KR20120005112A - Adaptive wireless power transmit apparatus and method for mobile device in wireless power transmission systems - Google Patents

Abstract

PURPOSE: An adaptive wireless power transmitting device and are provided to maintain transfer efficiency by updating matching parameter on a real time. CONSTITUTION: A training information receiving part(310) receives training information. A movement speed and location estimating part(320) estimates the movement speed and location of a receiving device based on the training information. A movement determining part determines whether the receiving device is moved or not. A movement direction estimator(340) estimates a movement direction of the receiving device. A wireless power receiver receives electricity from a wireless power transmitting device which applies matching parameter.

Description

Adaptive wireless power transmission apparatus and method for a mobile body in a wireless power transmission system TECHNICAL FIELD

TECHNICAL FIELD The present invention relates to an apparatus and a method for maintaining transmission efficiency when an apparatus for transmitting or receiving wireless power moves in a wireless power transmission system.

The research on wireless power transmission began to overcome the inconvenience of wired power supply due to the explosive increase of various electric devices including mobile devices, and the limitation of existing battery capacity.

However, in the wireless power transmission system, the power reception decreases as the distance between the power transmitter and the power receiver increases, and when the transmission / reception period becomes longer than a specific distance, power transmission and data communication are almost impossible. do. Therefore, when the power receiver is located outside the power transmission / reception area (hereinafter, referred to as a “transmission area”), wireless power transmission is impossible.

In addition, the transmission efficiency decreases because the distance between the power transmitter and the power receiver changes not only when the power receiver is located outside the power transmission area but also when the power receiver moves. Therefore, a technique for maintaining the transmission efficiency regardless of the distance change between the power transmitter and the power receiver has to be continuously studied.

According to an aspect, an adaptive wireless power receiver for a mobile device in a wireless power transmission system includes a training information receiver configured to receive training information for estimating a position and a moving speed of a receiver from a wireless power transmitter, based on the training information. A moving speed and position estimating unit for estimating a moving speed and a position of the receiving device, and whether the receiving device is moved based on the estimated change of the moving speed, position, and intensity of the received training information signal. A movement determining unit for determining, if it is determined that the receiving device moves, based on the moving direction predicting unit predicting the moving direction of the receiving device based on the estimated moving speed and position of the receiving device and the moving direction prediction information; Power from the wireless power transmitter applying the matching parameter determined Subject comprises a wireless power receiver.

The training information receiver may use power transmitted wirelessly from the wireless power transmitter as the training information signal.

The moving speed and the position estimating unit may estimate the moving speed of the receiving apparatus based on the Doppler frequency estimation of the received training information signal.

The moving speed and position estimating unit receives the received training information signal and the received position in a time difference of arrival (TDOA), a time of arrival (TOA), and a received signal strength indication (RSSI) scheme based on another communication device that knows the position. The location of the device can be estimated.

According to an aspect, an adaptive wireless power transmitter for a mobile device in a wireless power transmission system includes a training information transmitter configured to transmit training information for estimating a position and a moving speed of a wireless power receiver, and a movement direction of the wireless power receiver. A moving direction prediction information receiving unit for receiving prediction information, a matching parameter determining unit determining a matching parameter in an expected moving direction based on the moving direction prediction information of the wireless power receiver, and transmitting wireless power based on the determined matching parameter. It includes a wireless power transmitter.

According to another aspect, the adaptive wireless power transmission apparatus for a mobile object in the wireless power transmission system may further include a matching parameter update unit that periodically updates the matching parameter with respect to the determined matching parameter.

In another aspect, the adaptive wireless power transmission apparatus for a mobile in the wireless power transmission system further includes a transmission efficiency determination unit for determining whether the wireless power transmission efficiency has a value less than a predetermined value, updating the matching parameter The unit may increase the matching parameter update period when the wireless power transmission efficiency has a value smaller than a preset value.

In another aspect, an adaptive wireless power transmitter for a mobile device in a wireless power transmission system is a transmission efficiency determination unit for determining whether the wireless power transmission efficiency has a value less than a predetermined value and the wireless power transmission efficiency. If the value is smaller than the set value, the power transmission mode conversion unit for changing the power transmission frequency or the power transmission direction may further include a power transmission mode conversion unit.

According to an aspect, an adaptive wireless power transmitter for a mobile device in a wireless power transmission system includes a training information receiver configured to receive training information for estimating a position and a moving speed of a wireless power transmitter from a wireless power receiver, and the training information. A moving speed and position estimating unit for estimating a moving speed and a position of the wireless power transmitter based on the estimated movement speed and position of the wireless power transmitter and a change in intensity of the received training information signal; A movement determining unit that determines whether the wireless power transmitter moves, and when it is determined that the wireless power transmitter moves, the moving direction of the wireless power transmitter is determined based on the estimated moving speed and position of the wireless power transmitter. Moving direction predictor for predicting, moving room of the wireless power transmission device And a matching parameter determiner that determines a matching parameter in the expected moving direction based on the direction prediction, and a wireless power transmitter that transmits wireless power based on the determined matching parameter.

In an aspect, the adaptive wireless power receiver for a mobile device in a wireless power transmission system includes a training information transmitter configured to transmit training information for estimating a position and a moving speed of the wireless power transmitter, and the matching determined by the wireless power transmitter. Matching parameter synchronization unit for synchronizing with the parameter and a wireless power receiver for receiving a wireless power based on the synchronized matching parameter.

In one aspect, an adaptive wireless power reception method for a mobile object in a wireless power transmission system, the method comprising: receiving training information for estimating a position and a moving speed of a reception device from a wireless power transmission device, based on the training information; Estimating a moving speed and a position of a receiving apparatus, determining whether the receiving apparatus is moved based on the estimated change of the moving speed, the position and the intensity change of the received training information signal, and the receiving apparatus Is determined to move, the power from the wireless power transmitter applying the matching parameter determined based on the moving direction prediction information and predicting the moving direction of the receiving device based on the estimated moving speed and position of the receiving device. Receiving the.

