown. A separate wireless power transmission / reception device such as a relay or repeater for increasing the power transmission distance may be provided. In this case, power is transmitted from the wireless power transmission device 100 to the wireless power transmission / reception device, and the wireless power transmission / reception device may transmit power to the wireless power reception device 200 again.

Hereinafter, the wireless power receiver, the power receiver, and the receiver referred to herein refer to the wireless power receiving device 200. In addition, the wireless power transmitter, the power transmitter, and the transmitter referred to in this specification refer to the wireless power receiving and transmitting device 100.

3A shows electronic devices classified according to the amount of power transmitted and received in the wireless power transmission system. 3A, wearable devices such as a smart watch, a smart glass, a head mounted display (HMD), and a smart ring and earphones, a remote control, a smartphone, a PDA, and a tablet A small power (about 5 W or less or about 20 W or less) wireless charging method may be applied to mobile electronic devices such as PCs (or portable electronic devices).

Medium / small-sized household appliances such as laptops, robot cleaners, TVs, sound equipment, vacuum cleaners, and monitors may be applied with a medium power (about 50W or less or about 200W) wireless charging method. Personal mobile devices (or electronic devices / mobile devices) such as blenders, microwave ovens, kitchen appliances such as electric rice cookers, wheelchairs, electric kickboards, electric bicycles, and electric vehicles have high power (approximately 2 kW or less or 22 kW or less). Wireless charging may be applied.

The above-mentioned (or shown in FIG. 1) electronic devices / mobile means may each include a wireless power receiver described later. Accordingly, the above-mentioned electronic devices / mobile means can be charged by wirelessly receiving power from the wireless power transmitter.

Hereinafter, a mobile device to which the power wireless charging method is applied will be mainly described, but this is only an example, and the wireless charging method according to the present invention may be applied to various electronic devices described above.

Standards for wireless power transmission include wireless power consortium (WPC), air fuel alliance (AFA), and power matters alliance (PMA).

The WPC standard defines a baseline power profile (BPP) and an extended power profile (EPP). BPP relates to a wireless power transmitter and receiver supporting 5W power transmission, and EPP relates to a wireless power transmitter and receiver supporting power transmission in a range greater than 5W and smaller than 30W.

Various wireless power transmitters and receivers using different power levels are covered for each standard and may be classified into different power classes or categories.

For example, WPC classifies wireless power transmission and reception devices into power class (PC) -1, PC0, PC1, and PC2, and provides standard documents for each PC. The PC-1 standard relates to wireless power transmitters and receivers that provide less than 5W of guaranteed power. The application of PC-1 includes a wearable device such as a smart watch.

The PC0 standard relates to a wireless power transmitter and receiver that provide 5W guaranteed power. The PC0 standard includes EPP with guaranteed power up to 30W. In-band (IB) communication is a mandatory communication protocol of PC0, but out-band (OB) communication used as an optional backup channel may also be used. The wireless power receiver can identify whether OB is supported by setting an OB flag in a configuration packet. A wireless power transmission apparatus supporting OB may enter an OB handover phase by transmitting a bit-pattern for OB handover in response to the configuration packet. The response to the configuration packet may be NAK, ND, or a newly defined 8-bit pattern. The application of PC0 includes a smartphone.

The PC1 standard relates to a wireless power transmitter and receiver that provide guaranteed power of 30W to 150W. OB is an essential communication channel for PC1, and IB is used as initialization and link establishment to OB. The wireless power transmitter may enter the OB handover phase using a bit pattern for OB handover in response to the configuration packet. Applications for PC1 include laptops or power tools.

The PC2 standard relates to a wireless power transmission and reception device that provides a guaranteed power of 200W to 2kW, and its application includes kitchen appliances.

As such, PCs may be distinguished according to power levels, and whether to support the same compatibility between PCs may be optional or mandatory. Here, compatibility between the same PCs means that power transmission and reception between the same PCs is possible. For example, when a wireless power transmitter that is PC x can charge a wireless power receiver having the same PC x, it can be considered that compatibility between the same PCs is maintained. Similarly, compatibility between different PCs may also be supported. Here, the compatibility between different PCs means that power transmission and reception is possible between different PCs. For example, when a wireless power transmitter that is PC x can charge a wireless power receiver having PC y, it can be considered that compatibility between different PCs is maintained.

Supporting compatibility between PCs is a very important issue in terms of user experience and infrastructure construction. However, there are technically several problems in maintaining compatibility between PCs.

In the case of compatibility between the same PCs, for example, a lap-top charging wireless power receiver capable of stably charging only when power is continuously transmitted is a wireless power transmitter of the same PC. However, there may be a problem in that power is stably supplied from a wireless power transmission device of an electric tool type that transmits power discontinuously. In addition, in the case of compatibility between different PCs, for example, the wireless power transmitter with a minimum guaranteed power of 200 W transmits power to the wireless power receiver with a maximum guaranteed power of 5 W, and the wireless power receiver is caused by overvoltage. There is a risk of damage. As a result, PCs are difficult to use as indicators / standards for representative / indicating compatibility.

Wireless power transmission and reception devices can provide a very convenient user experience and interface (UX / UI). That is, a smart wireless charging service may be provided, and the smart wireless charging service may be implemented based on a UX / UI of a smart phone including a wireless power transmission device. For these applications, the interface between the smartphone's processor and the wireless charging receiver allows for "drop and play" two-way communication between the wireless power transmitter and receiver.

As an example, a user may experience a smart wireless charging service in a hotel. When the user enters the hotel room and puts the smartphone on the wireless charger in the room, the wireless charger transmits wireless power to the smartphone, and the smartphone receives wireless power. In this process, the wireless charger transmits information about the smart wireless charging service to the smartphone. When the smart phone detects that it is located on the wireless charger, detects the reception of wireless power, or the smart phone receives information about the smart wireless charging service from the wireless charger, the smartphone agrees to the user as an additional feature ( opt-in). To this end, the smartphone may display a message on the screen in a manner with or without an alarm sound. An example of the message may include the phrase "Welcome to ### hotel. Select" Yes "to activate smart charging functions: Yes | No Thanks." The smartphone receives input from a user who selects Yes or No Thanks, and performs the next procedure selected by the user. If Yes is selected, the smartphone transmits the information to the wireless charger. And the smart phone and wireless charger perform the smart charging function together.

The smart wireless charging service may also include receiving WiFi credentials auto-filled. For example, the wireless charger transmits the WiFi qualification to the smartphone, and the smartphone automatically enters the WiFi qualification received from the wireless charger by running the appropriate app.

The smart wireless charging service may also include executing a hotel application that provides hotel promotions, or obtaining remote check-in / check-out and contact information.

As another example, a user may experience a smart wireless charging service in a vehicle. When the user boards the vehicle and puts the smartphone on the wireless charger, the wireless charger transmits wireless power to the smartphone, and the smartphone receives wireless power. In this process, the wireless charger transmits information about the smart wireless charging service to the smartphone. When the smart phone detects the location of the wireless charger, detects the reception of wireless power, or when the smart phone receives information about the smart wireless charging service from the wireless charger, the smart phone prompts the user to confirm identity. Enter the inquiry state.

In this state, the smartphone is automatically connected to the car via WiFi and / or Bluetooth. The smartphone may display a message on the screen in a manner with or without an alarm sound. An example of a message may include the phrase "Welcome to your car. Select" Yes "to synch device with in-car controls: Yes | No Thanks." The smartphone receives input from a user who selects Yes or No Thanks, and performs the next procedure selected by the user. If Yes is selected, the smartphone transmits the information to the wireless charger. In addition, the smart phone and the wireless charger run the in-vehicle application / display software to perform the in-vehicle smart control function together. The user can enjoy the desired music and check the regular map location. In-vehicle applications / display software may include the ability to provide synchronous access for passers-by.

As another example, a user may experience smart wireless charging at home. When the user enters the room and puts the smartphone on the wireless charger in the room, the wireless charger transmits wireless power to the smartphone, and the smartphone receives wireless power. In this process, the wireless charger transmits information about the smart wireless charging service to the smartphone. When the smart phone detects that it is located on the wireless charger, detects the reception of wireless power, or the smart phone receives information about the smart wireless charging service from the wireless charger, the smartphone agrees to the user as an additional feature ( opt-in). To this end, the smartphone may display a message on the screen in a manner with or without an alarm sound. An example of the message may include the phrase "Hi xxx, Would you like to activate night mode and secure the building ?: Yes | No Thanks." The smartphone receives input from a user who selects Yes or No Thanks, and performs the next procedure selected by the user. If Yes is selected, the smartphone transmits the information to the wireless charger. Smartphones and wireless chargers can at least recognize the user's pattern and invite the user to lock doors and windows, turn off lights, or set an alarm.

Hereinafter, a 'profile' will be newly defined as an index / reference indicating / indicating compatibility. That is, it can be interpreted that power transmission / reception is not possible between wireless power transmission / reception devices having the same “profile,” since compatibility is maintained, and stable power transmission / reception is possible. The profile may be defined depending on the compatibility and / or application regardless of (or independently) power class.

The profiles can be broadly divided into i) mobile and computing, ii) power tools, and iii) kitchens.

Or, the profile can be largely divided into four types: i) mobile, ii) electric tool, iii) kitchen and iv) wearable.

In the case of the 'mobile' profile, the PC can be defined as PC0 and / or PC1, the communication protocol / method is IB and OB, and the operating frequency is 87 to 205 kHz. You can.

In the case of the 'motorized tool' profile, the PC can be defined as PC1, the communication protocol / method is IB, and the operating frequency can be defined as 87 to 145 kHz. An example of an application may include a power tool.

In the case of the 'kitchen' profile, the PC may be defined as PC2, the communication protocol / method is NFC-based, and the operating frequency may be defined as less than 100kHz, and examples of the application may include a kitchen / home appliance.

For power tools and kitchen profiles, NFC communication can be used between the wireless power transmitter and receiver. The wireless power transmitter and receiver can confirm that they are NFC devices with each other by exchanging WPC NDEF (NFC Data Exchange Profile Format). For example, the WPC NDEF may include an application profile field (eg 1B), a version field (eg 1B), and profile specific data (eg 1B), as shown in FIG. 3B. You can. The application profile field indicates whether the device is i) mobile and computing, ii) power tool, and iii) kitchen, and the upper nibble in the version field indicates the major version and the lower nibble. (lower nibble) indicates a minor version. In addition, profile-specific data defines the content for the kitchen.

In the case of the 'wearable' profile, the PC can be defined as PC-1, the communication protocol / method is IB, and the operating frequency is 87 to 205 kHz, and examples of the application may include wearable devices worn on the user's body.

Maintaining compatibility between the same profiles may be mandatory, and maintaining compatibility between different profiles may be optional.

The above-described profiles (mobile profile, power tool profile, kitchen profile, and wearable profile) may be generalized and expressed as first to nth profiles, and new profiles may be added / replaced according to WPC standards and embodiments.

When the profile is defined as described above, the wireless power transmission apparatus selectively transmits power only to the wireless power receiving apparatus of the same profile as itself, thereby enabling more stable power transmission. In addition, since the burden on the wireless power transmitter is reduced and power transmission to the incompatible wireless power receiver is not attempted, the risk of damage to the wireless power receiver is reduced.

PC1 in the 'mobile' profile can be defined by borrowing an optional extension such as OB based on PC0, and in the case of the 'powered tools' profile, the PC1 'mobile' profile can be defined simply as a modified version. In addition, until now, it was defined for the purpose of maintaining the compatibility between the same profiles, but later, the technology may be developed in the direction of maintaining the compatibility between different profiles. The wireless power transmitter or the wireless power receiver may inform the other party of his / her profile through various methods.

In the AFA standard, a wireless power transmitter is called a power transmitting unit (PTU), and a wireless power receiver is called a power receiving unit (PRU), and the PTU is classified into a number of classes as shown in Table 1, and the PRU is shown in Table 2. It is classified into multiple categories.

	P_{TX_IN_MAX} P _{TX_IN_MAX}	최소 카테고리 지원 요구사항Minimum category support requirements	지원되는 최대 기기 개수를 위한 최소값Minimum value for the maximum number of devices supported
Class 1 Class 1	2W 2W		1x 카테고리 11x Category 1	1x 카테고리 1 1x Category 1
Class 2 Class 2	10W 10W		1x 카테고리 31x Category 3	2x 카테고리 2 2x Category 2
Class 3 Class 3	16W 16W		1x 카테고리 41x Category 4	2x 카테고리 3 2x Category 3
Class 4 Class 4	33W 33W		1x 카테고리 51x Category 5	3x 카테고리 3 3x Category 3
Class 5 Class 5	50W 50W		1x 카테고리 61x Category 6	4x 카테고리 3 4x Category 3
Class 6 Class 6	70W70 W		1x 카테고리 71x Category 7	5x 카테고리 3 5x Category 3

PRUPRU	P_{RX_OUT_MAX'} P _{RX_OUT_MAX '}	예시 어플리케이션 Example application

Category 1Category 1	TBDTBD	블루투스 헤드셋 Bluetooth headset

Category 2Category 2	3.5W3.5W	피쳐폰 Feature phone

Category 3Category 3	6.5W6.5W	스마트폰Smartphone

Category 4Category 4	13W13W	태블릿, 패플릿Tablet, leaflet

Category 5Category 5	25W25W	작은 폼팩터 랩탑Small form factor laptop

Category 6Category 6	37.5W37.5W	일반 랩탑 Generic laptop

Category 7Category 7	50W50W	가전Home Appliances

As shown in Table 1, the maximum output power capability of class n PTU is greater than or equal to the value of P _{TX_IN_MAX} of the class. The PRU cannot draw more power than is specified in that category.

4A, the wireless power transmission system 10 includes a mobile device 450 that receives power wirelessly and a base station 400 that wirelessly transmits power.

The base station 400 is a device that provides inductive power or resonant power, and may include at least one wireless power transmitter 100 and a system unit 405. The wireless power transmitter 100 may transmit induction power or resonant power, and control transmission. The wireless power transmitter 100 transmits power to a power conversion unit 110 that converts electrical energy into a power signal by generating a magnetic field through a primary coil (s) and an appropriate level. Thus, it may include a communication / control unit (communications & control unit, 120) for controlling the communication and power transmission with the wireless power receiver 200. The system unit 405 may perform other operation control of the base station 400 such as input power provisioning, control of a plurality of wireless power transmitters, and user interface control.

The primary coil may generate an electromagnetic field using alternating current power (or voltage or current). The primary coil may receive AC power (or voltage or current) of a specific frequency output from the power conversion unit 110, thereby generating a magnetic field of a specific frequency. The magnetic field may be generated in a non-radiation type or a radial type, and the wireless power receiving device 200 receives this to generate a current. In other words, the primary coil is to transmit power wirelessly.

In the magnetic induction method, the primary coil and the secondary coil may have any suitable shapes, and may be copper wire wound around high permeability formations, such as ferrite or amorphous metal. The primary coil may also be referred to as a transmitting coil, a primary core, a primary winding, a primary loop antenna, or the like. Meanwhile, the secondary coil may be called a receiving coil, a secondary core, a secondary winding, a secondary loop antenna, or a pickup antenna. .

When using the self-resonance method, the primary coil and the secondary coil may be provided in the form of a primary resonant antenna and a secondary resonant antenna, respectively. The resonant antenna may have a resonant structure including a coil and a capacitor. At this time, the resonance frequency of the resonant antenna is determined by the inductance of the coil and the capacitance of the capacitor. Here, the coil may be formed in the form of a loop. Also, a core may be disposed inside the roof. The core may include a physical core such as a ferrite core or an air core.

Energy transmission between the primary resonant antenna and the secondary resonant antenna may be achieved through a resonance phenomenon of a magnetic field. Resonant phenomenon refers to a phenomenon in which high-efficiency energy transfer occurs between two resonant antennas when both resonant antennas are coupled to each other when adjacent resonant antennas are located when a near field corresponding to the resonant frequency occurs in one resonant antenna. . When a magnetic field corresponding to a resonance frequency is generated between the primary and secondary resonant antenna antennas, a phenomenon occurs in which the primary and secondary resonant antennas resonate with each other, and accordingly, in the general case, the primary resonant antenna The magnetic field is focused toward the secondary resonant antenna with higher efficiency than when the magnetic field is radiated into the free space, and thus energy can be transferred from the primary resonant antenna to the secondary resonant antenna with high efficiency. The magnetic induction method may be implemented similarly to the magnetic resonance method, but at this time, the frequency of the magnetic field need not be the resonance frequency. Instead, in the magnetic induction method, matching between the loops constituting the primary coil and the secondary coil is required, and the gap between the loops must be very close.

Although not shown in the drawing, the wireless power transmitter 100 may further include a communication antenna. The communication antenna may transmit and receive communication signals using communication carriers other than magnetic field communication. For example, the communication antenna may transmit and receive communication signals such as Wi-Fi, Bluetooth, Bluetooth LE, ZigBee, and NFC.

The communication / control unit 120 may transmit and receive information with the wireless power receiving device 200. The communication / control unit 120 may include at least one of an IB communication module or an OB communication module.

The IB communication module can transmit and receive information using a magnetic wave having a specific frequency as a center frequency. For example, the communication / control unit 120 performs in-band communication by transmitting communication information on the operating frequency of wireless power transmission through the primary coil or receiving the operating frequency containing the information through the primary coil. can do. At this time, modulation methods such as binary phase shift keying (BPSK) or amplitude shift keying (ASK) and Manchester coding or non-return-to-zero level (NZR-L) level) Coding methods such as coding can be used to store information on magnetic waves or to interpret magnetic waves containing information. Using such IB communication, the communication / control unit 120 can transmit and receive information up to a distance of several meters at a data rate of several kbps.

The OB communication module uses a frequency band different from the operating frequency of the IB, and may perform out-band communication through a communication antenna. For example, the communication / control unit 120 may be provided as a short-range communication module. Examples of the short-range communication module include a communication module such as Wi-Fi, Bluetooth, Bluetooth LE, ZigBee, NFC.

The communication / control unit 120 may control the overall operation of the wireless power transmission device 100. The communication / control unit 120 may perform various information calculation and processing, and control each component of the wireless power transmission apparatus 100.