In an aspect, the adaptive wireless power transmission method for a mobile device in a wireless power transmission system includes transmitting training information for estimating a position and a moving speed of a wireless power receiver, and moving direction prediction information of the wireless power receiver. Receiving a; determining a matching parameter in an expected moving direction based on the moving direction prediction information of the wireless power receiving apparatus; and transmitting wireless power based on the determined matching parameter.

In one aspect, an adaptive wireless power transmission method for a mobile device in a wireless power transmission system, receiving training information for estimating a position and a moving speed of a wireless power transmitter from a wireless power receiver, based on the training information Estimating a moving speed and a position of the wireless power transmitter based on the estimated change of the moving speed, the position, and a change in the strength of the received training information signal. Determining the movement of the wireless power transmitter based on the estimated moving speed and position of the wireless power transmitter, if the wireless power transmitter is determined to move. Matching parameter in the predicted moving direction based on the moving direction prediction of Determining a and transmitting wireless power based on the determined matching parameter.

In one aspect, an adaptive wireless power reception method for a mobile device in a wireless power transmission system includes transmitting training information for estimating a position and a moving speed of a wireless power transmitter, and matching parameters determined by the wireless power transmitter. Synchronizing and receiving wireless power based on the synchronized matching parameter.

In a wireless power transmission system, when a wireless power transmitter or a wireless power receiver moves, a method and apparatus for maintaining transmission efficiency by updating a matching parameter in real time may be provided.

In addition, in the wireless power transmission system, when the wireless power transmitter or the wireless power receiver moves, effective power transmission is possible without greatly changing the existing system structure.

In addition, in the wireless power transmission system, a method and an apparatus for maintaining transmission efficiency may be provided even when the wireless power transmitter and the wireless power receiver move simultaneously.

1 is a diagram illustrating a wireless power transmission system according to one side.
2 is a diagram illustrating a case in which a target moves in a wireless power transmission system according to one side.
3 is a block diagram of an adaptive wireless power receiver for a mobile device in a wireless power transmission system according to one side.
4 is a block diagram of an adaptive wireless power transmission apparatus for a mobile object in a wireless power transmission system according to one side.
5 is a diagram illustrating a meta-structured resonator according to one side.
FIG. 6 is a diagram illustrating an equivalent circuit of the resonator illustrated in FIG. 5.
7 is a diagram illustrating a meta-structured resonator according to another side.
8 is a view illustrating in detail the insertion position of the capacitor of FIG.
9 is a flowchart illustrating an adaptive wireless power transmission / reception method for a mobile body in a wireless power transmission system according to one side.
10 is a flowchart illustrating an adaptive wireless power transmission / reception method for a mobile device in a wireless power transmission system according to another embodiment.
11 is a flowchart illustrating an adaptive wireless power transmission / reception method for a mobile body in a wireless power transmission system according to another embodiment.

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

First, the wireless power transmission technology used in the wireless power transmission system will be described. Wireless power transmission technology can be classified into three types of electromagnetic induction method, radio wave reception method, electric field or magnetic field resonance method.

First, the electromagnetic induction method uses a phenomenon in which magnetic flux is generated when an alternating current flows in one coil after approaching two different coils close to each other, and thus electromotive force is generated in the other coil. The electromagnetic induction method has the most high efficiency and practical use, such as the power utilization efficiency is approximately 60-98%.

Second, in the radio wave reception method, radio wave energy is received and used by an antenna to convert an AC radio wave waveform into a direct current through a rectifier circuit to obtain power. Radio reception method is capable of transmitting wireless power over the longest distance (above several meters).

Third, the resonance method uses resonance of an electric field or a magnetic field, and transmits energy by resonating at the same frequency between devices. In case of using the resonance of the magnetic field, electric power is generated by using magnetic resonance coupling using the LC resonator structure. The magnetic resonance method is a technology that uses a near field effect of a short distance compared to the wavelength of the used frequency. Unlike the radio wave reception method, it is a non-radiative energy transmission, and matches the resonance frequency between the transmitter and the receiver. Send it. The magnetic resonance method increases the power transmission efficiency by about 50 ~ 60%, which is much higher than the radio wave reception type through radio wave radiation. Although the transmission / reception period distance is about several meters, although the technique used in the near field rather than the radio wave reception method, the power transmission is possible at a far distance than the electromagnetic induction type within a few mm.

1 is a diagram illustrating a wireless power transmission system according to one side.

In the example of FIG. 1, it is assumed that the wireless power transmitted through the wireless power transmission system is resonance power.

Referring to FIG. 1, a wireless power transmission system is a source-target structure consisting of a source and a target. That is, the wireless power transmission system includes a resonance power transmitter 110 corresponding to a source and a resonance power receiver 120 corresponding to a target.

The resonance power transmitter 110 includes a source unit 111 and a source resonator 115 that generate energy by receiving energy from an external voltage supply device. In this case, the external voltage source may be AC, DC, a battery, or the like. In addition, the resonance power transmission apparatus 110 may further include a matching control 113 that performs resonance frequency or impedance matching. In addition, the resonance power transmitter 110 may transmit data to the resonance power receiver 120 using the resonance frequency band. In addition, the resonance power transmission apparatus 110 may further include a matching network unit (not shown) to maximize the power delivered to the antenna for transmitting wireless power from an external voltage source. In this case, the power applied to the antenna is divided into the transmission power transmitted through the antenna and the reflected power reflected back. Since the reflected power should be minimized in order to increase the transmission efficiency, the resonance power transmitter 110 may include a sensing unit (not shown) capable of measuring the reflected power and a processor unit (not shown) to determine the matching parameter to minimize the reflected power. Or not).

The source unit 111 receives energy from an external voltage supply to generate resonance power. The source unit 111 rectifies an AC signal output from an AC-AC converter or an AC-AC converter for adjusting a signal level of an AC signal input from an external device to a desired level, thereby outputting a DC voltage having a predetermined level. It can include a DC-AC Inverter that generates an AC signal of several MHz to several tens of MHz band by fast switching the DC voltage output from the DC converter and the AC-DC converter. In addition, the source unit 111 may transmit the idle power to the target unit 125 while moving through the moving object rather than at a fixed position. For example, the source unit 111 may be included in a moving robot device.

The matching control 113 sets the resonance bandwidth of the source resonator 115 or the impedance matching frequency of the source resonator 115. The matching control unit 113 includes at least one of a source resonance bandwidth setting unit (not shown) or a source matching frequency setting unit (not shown). The source resonant bandwidth setting unit sets a resonance bandwidth of the source resonator 115. The source matching frequency setting unit sets the impedance matching frequency of the source resonator 115. In this case, the Q-factor of the source resonator 115 may be determined according to the resonance bandwidth of the source resonator or the impedance matching frequency of the source resonator.

The source resonator 115 transfers electromagnetic energy to the target resonator. That is, the source resonator 115 transmits the resonance power to the target device 120 through the magnetic coupling 101 with the target resonator 121. At this time, the source resonator 115 resonates within the set resonance bandwidth.

The resonance power receiver 120 includes a target resonator 121, a matching control unit 123 for performing resonance frequency or impedance matching, and a target unit 125 for transferring the received resonance power to a load. In addition, the resonance power receiver 120 may receive data from the resonance power transmitter 110 using the resonance frequency band.

The target resonator 121 receives electromagnetic energy from the source resonator 115. At this time, the target resonator 121 resonates within the set resonance bandwidth.

The matching control unit 123 sets at least one of a resonance bandwidth of the target resonator 121 or an impedance matching frequency of the target resonator 121. The matching control unit 123 includes at least one of a target resonance bandwidth setting unit (not shown) or a target matching frequency setting unit (not shown). The target resonance bandwidth setting unit sets a resonance bandwidth of the target resonator 121. The target matching frequency setting unit sets the impedance matching frequency of the target resonator 121. In this case, the Q-factor of the target resonator 121 may be determined according to the resonance bandwidth of the target resonator 121 or the impedance matching frequency of the target resonator 121.

The target unit 125 transfers the received resonance power to the load. At this time, the target unit 125 rectifies an AC signal received from the source resonator 115 to the target resonator 121 to generate a DC signal, and an AC-DC converter to adjust the signal level of the DC signal to adjust the device voltage. It may include a DC-DC converter that supplies a device or a load. The load capable of receiving the resonance power includes various home appliances including a digital photo frame, a speaker, a vacuum cleaner, a dryer, a shaver, a laptop PC, a computer, a peripheral device thereof, a mobile phone, a digital camera, a camcorder, an MP3 player, a PDA, and various portable devices. The device, in addition to the femtocell base station, various sensors and lighting equipment may be included.

The source resonator 115 and the target resonator 121 may be configured as a helix coil structure resonator, a spiral coil structure resonator, or a meta-structured resonator. The meta-structured resonator will be described in detail later with reference to FIG. 6.

Referring to FIG. 1, the control process of the cue-factor sets the resonance bandwidth of the source resonator 115 and the resonance bandwidth of the target resonator 121, and the source resonator 115 and the target resonator 121. And transferring electromagnetic energy from the source resonator 115 to the target resonator 121 through magnetic coupling therebetween. In this case, the resonance bandwidth of the source resonator 115 may be set to be wider or narrower than the resonance bandwidth of the target resonator 121. That is, since the resonance bandwidth of the source resonator 115 is set wider or narrower than the resonance bandwidth of the target resonator 121, the BW-factor of the source resonator and the BW-factor of the target resonator are maintained in an unbalanced relationship with each other. .

In resonant wireless power transmission, the resonance bandwidth is an important factor. When Qt is a Q-factor that considers the distance change between the source resonator 115 and the target resonator 121, the change in the resonance impedance, the impedance mismatch, the reflected signal, and the like, Qt is equal to the resonance bandwidth as shown in Equation 1 below. Have an inverse relationship.

[Equation 1]

는 대역폭,

는 공진기 사이의 반사 손실, BW_S는 소스 공진기(115)의 공진 대역폭, BW_D는 타겟 공진기(121)의 공진 대역폭을 나타낸다. 본 명세서에서 BW-factor는 1/ BW_S 또는 1/BW_D를 의미한다.In Equation 1, f0 is the center frequency,

Is the bandwidth,

Is the reflection loss between the resonators, BW _S is the resonance bandwidth of the source resonator 115, BW _D is the resonance bandwidth of the target resonator 121. In the present specification, the BW-factor means 1 / BW _S or 1 / BW _D.

On the other hand, impedance mismatching between the source resonator 115 and the target resonator 121 may occur due to external influences such as a change in distance between the source resonator 115 and the target resonator 121 or a change in one of the two positions. Can be. Impedance mismatch can be a direct cause of reducing the efficiency of power delivery. The matching control 113 may determine that impedance mismatch has occurred by sensing a reflected wave in which a part of the transmission signal is reflected and return, and perform impedance matching. In addition, the matching control 113 may change the resonance frequency by detecting the resonance point through the waveform analysis of the reflected wave. Here, the matching control 113 may determine a frequency having a minimum amplitude as the resonance frequency in the waveform of the reflected wave.

That is, the resonant power transmitter 110 may exchange not only power but also data with the resonant power receiver 120, and may simultaneously use the power transmission frequency band or use a separate independent frequency band. The resonance power receiver 120 receives power and supplies the load to the load. In this case, the energy field emitted from the resonance power transmitter 110 may have various unnecessary effects on the peripheral system.