The communication / control unit 120 may be implemented as a computer or similar device using hardware, software, or a combination thereof. In hardware, the communication / control unit 120 may be provided in the form of an electronic circuit that processes an electrical signal and performs a control function, and in software, in the form of a program that drives the hardware communication / control unit 120. Can be provided.

The communication / control unit 120 may control transmission power by controlling an operating point. The operating point to be controlled may correspond to a combination of frequency (or phase), duty cycle, duty ratio and voltage amplitude. The communication / control unit 120 may control transmission power by adjusting at least one of frequency (or phase), duty cycle, duty ratio, and voltage amplitude. In addition, the wireless power transmitter 100 supplies constant power, and the wireless power receiver 200 may also control the received power by controlling the resonance frequency.

The mobile device 450 receives and stores the power received from the wireless power receiving device (power receiver, 200) and the wireless power receiving device 200 that receives wireless power through a secondary coil (Secondary Coil) and stores the device It includes a load (455) supplied to the.

The wireless power receiver 200 may include a power pick-up unit 210 and a communication & control unit 220. The power pickup unit 210 may receive wireless power through a secondary coil and convert it into electrical energy. The power pickup unit 210 rectifies the AC signal obtained through the secondary coil and converts it into a DC signal. The communication / control unit 220 may control transmission and reception of wireless power (power transmission and reception).

The secondary coil may receive wireless power transmitted from the wireless power transmission device 100. The secondary coil may receive power using a magnetic field generated by the primary coil. Here, when a specific frequency is a resonance frequency, a self-resonance phenomenon occurs between the primary coil and the secondary coil, so that power can be efficiently transmitted.

Although not shown in FIG. 4A, the communication / control unit 220 may further include a communication antenna. The communication antenna may transmit and receive communication signals using communication carriers other than magnetic field communication. For example, the communication antenna may transmit and receive communication signals such as Wi-Fi, Bluetooth, Bluetooth LE, ZigBee, and NFC.

The communication / control unit 220 may transmit and receive information with the wireless power transmission device 100. The communication / control unit 220 may include at least one of an IB communication module or an OB communication module.

The IB communication module can transmit and receive information using a magnetic wave having a specific frequency as a center frequency. For example, the communication / control unit 220 transmits IB communication by transmitting communication information on an operating frequency used for wireless power transmission through a secondary coil or receiving an operating frequency containing communication information through a secondary coil. Can be done. At this time, modulation methods such as binary phase shift keying (BPSK) or amplitude shift keying (ASK) and Manchester coding or non-return-to-zero level (NZR-L) level) Coding methods such as coding can be used to store information on magnetic waves or to interpret magnetic waves containing information. Using such IB communication, the communication / control unit 220 can transmit and receive information up to a distance of several meters at a data rate of several kbps.

The OB communication module uses an operating frequency of wireless power transmission, but may perform out-band communication through a communication antenna. For example, the communication / control unit 220 may be provided as a short-range communication module.

Examples of the short-range communication module include a communication module such as Wi-Fi, Bluetooth, Bluetooth LE, ZigBee, NFC.

The communication / control unit 220 may control the overall operation of the wireless power receiving device 200. The communication / control unit 220 may perform various information calculation and processing, and control each component of the wireless power receiving device 200.

The communication / control unit 220 may be implemented as a computer or similar device using hardware, software, or a combination thereof. In hardware, the communication / control unit 220 may be provided in the form of an electronic circuit that processes an electrical signal to perform a control function, and in software, in the form of a program that drives the hardware communication / control unit 220. Can be provided.

When the communication / control unit 120 and the communication / control unit 220 are Bluetooth or Bluetooth LE as an OB communication module or a short-range communication module, the communication / control unit 120 and the communication / control unit 220 are respectively shown in FIG. 4B. It can be implemented and operated with the same communication architecture.

Referring to FIG. 4B, FIG. 4B (a) shows an example of a Bluetooth Basic Rate (BR) / Enhanced Data Rate (EDR) protocol stack supporting GATT, and (b) shows Bluetooth Low Energy (LE). Here is an example of a protocol stack.

Specifically, as shown in (a) of Figure 4b, the Bluetooth BR / EDR protocol stack is based on the host controller interface (Host Controller Interface, HCI, 18), the upper controller stack (Controller stack, 460) and the lower It may include a host stack (Host Stack, 470).

The host stack (or host module) 470 refers to a wireless transmission / reception module receiving a Bluetooth signal of 2.4 GHz and hardware for transmitting or receiving Bluetooth packets, and the controller stack 460 is connected to the Bluetooth module to connect the Bluetooth module. Control and perform actions.

The host stack 470 may include a BR / EDR PHY layer 12, a BR / EDR baseband layer 14, and a link manager layer (Link Manager 16).

The BR / EDR PHY layer 12 is a layer that transmits and receives a 2.4 GHz wireless signal. When using GFSK (Gaussian Frequency Shift Keying) modulation, it is possible to transmit data by hopping 79 RF channels.

The BR / EDR baseband layer 14 is responsible for transmitting a digital signal, selects a channel sequence hopping 1400 times per second, and transmits a time slot of 625us long for each channel.

The link manager layer 16 controls the overall operation (link setup, control, security) of the Bluetooth connection by utilizing the Link Manager Protocol (LMP).

The link manager layer 16 may perform the following functions.

-ACL / SCO logical transport, logical link setup and control.

-Detach: Terminates the connection and informs the other device of the reason for the interruption.

-Power control and role switch.

-Security (authentication, pairing, encryption) functions are performed.

The host controller interface layer 18 provides an interface between the host module and the controller module, so that the host provides commands and data to the controller, and the controller provides events and data to the host.

The host stack (or host module, 20) includes a logical link control and adaptation protocol (L2CAP, 21), an attribute protocol (Protocol, 22), a generic attribute profile (GATT, 23), and a generic access profile (Generic Access) Profile, GAP, 24), BR / EDR profile 25.

The logical link control and adaptation protocol (L2CAP, 21) may provide one bidirectional channel for transmitting data to a specific protocol or captive file.

The L2CAP 21 can multiplex various protocols, profiles, etc. provided by the upper Bluetooth.

L2CAP of Bluetooth BR / EDR uses dynamic channel, supports protocol service multiplexer, retransmission, streaming mode, and provides segmentation and reassembly, per-channel flow control, and error control.

The general attribute profile (GATT, 23) may be operable as a protocol that describes how the attribute protocol 22 is used when configuring services. For example, the general attribute profile 23 may be operable to specify how ATT attributes are grouped together into services, and may be operable to describe features associated with services.

Accordingly, the general attribute profile 23 and the attribute protocols ATT, 22 can use features to describe the device's state and services, and how features are related to each other and how they are used.

The attribute protocol 22 and the BR / EDR profile 25 define a service profile using Blues BR / EDR and an application protocol for exchanging and receiving these data, and the Generic Access Profile , GAP, 24) define device discovery, connectivity, and security levels.

As shown in FIG. 4B (b), the Bluetooth LE protocol stack includes a controller stack 480 operable to process a timing-critical wireless device interface and a host stack operable to process high level data. (Host stack, 490).

First, the controller stack 480 may be implemented using a communication module that may include a Bluetooth wireless device, for example, a processor module that may include a processing device such as a microprocessor.

The host stack 490 can be implemented as part of an OS running on a processor module, or as an instantiation of a package on top of the OS.

In some instances, the controller stack and host stack can be run or executed on the same processing device in the processor module.

The controller stack 480 includes a physical layer (PHY, 32), a link layer (Link Layer, 34) and a host controller interface (Host Controller Interface, 36).

The physical layer (PHY, wireless transmit / receive module, 32) is a layer that transmits and receives a 2.4 GHz wireless signal, and uses GFSK (Gaussian Frequency Shift Keying) modulation and a frequency hopping scheme consisting of 40 RF channels.

The link layer 34, which serves to transmit or receive Bluetooth packets, performs advertising and scanning functions using 3 advertising channels and then creates connections between devices, and up to 257 bytes of data packets through 37 data channels. It provides the function to send and receive.

The host stack includes a Generic Access Profile (GAP) 40, a logical link control and adaptation protocol (L2CAP, 41), a security manager (Security Manager, SM, 42), an attribute protocol (ATT, 440), and a general attribute profile. (Generic Attribute Profile, GATT, 44), Generic Access Profile (Generic Access Profile, 25), LT Profile 46. However, the host stack 490 is not limited thereto, and may include various protocols and profiles.

The host stack uses L2CAP to multiplex various protocols, profiles, etc. provided by Bluetooth.

First, Logical Link Control and Adaptation Protocol (L2CAP) 41 may provide one bidirectional channel for transmitting data to a specific protocol or profile.

The L2CAP 41 may be operable to multiplex data between upper layer protocols, segment and reassemble packages, and manage multicast data transmission.

In Bluetooth LE, three fixed channels (one for signaling CH, one for Security Manager, and one for Attribute protocol) are basically used. And, a dynamic channel may be used as needed.

On the other hand, a basic channel / enhanced data rate (BR / EDR) uses a dynamic channel, and supports protocol service multiplexer, retransmission, and streaming mode.

SM (Security Manager, 42) is a protocol for authenticating devices and providing key distribution.

ATT (Attribute Protocol, 43) defines the rules for accessing the data of the other device in the server-client (Server-Client) structure. ATT has the following 6 message types (Request, Response, Command, Notification, Indication, Confirmation).

① Request and Response message: The Request message is a message for requesting and delivering specific information from the client device to the server device, and the Response message is a response message to the Request message, which can be used for transmission from the server device to the client device Says

② Command message: This is a message that is mainly sent from the client device to the server device to instruct a command of a specific operation. The server device does not send a response to the command message to the client device.

③ Notification message: This is a message sent for notification, such as an event, from the server device to the client device. The client device does not send a confirmation message for the notification message to the server device.

④ Indication and Confirm message: This is a message sent for notification, such as an event, from the server device to the client device. Unlike the Notification message, the client device sends a confirmation message for the Indication message to the server device.

The present invention enables a client to clearly know the data length by transmitting a value for the data length when requesting long data in a GATT profile using the attribute protocol (ATT, 43), and is characterized from the server using a UUID. The value can be sent.

The general access profile (GAP, 45) is a newly implemented layer for Bluetooth LE technology, and is used to control role selection and multi-profile operation for communication between Bluetooth LE devices.

In addition, the general access profile 45 is mainly used for device discovery, connection creation, and security procedures, and defines a method for providing information to a user, and defines the following attribute types.

① Service: Defines the basic behavior of the device by combining data-related behaviors

② Include: Define the relationship between services

③ Characteristics: Data value used in service

④ Behavior: Computer-readable format defined by UUID (Universal Unique Identifier, value type)

The LE profile 46 is a profile having a dependency on GATT and is mainly applied to a Bluetooth LE device. The LE profile 46 may be, for example, Battery, Time, FindMe, Proximity, Time, etc., and the specific contents of the GATT-based Profiles are as follows.

①Battery: How to exchange battery information

②Time: How to exchange time information

③FindMe: Provide alarm service according to distance

④Proximity: How to exchange battery information

The general attribute profile (GATT, 44) may be operable as a protocol that describes how the attribute protocol 43 is used when configuring services. For example, the general attribute profile 44 can be operable to define how ATT attributes are grouped together into services, and can be operable to describe features associated with services.

Thus, the general attribute profile 44 and the attribute protocols ATT, 43 can use features to describe the device's state and services, and how features are related to each other and how they are used.

The design direction of the BLE GATT profile in relation to wireless power transmission is as follows.

1. The communication physical layer of WPC can be replaced from in-band communication to out-band communication.

2. If BLE is adopted as out-band communication, the BLE GATT profile should be designed to send and receive necessary messages at each stage in the WPC state machine.

3. The longest message in in-band communication is 8 bytes. Due to the characteristics of in-band communication, the bit per sec (bps) is low, and the communication performance may be poor due to the disturbance, so the system may be unstable to send and receive large messages at once. In a BLE with a relatively high bps, 20 bytes can be carried in a message. Therefore, necessary information for each phase can be stored for 20 bytes.

4. Since only the physical layer of WPC communication is converted from in-band communication to out-band communication, there should be no change in the sequence of sending and receiving messages using the existing in-band communication. Therefore, it should be designed to send and receive messages similar to WPC's state machine.

Hereinafter, procedures of Bluetooth Low Energy (BLE) technology will be briefly described.

The BLE procedure may be divided into a device filtering procedure, an advertising procedure, a scanning procedure, a discovery procedure, and a connecting procedure.

디바이스 필터링 절차(Device Filtering Procedure)Device Filtering Procedure

The device filtering procedure is a method for reducing the number of devices that respond to requests, instructions, and notifications from the controller stack.

Since it is unnecessary to respond to a request when all devices receive a request, the controller stack can control the BLE controller stack to reduce power consumption by reducing the number of request transmissions.

The advertising device or scanning device may perform the device filtering procedure to limit devices that receive advertising packets, scan requests, or connection requests.

Here, the advertisement device refers to a device that transmits an advertisement event, that is, performs an advertisement, and is also expressed as an advertiser.

The scanning device refers to a device that performs scanning and a device that transmits a scan request.

In BLE, when the scanning device receives some advertisement packets from the advertisement device, the scanning device must send a scan request to the advertisement device.

However, when a device filtering procedure is used and transmission of a scan request is unnecessary, the scanning device may ignore advertisement packets transmitted from the advertisement device.

The device filtering procedure may also be used in the connection request process. If device filtering is used in the connection request process, it is unnecessary to transmit a response to the connection request by ignoring the connection request.

광고 절차(Advertising Procedure)Advertising Procedure

The advertising device performs an advertising procedure to perform non-directional broadcasting to devices in the area.

Here, the non-directed broadcast (Undirected Advertising) is not a broadcast to a specific device, but rather to all (all) devices advertising (Advertising), all devices scan the advertisement (Advertising) to request additional information or You can make a connection request.

On the other hand, in directed advertising, only a device designated as a receiving device may scan an advertisement and request additional information or a connection.

The advertising procedure is used to establish a Bluetooth connection with a nearby initiating device.

Alternatively, the advertising procedure can be used to provide periodic broadcasts of user data to scanning devices that are listening on the advertising channel.

In the advertisement process, all advertisements (or advertisement events) are broadcast through the advertisement physical channel.

Advertising devices may receive a scan request from listening devices that are performing listening to obtain additional user data from the advertising device. The advertisement device transmits a response to the scan request to the device that transmitted the scan request through the same advertisement physical channel as the advertisement physical channel that received the scan request.

Broadcast user data sent as part of advertising packets is dynamic data, while scan response data is generally static data.

The advertising device may receive a connection request from the initiating device on the advertising (broadcast) physical channel. If the advertisement device uses a connectable advertisement event, and the initiating device is not filtered by the device filtering procedure, the advertisement device stops advertisement and enters connected mode. The advertising device may start advertising again after the connected mode.

스캐닝 절차(Scanning Procedure)Scanning Procedure

A device that performs scanning, that is, a scanning device, performs a scanning procedure to listen to a non-directional broadcast of user data from advertising devices using an advertising physical channel.

The scanning device sends a scan request to the advertising device through the advertising physical channel to request additional data from the advertising device. The advertisement device transmits a scan response in response to the scan request, including additional data requested by the scanning device through the advertisement physical channel.

The scanning procedure can be used while connecting to other BLE devices in the BLE piconet.

If the scanning device receives a broadcast advertisement event and is in an initiator mode capable of initiating a connection request, the scanning device sends the connection request to the advertisement device through the advertisement physical channel, thereby advertising device And Bluetooth connection can be started.

When the scanning device sends a connection request to the advertising device, the scanning device stops the initiator mode scanning for further broadcast and enters the connected mode.

디스커버링 절차(Discovering Procedure)Discovering Procedure

Devices capable of Bluetooth communication (hereinafter referred to as 'Bluetooth Devices') perform advertisement and scanning procedures to discover nearby devices or to be discovered by other devices within a given area.

The discovery procedure is performed asymmetrically. A Bluetooth device that seeks to find other devices around it is called a discovering device and listens to devices that advertise a scannable advertising event. A Bluetooth device found and available from another device is called a discoverable device, and actively broadcasts an advertising event to allow other devices to scan through the advertising (broadcast) physical channel.

Both the discovering device and the discoverable device may already be connected to other Bluetooth devices in the piconet.

연결 절차(Connecting Procedure)Connecting Procedure

The connection procedure is asymmetric, and the connection procedure requires that another Bluetooth device perform the scanning procedure while the specific Bluetooth device performs the advertisement procedure.

That is, the advertising process can be an objective, and as a result, only one device will respond to the advertisement. After receiving a connectable advertisement event from the advertisement device, the connection can be initiated by sending a connection request to the advertisement device through the advertisement (broadcast) physical channel.

Next, the operation state in the BLE technology, that is, the advertising state (Advertising State), the scanning state (Scanning State), the initiating state (Initiating State), and the connection state (connection state) will be briefly described.

광고 상태(Advertising State)Advertising State

The link layer LL enters the advertisement state by the instruction of the host (stack). When the link layer is in an advertisement state, the link layer transmits advertisement packet data units (PDUs) in advertisement events.

Each advertisement event is composed of at least one advertisement PDU, and advertisement PDUs are transmitted through advertisement channel indexes used. The advertisement event may be terminated when the advertisement PDU is transmitted through the advertisement channel indexes used, respectively, or the advertisement event may be terminated earlier if the advertisement device needs to reserve space for performing other functions.

스캐닝 상태(Scanning State)Scanning State

The link layer enters the scanning state at the instruction of the host (stack). In the scanning state, the link layer listens to the advertisement channel indices.

There are two types of scanning states: passive scanning and active scanning, and each scanning type is determined by the host.

No separate time or advertisement channel index is defined to perform scanning.

During the scanning state, the link layer listens to the advertisement channel index during the scanWindow duration. The scan interval (scanInterval) is defined as the interval (interval) between the start points of two consecutive scan windows.

If there is no scheduling conflict, the link layer should listen to complete all scan intervals of the scan window as indicated by the host. In each scan window, the link layer must scan different ad channel indexes. The link layer uses all available advertising channel indices.

In passive scanning, the link layer only receives packets, and cannot transmit any packets.

In the case of active scanning, the link layer performs listening to rely on the advertisement PDUs that can request advertisement PDUs and additional information related to the advertisement device to the advertisement device.

개시 상태(Initiating State)Initiating State

The link layer enters the start state by the instruction of the host (stack).