2 is a diagram illustrating a case in which a target moves in a wireless power transmission system according to one side.

Referring to FIG. 2, the wireless power transmitter may transmit power and data to the wireless power receiver. In this case, the wireless power receiver may be included in the target. Since the target may include various mobile devices such as a mobile phone, a digital camera, a camcorder, an MP3 player, a PDA, and the like, the target may move not only in a fixed position. In addition, since the wireless power transmission device may be included in a moving object such as a robot, it can be moved. Transmission efficiency is greatly affected by the distance between the wireless power transmitter and the wireless power receiver. Therefore, as the wireless power receiver moves, the transmission efficiency is reduced if the frequency and matching parameters used for power transmission are not changed.

3 is a block diagram of an adaptive wireless power receiver for a mobile device in a wireless power transmission system according to one side.

Referring to FIG. 3, the adaptive wireless power receiver for a moving object includes a training information receiver 310, a movement speed and position estimator 320, a movement determiner 330, a movement direction predictor 340, and wireless power. It includes a receiver 350.

The training information receiver 310 receives training information for estimating the position and the moving speed of the receiver from the wireless power transmitter. The training information receiver 310 receives a training information signal transmitted from a wireless power transmitter. The training information is used to estimate the position and the movement speed of the wireless power receiver, and may determine whether the wireless power receiver is moved by estimating the position and the movement speed. In addition, the training information may be used to estimate the position and the moving speed of the wireless power transmitter even when the wireless power transmitter moves. In addition, the training information signal may include a wireless power transmission signal, so that the received power may be used as the training information.

The movement speed and position estimator 320 estimates the movement speed and the position of the receiving device based on the training information. Here, the training information signal means a signal for positioning and velocity estimation. The movement speed and position estimator 320 may estimate the movement speed through Doppler frequency spread estimation of the received training information signal. That is, the moving speed and the position estimating unit 320 may calculate the moving speed using the Doppler effect with a difference in frequency generated during the moving process of the receiving apparatus. In addition, the movement speed and position estimator 320 may estimate the position of the receiving apparatus using a time difference of arrival (TDOA), a time of arrival (TOA), and a received signal strength indication (RSSI) method. The TDOA measures signal delay of adjacent APs based on the location of the receiving device. As a result of measuring a signal arrival time difference of a location search signal through an adjacent AP of a receiving device, a plurality of hyperbolas are generated, and an intersection of the hyperbolas may be estimated as a location of a wireless power receiver. The DOA estimates the position of the wireless power receiver based on the angle of arrival of the receiver received from the surrounding AP. In a real environment, three or more APs are required due to multipath, noise, and limited resolution of measurement angles. RSSI mathematically uses the signal strength according to the distance. The RSSI is applied to the strength of the received signal as the distance increases. In addition, the movement speed and position estimator 320 may estimate the movement speed and the position of the receiving device based on the training information signal transmitted periodically.

The movement determining unit 330 determines whether the receiving apparatus moves based on the estimated moving speed, position, and intensity change of the received training information signal. The movement determiner 330 may determine whether the receiver moves, when the position and the movement speed of the receiver are estimated through the movement speed and the position estimator 320. In addition, even if the strength of the received training information signal changes, it is possible to estimate whether the movement. In order to determine the accuracy of movement, the movement of the receiving apparatus may be determined by comprehensively considering the estimated movement speed, position, and strength change of the training test signal of the receiving apparatus.

When it is determined that the receiving device moves, the moving direction predicting unit 340 predicts the moving direction of the receiving device based on the estimated moving speed and position of the receiving device. The movement speed and position estimator 320 may periodically estimate the movement speed and the position of the receiving device. The movement direction predictor 340 may predict the movement direction of the receiver by applying linear prediction and regression based on the estimated movement speed and position information of the receiver.

The wireless power receiver 350 receives power from the wireless power transmitter applying the matching parameter determined based on the moving direction prediction information. That is, the wireless power receiver may transmit the prediction information about the moving direction of the receiving device predicted by the moving direction predictor 340 to the wireless power transmitter. In addition, the wireless power transmitter may receive the moving direction prediction information to determine a matching parameter in the expected moving direction. Therefore, the wireless power receiver may receive power from the wireless power transmitter that transmits the wireless power by applying the determined matching parameter.

In addition, in the wireless power transmission system according to the other side, the adaptive wireless power receiver for the moving object is to estimate the position and the moving speed of the wireless power transmitter when the wireless power transmitter is moved and the wireless power receiver is fixed. Training information transmitting unit for transmitting the training information for, a matching parameter synchronization unit for synchronizing with the matching parameter determined in the wireless power transmission apparatus and a wireless power receiver for receiving wireless power based on the synchronized matching parameter.

4 is a block diagram of an adaptive wireless power transmission apparatus for a mobile object in a wireless power transmission system according to one side.

Referring to FIG. 4, the apparatus for adaptive wireless power transmission for a mobile object includes a training information transmitter 410, a movement direction prediction information receiver 420, a matching parameter determiner 430, and a wireless power transmitter 440. .

The training information transmitter 410 transmits training information for estimating the position and the moving speed of the wireless power receiver. The training information transmitter 410 transmits a training information signal used to estimate a position and a moving speed of the wireless power receiver required to determine whether the wireless power receiver is moved.

The movement direction prediction information receiver 420 receives the movement direction prediction information of the wireless power receiver. The movement direction prediction information receiver 420 receives the movement direction prediction information of the reception device predicted from the wireless power receiver.

The matching parameter determiner 430 determines the matching parameter in the expected moving direction based on the moving direction prediction information of the wireless power receiver. The matching parameter determiner 430 determines the matching parameter in advance based on the predicted moving direction of the receiving device.

The wireless power transmitter 440 transmits wireless power based on the determined matching parameter.