When the link layer is in the initiating state, the link layer performs listening on advertisement channel indexes.

During the initiation state, the link layer listens to the advertisement channel index during the scan window period.

연결 상태(connection state)Connection state

The link layer enters a connection state when a device performing a connection request, that is, when the initiating device sends the CONNECT_REQ PDU to the advertising device or when the advertising device receives the CONNECT_REQ PDU from the initiating device.

After entering the connection state, it is considered that a connection is created. However, it is not necessary to be considered to be established when the connection enters the connection state. The only difference between a newly created connection and an established connection is the link layer connection supervision timeout value.

When two devices are connected, they act in different roles.

The link layer performing the master role is called a master, and the link layer performing the slave role is called a slave. The master adjusts the timing of the connection event, and the connection event refers to the point in time between synchronization between the master and the slave.

Hereinafter, a packet defined in the Bluetooth interface will be briefly described. BLE devices use the packets defined below.

패킷 포맷(Packet Format)Packet Format

The link layer has only one packet format used for both advertising channel packets and data channel packets.

Each packet consists of four fields: Preamble, Access Address, PDU and CRC.

When one packet is transmitted on the advertisement channel, the PDU will be the advertisement channel PDU, and when one packet is transmitted on the data channel, the PDU will be the data channel PDU.

광고 채널 PDU(Advertising Channel PDU)Advertising Channel PDU (Advertising Channel PDU)

The advertising channel PDU (Packet Data Unit) has a 16-bit header and payloads of various sizes.

The PDU type field of the advertisement channel PDU included in the header indicates a PDU type as defined in Table 3 below.

PDU TypePDU Type	Packet NamePacket Name
00000000	ADV_INDADV_IND
00010001	ADV_DIRECT_INDADV_DIRECT_IND
00100010	ADV_NONCONN_INDADV_NONCONN_IND
00110011	SCAN_REQSCAN_REQ
01000100	SCAN_RSPSCAN_RSP
01010101	CONNECT_REQCONNECT_REQ
01100110	ADV_SCAN_INDADV_SCAN_IND
0111-11110111-1111	ReservedReserved

The advertising channel PDU types below the advertising PDU (advertising PDU) are called advertising PDUs and are used in specific events.

ADV_IND: Connectable non-directional advertising event

ADV_DIRECT_IND: Connectable directional advertising event

ADV_NONCONN_IND: Non-connectable non-directional advertising event

ADV_SCAN_IND: scannable non-directional advertising event

The PDUs are transmitted in the link layer in an advertisement state and received by the link layer in a scanning state or an initiating state.

스캐닝 PDU(Scanning PDU)Scanning PDU

The advertising channel PDU type below is called a scanning PDU and is used in the state described below.

SCAN_REQ: transmitted by the link layer in the scanning state and received by the link layer in the advertising state.

SCAN_RSP: transmitted by the link layer in the advertisement state, and received by the link layer in the scanning state.

개시 PDU(Initiating PDU)Initiating PDU

The advertising channel PDU type below is called a starting PDU.

CONNECT_REQ: transmitted by the link layer in the initiation state, and received by the link layer in the advertising state.

데이터 채널 PDU(Data Channel PDU)Data Channel PDU

The data channel PDU has a 16-bit header, a payload of various sizes, and may include a message integrity check (MIC) field.

The procedures, states, and packet formats in the BLE technology described above can be applied to perform the methods proposed in this specification.

Referring again to FIG. 4A, the load 455 may be a battery. The battery may store energy using power output from the power pickup unit 210. Meanwhile, the battery is not necessarily included in the mobile device 450. For example, the battery may be provided in an external configuration in a removable form. For another example, the wireless power receiving apparatus 200 may include driving means for driving various operations of the electronic device instead of the battery.

The mobile device 450 is shown to include the wireless power receiving device 200, and the base station 400 is shown to include the wireless power transmitting device 100, but in a broad sense, the wireless power receiving device ( 200) may be identified with the mobile device 450, and the wireless power transmitter 100 may be identified with the base station 400.

When the communication / control unit 120 and the communication / control unit 220 include Bluetooth or Bluetooth LE as an OB communication module or a short-range communication module other than the IB communication module, wireless power transmission including the communication / control unit 120 The wireless power receiving apparatus 200 including the apparatus 100 and the communication / control unit 220 may be represented by a simplified block diagram as shown in FIG. 4C.

Referring to Figure 4c, the wireless power transmission device 100 includes a power conversion unit 110 and the communication / control unit 120. The communication / control unit 120 includes an in-band communication module 121 and a BLE communication module 122.

Meanwhile, the wireless power receiving apparatus 200 includes a power pickup unit 210 and a communication / control unit 220. The communication / control unit 220 includes an in-band communication module 221 and a BLE communication module 222.

In one aspect,

BLE communication modules

122 and 222 perform the architecture and operation according to FIG. 4B. For example, the

BLE communication modules

122 and 222 may be used to establish a connection between the wireless power transmitter 100 and the wireless power receiver 200 and exchange control information and packets necessary for wireless power transmission. have.

In another aspect, the communication / control unit 120 can be configured to operate a profile for wireless charging. Here, the profile for wireless charging may be GATT using BLE transmission.

Meanwhile, the communication /

control units

120 and 220 include only the in-

band communication modules

121 and 221, respectively, as shown in FIG. 4D, and the

BLE communication modules

122 and 222 are communication / control units 120 and It is also possible to be provided separately from 220).

Hereinafter, the coil or coil part may also be referred to as a coil assembly, a coil cell, or a cell, including a coil and at least one element close to the coil.

Referring to FIG. 5, power transmission from a wireless power transmission apparatus to a receiver according to an embodiment of the present invention is largely selected (selection phase, 510), ping phase (ping phase, 520), identification and configuration steps (identification) and configuration phase, 530), negotiation phase (negotiation phase, 540), calibration phase (calibration phase, 550), power transfer phase (power transfer phase, 560) phase and renegotiation phase (renegotiation phase, 570). .

The selection step 510 transitions when a specific error or specific event is detected while starting or maintaining the power transmission, including the steps S502, S504, S508, S510, and S512, for example. You can. Here, specific errors and specific events will be clarified through the following description. In addition, in the selection step 510, the wireless power transmitter may monitor whether an object is present on the interface surface. If the wireless power transmitter detects that an object is placed on the interface surface, it may transition to the ping step 520. In the selection step 510, the wireless power transmitter transmits an analog ping signal, which is a power signal (or pulse) corresponding to a very short duration, and the current of a transmitting coil or a primary coil. Based on the change, it is possible to detect whether an object exists in the active area of the interface surface.

When an object is detected in the selection step 510, the wireless power transmitter may measure the quality factor of the wireless power resonant circuit (eg, power transmission coil and / or resonant capacitor). In an embodiment of the present invention, when an object is detected in the selection step 510, a quality factor may be measured to determine whether a wireless power receiving device is placed with a foreign object in the charging area. The coil provided in the wireless power transmission device may reduce inductance and / or series resistance components in the coil due to environmental changes, thereby reducing the quality factor value. In order to determine whether a foreign substance is present using the measured quality factor value, the wireless power transmitter may receive a reference quality factor value previously measured from the wireless power receiver in a state where no foreign substance is disposed in the charging area. The presence or absence of a foreign material may be determined by comparing the reference quality factor value received in the negotiation step 540 with the measured quality factor value. However, in the case of a wireless power receiving device having a low reference quality factor value-for example, a specific wireless power receiving device may have a low reference quality factor value according to the type, use, and characteristics of the wireless power receiving device-where foreign matter exists In the case, since there is no large difference between the measured quality factor value and the reference quality factor value, it may be difficult to determine whether a foreign substance exists. Therefore, it is necessary to further consider other judgment factors or to determine whether a foreign object is present using another method.

In another embodiment of the present invention, when an object is detected in the selection step 510, a quality factor value in a specific frequency domain (ex operating frequency domain) may be measured to determine whether it is disposed with a foreign material in the filling region. The coil of the wireless power transmitter may reduce inductance and / or series resistance components in the coil due to environmental changes, thereby changing (shifting) the resonance frequency of the coil of the wireless power transmitter. That is, the peak frequency of the quality factor, which is the frequency at which the maximum quality factor value in the operating frequency band is measured, may be moved.

In step 520, when an object is detected, the wireless power transmitter activates (wakes up) the receiver, and transmits a digital ping to identify whether the detected object is a wireless power receiver. In the ping step 520, if the wireless power transmitter does not receive a response signal for digital ping, for example, a signal strength packet, from the receiver, the wireless power transmitter may transition to the selection step 510 again. In addition, in the ping step 520, the wireless power transmitter may transition to the selection step 510 when it receives a signal indicating that power transmission is completed, that is, a charging complete packet, from the receiver.

When the ping step 520 is completed, the wireless power transmitter may transition to the identification and configuration step 530 for identifying the receiver and collecting receiver configuration and status information.

In the identification and configuration step 530, the wireless power transmitter may receive an unexpected packet, an undesired packet for a predetermined time (time out), or a packet transmission error (transmission error), If no power transfer contract is established (no power transfer contract), the process may transition to the selection step 510.

The wireless power transmitter may check whether entry into the negotiation step 540 is necessary based on the value of the negotiation field of the configuration packet received in the identification and configuration step 530. As a result of the check, if negotiation is required, the wireless power transmitter may enter a negotiation step 540 and perform a predetermined FOD detection procedure. On the other hand, as a result of the verification, if negotiation is not required, the wireless power transmission device may immediately enter the power transmission step 560.

In the negotiation step 540, the wireless power transmitter may receive a Foreign Object Detection (FOD) status packet including a reference quality factor value. Alternatively, an FOD status packet including a reference peak frequency value may be received. Alternatively, a status packet including a reference quality factor value and a reference peak frequency value may be received. At this time, the wireless power transmission apparatus may determine a quality factor threshold for FO detection based on the reference quality factor value. The wireless power transmitter may determine a peak frequency threshold for FO detection based on the reference peak frequency value.

The wireless power transmitter may detect whether the FO exists in the charging area using the determined quality factor threshold for detecting the FO and the currently measured quality factor value (quality factor value measured before the ping step). Accordingly, power transmission can be controlled. For example, when a FO is detected, power transmission may be stopped, but is not limited thereto.

The wireless power transmitter can detect whether the FO exists in the charging area by using the determined peak frequency threshold for detecting the FO and the currently measured peak frequency value (the peak frequency value measured before the ping step). Accordingly, power transmission can be controlled. For example, when a FO is detected, power transmission may be stopped, but is not limited thereto.

When the FO is detected, the wireless power transmitter may return to the selection step 510. On the other hand, if the FO is not detected, the wireless power transmission device may enter the power transmission step 560 through a correction step 550. In detail, when the FO is not detected, the wireless power transmission device determines the intensity of the power received at the receiving end in the correction step 550, and determines the intensity of the power transmitted by the transmitting end. Power loss at the transmitting end can be measured. That is, the wireless power transmitter may predict the power loss based on the difference between the transmitting power of the transmitting end and the receiving power of the receiving end in the correction step 550. The wireless power transmission apparatus according to an embodiment may correct the threshold for FOD detection by reflecting the predicted power loss.

In the power transmission step 560, the wireless power transmission device receives an unsolicited packet (unexpected packet), a desired packet for a predefined time (time out), or a violation of a preset power transmission contract occurs. Or (power transfer contract violation), or when charging is completed, may transition to the selection step 510.

In addition, in the power transmission step 560, the wireless power transmission device may transition to the renegotiation step 570 when it is necessary to reconfigure the power transmission contract according to a change in the state of the wireless power transmission device. At this time, when the renegotiation is normally completed, the wireless power transmission device may return to the power transmission step 560.

In this embodiment, although the correction step 550 and the power transfer step 560 are divided into separate steps, the correction step 550 may be integrated into the power transfer step 560. In this case, in the correction step 550 The operations can be performed at power transfer step 560.

The above-described power transmission contract may be set based on the status and characteristic information of the wireless power transmission device and the receiver. For example, the wireless power transmission device status information may include information on the maximum transmittable power amount, information on the maximum number of receivers that can be accommodated, and the receiver status information may include information on required power.

6 illustrates a power control control method according to an embodiment.

In the power transmission step 560 in FIG. 6, the wireless power transmission device 100 and the wireless power reception device 200 may control the amount of power delivered by performing communication in parallel with power transmission and reception. The wireless power transmitter and the wireless power receiver operate at specific control points. The control point represents a combination of voltage and current provided at the output of the wireless power receiver when power transmission is performed.

In more detail, the wireless power receiving device selects a desired control point-a desired output current / voltage, a temperature of a specific location of the mobile device, and additionally, an actual control point currently operating. ). The wireless power receiver may calculate a control error value using a desired control point and an actual control point, and transmit it to the wireless power transmitter as a control error packet.

In addition, the wireless power transmitter may control / transmit power by setting / controlling a new operation point-amplitude, frequency, and duty cycle-using the received control error packet. Therefore, the control error packet is transmitted / received at regular time intervals in the strategy delivery step, and as an embodiment, the wireless power receiving device has a negative control error value to decrease the current of the wireless power transmitter and a control error when increasing the current. You can set the value to a positive number and send it. In this way, in the induction mode, the wireless power receiver can control power transmission by transmitting a control error packet to the wireless power transmitter.

In the resonance mode, which will be described below, it may operate in a different way than in the induction mode. In the resonance mode, one wireless power transmitter must be able to simultaneously serve multiple wireless power receivers. However, in the case of controlling power transmission as in the above-described induction mode, power transmission to additional wireless power reception devices may be difficult to control because the transmitted power is controlled by communication with one wireless power reception device. Therefore, in the resonance mode of the present invention, the wireless power transmission device commonly transmits basic power, and the wireless power reception device controls a resonance frequency of itself to use a method of controlling the amount of power received. However, even in the operation of the resonance mode, the method described in FIG. 6 is not completely excluded, and additional transmission power may be controlled by the method of FIG. 6.

7 is a block diagram of a wireless power transmission apparatus according to another embodiment. This may belong to a wireless power transmission system in a self-resonant mode or a shared mode. The shared mode may refer to a mode for performing one-to-many communication and charging between the wireless power transmitter and the wireless power receiver. The shared mode may be implemented by a magnetic induction method or a resonance method.

Referring to FIG. 7, the wireless power transmission apparatus 700 includes a cover 720 that covers the coil assembly, a power adapter 730 that supplies power to the power transmitter 740, a power transmitter 740 that transmits wireless power, or It may include at least one of the user interface 750 providing power transmission progress and other related information. In particular, the user interface 750 may be optionally included, or may be included as another user interface 750 of the wireless power transmission device 700.

The power transmitter 740 may include at least one of a coil assembly 760, an impedance matching circuit 770, an inverter 780, a communication unit 790, or a control unit 710.

The coil assembly 760 includes at least one primary coil that generates a magnetic field, and may be referred to as a coil cell.

The impedance matching circuit 770 may provide impedance matching between the inverter and the primary coil (s). The impedance matching circuit 770 may generate resonance at a suitable frequency that boosts the primary coil current. The impedance matching circuit in the multi-coil power transmitter 740 may further include a multiplex that routes the signal from the inverter to a subset of the primary coils. The impedance matching circuit may also be referred to as a tank circuit.

The impedance matching circuit 770 may include capacitors, inductors, and switching elements to switch their connections. Impedance matching detects the reflected wave of wireless power transmitted through the coil assembly 760, and switches the switching element based on the detected reflected wave to adjust the connection state of the capacitor or inductor, adjust the capacitance of the capacitor, or inductance of the inductor It can be performed by adjusting. In some cases, the impedance matching circuit 770 may be omitted and implemented, and the present specification also includes an embodiment of the wireless power transmitter 700 in which the impedance matching circuit 770 is omitted.

The inverter 780 may convert a DC input into an AC signal. Inverter 780 may be driven as a half-bridge or full-bridge to generate adjustable frequency pulse waves and duty cycles. In addition, the inverter may include a plurality of stages to adjust the input voltage level.

The communication unit 790 may perform communication with the power receiver. The power receiver performs load modulation to communicate requests and information to the power transmitter. Accordingly, the power transmitter 740 may use the communication unit 790 to monitor the amplitude and / or phase of the current and / or voltage of the primary coil to demodulate the data transmitted by the power receiver.

In addition, the power transmitter 740 may control output power to transmit data using a FSK (Frequency Shift Keying) method through the communication unit 790.

The control unit 710 may control communication and power transmission of the power transmitter 740. The control unit 710 may control power transmission by adjusting the above-described operation point. The operating point may be determined, for example, by at least one of an operating frequency, duty cycle, and input voltage.

The communication unit 790 and the control unit 710 may be provided as separate units / elements / chipsets, or may be provided as one unit / element / chipset.

8 shows a wireless power receiving apparatus according to another embodiment. This may belong to a wireless power transmission system in a self-resonant mode or a shared mode.

In FIG. 8, the wireless power receiving device 800 includes a user interface 820 providing power transmission progress and other related information, a power receiver 830 receiving wireless power, a load circuit 840 or a coil assembly It may include at least one of the base 850 to cover the support. In particular, the user interface 820 may be optionally included, or may be included as another user interface 82 of the power receiving equipment.

The power receiver 830 may include at least one of a power converter 860, an impedance matching circuit 870, a coil assembly 880, a communication unit 890, or a control unit 810.

The power converter 860 may convert AC power received from the secondary coil into voltage and current suitable for a load circuit. As an embodiment, the power converter 860 may include a rectifier. The rectifier may rectify the received wireless power to convert AC to DC. The rectifier converts alternating current to direct current using a diode or transistor, and can smooth it using a capacitor and a resistor. As a rectifier, a full-wave rectifier implemented by a bridge circuit, etc., a half-wave rectifier, and a voltage multiplier may be used. Additionally, the power converter may adapt the reflected impedance of the power receiver.

The impedance matching circuit 870 may provide impedance matching between the secondary coil and the combination of the power converter 860 and the load circuit 840. As an embodiment, the impedance matching circuit may generate resonance around 100 kHz, which can enhance power transfer. The impedance matching circuit 870 may be composed of a switching element that switches capacitors, inductors, and combinations thereof. Matching of impedance may be performed by controlling a switching element of a circuit constituting the impedance matching circuit 870 based on the received voltage value, current value, power value, frequency value, etc. of the wireless power. In some cases, the impedance matching circuit 870 may be omitted and implemented, and the present specification also includes an embodiment of the wireless power receiving apparatus 200 in which the impedance matching circuit 870 is omitted.