In addition, in the wireless power transmission system according to the other side, the adaptive wireless power transmitter for the moving object is training information for estimating the position and the moving speed of the wireless power transmitter from the wireless power receiver when the wireless power transmitter moves. A training information receiving unit for receiving a moving speed and position estimating unit for estimating a moving speed and a position of the wireless power transmitter based on the training information, the estimated moving speed, the position and the received power of the wireless power transmitter; A movement determining unit that determines whether the wireless power transmitter moves, based on a change in strength of a training information signal, and when it is determined that the wireless power transmitter moves, based on the estimated moving speed and position of the wireless power transmitter; A mobile room predicting a moving direction of the wireless power transmitter A prediction unit, based on the matching parameter determination unit and the determined matching parameter to determine a matching parameter in the direction of movement estimated on the basis of the moving direction of prediction of the wireless power transmission device and includes a wireless power transmitter for transmitting the wireless power. That is, the wireless power transmitter receives the training information signal from the wireless power receiver, estimates the movement speed and position of the wireless power transmitter or the wireless power receiver, estimates the movement direction, and based on the predicted movement direction. To determine the matching parameter of the wireless power transmission device, and transmits wireless power.

In addition, the adaptive wireless power transmission apparatus for a mobile in the wireless power transmission system according to the other side may further include a matching parameter update unit for periodically updating the matching parameter with respect to the determined matching parameter. The matching parameter updater may periodically update the matching parameters of the wireless power transmitter to maintain wireless power transfer efficiency through self resonance of the moving wireless power transmitter and the wireless power receiver.

The adaptive wireless power transmitter for a mobile device in the wireless power transmission system according to the other side further includes a transmission efficiency determination unit for determining whether the wireless power transmission efficiency has a value smaller than a preset value, and the matching parameter update unit When the wireless power transmission efficiency has a value smaller than a preset value, the matching parameter update period may be increased. In this case, increasing the matching parameter update period means increasing the number of update repetitions at the same time. In addition, the transmission efficiency may be calculated through the power transmitted or the reflected power relative to the power input to the antenna. When the transmission efficiency is less than the preset value, the wireless power transmitter may increase the number of updates of the matching parameter to correspond to the change of the matching parameter necessary to maintain the transmission efficiency. However, when the moving speed is so large that the matching parameter change is larger than the update period, it may be more efficient to determine the matching parameter by predicting the moving direction. The preset value is a power transmission efficiency required by the target, and the value may be changed according to the target.

In addition, in the wireless power transmission system according to the other side, the adaptive wireless power transmission apparatus for a mobile object includes a transmission efficiency determination unit for determining whether the wireless power transmission efficiency has a smaller value than a preset value and the wireless power transmission efficiency is preset. If the value is smaller than the value, the power transmission mode conversion unit for changing the power transmission frequency or the power transmission direction may further include a power transmission mode conversion unit. Herein, the power transmission mode conversion means changing the power transmission frequency or the power transmission direction. Changing the power transmission frequency may include frequency hopping, and changing the power transmission direction may include using a directional antenna.

5 is a diagram illustrating a meta-structured resonator according to one side.

Referring to FIG. 5, the meta-structured resonator includes a transmission line 510 and a capacitor 520. Here, the capacitor 520 is inserted in series at a specific position of the transmission line 510, and the electric field is trapped in the capacitor.

In addition, as shown in FIG. 5, the meta-structured resonator has a form of a three-dimensional structure. Unlike the illustrated in FIG. 5, the resonator may be implemented in a two-dimensional structure in which transmission lines are arranged in x and z planes.

The capacitor 520 is inserted into the transmission line 510 in the form of a lumped element and a distributed element, for example, an interdigital capacitor or a gap capacitor centered on a substrate having a high dielectric constant. As the 520 is inserted into the transmission line 510, the resonator may have a metamaterial characteristic.

Here, the metamaterial is a material having special electrical properties that cannot be found in nature, and has an artificially designed structure. The electromagnetic properties of all materials in nature have inherent permittivity or permeability, and most materials have positive permittivity and positive permeability. In most materials, the right-hand rule applies to electric fields, magnetic fields and pointing vectors, so these materials are called RHM (Right Handed Material). However, metamaterials are materials with a permittivity or permeability of less than 1, and according to the sign of permittivity or permeability, ENG (epsilon negative) material, MNG (mu negative) material, DNG (double negative) material, NRI (negative refractive index) Substances, and left-handed (LH) substances.

At this time, when the capacitance of the capacitor inserted as the lumped element is properly determined, the resonator may have the characteristics of the metamaterial. In particular, by appropriately adjusting the capacitance of the capacitor, the resonator may have a negative permeability, so that the resonator according to an embodiment of the present invention may be referred to as an MNG resonator.

The MNG resonator may have a zero-order resonance characteristic having a frequency when the propagation constant is 0 as a resonance frequency. Since the MNG resonator may have a zeroth resonance characteristic, the resonant frequency may be independent of the physical size of the MNG resonator. That is, as will be described again below, in order to change the resonant frequency in the MNG resonator, it is sufficient to design the capacitor appropriately, so that the physical size of the MNG resonator may not be changed.

In addition, in the near field, the electric field is concentrated on the series capacitor 520 inserted into the transmission line 510, so that the magnetic field is dominant in the near field due to the series capacitor 520.

In addition, the MNG resonator may have a high Q-Factor using the capacitor 520 to the lumped element, thereby improving the efficiency of power transmission.

In addition, the MNG resonator may include a matcher 530 for impedance matching. At this time, the matcher 530 properly tunable the strength of the magnetic field for coupling with the MNG resonator, and the impedance of the MNG resonator is adjusted by the matcher 530. The current flows into or out of the MNG resonator through the connector 540.

In addition, although not explicitly illustrated in FIG. 5, a magnetic core penetrating the MNG resonator may be further included. Such a magnetic core may perform a function of increasing a power transmission distance.

The characteristics of the MNG resonator of the present invention will be described in detail below.

FIG. 6 is a diagram illustrating an equivalent circuit of the resonator illustrated in FIG. 5.

The resonator shown in FIG. 5 may be modeled with the equivalent circuit shown in FIG. 6. In the equivalent circuit of FIG. 6, C _L represents a capacitor inserted in the form of a lumped element at the interruption of the transmission line of FIG. 5.

를 공진 주파수로 갖는다고 가정한다. 이 때, 공진 주파수

는 하기 수학식 2와 같이 표현될 수 있다. 여기서, MZR은 Mu Zero Resonator를 의미한다.
At this time, the resonator for wireless power transmission shown in FIG. 5 has a zeroth resonance characteristic. That is, when the propagation constant is 0, the resonator for wireless power transmission

Suppose we have a resonant frequency. At this time, the resonance frequency

May be expressed as Equation 2 below. Here, MZR means Mu Zero Resonator.

[Equation 2]

는

에 의해 결정될 수 있고, 공진 주파수

와 공진기의 물리적인 사이즈는 서로 독립적일 수 있음을 알 수 있다. 따라서, 공진 주파수

와 공진기의 물리적인 사이즈가 서로 독립적이므로, 공진기의 물리적인 사이즈는 충분히 작아질 수 있다.
Referring to Equation 2, the resonant frequency of the resonator

Is

Can be determined by the resonant frequency

It can be seen that the physical size of the and the resonator may be independent of each other. Thus, resonant frequency

Since the physical sizes of the and resonators are independent of each other, the physical sizes of the resonators can be sufficiently small.

7 is a diagram illustrating a meta-structured resonator according to another side.

Referring to FIG. 7, the meta-structured resonator includes a transmission line unit 710 and a capacitor 720. In addition, the resonator according to an embodiment of the present disclosure may further include a feeding unit 730.

In the transmission line unit 710, a plurality of transmission line sheets are arranged in parallel. A configuration in which a plurality of transmission line sheets are arranged in parallel will be described in more detail with reference to FIG. 8.

The capacitor 720 is inserted at a specific position of the transmission line unit 710. In this case, the capacitor 720 may be inserted in series at the interruption of the transmission line unit 710. At this time, the electric field generated in the resonator is trapped in the capacitor 720.

The capacitor 720 may be inserted into the transmission line unit 710 in the form of a lumped element and a distributed element, for example, an interdigital capacitor or a gap capacitor centered on a substrate having a high dielectric constant. As the capacitor 720 is inserted into the transmission line unit 710, the resonator may have a metamaterial characteristic.

The feeding unit 730 may perform a function of supplying current to the MNG resonator. In this case, the feeding unit 730 may be designed to distribute the current supplied to the resonator evenly to the plurality of transmission line sheets.

8 is a view illustrating in detail the insertion position of the capacitor 720 of FIG.

Referring to FIG. 8, the capacitor 720 is inserted into the interruption portion of the transmission line unit 710. In this case, the interruption portion of the transmission line unit 710 may be open so that the capacitor 720 may be inserted, and each of the transmission line sheets 710-1, 710-2, and 710-n may be formed. It can be configured in the form of parallel to each other at the stop.

9 is a flowchart illustrating an adaptive wireless power transmission / reception method for a mobile body in a wireless power transmission system according to one side.

Referring to FIG. 9, the wireless power transmitter transmits training information 910 to the wireless power receiver. The training information is used to estimate the moving speed and position of the moving wireless power receiver. The training information signal may include a signal for positioning and velocity estimation. The wireless power receiver estimates the moving speed and the position of the receiver based on the received training information (920). The moving speed may be calculated through Doppler frequency estimation, and the position may be estimated using TDOA (Time Difference of Arrival), TOA (Time of Arrival), or RSSI (Received Signal Strength Indication). The receiving device determines whether the receiving device has moved in consideration of the estimated moving speed, the position and the strength of the training information comprehensively (930), and if it is determined that the receiving device has moved, the receiving device based on the estimated moving speed and the position information. Predict the moving direction of (940). In this case, linear prediction and regression may be applied to the prediction of the moving direction. If it is determined that the receiving device does not move, the receiving device receives the training information from the wireless power transmitter, and repeats the above procedure. The receiving apparatus transmits the movement direction prediction information to the wireless power transmitter 950, and the wireless power transmitter determines a matching parameter based on the received movement direction prediction information 960. The wireless power transmitter transmits the wireless power by applying the determined matching parameter (970).

10 is a flowchart illustrating an adaptive wireless power transmission / reception method for a mobile device in a wireless power transmission system according to another embodiment.

Referring to FIG. 10, the wireless power receiver transmits training information to the wireless power transmitter (1010). The wireless power transmitter estimates a moving speed and a position of the transmitter based on the received training information (1020). The wireless power transmitter determines whether the transmitter moves, in consideration of the estimated movement speed, location, and strength of the training information signal, in operation 1030. If it is determined that the wireless device has moved, the wireless power transmitter estimates the moving direction of the transmitting device based on the estimated moving speed and position of the transmitting device (1040). The wireless power transmitter continuously transmits power wirelessly when it is determined that the transmitter does not move. The wireless power transmitter determines a matching parameter based on the movement direction information of the predicted transmitter (1050). When the matching parameter is determined in the wireless power transmitter, the wireless power receiver increases transmission efficiency by synchronizing to match the matching parameter of the transmitter (1060). The wireless power transmitter transmits the wireless power by applying the determined matching parameter in operation 1070.

The wireless power transmitter may further include periodically updating the matching parameter with respect to the determined matching parameter. The wireless power transmitter may further include determining whether the wireless power transmission efficiency has a smaller value than a preset value, and updating the matching parameter may include determining a value in which the wireless power transmission efficiency is smaller than a preset value. If so, the matching parameter update period may be increased.