The coil assembly 880 includes at least one secondary coil, and may optionally further include an element that shields a metal portion of the receiver from a magnetic field.

The communication unit 890 may perform load modulation to communicate requests and other information to the power transmitter.

To this end, the power receiver 830 may switch resistors or capacitors to change the reflected impedance.

The control unit 810 may control the received power. To this end, the control unit 810 may determine / calculate the difference between the actual operating point of the power receiver 830 and the desired operating point. In addition, the control unit 810 may adjust / reduce the difference between an actual operation point and a desired operation point by adjusting the reflection impedance of the power transmitter and / or requesting the operation point adjustment of the power transmitter. When this difference is minimized, optimal power reception can be performed.

The communication unit 890 and the control unit 810 may be provided as separate elements / chipsets, or may be provided as one element / chipset.

9 shows a communication frame structure according to an embodiment. This may be a communication frame structure in a shared mode.

9, in the shared mode, different types of frames may be used together. For example, in the shared mode, a slotted frame having a plurality of slots such as (A) and a free format frame without a specific shape such as (B) may be used. More specifically, the slot frame is a frame for transmission of short data packets from the wireless power receiver 200 to the wireless power transmitter 100, and the free-form frame does not have a plurality of slots, so long data packets It may be a frame that can be transmitted.

Meanwhile, the slot frame and the free-form frame may be changed to various names by those skilled in the art. For example, the slot frame may be changed to a channel frame, and the free-form frame may be changed to a message frame or the like.

More specifically, the slot frame may include a sync pattern indicating the start of a slot, a measurement slot, nine slots, and an additional sync pattern having the same time interval before each of the nine slots.

Here, the additional sync pattern is a sync pattern different from the sync pattern indicating the start of the frame described above. More specifically, the additional sync pattern may indicate information related to adjacent slots (ie, two consecutive slots located on both sides of the sync pattern) without indicating the start of a frame.

A sync pattern may be located between two consecutive slots among the nine slots. In this case, the sync pattern may provide information related to the two consecutive slots.

In addition, the sync patterns provided prior to each of the 9 slots and the 9 slots may have the same time interval. For example, the nine slots may have a time interval of 50ms. Also, the nine sync patterns may have a time length of 50 ms.

Meanwhile, the free-form frame such as (B) may not have a specific shape other than a sync pattern and a measurement slot indicating the start of the frame. That is, the free-form frame is for performing a different role from the slot frame, for example, long data packets (eg, additional owner information packets) between the wireless power transmitter and the wireless power receiver. It can be used to perform a communication, or in a wireless power transmission device composed of a plurality of coils, to select any one of the plurality of coils.

Hereinafter, a sync pattern included in each frame will be described in more detail with reference to the drawings.

10 is a structure of a sink pattern according to an embodiment.

Referring to FIG. 10, the sync pattern is composed of a preamble, a start bit, a response field, a type field, an info field, and a parity bit. Can be. In FIG. 10, the start bit is shown as ZERO.

More specifically, the preamble consists of consecutive bits, and all may be set to zero. That is, the preamble may be bits for matching the time length of the sync pattern.

The number of bits constituting the preamble may be dependent on the operating frequency such that the length of the sync pattern is closest to 50 ms, but not exceeding 50 ms. For example, when the operating frequency is 100 kHz, the sync pattern may consist of two preamble bits, and when the operating frequency is 105 kHz, the sync pattern may consist of three preamble bits.

The start bit is a bit following the preamble, which may mean zero. The zero (ZERO) may be a bit indicating the type of the sync pattern. Here, the type of the sync pattern may include a frame sync including information related to the frame and a slot sync including information on the slot. That is, the sync pattern is located between consecutive frames, is a frame sync indicating the start of a frame, or is located between consecutive slots among a plurality of slots constituting a frame, and information related to the consecutive slots It may be a slot sync.

For example, when the zero is 0, it means that the corresponding slot is a slot sync located between the slot and the slot, and if 1, the corresponding sync pattern is a frame sync located between the frame and the frame.

The parity bit is the last bit of the sync pattern and may indicate information on the number of bits constituting the data fields (ie, response field, type field, and information field) of the sync pattern. For example, the number of bits constituting the data fields of the sync pattern may be 1 in case of an even number, or 0 in other cases (that is, in an odd number).

The Response field may include response information of the wireless power transmitter in communication with the wireless power receiver in a slot before the sync pattern. For example, the response field may have '00' when communication with the wireless power receiver is not detected. In addition, the response field may have '01' when a communication error is detected in communication with the wireless power receiver. The communication error may be a case where two or more wireless power receivers attempt to access one slot, and a collision occurs between two or more wireless power receivers.

In addition, the response field may include information indicating whether the data packet has been correctly received from the wireless power receiver. More specifically, the response field is "10" (10-not acknowledge, NAK) when the wireless power transmitter rejects the data packet (deni), when the wireless power transmitter confirms the data packet (confirm) , "11" (11-acknowledge, ACK).

The type field may indicate the type of sync pattern. More specifically, the type field may have a '1' indicating that the frame is synchronized when the sync pattern is the first sync pattern of the frame (ie, the first sync pattern of the frame, located before the measurement slot).

In addition, the type field may have a '0' indicating that it is a slot sync when the sync pattern is not the first sync pattern of the frame in the slot frame.

Also, the meaning of the value of the information field may be determined according to the type of sync pattern indicated by the type field. For example, when the type field is 1 (ie, indicating a frame sync), the meaning of the information field may indicate the type of frame. That is, the information field may indicate whether the current frame is a slotted frame or a free-format frame. For example, when the information field is '00', a slot frame may be represented, and when the information field is '01', a free-form frame may be indicated.

Alternatively, when the type field is 0 (ie, slot sync), the information field may indicate the state of the next slot located after the sync pattern. More specifically, the information field is '00' when the next slot is a slot allocated to a specific wireless power receiver, '00', when a specific wireless power receiver is temporarily used, and is a locked slot, '01', or if any wireless power receiver is a freely usable slot, may have '10'.

Referring to FIG. 11, the wireless power receiver operating in the shared mode includes a selection phase 1100, an introduction phase 1110, a configuration phase 1120, and a negotiation state. It may operate in any one of (Negotiation Phase) 1130 and Power Transfer Phase (1140).

First, the wireless power transmitter according to an embodiment may transmit a wireless power signal in order to detect the wireless power receiver. That is, a process of detecting a wireless power receiver using a wireless power signal may be referred to as analog ping.

Meanwhile, the wireless power receiver that has received the wireless power signal may enter the selection state 1100. As described above, the wireless power receiving device that has entered the selection state 1100 may detect the presence of an FSK signal on the wireless power signal.

That is, the wireless power receiver may perform communication in either an exclusive mode or a shared mode depending on whether an FSK signal is present.

More specifically, if the FSK signal is included in the wireless power signal, the wireless power receiver may operate in the shared mode, or otherwise, in the exclusive mode.

When the wireless power receiving device operates in the shared mode, the wireless power receiving device may enter the introduction state 1110. In the introduction state 1110, the wireless power receiver may transmit a control information packet to the wireless power transmitter in order to transmit a control information packet (CI) in a set state, a negotiation state, and a power transmission state. have. The control information packet may have a header and information related to control. For example, the control information packet may have a header of 0X53.

In the introduction state 1110, the wireless power receiver performs an attempt to request a free slot to transmit a control information (CI) packet through the following configuration, negotiation, and power transmission steps. At this time, the wireless power receiver selects a free slot and transmits the first CI packet. If the wireless power transmission device responds with an ACK to the corresponding CI packet, the wireless power transmission device enters the configuration step. If the wireless power transmission device responds with a NAK, another wireless power reception device is in progress through the configuration and negotiation phase. In this case, the wireless power receiving device retries the request of the free slot.

If the wireless power receiver receives the ACK in response to the CI packet, the wireless power receiver determines the location of the private slot in the frame by counting the remaining slot sinks up to the first frame sink. In all subsequent slot-based frames, the wireless power receiver transmits a CI packet through the corresponding slot.

If the wireless power transmitter allows the wireless power receiver to proceed to the configuration stage, the wireless power transmitter provides a series of locked slots for exclusive use of the wireless power receiver. This ensures that the wireless power receiver proceeds with the configuration steps without collision.

The wireless power receiver transmits sequences of data packets such as two identification data packets (IDHI and IDLO) using a lock slot. Upon completion of this step, the wireless power receiver enters the negotiation phase. In the negotiating phase, the wireless power transmitter continues to provide the wireless power receiver with a lock slot for exclusive use. This ensures that the wireless power receiver proceeds through the negotiation phase without conflict.

The wireless power receiver transmits one or more negotiation data packets using the corresponding lock slot, which may be mixed with private data packets. Eventually, the sequence ends with a specific request (SRQ) packet. Upon completion of the sequence, the wireless power receiver enters the power transmission phase, and the wireless power transmitter stops providing the lock slot.

In the power transmission state, the wireless power receiver performs transmission of a CI packet using the allocated slot and receives power. The wireless power receiver may include a regulator circuit. The regulator circuit can be included in the communication / control unit. The wireless power receiver can self-regulate the reflected impedance of the wireless power receiver through a regulator circuit. In other words, the wireless power receiver can adjust the reflected impedance to transmit the amount of power required by the external load. This can prevent excessive power reception and overheating.

In the shared mode, since the wireless power transmitter may not perform the power adjustment in response to the received CI packet (depending on the operation mode), in this case, control to prevent an overvoltage condition may be required.

회귀 분석에 기반한 이물질 검출 알고리즘Foreign object detection algorithm based on regression analysis

Hereinafter, a wireless power transmission apparatus and method for performing wireless power transmission based on foreign substance detection, and a wireless power reception apparatus and method for performing wireless power reception are disclosed.

There are two main causes of heat generation by foreign substances such as metals: Eddy Current Loss and Magnetic Hysteresis Loss. The causes and the heat generation process for each cause are as follows.

The eddy current loss is when the AC magnetic field for wireless charging acts on a metal foreign material, and the metal foreign material generates an eddy current to create an opposite magnetic field for canceling it, which means the power loss generated in the process. The generation of electric current (I) to create a magnetic field in the opposite direction to counteract the temporally changing magnetic field (AC magnetic field) in metallic foreign matter is according to Lenz's law. The current I has a problem of generating I ² R heat by the resistance R of the metal foreign material.

Magnetic hysteresis loss occurs when a magnetic foreign material is affected by a magnetic field for wireless charging during the charging process, and magnetic hysteresis occurs in a process in which the magnetic state inside the magnetic material changes according to an external magnetic field. Power loss. The magnetic hysteresis loss is caused by various reasons, such as a domain wall, in the process of aligning the magnetic moment inside the material or the magnetic domain with the external magnetic field. , Heat is generated.

In the process of performing wireless power transmission as described above, a problem of overheating due to foreign substances such as metal may affect the human body and devices. The severity of foreign object detection errors may be greater in the case of rapid wireless charging or medium / large power devices. Therefore, it is necessary to further improve the accuracy and reliability of foreign matter detection performance in the wireless power transmission system.

The foreign matter detection method includes, for example, Q-factor detection, power loss detection, frequency shift, and the like. However, since there are differences in various Q-factors, power loss, and frequency shifts by various wireless power receivers (eg, smart phones, smart watches, etc.) under the same conditions, the characteristics of wireless power receivers are different. It is very difficult to detect foreign substances (eg, 10 cents (US dime) coins) that give small changes compared to the difference in large Q-factor, power loss and frequency shift caused by. In addition, there is a method of detecting a foreign material by using a sensing coil that detects the foreign material, but additional cost problems may occur. For example, considering the US dime as a foreign material, there is no foreign material detection method capable of distinguishing the US dime without an additional sensing coil with the technology to date. The reason is the wide friendly metal effect of the phone. US Dime's small Q-factor change and power loss effect do not overcome the phenomenon of being buried in the friendly metal variation of mobile phones (SNR problem).

Several experiments were conducted to confirm the accuracy of the existing foreign substance detection method.

12 illustrates a histogram of a wireless power receiving device and a wireless power receiving device + foreign matter according to an example. This is a case where foreign matter is detected based only on power loss (P _loss ).

Referring to Figure 12, the iPhone 6+, Galaxy S6E, Galaxy S8 three types of smartphones and the three types of smartphones + foreign material samples are measured power loss. When the foreign object detection is performed using only the power loss, since the situation in which only the wireless power receiving device exists and the situation in which the wireless power receiving device and the foreign material are present are not distinguished, it can be confirmed that the foreign material cannot be completely detected. have.

13 shows a histogram of a wireless power receiving device and a wireless power receiving device + foreign matter according to another example. This is a case where foreign substances are detected based only on the Q-factor.

13, the iPhone 6+, the Galaxy S6E, and the Galaxy S8 are three types of smartphones, the three types of smartphones, and the three smartphones + foreign materials, and the Q factor is measured. When the foreign matter detection is performed using only the Q factor, since the situation where only the wireless power receiving device is present and the situation where the wireless power receiving device and the foreign material are present are not distinguished, it can be confirmed that foreign matter cannot be completely detected. have.

14 illustrates a histogram of a wireless power receiving device and a wireless power receiving device + foreign matter according to another example. This is a case where foreign matter is detected based only on the current I _tx flowing in the primary coil.

Referring to FIG. 14, primary coil currents are measured for three types of smartphones, the three types of smartphones, and the three smartphones + foreign material samples such as iPhone 6+, Galaxy S6E, and Galaxy S8.

(a) is a situation in which only the wireless power receiving device exists compared to the detection of a foreign substance using only the power factor (FIG. 12) or the detection of a foreign substance using only the Q factor when detecting foreign substances using only the primary coil current (FIG. 13). , It can be seen that the situation in which the wireless power receiving device and the foreign material exist together is better classified.

However, in the case of (b) having different data sections, when performing foreign object detection using only the primary coil current, the situation in which only the wireless power receiving device exists and the situation in which the wireless power receiving device and the foreign material exist together are not distinguished. As a result, it can be confirmed that foreign matter cannot be completely detected.

15 illustrates a histogram of a wireless power receiver and a wireless power receiver + foreign matter according to another example. This is a case of detecting a foreign object based on a simple calculation (multiplication: P _Loss * ΔQ) between the Q factor and the power loss.

Referring to Figure 15, iPhone 6+, Galaxy S6E, Galaxy S8 three types of smartphones and the above three types of smartphones and the three smartphones + foreign material samples are measured for Q factor and power loss, multiplied by them Values are represented by histograms. As a result of plotting P _Loss * ΔQ as a histogram, it can be seen that the situation in which only the wireless power receiving device exists and the situation in which the wireless power receiving device and the foreign material exist together do not overlap, but are quite close. When this same foreign matter detection method is applied to other types of smartphones not used in this experiment, there is still a possibility of an error in foreign matter detection.

16 illustrates a histogram of a wireless power receiving device and a wireless power receiving device + foreign matter according to another example. This is a case where foreign matter is detected based on the result of simple calculation (multiplication and division: ΔQ * P _Loss / I _tx ) of Q factor, power loss, and current of the primary coil.

Referring to Figure 16, iPhone 6+, Galaxy S6E, Galaxy S8 three types of smartphones and the above three types of smartphones and the three smartphones + foreign substances sample Q factor and power loss, the current of the primary coil Is measured, and these are represented by histograms of simple calculation values. As a result of representing ΔQ * P _Loss / I _tx as a histogram, the situation where only the wireless power receiving device exists and the situation where the wireless power receiving device and the foreign material exist together are separated, but the actual power is detected due to the small separation power (Resolving Power). It is difficult to apply to.

12 to 16, when the wireless power receiving devices (for example, smart phones) have a large characteristic difference (or noise), a method of detecting foreign substances through a simple operation or applying each variable in a fractional way is a foreign matter existence / It is still difficult to detect the difference in nothing.

Therefore, the present embodiment maximizes foreign material performance by simultaneously using all of various variables that can be obtained before the start of the wireless power transmission (that is, before entering the power transmission phase) or during the wireless power transmission (that is, after entering the power transmission phase). The method is disclosed. In this case, a regression analysis technique using various variables may be applied. Based on the regression analysis technique, it is possible to implement a high-performance foreign substance detection algorithm by dramatically improving the resolution of the wireless power receiver (i.e. mobile phone) vs. wireless power receiver + foreign substances. In this case, it is confirmed that using the current of the primary coil as a new parameter is more effective.

Hereinafter, this specification discloses a method for maximizing the detection performance of a foreign substance by defining parameters that can be used by the wireless power transmission device or the reception device for foreign matter detection and simultaneously applying all parameters. The parameter for changing characteristics due to a foreign material can be measured and / or calculated by the primary coil before or during wireless charging, and can be said to be a parameter affected by the presence or absence of a foreign material. Hereinafter, the parameter for changing properties due to foreign substances is simply referred to as a FOD parameter.

According to an embodiment, the FOD parameter may include a current change of the primary coil of the wireless power transmission device. When a foreign object is placed on the wireless power transmitter, the digital ping signal before charging or the amount of current during charging changes (power loss due to foreign material). For the case where only the wireless power receiving device (ie mobile phone) is placed and both the wireless power receiving device and foreign matter (ie coins) are placed, FIG. 17 is the current of the primary coil measured before the start of wireless power transmission, and FIG. 18 Is the primary coil current measured during wireless power transmission.

17 and 18, the y-axis is the current value of the primary coil, and the x-axis is Δ (delta) Q. [Delta] Q is a value indicating the Q value drop amount of the primary coil by each wireless power receiving device (Phone) and wireless power receiving device + foreign material (Phone + FO). As can be seen in FIGS. 17 and 18, a difference may occur in the current of the primary coil before or during wireless power transmission depending on the presence / absence of a foreign material. The wireless power transmission device and / or the wireless power reception device may be 1 It is possible to distinguish a state in which only the wireless power receiving device is present and a state in which both the wireless power receiving device and a foreign material are present using the current change or difference of the primary coil.

Compared to other FOD parameters, the current of the primary coil shows a better difference in characteristics when only the wireless power receiving device is present (Rx) and when both the wireless power receiving device and foreign matter are present (Rx + FO). 17 and 18, when looking at the size ratio of the primary coil current, the current before the start of the wireless power transmission is greater than the current during the wireless power transmission, but the dispersion needs to be considered. The first FOD parameter value obtained when only the wireless power receiving device is present, and the second FOD parameter value obtained when both the wireless power receiving device and foreign matter are present, and the difference between the first FOD parameter value and the second FOD parameter value It is possible to detect foreign substances by using. However, if only the differences between the FOD parameters of the same type are compared, the change in the wireless power receiving device may be more difficult than the difference due to the presence / absence of foreign matter, making FOD difficult. Therefore, in addition to the primary coil current, Q-factor, power loss, and frequency shift can be used as FOD parameters.

According to another embodiment, the FOD parameter is the current change of the primary coil, Q-factor, power loss, frequency shift and / or additional parameters calculated using these values (or in the wireless power transmitter and / or receiver) And system parameters that can be measured or obtained. As an example, the FOD parameter may include power loss, Q-factor, frequency change, current of the primary coil before wireless power transmission, current of the primary coil during wireless power transmission, resistance, inductance, and the like. In this case, the foreign material detection algorithm may be designed or implemented based on the plurality of FOD parameters. Therefore, the wireless power transmission device and / or the wireless power reception device may perform foreign material detection using the foreign material detection algorithm. That is, this embodiment creates and applies a foreign matter detection algorithm that can simultaneously and complementarily utilize the parameters calculated by using all measurable parameters and measured parameters for foreign matter detection in a wireless power transmission system. In this case, the wireless power receiver and the foreign matter can be clearly distinguished, and the limitation of serial parameter application can be overcome to maximize the foreign matter detection performance. As another example, FOD parameters are parameters that can be measured in the wireless power transmission process (power loss, Q-factor, frequency change, current of the primary coil before wireless power transmission, current, resistance, and inductance of the primary coil during wireless power transmission). Etc.) New parameters calculated by performing arithmetic operations among themselves may be included. However, when detecting a foreign object by comparing the difference in FOD parameters between the Rx Only state and the Rx + FO state, the diversity of the wireless power receiving device is greater than the difference due to the presence / absence of the foreign material, and thus the detection accuracy of the foreign material may be very low. Therefore, it is necessary to design a foreign matter detection algorithm that can simultaneously consider all possible FOD parameters affected by foreign matter.

According to another embodiment, in the above embodiment, various FOD parameters are simultaneously applied to the foreign matter detection algorithm in parallel, but the foreign matter detection algorithm is based on a regression analysis to optimize and maximize the performance of the foreign matter detection algorithm. The weight for each FOD parameter used in can be obtained.

When the current of the primary coil (I _{Tx coil} ) is excluded from the FOD parameter and applied to more than 10 types of mobile phones, including the iPhone series, which has a big problem in detecting foreign matter, it is impossible to distinguish between the mobile phone and the foreign material. However (Z <0), the new foreign material detection algorithm according to the present embodiment provides Z = 8.43 (average criterion is Z = 11.03). Furthermore, it was experimentally confirmed that if the current of the primary coil is applied as a FOD parameter, the performance of foreign matter detection according to this embodiment is further improved. Specifically, when adopting the current of the primary coil as the FOD parameter for the three types of smartphones such as iPhone 6+, Galaxy S6E, and Galaxy S8, it was confirmed that Z >> 10. This means that foreign matter can be completely detected. Here, z is a normal distribution characteristic of the system, and is a value indicating how many times the width from the average value to the system spec value is about 67% of the standard deviation. If the z value is 6 or more, it is evaluated as a statistically good value. In order to eliminate the heat generation problem caused by foreign matters as described above, when regression analysis is performed based on various variables that can be obtained before or during wireless charging, foreign matter detection performance can be maximized.

Referring to FIG. 19, regression analysis is applied to the Q factor, power loss (IPL), and current (I _{tx, 0 offset} ) of the primary coil before the start of wireless power transmission. The regression equation using Q factor, power loss (IPL), and current (I _{tx, 0 offset} ) of the primary coil before the start of wireless power transmission as FOD parameters (or variables) may be expressed by the following equation.

Here, the regression equation may be called a foreign matter detection algorithm, and the result value of the regression analysis equation may be called a regression response or a foreign matter detection result. To obtain a constant value of Equation 1, weights or coefficients a, b, and c multiplied by each FOD parameter, Q factor, power loss (IPL), and wireless power transmission as shown in FIG. 20. The current (I _{tx, 0 offset} ) of the primary coil before initiation is applied to the regression analysis.

As a result, constant values of 388.1 and coefficients are obtained as a = -0.00431, b = 241.2, and c = -19.42, respectively. Accordingly, Equation 1 is completed as Equation 2.

Here, VIF is large, but it can be ignored when considering the purpose of verifying the detection of foreign substances and the process of applying regression analysis.

When the three FOD parameters measured or calculated in the Rx Only state and the three FOD parameters measured or calculated in the Rx + FO state are substituted into the regression equation or the foreign matter detection algorithm according to Equation 2, the variance shown in FIG. (distribution) or histogram.

Referring to FIG. 20, Q factor, power loss (IPL), and wireless power for the iPhone 6+, Galaxy S6E, and Galaxy S8 three types of smartphones, the three types of smartphones, and the three smartphones + foreign material samples The current I _{tx (0 offset)} of the primary coil before transmission start was measured, and these were substituted into Equation (2). As a result, it can be seen that the separation power (Resolving Power) is very large between a situation in which only the wireless power receiving apparatus exists (Rx only) and a situation in which the wireless power receiving apparatus and a foreign substance exist together (Rx + FO). The process is as follows.

	P_Loss P _Loss	I_Tx0 I _Tx0	QQ	ResponseResponse	회귀식 대입Regression assignment
iPhone6+iPhone6 +	5.47E+045.47E + 04	44	5757	-1.00E+00-1.00E + 00	-1.01E+00-1.01E + 00
Galaxy S6EGalaxy S6E	2.51E+042.51E + 04	2.32.3	42.642.6	-1.00E+00-1.00E + 00	-1.00E+00-1.00E + 00
Galaxy8Galaxy8	1.25E+041.25E + 04	2.052.05	43.343.3	-1.00E+00-1.00E + 00	-1.00E+00-1.00E + 00
Us 다임+Us Dime + iPhone6+iPhone6 +	9.38E+049.38E + 04	4.654.65	52.452.4	1.00E+001.00E + 00	9.80E-019.80E-01
Us 다임+ Galaxy S6EUs Dime + Galaxy S6E	7.20E+047.20E + 04	3.353.35	4040	1.00E+001.00E + 00	9.85E-019.85E-01
Us 다임+ Galaxy8Us Dime + Galaxy8	3.97E+043.97E + 04	2.752.75	40.340.3	1.00E+001.00E + 00	9.93E-019.93E-01

Here, in this experiment, the data on the x-axis is the result of the regression equation, and when only the wireless power transmitter is present (Rx only), the result of the regression equation is output as 1, and both the wireless power transmitter and foreign matter are present. (Rx + FO) It assumes a digitized state that outputs the result of the regression equation as -1.

The Rx Only state and the Rx + FO state according to FIG. 20 are much better distinguished than the embodiments according to FIGS. 12 to 18. That is, when a foreign object detection algorithm is designed based on a number of FOD parameters as shown in FIG. 20, the scatter plot between Rx Only and Rx + FO is clearly distinguished. Compared to the case where Rx only and Rx + FO are compared by simple operation, it can be seen that the performance of foreign matter detection is much improved.

19 and 20 are cases in which three FOD parameters are considered when designing a foreign object detection algorithm based on regression analysis. However, as the number of useful FOD parameters increases, the accuracy of foreign matter detection can be improved in the foreign matter detection algorithm.

Referring to FIG. 21, four FOD parameters (Q factor, power loss (P Loss), current of the primary coil before starting wireless power transmission (I _{tx_0} ), and current of the primary coil during wireless power transmission (I _{tx_crg} ) Based on), the weights constituting the regression equation are obtained, and the FOD algorithm is derived (or configured) based on the weights to show the experimental results.

Q factor, the regression equation to a power loss (P Loss), the wireless power transmit the first current of the secondary coil before the start of (I _{tx_0),} the FOD parameter (or variable) current of the primary coil of the wireless power transmission (I _{tx_crg)} is It can be expressed by the following equation.

Here, the regression equation may be called a foreign matter detection algorithm, and the result value of the regression analysis equation may be called a regression response or a foreign matter detection result. In order to obtain a constant value of Equation 3, a weight or a coefficient multiplied by each FOD parameter a, b, c, and d, Q factor and power loss (IPL), wireless, as shown in FIG. The current (I _{tx, 0 offset} ) of the primary coil before starting power transmission and the current (I _{tx, in charging} ) of the primary coil during wireless power transmission are applied to regression analysis.

As a result, a constant value of -0.36 and coefficients are obtained as a = -0.000065, b = 3.24, c = -0.232, d = 0.654, respectively. Accordingly, Equation 3 is completed as Equation 4.

The graph of FIG. 22 can be obtained by inputting each of the measured / calculated FOD parameters (IPL, I _{Tx (0 offset)} , Q, and I _{tx (in charging)} ) _in the foreign matter detection algorithm according to Equation (4 ₎ .

Referring to FIG. 22, the distribution of the result of Rx Only and Rx + FO according to the foreign material detection algorithm derived based on the four FOD parameters has a smaller and more pronounced difference than the case of applying three FOD parameters according to FIG. 20. And the separated state. That is, the more statistically useful FOD parameters are applied to the foreign matter detection algorithm, the better the performance of foreign matter detection is, and the usefulness of the FOD parameters can be confirmed in the regression analysis process.

Referring to Figure 23, the five FOD parameter (Q factor, the power loss (P Loss), the wireless power transmit the first current of the secondary coil before the start of (I _{tx_0),} the first current of the secondary coil of the wireless power transmission (I _{tx_crg)} , Regression analysis based on resistance (R) to obtain the weights constituting the regression equation, and based on the weights, shows the results of experiments that derive (or construct) the FOD algorithm.

F factor (or variable) of Q factor, power loss (P Loss), current of primary coil before starting wireless power transmission (I _{tx_0} ), current of primary coil during wireless power transmission (I _{tx_crg} ) and resistance (R) The regression equation to be can be expressed by the following equation.

Here, the regression equation may be called a foreign matter detection algorithm, and the result value of the regression analysis equation may be called a regression response or a foreign matter detection result. In order to obtain a constant value of Equation 5, a weight or a coefficient multiplied by each FOD parameter, a, b, c, d, e, Q factor and power loss (IPL) as shown in FIG. 23. , The current of the primary coil (I _{tx, 0 offset} ) before the start of wireless power transmission, the current of the primary coil (I _{tx, in charging} ), and resistance (R) during wireless power transmission are applied to regression analysis.

As a result, a constant value of 19.14 and coefficients are obtained as a = -0.000131, b = 4.494, c = -0.6749, d = -1.466, e = -1.384, respectively. Accordingly, Equation 5 is completed as in Equation 6.

If the FOD parameters (IPL, I _{Tx (0 offset)} , Q, R, and I _{tx (in charging)} ) are input to the foreign matter detection algorithm according to Equation 6, the graph of FIG. 24 may be obtained. You can.

Referring to FIG. 24, the distribution of the result of Rx Only and Rx + FO according to the foreign material detection algorithm derived based on the 5 FOD parameters is smaller and has a more pronounced difference than when the 4 FOD parameters according to FIG. 22 are applied. And the separated state.

In the following, additional FOD parameters and combinations to be used in regression analysis to overcome the unique and various friendly metal effects of various mobile phones, as well as experimental processes and actual products based on an optimal foreign substance detection algorithm are derived. Start the test results.

25, nine FOD parameters (Q factor, power loss (P Loss), rail voltage (Vrail), rail current (Irail), input power (Input P), internal loss (Inter Loss), received power Regression analysis based on packet (RPP), (Ploss + RPP) / Icoil, Tloss * DQ / Icoil) to obtain the weights constituting the regression equation and derive (or construct) the FOD algorithm based on the weights Shows the result. Here, Icoil is the current of the primary coil, and DQ is delta Q. Equation 7 is obtained when the regression equation according to this is obtained.

Galaxy S8, Galaxy S9, Galaxy S9 +, iPhone 8, iPhone 8+, G4, iPhone 7 Each of the FOD parameters measured / calculated while only 7 smartphone models exist, and the 7 smartphone models If each of the FOD parameters measured / calculated in the presence of the US Dime is input to the foreign matter detection algorithm according to Equation 7, the result of the regression analysis in Table 5 can be obtained. Can be obtained.

	RegressionRegression
Galaxy S8Galaxy S8	-1.008906988-1.008906988
Galaxy S9Galaxy S9	-1.063851148-1.063851148
Galaxy S9+Galaxy S9 +	-1.024482115-1.024482115
iPhone 8iPhone 8	-1.007335535-1.007335535
iPhone 8+ iPhone 8+	-0.848964969-0.848964969
G4G4	-1.026311776-1.026311776
iPhone 7iPhone 7	-1.214701995-1.214701995

Galaxy S8+US DimeGalaxy S8 + US Dime	0.9418672030.941867203
Galaxy S9+US DimeGalaxy S9 + US Dime	0.9969461380.996946138
Galaxy S9++US DimeGalaxy S9 ++ US Dime	0.891375920.89137592

iPhone 8+US DimeiPhone 8 + US Dime	0.8374177120.837417712
iPhone 8++US Dime iPhone 8 ++ US Dime	0.8539116410.853911641
G4+US DimeG4 + US Dime	0.9422524040.942252404

iPhone 7+US DimeiPhone 7 + US Dime	1.1416545341.141654534

Referring to FIG. 26, in the normal distribution of the histogram, the z value is represented as 17.39, and since it is 6 or more, it is evaluated as a statistically good value.

Referring to FIG. 27, 12 FOD parameters (power loss (P Loss), rail voltage (Vrail), rail current (Irail), input power (Input P), internal loss (Inter Loss), received power packet (RPP) ), Tloss / Inter Loss, Tloss * DQ, Tloss / DQ, R (V / I), (Ploss + RPP) / Icoil2, Q factor) to obtain weights constituting the regression equation by regression analysis Based on the results, the experimental results are derived (or configured) of the FOD algorithm. Here, Icoil is the current of the primary coil, and DQ is delta Q. Equation 8 is obtained when the regression equation according to this is obtained.

Galaxy S8, Galaxy S9, Galaxy S9 +, iPhone 8, iPhone 8+, G4, iPhone 7 Each of the FOD parameters measured / calculated while only 7 smartphone models exist, and the 7 smartphone models If each of the FOD parameters measured / calculated in the presence of the US Dime is input to the foreign matter detection algorithm according to Equation 7, the result of the regression analysis in Table 6 can be obtained. Can be obtained.

	RegressionRegression
Galaxy S8Galaxy S8	-1.1428-1.1428
Galaxy S9Galaxy S9	-1.1469-1.1469
Galaxy S9+Galaxy S9 +	-1.11621-1.11621
iPhone 8iPhone 8	-1.08467-1.08467

iPhone 8+iPhone 8+	-1.11097-1.11097
G4G4	-1.11983-1.11983
iPhone 7iPhone 7	-1.09594-1.09594

Galaxy S8+US DimeGalaxy S8 + US Dime	0.8073480.807348
Galaxy S9+US DimeGalaxy S9 + US Dime	0.8117990.811799
Galaxy S9++US DimeGalaxy S9 ++ US Dime	0.8152940.815294

iPhone 8+US DimeiPhone 8 + US Dime	0.860510.86051

iPhone 8++US DimeiPhone 8 ++ US Dime	0.8926440.892644
G4+US DimeG4 + US Dime	0.8075160.807516

iPhone 7+US DimeiPhone 7 + US Dime	0.897880.89788

Referring to FIG. 28, in the normal distribution of the histogram, the z value is 84, which is 6 or more, so it is evaluated as a statistically good value.

Referring to FIGS. 29A and 29B, weights constituting a regression equation are obtained by regression analysis based on a total of 22 FOD parameters, and experimental results of deriving (or constructing) an FOD algorithm based on the weights are shown.

GALAXY S8, GALAXY S9, GALAXY S9 +, iPhone 8, iPhone 8+, G4, iPhone 7, G6, V30 Each of the FOD parameters measured / calculated while only nine smartphone models exist, and the nine smarts Each of the FOD parameters measured / calculated in the presence of the phone models and various kinds of foreign substances (US Dime, Clip, Hairpin, US Quarter, US 1c, CHF Coin) is shown in FIGS. 29A and 29B (ie , Foreign object detection algorithm) to obtain the result value of the regression analysis of Table 7, if it is represented by a scatter plot, the graph of FIG. 30 can be obtained.