The wireless power transmitter determines whether the wireless power transfer efficiency has a value smaller than a preset value, and when the wireless power transfer efficiency has a value smaller than a preset value, changes the power transmission frequency or the power transfer direction. The method may further include converting a power transmission mode.

11 is a flowchart illustrating an adaptive wireless power transmission / reception method for a mobile body in a wireless power transmission system according to another embodiment.

Referring to FIG. 11, the wireless power transmitter transmits training information 1101 to a wireless power receiver. The training information signal may include a signal for positioning and velocity estimation. The wireless power receiver estimates the moving speed and the position of the receiver based on the received training information (1103). The moving speed may be calculated through Doppler frequency estimation, and the position may be estimated using TDOA (Time Difference of Arrival), TOA (Time of Arrival), or RSSI (Received Signal Strength Indication). The receiving device determines whether the receiving device has moved in consideration of the estimated moving speed, the location, and the strength of the training information signal (1105), and transmits the receiving device moving information to the wireless power transmitter when the receiving device moves ( 1107).

When the wireless power transmitter receives the information indicating that the receiving apparatus moves, the wireless power transmitter increases the matching parameter update period of the transmitting apparatus (1109), and transmits the wireless power by applying the updated matching parameter (1111). The wireless power transmitter determines whether the wireless power transfer efficiency to which the updated matching parameter is applied is smaller than a predetermined value required by the target (1113). In this case, the transmission efficiency may be calculated through the power transmitted or the reflected power compared to the power input to the antenna. When the transmission efficiency is smaller than the preset value, the wireless power transmitter transmits information to the wireless power receiver that the transmission efficiency is smaller than the preset value (1115). The wireless power receiver estimates the moving direction of the receiving device based on the estimated moving speed and the position of the receiving device (1117), and transmits the predicted moving direction information to the wireless power transmitting device (1119).

When the wireless power transmitter receives the information for which the moving direction of the receiving device is predicted, the wireless power transmitter determines a direction in which the receiving device moves to determine a matching parameter of the transmitting device (1121). The wireless power transmitter transmits wireless power by applying the determined matching parameter in operation 1123. In operation 1125, the wireless power transmitter determines whether the wireless power transmission efficiency applying the matching parameter determined by predicting the moving direction of the receiving device is smaller than a predetermined value required by the target. When the transmission efficiency is less than the preset value, the wireless power transmitter converts the power transmission mode (1127). Herein, the power transmission mode conversion means changing the power transmission frequency or the power transmission direction. The wireless power transmitter transmits wireless power by converting the power transfer mode (1129). The wireless power transmitter determines whether the wireless power transfer efficiency transmitted by converting the power transfer mode is smaller than a predetermined value required by the target (1131). When the transmission efficiency is smaller than the preset value, the wireless power transmitter may not be able to efficiently charge the power required by the wireless power receiver even when the power is transmitted (S1333).

Methods according to an embodiment of the present invention can be implemented in the form of program instructions that can be executed by various computer means and recorded in a computer readable medium. The computer readable medium may include program instructions, data files, data structures, etc. alone or in combination. Program instructions recorded on the media may be those specially designed and constructed for the purposes of the present invention, or they may be of the kind well-known and available to those having skill in the computer software arts.

As described above, the present invention has been described by way of limited embodiments and drawings, but the present invention is not limited to the above embodiments, and those skilled in the art to which the present invention pertains various modifications and variations from such descriptions. This is possible.

Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined not only by the claims below but also by the equivalents of the claims.

Claims (23)