	Regression of All FO (76%)Regression of All FO (76%)
Galaxy S8Galaxy S8	1.5429595291.542959529
Galaxy S9Galaxy S9	1.0350123031.035012303
Galaxy S9+Galaxy S9 +	1.7911602111.791160211
iPhone 8iPhone 8	0.7695128010.769512801
iPhone 8+iPhone 8+	1.1772788091.177278809
G4G4	-0.074689448-0.074689448
iPhone 7iPhone 7	1.0121309461.012130946
G6G6	2.3909781752.390978175
V30V30	1.9147133351.914713335

Galaxy S8+US DimeGalaxy S8 + US Dime	3.8099790893.809979089
Galaxy S9+US DimeGalaxy S9 + US Dime	3.2961633693.296163369
Galaxy S9++US DimeGalaxy S9 ++ US Dime	3.3004655023.300465502
iPhone 8+US DimeiPhone 8 + US Dime	2.9268208542.926820854
iPhone 8++US DimeiPhone 8 ++ US Dime	2.875378932.87537893
G4+US DimeG4 + US Dime	2.5292971062.529297106
iPhone 7+US DimeiPhone 7 + US Dime	3.151451613.15145161
G6+USDG6 + USD	3.9567918963.956791896
V30+USDV30 + USD	3.9558242323.955824232

iPhone 7+ClipiPhone 7 + Clip	2.9910908872.991090887
G4+ClipG4 + Clip	2.3581788762.358178876
Galaxy S9+ClipGalaxy S9 + Clip	3.2901022413.290102241
Galaxy S8+ClipGalaxy S8 + Clip	3.6171218033.617121803
iPhone8++ClipiPhone8 ++ Clip	3.2998060723.299806072
iPhone8+ClipiPhone8 + Clip	2.8732722662.873272266
Galaxy S9++ClipGalaxy S9 ++ Clip	3.5790841983.579084198
G6+ClipG6 + Clip	3.8567721233.856772123

Galaxy S9+USQGalaxy S9 + USQ	4.2305074944.230507494
Galaxy S9+US1cGalaxy S9 + US1c	3.8103778723.810377872
Galaxy S9+CHFGalaxy S9 + CHF	3.9792836573.979283657
Galaxy S9++USQGalaxy S9 ++ USQ	4.3427542344.342754234
Galaxy S9++US1cGalaxy S9 ++ US1c	3.7969790343.796979034
Galaxy S9++CHFGalaxy S9 ++ CHF	3.4003242393.400324239
Galaxy S8+USQGalaxy S8 + USQ	3.848441863.84844186
Galaxy S8+US1cGalaxy S8 + US1c	3.7947521653.794752165
Galaxy S8+CHFGalaxy S8 + CHF	4.0797502324.079750232
iPhone 8+USQiPhone 8 + USQ	3.4053881993.405388199
iPhone 8+US1ciPhone 8 + US1c	3.1163733713.116373371
iPhone 8+CHFiPhone 8 + CHF	3.215561913.21556191
iPhone 8++USQiPhone 8 ++ USQ	3.6391029623.639102962
iPhone 8++US1ciPhone 8 ++ US1c	3.3422686223.342268622
iPhone 8++CHFiPhone 8 ++ CHF	3.7084468113.708446811
G6+USQG6 + USQ	4.8879596514.887959651
G6+US1cG6 + US1c	4.5449013334.544901333
G6+CHFG6 + CHF	4.1713067314.171306731
V30+USQV30 + USQ	5.0958774275.095877427
V30+US1cV30 + US1c	4.2035795864.203579586
V30+CHFV30 + CHF	4.2952970274.295297027

Galaxy S9+HiarpinGalaxy S9 + Hiarpin	3.0867207133.086720713
Galaxy S8+HiarpinGalaxy S8 + Hiarpin	3.9113119813.911311981
iPhone8++HiarpiniPhone8 ++ Hiarpin	2.9494760222.949476022
iPhone8+HiarpiniPhone8 + Hiarpin	3.5021946413.502194641
Galaxy S9++HiarpinGalaxy S9 ++ Hiarpin	4.3214521934.321452193
G6+HiarpinG6 + Hiarpin	4.4611434084.461143408
V30+HiarpinV30 + Hiarpin	3.4279244233.427924423

Referring to FIG. 30, the z value in the normal distribution of the histogram is 1.48.

Referring to FIGS. 31A and 31B, weights constituting a regression equation are obtained by regression analysis based on a total of 14 FOD parameters, and an experimental result of deriving (or constructing) an FOD algorithm based on the weights is shown.

GALAXY S8, GALAXY S9, GALAXY S9 +, iPhone 8, iPhone 8+, G4, iPhone 7, G6, V30 Each of the FOD parameters measured / calculated while only nine smartphone models exist, and the nine smarts If the FOD parameters measured / calculated in the presence of the phone models and two types of foreign matters (US Dime, Clip) are present in the Responses (i.e., foreign matter detection algorithm) of FIGS. 31A and 31B, Table 8 The result of the regression analysis can be obtained, and if it is represented by a scatter plot, the graph of FIG. 32 can be obtained.

	Regression for Algori 1+Hairpin (96%)Regression for Algori 1 + Hairpin (96%)
Galaxy S8Galaxy S8	-0.160014341-0.160014341
Galaxy S9Galaxy S9	-0.399945539-0.399945539
Galaxy S9+Galaxy S9 +	-0.380820715-0.380820715
iPhone 8iPhone 8	-0.389134164-0.389134164
iPhone 8+ iPhone 8+	-0.329699639-0.329699639
G4G4	-0.265978639-0.265978639
iPhone 7iPhone 7	-0.46016258-0.46016258
G6G6	0.0404337540.040433754
V30V30	0.0504483520.050448352

Galaxy S8+US DimeGalaxy S8 + US Dime	2.2772254512.277225451
Galaxy S9+US DimeGalaxy S9 + US Dime	1.5741451821.574145182
Galaxy S9++US DimeGalaxy S9 ++ US Dime	1.7015082941.701508294

iPhone 8+US DimeiPhone 8 + US Dime	1.5255718591.525571859
iPhone 8++US Dime iPhone 8 ++ US Dime	1.8888733651.888873365
G4+US DimeG4 + US Dime	2.0079555682.007955568

iPhone 7+US DimeiPhone 7 + US Dime	1.1891971731.189197173
G6+USDG6 + USD	1.9108505051.910850505
V30+USDV30 + USD	1.9425123971.942512397


iPhone 7+ClipiPhone 7 + Clip	1.7529344361.752934436
G4+ClipG4 + Clip	1.8467823791.846782379
Galaxy S9+ClipGalaxy S9 + Clip	1.9814060541.981406054
Galaxy S8+ClipGalaxy S8 + Clip	1.9822781511.982278151
iPhone8++ClipiPhone8 ++ Clip	1.7176348991.717634899
iPhone8+ClipiPhone8 + Clip	2.0348409012.034840901
Galaxy S9++ClipGalaxy S9 ++ Clip	2.1326631432.132663143
G6+ClipG6 + Clip	2.0492526362.049252636
V30+ClipV30 + Clip	1.9214152531.921415253

Galaxy S9+HiarpinGalaxy S9 + Hiarpin	1.5209604941.520960494
Galaxy S8+HiarpinGalaxy S8 + Hiarpin	2.0811502072.081150207
iPhone8++HiarpiniPhone8 ++ Hiarpin	2.2086784082.208678408
iPhone8+HiarpiniPhone8 + Hiarpin	1.8434918041.843491804
Galaxy S9++HiarpinGalaxy S9 ++ Hiarpin	2.3555040652.355504065
G6+HiarpinG6 + Hiarpin	2.3755671522.375567152
V30+HiarpinV30 + Hiarpin	2.0842635672.084263567

FIG. 32 is a histogram simulating the performance of a foreign material detection algorithm derived based on a regression analysis using 14 FOD parameters according to FIGS. 31A and 31B.

Referring to FIG. 32, in the normal distribution of the histogram, the z value is 7.56.

Referring to FIGS. 33A and 33B, weights constituting a regression equation are obtained by regression analysis based on a total of 13 FOD parameters, and an experimental result of deriving (or constructing) an FOD algorithm based on the weights is shown.

GALAXY S8, GALAXY S9, GALAXY S9 +, iPhone 8, iPhone 8+, G4, iPhone 7, G6, V30 Each of the FOD parameters measured / calculated while only nine smartphone models exist, and the nine smarts Each of the FOD parameters measured / calculated in the presence of the phone models and the three types of foreign matters (US Quarter, US 1 cent, CHF Coin) in the Response (ie, foreign matter detection algorithm) of FIGS. 33A and 33B. If input, the result of regression analysis in Table 9 can be obtained, and if it is represented as a scatter plot, the graph in FIG. 34 can be obtained.

	Regression for Algori 2(92%)Regression for Algori 2 (92%)
Galaxy S8Galaxy S8	-1.039304544-1.039304544
Galaxy S9Galaxy S9	-1.871895313-1.871895313
Galaxy S9+Galaxy S9 +	-1.270823771-1.270823771
iPhone 8iPhone 8	-1.347822278-1.347822278
iPhone 8+ iPhone 8+	-1.219328447-1.219328447
G4G4	-1.185674252-1.185674252
iPhone 7iPhone 7	-1.590953387-1.590953387
G6G6	-1.374424487-1.374424487
V30V30	-1.117066915-1.117066915

Galaxy S9+USQGalaxy S9 + USQ	0.4313314070.431331407
Galaxy S9+US1cGalaxy S9 + US1c	0.1233445240.123344524
Galaxy S9+CHFGalaxy S9 + CHF	0.5115341840.511534184
Galaxy S9++USQGalaxy S9 ++ USQ	0.3763108130.376310813
Galaxy S9++US1cGalaxy S9 ++ US1c	0.3272871270.327287127
Galaxy S9++CHFGalaxy S9 ++ CHF	0.4275701820.427570182
Galaxy S8+USQGalaxy S8 + USQ	0.4831785260.483178526
Galaxy S8+US1cGalaxy S8 + US1c	0.42338920.4233892
Galaxy S8+CHFGalaxy S8 + CHF	0.6676892430.667689243

iPhone 8+USQiPhone 8 + USQ	0.301646720.30164672

iPhone 8+US1ciPhone 8 + US1c	0.2401801740.240180174

iPhone 8+CHFiPhone 8 + CHF	0.4369619350.436961935

iPhone 8++USQiPhone 8 ++ USQ	0.5012221560.501222156

iPhone 8++US1ciPhone 8 ++ US1c	0.5804513670.580451367

iPhone 8++CHFiPhone 8 ++ CHF	0.592792720.59279272
G6+USQG6 + USQ	0.2976740730.297674073
G6+US1cG6 + US1c	0.737768770.73776877
G6+CHFG6 + CHF	0.1804208270.180420827
V30+USQV30 + USQ	0.0935172840.093517284
V30+US1cV30 + US1c	0.563045790.56304579
V30+CHFV30 + CHF	0.5159320160.515932016

FIG. 34 is a histogram simulating the performance of a foreign material detection algorithm derived based on regression analysis using 13 FOD parameters according to FIGS. 33A and 33B.

Referring to FIG. 34, in the normal distribution of the histogram, the z value is 5.54.

Referring to FIGS. 35A and 35B, weights constituting a regression equation are obtained by regression analysis based on a total of 15 FOD parameters, and an experimental result of deriving (or constructing) an FOD algorithm based on the weights is shown.

GALAXY S8, GALAXY S9, GALAXY S9 +, iPhone 8, iPhone 8+, G4, iPhone 7, G6, V30 Each of the FOD parameters measured / calculated while only nine smartphone models exist, and the nine smarts When the FOD parameters measured / calculated in the presence of the phone models and the US Dime are input to the responses of FIG. 35A and FIG. 35B (ie, foreign material detection algorithm), the results of the regression analysis in Table 10 can be obtained. , If this is represented by a scatter diagram, the graph of FIG. 36 can be obtained.

	Regression (99%)Regression (99%)
Galaxy S8Galaxy S8	-1.098601378-1.098601378
Galaxy S9Galaxy S9	-1.087930358-1.087930358
Galaxy S9+Galaxy S9 +	-1.088086945-1.088086945
iPhone 8iPhone 8	-1.071508808-1.071508808
iPhone 8+ iPhone 8+	-1.065436806-1.065436806
G4G4	-1.051447611-1.051447611
iPhone 7iPhone 7	-1.069836477-1.069836477
G6G6	-1.109108023-1.109108023
V30V30	-1.106766146-1.106766146

Galaxy S8+US DimeGalaxy S8 + US Dime	0.8817960730.881796073
Galaxy S9+US DimeGalaxy S9 + US Dime	0.8840306710.884030671
Galaxy S9++US DimeGalaxy S9 ++ US Dime	0.8737155120.873715512
iPhone 8+US Dime iPhone 8 + US Dime	0.9374170120.937417012
iPhone 8++US Dime iPhone 8 ++ US Dime	0.9187983320.918798332
G4+US DimeG4 + US Dime	0.9160121960.916012196

iPhone 7+US DimeiPhone 7 + US Dime	0.8804646760.880464676
G6+USDG6 + USD	0.8373492820.837349282
V30+USDV30 + USD	0.8546251650.854625165

Referring to FIG. 36, the z value in the normal distribution of the histogram is 96.78.

Referring to FIG. 37, weights constituting a regression equation are obtained by regression analysis based on a total of 13 FOD parameters, and an experimental result of deriving (or constructing) an FOD algorithm based on the weights is shown.

Galaxy F8, Galaxy S9, Galaxy S9 +, iPhone 8, iPhone 8+, G4, iPhone 7, G6, V30 Each of the FOD parameters measured / calculated while only nine smartphone models exist, and the nine Smart When the FOD parameters measured / calculated in the presence of the phone models and the clip are input to the Response of FIG. 37 (that is, the foreign matter detection algorithm), the result of the regression analysis of Table 11 can be obtained, If this is represented as a scatter diagram, the graph of FIG. 38 can be obtained.

	Regression (99%)Regression (99%)
Galaxy S8Galaxy S8	-0.973972525-0.973972525
Galaxy S9Galaxy S9	-1.018833459-1.018833459
Galaxy S9+Galaxy S9 +	-0.993917115-0.993917115
iPhone 8iPhone 8	-1.020307175-1.020307175
iPhone 8+ iPhone 8+	-1.011496845-1.011496845
G4G4	-0.999733151-0.999733151
iPhone 7iPhone 7	-1.013551321-1.013551321
G6G6	-1.001666087-1.001666087
V30V30	-0.988396254-0.988396254

iPhone 7+ClipiPhone 7 + Clip	1.0466742291.046674229
G4+ClipG4 + Clip	1.0210372621.021037262
Galaxy S9+ClipGalaxy S9 + Clip	1.0294042991.029404299
Galaxy S8+ClipGalaxy S8 + Clip	1.0326973021.032697302
iPhone8++ClipiPhone8 ++ Clip	1.0268045391.026804539
iPhone8+ClipiPhone8 + Clip	0.9795910990.979591099
Galaxy S9++ClipGalaxy S9 ++ Clip	1.0441133871.044113387
G6+ClipG6 + Clip	1.0490010651.049001065

Referring to FIG. 38, the z value in the normal distribution of the histogram is 129.

Referring to FIG. 39, weights constituting a regression equation are obtained by regression analysis based on a total of nine FOD parameters, and an experimental result of deriving (or constructing) an FOD algorithm based on the weights is shown.

GALAXY S8, GALAXY S9, GALAXY S9 +, iPhone 8, iPhone 8+, G4, iPhone 7, G6, V30 Each of the FOD parameters measured / calculated while only nine smartphone models exist, and the nine smarts When the FOD parameters measured / calculated in the presence of the phone models and the hairpin are input to the response of FIG. 39 (that is, the foreign matter detection algorithm), the result of the regression analysis of Table 12 can be obtained. If this is represented by a scatter diagram, the graph of FIG. 40 can be obtained.

	Regression (99%)Regression (99%)
Galaxy S8Galaxy S8	-0.228951988-0.228951988
Galaxy S9Galaxy S9	-0.375884029-0.375884029
Galaxy S9+Galaxy S9 +	-0.357215804-0.357215804
iPhone 8iPhone 8	-0.409313423-0.409313423
iPhone 8+ iPhone 8+	-0.38551821-0.38551821
G4G4	-0.674340524-0.674340524
iPhone 7iPhone 7	-0.434459937-0.434459937
G6G6	-0.267304071-0.267304071
V30V30	-0.130089501-0.130089501

Galaxy S9+HiarpinGalaxy S9 + Hiarpin	1.8116205131.811620513
Galaxy S8+HiarpinGalaxy S8 + Hiarpin	1.8411625361.841162536
iPhone8++HiarpiniPhone8 ++ Hiarpin	1.6685562121.668556212
iPhone8+HiarpiniPhone8 + Hiarpin	1.6968109591.696810959
Galaxy S9++HiarpinGalaxy S9 ++ Hiarpin	1.8861182991.886118299
G6+HiarpinG6 + Hiarpin	1.9933782111.993378211
V30+HiarpinV30 + Hiarpin	1.8862139431.886213943

Referring to FIG. 40, the z value in the normal distribution of the histogram is 13.3.

Referring to FIGS. 41A and 41B, weights constituting a regression equation are obtained by regression analysis based on a total of 13 FOD parameters, and an experimental result of deriving (or constructing) an FOD algorithm based on the weights is shown.

GALAXY S8, GALAXY S9, GALAXY S9 +, iPhone 8, iPhone 8+, G4, iPhone 7, G6, V30 Each of the FOD parameters measured / calculated while only nine smartphone models exist, and the nine smarts When the FOD parameters measured / calculated in the presence of the phone models and the US quarter are input to the responses of FIG. 41A and FIG. 41B (that is, the foreign matter detection algorithm), the results of the regression analysis of Table 13 are obtained. It can be obtained, and if it is represented by a scatter diagram, the graph of FIG. 42 can be obtained.

	Regression (99%)Regression (99%)
Galaxy S8Galaxy S8	-1.006295721-1.006295721
Galaxy S9Galaxy S9	-0.987543493-0.987543493
Galaxy S9+Galaxy S9 +	-0.989622754-0.989622754
iPhone 8iPhone 8	-0.955461384-0.955461384
iPhone 8+ iPhone 8+	-0.960210646-0.960210646
G4G4	-0.999500749-0.999500749
iPhone 7iPhone 7	-1.072806286-1.072806286
G6G6	-0.986731956-0.986731956
V30V30	-0.997042554-0.997042554
Galaxy S9+USQGalaxy S9 + USQ	0.9883588220.988358822
Galaxy S9++USQGalaxy S9 ++ USQ	1.0074242971.007424297
Galaxy S8+USQGalaxy S8 + USQ	1.0051176741.005117674

iPhone 8+USQiPhone 8 + USQ	1.0033740861.003374086

iPhone 8++USQiPhone 8 ++ USQ	1.0077022271.007702227
G6+USQG6 + USQ	1.0000225871.000022587
V30+USQV30 + USQ	0.9903816510.990381651

FIG. 42 is a histogram simulating the performance of a foreign material detection algorithm derived based on regression analysis using 13 FOD parameters according to FIGS. 41A and 41B.

Referring to FIG. 42, the z value in the normal distribution of the histogram is 58.7.

Referring to FIGS. 43A and 43B, weights constituting a regression equation are obtained by regression analysis based on a total of 11 FOD parameters, and an experimental result of deriving (or constructing) an FOD algorithm based on the weights is shown.

GALAXY S8, GALAXY S9, GALAXY S9 +, iPhone 8, iPhone 8+, G4, iPhone 7, G6, V30 Each of the FOD parameters measured / calculated while only nine smartphone models exist, and the nine smarts When each FOD parameter measured / calculated in the presence of the phone models and the US 1 cent is input to the response (ie, foreign material detection algorithm) of FIGS. 43A and 43B, the result of regression analysis of Table 14 can be obtained. If it is represented by a scatter diagram, the graph of FIG. 44 can be obtained.