A training information receiver configured to receive training information for estimating a position and a moving speed of the receiver from the wireless power transmitter;
A moving speed and position estimating unit for estimating a moving speed and a position of the receiving device based on the training information;
A movement determination unit determining whether the reception apparatus is moved based on the estimated movement speed, position, and intensity change of the received training information signal;
A moving direction predicting unit predicting a moving direction of the receiving device based on the estimated moving speed and position of the receiving device when it is determined that the receiving device moves; And
A wireless power receiver for receiving power from a wireless power transmitter applying a matching parameter determined based on the moving direction prediction information.
Adaptive wireless power receiving device for a mobile in a wireless power transmission system comprising a. The method of claim 1,
The training information receiver
Adaptive wireless power receiving apparatus for a moving object in a wireless power transmission system, characterized in that for using the power transmitted wirelessly from the wireless power transmission apparatus as the training information signal. The method of claim 1,
The moving speed and position estimating unit
Adaptive wireless power receiver for a mobile in the wireless power transmission system, characterized in that for estimating the moving speed of the receiving device through the Doppler frequency estimation of the received training information signal. The method of claim 1,
The moving speed and position estimating unit
A radio for estimating the location of the receiving device in a time difference of arrival (TDOA), a time of arrival (TOA), and a received signal strength indication (RSSI) method based on the received training information signal and another communication device having a known position; Adaptive wireless power receiver for mobile in power transmission system. A training information transmitter to transmit training information for estimating a position and a moving speed of the wireless power receiver;
A moving direction prediction information receiving unit which receives moving direction prediction information of the wireless power receiver;
A matching parameter determiner configured to determine a matching parameter in an expected moving direction based on the moving direction prediction information of the wireless power receiver; And
A wireless power transmitter for transmitting wireless power based on the determined matching parameter
Adaptive wireless power transmission device for a moving object in a wireless power transmission system comprising a. The method of claim 5,
Matching parameter updating unit for periodically updating the matching parameter with respect to the determined matching parameter
Adaptive wireless power transmission device for a moving object in a wireless power transmission system further comprising. The method of claim 6,
The apparatus may further include a transmission efficiency determination unit configured to determine whether the wireless power transmission efficiency has a smaller value than the preset value.
And the matching parameter update unit increases a matching parameter update period when the wireless power transmission efficiency has a value smaller than a predetermined value. The method of claim 5,
A transmission efficiency determination unit to determine whether the wireless power transmission efficiency has a value smaller than a preset value; And
When the wireless power transmission efficiency has a value less than a predetermined value, the power transmission mode conversion unit for changing the power transmission mode or the power transmission direction by changing the power transmission mode
Adaptive wireless power transmission device for a moving object in a wireless power transmission system further comprising. A training information receiver configured to receive training information for estimating a position and a moving speed of the wireless power transmitter from the wireless power receiver;
A moving speed and position estimating unit for estimating a moving speed and a position of the wireless power transmitter based on the training information;
A movement determining unit determining whether the wireless power transmitter moves, based on the estimated movement speed, position of the wireless power transmitter, and intensity change of the received training information signal;
A moving direction predicting unit predicting a moving direction of the wireless power transmitting apparatus based on the estimated moving speed and position of the wireless power transmitting apparatus when it is determined that the wireless power transmitting apparatus moves;
A matching parameter determiner that determines a matching parameter in an expected moving direction based on the moving direction prediction of the wireless power transmitter; And
A wireless power transmitter for transmitting wireless power based on the determined matching parameter
Adaptive wireless power transmission device for a moving object in a wireless power transmission system comprising a. 10. The method of claim 9,
Matching parameter updating unit for periodically updating the matching parameter with respect to the determined matching parameter
Adaptive wireless power transmission device for a moving object in a wireless power transmission system further comprising. The method of claim 10,
The apparatus may further include a transmission efficiency determination unit configured to determine whether the wireless power transmission efficiency has a smaller value than the preset value.
And the matching parameter update unit increases a matching parameter update period when the wireless power transmission efficiency has a value smaller than a predetermined value. 10. The method of claim 9,
A transmission efficiency determination unit to determine whether the wireless power transmission efficiency has a value smaller than a preset value; And
When the wireless power transmission efficiency has a value less than a predetermined value, the power transmission mode conversion unit for changing the power transmission mode or the power transmission direction by changing the power transmission mode
Adaptive wireless power transmission device for a moving object in a wireless power transmission system further comprising. A training information transmitter for transmitting training information for estimating a position and a moving speed of the wireless power transmitter;
A matching parameter synchronizer configured to synchronize the matching parameter determined by the wireless power transmitter; And
A wireless power receiver for receiving wireless power based on the synchronized matching parameter
Adaptive wireless power receiving device for a mobile in a wireless power transmission system comprising a. Receiving training information for estimating the position and the moving speed of the receiving apparatus from the wireless power transmitter;
Estimating a moving speed and a position of the receiving device based on the training information;
Determining whether the receiving device moves based on the estimated moving speed, position, and intensity change of the received training information signal;
If it is determined that the receiving device moves, estimating a moving direction of the receiving device based on the estimated moving speed and position of the receiving device; And
Receiving power from a wireless power transmitter applying a matching parameter determined based on the moving direction prediction information;
Adaptive wireless power receiving method for a mobile in a wireless power transmission system comprising a. Transmitting training information for estimating a position and a moving speed of the wireless power receiver;
Receiving moving direction prediction information of the wireless power receiver;
Determining a matching parameter in an expected movement direction based on movement direction prediction information of the wireless power receiver; And
Transmitting wireless power based on the determined matching parameter
Adaptive wireless power transmission method for a mobile in a wireless power transmission system comprising a. 16. The method of claim 15,
Periodically updating a matching parameter with respect to the determined matching parameter
Adaptive wireless power transmission method for a moving object in a wireless power transmission system further comprising. The method of claim 16,
Determining whether the wireless power transmission efficiency has a value smaller than a preset value;
The updating of the matching parameter may include increasing a matching parameter update period when the wireless power transmission efficiency has a value smaller than a preset value, the adaptive wireless power transmission method for a mobile unit in the wireless power transmission system. 16. The method of claim 15,
Determining whether the wireless power transmission efficiency has a value smaller than a preset value; And
Converting a power transmission mode by changing a power transmission frequency or a power transmission direction when the wireless power transmission efficiency has a value smaller than a predetermined value;
Adaptive wireless power transmission method for a moving object in a wireless power transmission system further comprising. Receiving training information for estimating a position and a moving speed of the wireless power transmitter from the wireless power receiver;
Estimating a moving speed and a position of the wireless power transmitter based on the training information;
Determining whether the wireless power transmitter is moved based on the estimated moving speed, position, and intensity change of the received training information signal;
If it is determined that the wireless power transmitter is moving, estimating a moving direction of the wireless power transmitter based on the estimated speed and position of the wireless power transmitter;
Determining a matching parameter in the expected moving direction based on the moving direction prediction of the wireless power transmitter; And
Transmitting wireless power based on the determined matching parameter
Adaptive wireless power transmission method for a mobile in a wireless power transmission system comprising a. 20. The method of claim 19,
Periodically updating a matching parameter with respect to the determined matching parameter
Adaptive wireless power transmission method for a moving object in a wireless power transmission system further comprising. The method of claim 20,
Determining whether the wireless power transmission efficiency has a value smaller than a preset value;
The updating of the matching parameter may include increasing a matching parameter update period when the wireless power transmission efficiency has a value smaller than a preset value, the adaptive wireless power transmission method for a mobile unit in the wireless power transmission system. 20. The method of claim 19,
Determining whether the wireless power transmission efficiency has a value smaller than a preset value; And
Converting a power transmission mode by changing a power transmission frequency or a power transmission direction when the wireless power transmission efficiency has a value smaller than a predetermined value;
Adaptive wireless power transmission method for a moving object in a wireless power transmission system further comprising. Transmitting training information for estimating a position and a moving speed of the wireless power transmitter;
Synchronizing with a matching parameter determined at the wireless power transmitter; And
Receiving wireless power based on the synchronized matching parameter
Adaptive wireless power receiving method for a mobile in a wireless power transmission system comprising a.

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