	Regression (99.9%)Regression (99.9%)
Galaxy S8Galaxy S8	-1.319068-1.319068
Galaxy S9Galaxy S9	-1.452613-1.452613
Galaxy S9+Galaxy S9 +	-1.40939-1.40939
iPhone 8iPhone 8	-1.396964-1.396964
iPhone 8+ iPhone 8+	-1.291339-1.291339
G4G4	-1.23445-1.23445
iPhone 7iPhone 7	-1.354082-1.354082
G6G6	-1.459778-1.459778
V30V30	-1.478478-1.478478
Galaxy S9+US1cGalaxy S9 + US1c	0.54007360.5400736
Galaxy S9++US1cGalaxy S9 ++ US1c	0.43998190.4399819
Galaxy S8+US1cGalaxy S8 + US1c	0.37577370.3757737

iPhone 8+US1ciPhone 8 + US1c	0.65342890.6534289

iPhone 8++US1ciPhone 8 ++ US1c	0.52574970.5257497
G6+US1cG6 + US1c	0.36927840.3692784
V30+US1cV30 + US1c	0.35548410.3554841

Referring to FIG. 44, in the normal distribution of the histogram, the z value is 20.7.

Referring to FIGS. 45A and 45B, weights constituting a regression equation are obtained by regression analysis based on a total of 11 FOD parameters, and an experimental result of deriving (or constructing) an FOD algorithm based on the weights is shown.

GALAXY S8, GALAXY S9, GALAXY S9 +, iPhone 8, iPhone 8+, G4, iPhone 7, G6, V30 Each of the FOD parameters measured / calculated while only nine smartphone models exist, and the nine smarts When the FOD parameters measured / calculated in the presence of the phone models and the Swiss franc (CHF) are input to the responses of FIG. 45A and FIG. 45B (ie, foreign material detection algorithm), the results of the regression analysis in Table 15 are obtained. It can be obtained, and if it is represented by a scatter diagram, the graph of FIG. 46 can be obtained.

	Regression (99.9%)Regression (99.9%)
Galaxy S8Galaxy S8	-1.02071-1.02071
Galaxy S9Galaxy S9	-1.040825-1.040825
Galaxy S9+Galaxy S9 +	-1.03686-1.03686
iPhone 8iPhone 8	-1.026157-1.026157
iPhone 8+ iPhone 8+	-1.000727-1.000727
G4G4	-1.018573-1.018573
iPhone 7iPhone 7	-1.046581-1.046581
G6G6	-1.046291-1.046291
V30V30	-1.031088-1.031088
Galaxy S9+CHFGalaxy S9 + CHF	0.89181240.8918124
Galaxy S9++CHFGalaxy S9 ++ CHF	0.9522330.952233
Galaxy S8+CHFGalaxy S8 + CHF	0.97403520.9740352

iPhone 8+CHFiPhone 8 + CHF	0.96508680.9650868

iPhone 8++CHFiPhone 8 ++ CHF	0.94417370.9441737
G6+CHFG6 + CHF	0.91395680.9139568
V30+CHFV30 + CHF	0.93685450.9368545

FIG. 46 is a histogram simulating the performance of a foreign material detection algorithm derived based on a regression analysis applying 11 FOD parameters according to FIG. 45.

Referring to FIG. 46, in the normal distribution of the histogram, the z value is represented as 128.

47A and 47B, a total of seven basic FOD parameters (Q factor, power loss (PLoss), rail voltage (Vrail), rail current (Irail), internal loss (internal loss), and received power packet (RPP) ), Primary coil current, temperature loss (TLoss)) and those obtained by measurement, and the secondary FOD parameters are 12, including those that can be calculated by performing arithmetic operations on at least some of the basic FOD parameters. do.

When the basic FOD parameters and the additional FOD parameters are combined, there are a total of 19 types, all of which are applied to regression analysis to obtain weights constituting a regression equation, and derive (or construct) an FOD algorithm based on the weights. .

And the Galaxy S8, Galaxy S9, Galaxy S9 +, iPhone 8, iPhone 8+, G6, and V30, each of the FOD parameters measured / calculated while there are only 7 smartphone models, and the 7 smartphone models When each FOD parameter measured / calculated in the presence of the Swiss franc (CHF) is represented in a scatter diagram by substituting the FOD algorithm, the graphs of FIGS. 48A to 48C can be obtained.

Referring to FIGS. 48A to 48C, (a) substitutes each FOD parameter measured / calculated in the Rx only state and each FOD parameter measured / calculated in the Rx + US Dime state into the FOD algorithm. , (b) is a Fx parameter measured / calculated in the state of Rx only, and each FOD parameter measured / calculated in the state of Rx + Clip is substituted into the FOD algorithm, and (c) is Rx only. In each of the FOD parameters measured / calculated in Rx and each FOD parameter measured / calculated in the Rx + Hairpin state, the FOD algorithm is substituted, and (d) represents each FOD parameter measured / calculated in the Rx only state. , Each FOD parameter measured / calculated in the state of Rx + US Quarter is substituted into the FOD algorithm, (e) each FOD parameter measured / calculated in the state of Rx only, and Rx + US 1 Cent Each FOD wave measured / calculated at The meters are substituted into the FOD algorithm, and (f) is the FOD parameter measured / calculated in the Rx only state and the FOD parameters measured / calculated in the Rx + CHF 5 state in the FOD algorithm. will be.

For (a), the z value is 490, for (b), the z value is 39, for (c), the z value is 44, for (d), the z value is 142, and for (e), z The value is 11.6, and for (f) the z value is 72. Since all of them have a z value of 6 or more, it is evaluated as a statistically good value.

The following embodiments complementarily use additional FOD parameter (s) calculated through basic FOD parameter (s) and / or measured FOD parameter (s) measurable for detecting foreign matter in a wireless power transmission system. Disclosed is a method for performing FOD. This embodiment maximizes the foreign substance detection performance beyond the application limits of multiple FOD parameters. In addition, this embodiment applies FOD parameters at the same time. In the process of simultaneously applying the FOD parameters, the weight (or regression coefficient) of each parameter is obtained and applied to maximize the detection performance of foreign matter.

Referring to FIG. 49, the wireless power transmitter (or receiver) measures and / or calculates predetermined FOD parameters (S4900). The predetermined FOD parameters may include at least one basic FOD parameter and / or at least one additional FOD parameter, for example, as shown in FIGS. 47A and 47B. For example, the predefined FOD parameters may include Q-factor, power loss, frequency shift, and primary coil current. The FOD algorithm can utilize all the system parameters that can be measured during the wireless charging process, such as Q-factor, power loss, frequency shift, and primary current, and additional parameters calculated after arithmetic by utilizing them. As the number of FOD parameters used as variables in the foreign matter detection algorithm increases, the performance and accuracy of foreign matter detection may increase.

The wireless power transmission device (or the reception device) inputs the measured and / or calculated FOD parameters to a foreign material detection algorithm derived by regressing the predetermined FOD parameters (S4905). The foreign material detection algorithm in step S4905 may use a regression equation, and may be designed or implemented by various methods previously exemplarily described herein. As an example, the foreign substance detection algorithm uses a regression equation using the predetermined FOD parameters as a variable, and the regression equation applies the predetermined FOD parameters to a regression analysis to determine a regression coefficient or weight for each FOD parameter. It can be designed or obtained by obtaining. Here, the foreign material detection algorithm may be performed based on a plurality of regression analysis results obtained by performing regression analysis individually for each FOD parameter. In this case, FOD performance may be maximized.

The wireless power transmission device (or the reception device) determines whether a foreign object exists based on the result value of the foreign material detection algorithm (S4910). Here, the foreign matter detection algorithm is a regression equation. When only the wireless power transmission device is present (Rx only), the result of the foreign matter detection algorithm is output as 1, and when both the wireless power transmission device and the foreign material are present (Rx + FO). The result value of the foreign object algorithm can be designed in a digitized state to be output as -1. In this case, if the result value of the foreign matter detection algorithm is -1 or an approximate value, the wireless power transmitter (or receiver) determines that the foreign matter exists. On the other hand, if the result value of the foreign substance detection algorithm is 1 or an approximate value, the wireless power transmitter (or the receiving apparatus) determines that the foreign substance does not exist.

The wireless power transmitter in this embodiment corresponds to the wireless power transmitter or wireless power transmitter or power transmitter disclosed in FIGS. 1 to 11. Accordingly, the operation of the wireless power transmission apparatus in this embodiment is implemented by one or a combination of two or more of each component of the wireless power transmission apparatus in FIGS. 1 to 11. For example, in this embodiment, the derivation of the FOD algorithm by the wireless power transmission device and the FOD performing operation according to the FOD algorithm may be performed by the communication / control unit 120. In addition, the wireless power receiver in this embodiment corresponds to the wireless power receiver or wireless power receiver or power receiver disclosed in FIGS. 1 to 11. Accordingly, the operation of the wireless power receiving apparatus in this embodiment is implemented by one or a combination of two or more of each component of the wireless power receiving apparatus in FIGS. 1 to 11. For example, in this embodiment, the derivation of the FOD algorithm by the wireless power receiver and the FOD performing operation according to the FOD algorithm may be performed by the communication / control unit 220.

Step S4910 may include a foreign material detection algorithm according to FIG. 50.

50 is a flowchart illustrating a method of detecting a foreign material according to another embodiment. Hereinafter, the method for performing FOD is described as being performed by a wireless power transmission device, but the method for performing FOD can be provided by a wireless power receiving device as well.

Referring to FIG. 50, the wireless power transmission apparatus may perform foreign matter detection by sequentially using a plurality of different foreign matter detection algorithms.

To derive a plurality of foreign matter detection algorithms, regression analysis of FO ₁ , regression analysis of FO ₂ , ... , Like FO _N regression analysis, the number and range of regression analysis can be selected to detect FOs of all areas (or all predefined types).

Here, the judgment function “regression analysis of _k ≤ FO _K ≤ _k ” may mean a band pass filter that passes only the wireless power receiver. Here, j and k are the minimum and maximum values of the data range passing through the band pass filter, respectively. This is the range treated as the absence of foreign substances. Alternatively, the judgment "Regression of j≤FO ≤k _K" which is a function is applied to the conditions that can distinguish between a case in which all case be only a wireless power receiving apparatus and a wireless power receiving apparatus and exists FO (FO Rx + _K) After regression analysis, it may mean an area through which only the wireless power receiving device passes.

The wireless power transmission apparatus performs a step of determining whether the result of the regression equation satisfies the regression analysis ≤b of a≤FO ₁ , which is a condition of FO free for the first FO (S5000).

As a result of the determination, if the result of the regression equation satisfies the regression analysis ≤ b of a≤FO _{1, which} is a condition where there is no foreign matter related to the first FO (yes), the wireless power transmission device does not have a foreign matter related to the next second FO. It is determined whether the regression analysis of c ≤ FO ₂ satisfies (d) (S5005).

On the other hand, if the result of the determination, the result of the regression equation does not satisfy the regression analysis ≤b of a≤FO _{1, which} is a condition where there is no foreign matter related to the first FO, the wireless power transmitter determines that the foreign matter exists and transmits the wireless power. Is stopped (S5025).

In the same manner, foreign material detection algorithms for different FOs are performed in steps S5005 to S5015. If no foreign matter is detected until the last foreign matter FO _N , the wireless power transmission apparatus proceeds with wireless power transmission (S5020).

In this embodiment, assuming that there are a total of N FOs, N cyclic regression equations (or N foreign matter detection algorithms) are defined, but this is only an example. Here, FO _K may be a specific single FO or a group including several types of FOs.

FOD 파라미터의 구간별 회귀 분석에 기반한 이물질 검출 알고리즘Foreign object detection algorithm based on regression analysis for each section of FOD parameter

The wireless power receiver can be placed in various locations on the wireless power transmitter.

As shown in (a) of FIG. 51, when the wireless power receiving device and the foreign matter are aligned with the center of the wireless power transmission device (without offset), the presence and absence of the foreign matter (US dime) is well distinguished on the histogram. However, as shown in (b), when the wireless power receiving device and / or the foreign material are somewhat offset from the center of the wireless power transmitting device (with offset), the situation in which the foreign material exists and the situation in which the foreign material does not exist may not be well distinguished. . That is, it may be difficult to distinguish foreign substances due to the misalignment of the wireless power receiver and / or foreign substances. Therefore, this embodiment performs regression analysis considering the alignment of the wireless power receiver and derives a more advanced foreign matter detection algorithm based on this.

According to this embodiment, in order to compensate for the deterioration of the foreign matter detection performance due to the misalignment of the foreign matter and / or the wireless power receiving apparatus, the FOD parameter (for example, R) used in regression analysis is divided into multiple intervals. By separating and performing regression analysis for each section, a foreign material detection algorithm can be derived or designed.

In classifying the presence / absence of a foreign material by applying the change of the FOD parameter by the foreign material and / or the wireless power receiving device to the regression analysis, in order to improve the performance of distinguishing between Rx Only and Rx + FO situations , The section of the regression analysis (or the entire section of a specific FOD parameter) may be subdivided or reduced.

Referring to FIGS. 52A and 52B, this experiment shows the FOD parameters of rail current (I rail), input power (Internal Power), internal loss (Internal Loss), received power packet (RPP), power loss (P Loss), The rail voltage (V rail), the primary coil current (I coil) and the resistance (R = V / I) can be divided into five measurable ranges, each of five sections (1, 2, 3, 4, 5), The FOD parameters of each section were applied to the regression analysis to derive the explanatory power (R-sq) for each section.

Based on the statistical explanatory power (R-sq (adj)), it was found that the FOD parameter that provides the best explanatory power for interval-wise regression analysis is resistance (R) (average explanatory power = 92.2). That is, in the regression analysis for each section, the index that is most effective for a resolution for distinguishing a situation that is Rx Only and a situation that is Rx + FO is resistance.

In particular, as a result of performing regression analysis by dividing the entire area of the resistance (R = Vrail / Irail) into several sections (Interval), the smaller the size of the section (i.e., the greater the number of sections), the higher the resolution (or Z value) This enlargement was confirmed. This is a quasi self-consistent method, which can compensate for shortcomings (new phones, unknown FOs) of wireless power receiver filters or foreign matter filters.

53 is a flowchart illustrating a method of detecting a foreign material according to another embodiment. Hereinafter, the method for performing FOD is described as being performed by a wireless power transmission device, but the method for performing FOD can be provided by a wireless power receiving device as well.

Referring to FIG. 53, the wireless power transmitter (or receiver) measures and / or calculates a predetermined FOD parameter (S5300). The predetermined FOD parameter may be, for example, a resistance (R = V _rail / I _rail ) as described in detail with reference to FIGS. 52A and 52B. As described with reference to FIGS. 52A and 52B, when the resistance R is divided into a plurality of sections and subjected to regression analysis, it has been confirmed that the classification performance of the presence / absence of foreign matter is the best. Of course, the FOD parameter measured or calculated in step S5300 may be various FOD parameters disclosed herein in addition to the resistance R.

The wireless power transmitter (or receiver) determines whether the measured value of the FOD parameter measured in step S5300 belongs to the n-th section (S5305). Here, the n-th section may be defined as a section in which the measured value is greater than or equal to a _{n and} less than or equal to b _n . For example, when the FOD parameter to be measured is R, a _n ≤ R _n (= V _rail / I _rail ) ≤ b _n may be defined.

In step S5305, if the measured value of the FOD parameter does not belong to the nth section, the wireless power transmitter (or the receiving device) updates n to the next section, n + 1 (S5310), and the measured value of the FOD parameter is removed again. The process of determining whether it belongs to the n + 1 section is repeated (S5305). In this process, when the measured value belongs to the n-th section, the wireless power transmitter (or the receiving device) performs FOD based on the regression equation of the n-th section (S5315). The regression equation of the n-th interval may be called a foreign matter detection algorithm of the n-th interval.

According to the present embodiment, the regression equation is defined for each section, and a bandpass filter may be defined for each regression equation for each section. For example, if the band pass filter in the regression equation of the nth interval is referred to as an nth band pass filter, the nth band pass filter may be defined as a range greater than or equal to i _{n and} less than or equal to j _n (i _n ≤ Regression of R _n for Interval n ≤ j _n ). Therefore, in the method of performing FOD in step S5315, the wireless power transmission device (or receiving device) substitutes the FOD parameter measurement value into the regression equation for the n-th interval (or foreign matter detection algorithm for the n-th interval) to obtain the result value. Derivation step, determining whether the foreign matter is present or not depending on whether the result value is included in the n-th band pass filter range, and when it is determined that the foreign matter is present, the wireless power transmission is stopped and the foreign matter is determined to be absent. May include performing wireless power transmission.

In addition, the foreign matter detection method in each section may include the foreign matter detection method according to FIG. 50.

54A to 54C, (a) is a histogram when the resistance value range is not divided, (b) is a histogram when the resistance value range is divided into two sections, and (c) is The histogram when the range of resistance values is divided into 4 sections, (d) is the histogram when the range of resistance values is divided into 7 sections, and (e) the range of the resistance value is divided into 13 sections. This is a histogram in one case, and (f) is a histogram when the range of resistance values is divided into 27 sections.

It can be seen that as the range of the resistance value is divided into more sections, the z value becomes larger. The z value obtained by dividing the R measurement value (from 2.90 to 6.00) into multiple sections is as shown in the following table.

Full Range/27Full Range / 27		Full Range/13Full Range / 13		Full Range/7Full Range / 7		Full Range/4Full Range / 4		Full Range/2Full Range / 2		Full RangeFull Range
R(V/I)R (V / I)	Z 값Z value	R(V/I)R (V / I)	Z 값Z value	R(V/I)R (V / I)	Z 값Z value	R(V/I)R (V / I)	Z 값Z value	R(V/I)R (V / I)	Z 값Z value	R(V/I)R (V / I)	Z 값Z value
2.90 2.90	46.00 46.00	2.95 2.95	22.40 22.40
3.00 3.00	23.00 23.00			3.05 3.05	4.08 4.08
3.10 3.10	10.90 10.90	3.15 3.15	4.93 4.93
3.20 3.20	6.116.11					3.23 3.23	1.89 1.89
3.30 3.30	10.10 10.10	3.35 3.35	11.20 11.20
3.40 3.40	20.60 20.60			3.41 3.41	4.30 4.30
3.45 3.45	11.00 11.00	3.48 3.48	8.08 8.08
3.50 3.50	11.30 11.30							3.42 3.42	1.00 1.00
3.52 3.52	28.00 28.00	3.53 3.53	6.57 6.57
3.54 3.54	7.10 7.10			3.56 3.56	4.75 4.75
3.56 3.56	12.00 12.00	3.58 3.58	6.14 6.14
3.60 3.60	8.63 8.63					3.61 3.61	1.95 1.95
3.63 3.63	11.50 11.50	3.63 3.63	9.13 9.13
3.64 3.64	9.42 9.42			3.66 3.66	8.86 8.86
3.67 3.67	14.70 14.70	3.69 3.69	7.42 7.42							3.73 3.73	0.180.18
3.70 3.70	13.70 13.70
3.73 3.73	6.43 6.43	3.74 3.74	4.87 4.87
3.75 3.75	9.38 9.38			3.76 3.76	3.76 3.76
3.77 3.77	28.20 28.20	3.79 3.79	8.62 8.62
3.80 3.80	11.60 11.60					3.85 3.85	3.76 3.76
3.85 3.85	9.09 9.09	3.88 3.88	4.46 4.46					4.05 4.05	1.99 1.99
3.90 3.90	13.90 13.90			3.93 3.93	3.60 3.60
3.97 3.97	8.01 8.01	3.99 3.99	6.89 6.89			4.25 4.25	2.11 2.11
4.00 4.00	11.00 11.00			4.57 4.57	2.93 2.93
4.30 4.30	8.32 8.32	5.15 5.15	8.42 8.42
6.00 6.00	19.90 19.90

Also, a graph showing the correspondence between the number of sections in Table 16 and the z value is shown in FIG. 55.

55 is a graph showing a correspondence relationship between the number of sections and the z value for the R measurement value. Referring to FIG. 55, as the range of the resistance value is divided into more sections (or the range of each section is shorter), a distinction is made between a state in which no foreign material exists (Rx only) and a state in which a foreign material exists (Rx + FO). It was found that this became more pronounced. Therefore, the performance of foreign matter detection is improved as the number of sections divided by the measured value of R increases.

Summarizing the above-described experimental results, the following conclusions are drawn. First, there is a limit in improving the performance of foreign matter detection by only detecting foreign matter using Q factor or power loss. Second, when designing a foreign object detection algorithm based on regression analysis, rather than designing a foreign object detection algorithm based on simple arithmetic operations between FOD parameters, the foreign material detection performance is much improved. Third, when dividing the measured value of the resistance (R = V _rail / I _rail ) into multiple sections during wireless power transmission, and deriving a foreign matter detection algorithm through regression analysis for each section, the foreign matter detection performance may be further improved. . Fourth, since the number of sections related to the measured value of the resistance is proportional to the foreign matter detection performance, it is necessary to select an appropriate number of sections. Fourth, the foreign material detection algorithm according to the regression analysis for each section can detect foreign objects even in a situation where the wireless power receiving device and the foreign materials are separated by an offset from the center of the wireless power transmission device. Do. Fifth, the foreign matter detection algorithm according to the present embodiment is based on a statistical and / or empirical methodology, and uses a section based on an internal index using a FOD parameter (that is, a resistance value) of a wireless power transmission system. It provides Quasi Self Consistent that can be applied to new wireless power receivers.

무선전력 수신장치의 비정렬(misalignment) 검출 방법Method for detecting misalignment of wireless power receiver

When the center of the wireless power receiving device is spaced apart from the center of the wireless power transmitting device, this is called misalignment. The misalignment of the wireless power receiving apparatus causes deterioration of charging efficiency. This is because the secondary coil deviates from the distribution of the magnetic field generated from the primary coil and eventually loses the magnetic field. In addition, the misalignment of the wireless power receiver may cause overheating, which requires the wireless power transmitter to generate more magnetic fields in order to receive the required electromotive force, and the heat generated by the overcurrent in this process Because it occurs. Therefore, a method for detecting (or sensing) the position or misalignment of the wireless power receiver is required.

In this embodiment, the wireless power transmission apparatus and / or the wireless power reception apparatus detects the misalignment of the wireless power reception apparatus, and performs an operation of notifying or notifying the user.

As an example, when a misalignment is detected, the wireless power transmission device may notify or notify the user of information (or a result of the misalignment detection) indicating that the power transmission is stopped and / or the misalignment has been detected. Alternatively, the notification or notification of the result of the misalignment may be performed by the wireless power receiver. In the non-alignment detection process, information related to non-alignment may be exchanged between the wireless power transmitter and the wireless power receiver. This allows the user to correct the misalignment problem so that normal wireless power transmission can be performed.

As another example, the wireless power transmission device and / or the wireless power reception device detects a misalignment of the wireless power reception device or a position difference between Tx-Rx centers based on the wireless power transmission system parameters obtainable in the wireless power transmission process. can do. To this end, the wireless power transmitter and / or wireless power receiver can monitor various wireless power transmission system parameters.

As another example, the wireless power transmitter and / or the wireless power receiver may detect a misalignment of the wireless power receiver or a position difference between Tx-Rx centers based on regression analysis to which the wireless power transmission system parameters are applied. . Here, the wireless power transmission system parameters applied to the regression analysis include basic parameters that can be measured directly by the wireless power transmission device and / or wireless power reception device, and / or additional parameters calculated by mutual calculation between the basic parameters. It can contain.

56A and 56B are simulation results showing a histogram of a wireless power receiving device (phone) located at the center of a wireless power transmitting device and a wireless power receiving device 5 to 7 mm away from the center based on regression analysis according to an example. Here, the system parameters used to derive the regression equation are Q-factor, power loss (P _loss ), and rail voltage (V _rail ).

56A and 56B, (a) is a result of performing regression analysis in a state where the V30 model is positioned at the center of the wireless power transmitter and 5 to 7 mm apart from the center, and (b) is the galaxy The results of regression analysis are performed with the S9 model positioned at the center of the wireless power transmitter and 5 to 7 mm apart from the center, and (c) shows the G6 model positioned at the center of the wireless power transmitter. This is the result of regression analysis performed at a distance of 5 to 7 mm from the center, and (d) shows regression analysis when the iPhone 8 model is positioned at the center of the wireless power transmitter and at a distance of 5 to 7 mm from the center. This is the result. As a result of analyzing the characteristics of regression analysis for each smartphone model, it can be seen that alignment and unalignment are clearly distinguished when three system parameters are used in all models.

57A and 57B show histograms of multiple wireless power receivers located at the center of the wireless power transmitter and multiple wireless power receivers 0 mm, 5 mm, and 7 mm off the center based on regression analysis according to another example. It is a simulation result. Here, there are three system parameters used to derive the regression equation: Q-factor, power loss (P _loss ), and rail voltage (V _rail ), and the smartphones used in the experiment are Galaxy S9, Galaxy S8, Galaxy S8 +, iPhone 8, iPhone 8+, V30, G6 There are a total of seven.

Referring to FIGS. 57A and 57B, (a) is a result of performing regression analysis in a state in which 7 smartphones are positioned at the center of a wireless power transmitter and 5 to 7 mm apart from the center, (b) Is a result of performing regression analysis in a state in which 7 smartphones are positioned at 5 mm from the center and center of the wireless power transmitter, and 7 mm apart from the center, and (c) shows 7 smartphones in wireless power transmission. It is the result of performing regression analysis in the state positioned at the center of the device and 5 mm apart from the center.

As a result of analyzing the regression analysis characteristics in a state in which a plurality of smartphone models are spaced apart from the center and a certain distance, it is possible to distinguish when all seven types of smartphones are in the center of the primary coil and when they are separated by an offset. can confirm. As shown in Figs. 56A and 56B, the dispersion is larger than that of the experiment with a single smartphone, but the location of the phone is still distinguishable.

Referring to FIG. 58, the wireless power transmitter (or receiver) measures and / or calculates system parameters sensitive to location or misalignment (S5800).

As an example, the system parameters of the wireless power transmitter or the system parameters of the wireless power receiver, which are affected by position or misalignment, may include, for example, an input voltage or current detected in the wireless power transmission process, a voltage induced in the secondary coil, or It includes current, power loss, Q factor, and received power packet (RPP).

As another example, system parameters of the wireless power transmitter or system parameters of the wireless power receiver that are affected by position or misalignment may include, for example, additional parameters calculated by simple arithmetic operations between the system parameters. .

As described above, the location information of the wireless power receiving device can be obtained by using system parameters showing different values according to the position of the wireless power receiving device. The present invention experimented with the relationship between the system parameters and the location of the wireless power receiver to select system parameters affected by the location of the wireless power receiver. In the present invention, a method of modifying the multiple linear regression method was employed as a method for finding the association. Multiple linear regression is a method of analyzing the relationship between two or more factors (independent variables) and measured values (dependent variables). The present invention derives a position detection algorithm for estimating the position of the wireless power receiving device by analyzing the relationship between the position change of the wireless power receiving device and system parameters using a multiple linear regression analysis method.

The wireless power transmitter (or receiver) inputs the measured value and / or the calculated value to a position detection algorithm derived by regression analysis of system parameters and / or additional parameters (S5805). The position detection algorithm in step S5805 may be derived based on regression analysis, and may be designed or implemented by various methods previously exemplarily described herein. As an example, the position detection algorithm uses a regression equation using the system parameters as variables, and the regression equation applies the predetermined system parameters to a regression analysis to determine a regression coefficient or weight for each system or additional parameters. It can be designed or obtained by obtaining. Here, the position detection algorithm may be performed based on a plurality of regression analysis results obtained by performing regression analysis individually for each system or each additional parameter. In this case, the position detection performance can be maximized.

That is, this embodiment applies the system parameters of the wireless power transmitter and the system parameters of the wireless power receiver to statistical regression analysis, and when the distance between the centers of the primary coil and the secondary coil is 0 during wireless charging and deviates from 0. We derive a position detection algorithm that distinguishes the time difference.

Here, the subject performing location detection according to the location detection algorithm may be a wireless power transmission device or a wireless power reception device.

As an example, when the wireless power transmitter performs position detection, the wireless power receiver transmits information about the measured value of system parameters measured by itself or the calculated value of additional parameters calculated by itself to the wireless power transmitter. The step may be additionally performed, thereby allowing the wireless power transmission device to use the corresponding measured value and calculated value.

As another example, when the wireless power receiving device performs position detection, the wireless power transmitting device transmits information about the measured value of the system parameter measured by itself or the calculated value of the additional parameter calculated by itself to the wireless power receiving device. The step may be additionally performed, so that the wireless power receiving device can use the corresponding measured value and calculated value.

Meanwhile, the system parameters of the wireless power transmitter and the system parameters of the wireless power receiver may be applied independently to the regression analysis or simultaneously. If the system parameters of the wireless power transmission device and the system parameters of the wireless power reception device are applied simultaneously, communication is required to exchange information regarding the system parameters between the wireless power transmission device and the wireless power reception device.

The wireless power transmitter (or receiver) detects the position or misalignment of the wireless power receiver based on the result of the location detection algorithm (S5810). Here, the position detection algorithm is a regression equation, and the result value is output as 1 when the wireless power receiving device is in the aligned state, and the result value is digitized to be output as -1 when the wireless power receiving device is in the unaligned state. It can be designed in (Digitized) state.

In this case, if the result value of the position detection algorithm falls within -1 or an approximate range, the wireless power transmitter (or receiver) determines that it is "misalignment." On the other hand, if the result value of the position detection algorithm falls within 1 or an approximate range, the wireless power transmitter (or receiver) determines "alignment". 59 is a more detailed embodiment of step S5810.

59 is a flowchart illustrating a method for detecting a location according to another embodiment. The position detection method in this embodiment may be performed by a wireless power transmitter or wireless power receiver. In this embodiment, a mobile phone is described as an example.

Referring to FIG. 59, after the start of wireless power transmission (start charging), the wireless power transmitter or the wireless power receiver may perform alignment or misalignment detection using position detection algorithms.

The wireless power transmission device or the wireless power reception device performs a step of determining whether a result of the regression equation for position detection satisfies a regression analysis ≤b of a≤PPS (phone positioning sensing), which is a position alignment condition (S5900).

Here, the determination function “a≤PPS regression analysis≤b” may mean a band pass filter that passes only the aligned mobile phones. a and b are the minimum and maximum values of the data range passing through the band pass filter, respectively. Alternatively, the judgment function “a≤PPS regression analysis≤b” refers to an area that passes only the sorted cell phone after regression analysis that applies conditions that can distinguish the cell phone from being sorted and the cell phone is not sorted. You can. The range of regression analysis may be differently specified so that alignment / misalignment can be detected in the case of performing power transmission for a single mobile phone and in the case of performing power transmission for multiple mobile phones.

As a result of the determination, if the result value of the regression equation satisfies the regression analysis ≤b of the position alignment condition a≤PPS (yes), the power transmission is continued (S5905). Step S5905 is a case where it is determined that the center distance of the Tx-Rx coil is less than or equal to a reference by a position detection algorithm using a regression equation (or regression analysis).

On the other hand, if the result of the determination, if the result of the regression equation does not satisfy the regression analysis ≤b of the position alignment condition a≤FO ₁ , the wireless power transmitter may determine the position misalignment and stop the wireless power transmission ( S5910).

Step S5910 is a case where it is determined that the center distance of the Tx-Rx coil is greater than or equal to a reference by a position detection algorithm using a regression equation (or regression analysis). Therefore, the wireless power transmission device stops the power transmission, and the wireless power transmission device notifies the user that the position of the wireless power reception device needs to be corrected by itself or the wireless power reception device notifies the result of the misalignment detection. It allows the user to be notified that a position correction is necessary. Alternatively, the wireless power receiving device may notify the user that the position of the wireless power receiving device needs to be corrected.

Here, the means for notifying or notifying the user may include visual means, auditory means, and physical means. For example, the wireless power receiver or the wireless power transmitter outputs information about the location or misalignment of the wireless power receiver through a display, or outputs sound through a speaker of the wireless power receiver or wireless power transmitter. , It is possible to output the vibration through the vibration means in the wireless power receiver or wireless power transmitter.

In this embodiment, it is necessary to measure system parameters according to the location of the wireless power receiver in advance for measurement by empirical and statistical methods, and regression analysis is performed using the measured data to determine the Tx-Rx center distance tolerance. By algorithmizing this process, it is possible to detect the degree of separation or central separation between the wireless power transmitter and the receiver without additional cost such as a sensing coil. In addition, when the secondary coil moves away from the center of the primary coil, a decrease in charging efficiency can be prevented and heat generated by overcurrent can be prevented. Furthermore, it is possible to enable normal operation by position calibration by displaying the result of the position or misalignment detection of the wireless power receiving device on the screen or notifying the user by sound.

Since the above-described wireless power transmission method and apparatus, or reception apparatus and method according to the embodiment of the present invention are not necessarily all of the components or steps, the wireless power transmission apparatus and method, or reception apparatus and method, are the above-described components. Or it may be performed including some or all of the steps. In addition, embodiments of the above-described wireless power transmission apparatus and method, or reception apparatus and method may be performed in combination with each other. In addition, each component or step described above is not necessarily performed in the order described, it is also possible that the steps described later are performed prior to the steps described first.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and variations without departing from the essential characteristics of the present invention. Therefore, the embodiments of the present invention described above may be implemented separately or in combination with each other.

Therefore, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention, but to explain, and the scope of the technical spirit of the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted by the claims below, and all technical spirits within the scope equivalent thereto should be interpreted as being included in the scope of the present invention.

Claims

In the apparatus for receiving wireless power from the wireless power transmission device based on the detection of foreign matter in the wireless power transmission system,

A power pick-up unit configured to receive wireless power from the wireless power transmission device by magnetic coupling with the wireless power transmission device and convert an AC signal generated by the wireless power into a DC signal. -up unit);

A communication / control unit configured to receive the DC signal from the power pickup unit and perform control of the wireless power; And

A load configured to receive the DC signal from the power pickup unit,

The communication / control unit, characterized in that for performing a foreign object detection using the first regression (regression) equation determined based on at least one parameter that can be measured in the wireless power transmission system.
According to claim 1,

The at least one parameter includes the current of the primary coil provided in the wireless power transmission device,

Wherein the current is measured before or during the reception of the wireless power.
According to claim 1,

The at least one parameter includes a quality factor, a rail voltage (Vrail) and a rail current (Irail) of the wireless power transmission device, and a power loss (Ploss) generated in the process of receiving the wireless power, the wireless power transmission device Device characterized in that it comprises at least three of the current of the primary coil provided in the.
The method of claim 3,

The first regression equation includes the quality factor, the rail voltage (Vrail) and the rail current (Irail) of the wireless power transmitter, the power loss (Ploss) generated in the process of receiving the wireless power, and the wireless power transmission The device is characterized in that it is determined based on at least two or more parameters of the current of the primary coil provided in the device.
According to claim 1,

The first regression equation includes the quality factor, the rail voltage (Vrail) and the rail current (Irail) of the wireless power transmitter, the power loss (Ploss) generated in the process of receiving the wireless power, and the wireless power transmission Device characterized in that it is determined based on additional parameters calculated by arithmetic calculation of at least two or more parameters of the current of the primary coil provided in the device.
According to claim 1, The foreign matter detection procedure,

The communication / control unit measuring the at least one parameter to obtain a measurement value;

Obtaining the result value by substituting the measured value into the first regression equation,

And performing a step of determining whether a foreign substance is detected based on whether the result value falls within a range handled as a non-existent substance.
According to claim 1,

Device, characterized in that the first regression equation is individually defined for each type of foreign material.
According to claim 1,

The first regression equation is characterized in that when the measured value of the at least one parameter is divided into a plurality of sections, each section is individually defined.
The method of claim 8,

The at least one parameter is characterized in that the resistance value (= rail voltage / rail current) measured by the wireless power transmission device.
According to claim 1,

And the communication / control unit detects a position alignment of the wireless power receiver using a second regression equation determined based on at least one parameter measurable in the wireless power transmission system.