Power transmission device, wireless power transmission system, control method, and control program

Abstract

To appropriately control the directivity of an antenna based on the wave propagation channel characteristic of an input signal.SOLUTION: Transmission equipment 10 includes: a reception section which executes reception of an input signal transmitted from a power reception device; a transmission section which executes transmission of a transmitter signal to the power reception device with an antenna; and a weight generation section 17 which controls the directivity of the antenna based on the size of an object different from the power reception device so that the intensity of a wave transmitting a transmitter signal in an area in which the object exists is equal to or less than a prescribed value.SELECTED DRAWING: Figure 14

Description

[Technical field]

[0001] The present application relates to a power transmitting device, a wireless power transmission system, a control method, and a control program. [Background technology]

[0002] In wireless power supply using an array antenna, a retrodirective method is sometimes used. In the retrodirective method, a pilot signal is transmitted from a power receiving device prior to power transmission, and the power transmitting device estimates the radio wave propagation channel characteristics of the pilot signal and generates a transmission weight based on the estimation, thereby controlling the antenna directivity. Patent Document 1 discloses a wireless power supply device that calculates a propagation coefficient between multiple antenna elements and an antenna of a device to be powered, and adjusts the phase and amplitude of a power supply signal for each of the multiple antenna elements based on the propagation coefficient. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-10485 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the retrodirective method, when a human is present between the power receiving device and the power transmitting device, the pilot signal transmitted by the power receiving device is significantly attenuated by the human body, so if the antenna directivity is controlled based on the radio wave propagation channel characteristics of the pilot signal, the strength of the radio waves radiated from the power transmitting device toward the human body is weakened, which is considered to be safe for the human body. However, there is room for improvement in the appropriate radiation of radio waves from the power transmitting device. [Means for solving the problem]

[0005] A power transmitting device in one aspect includes a receiving unit that receives a received signal transmitted from a power receiving device, a transmitting unit that transmits a transmitted signal to the power receiving device via an antenna, and a weight generating unit that controls the directivity of the antenna based on the size of the object so that the strength of radio waves transmitting the transmitted signal in an area where an object other than the power receiving device is present is below a predetermined value.

[0006] A wireless power transmission system according to one embodiment includes a power receiving device, a receiving unit that receives a received signal transmitted from the power receiving device, a transmitting unit that transmits a transmitted signal to the power receiving device via an antenna, and a power transmitting device having a weight generating unit that controls the directivity of the antenna based on the size of an object so that the strength of radio waves transmitting the transmitted signal in an area where an object other than the power receiving device is present is below a predetermined level.

[0007] A control method according to one embodiment includes a receiving process for receiving a received signal transmitted from a power receiving device, a transmitting process for transmitting a transmitted signal to the power receiving device using an antenna, and a control process for controlling the directivity of the antenna based on the size of the object so that the strength of radio waves transmitting the transmitted signal in an area where an object other than the power receiving device is present is below a predetermined value. In addition, a control program according to one embodiment causes a computer to execute a receiving process for receiving a received signal transmitted from a power receiving device, a transmitting process for transmitting a transmitted signal to the power receiving device via an antenna, and a control process for controlling the directivity of the antenna based on the size of the object so that the strength of radio waves transmitting the transmitted signal in an area where an object other than the power receiving device is present is equal to or less than a predetermined value. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram for explaining an overview of a wireless power transmission system according to an embodiment. [Diagram 2]FIG. 2 is a diagram showing an example of the results of calculating, by computer simulation, the intensity distribution of radio waves radiated by a reference power transmitting device in a conventional retrodirective system. [Diagram 3] FIG. 3 is a diagram illustrating an example of the configuration of the power transmitting device according to the first embodiment. [Figure 4] FIG. 4 is a diagram showing an example of an equivalent low-pass system analysis model of an adaptive array antenna. [Diagram 5] FIG. 5 is a diagram showing an example of an adaptive array antenna and its directivity. [Figure 6] FIG. 6 is a diagram illustrating an example of the configuration of the power receiving device according to the first embodiment. [Figure 7] FIG. 7 is a diagram for explaining an example of a processing procedure of the power transmitting device in the system shown in FIG. [Figure 8] FIG. 8 is a diagram for explaining a data flow of the power transmitting device shown in FIG. [Figure 9] FIG. 9 is a diagram for explaining an operation example of the power transmitting device according to the first embodiment. [Figure 10] FIG. 10 is a diagram showing an example of the results of calculating, by computer simulation, the intensity distribution of radio waves radiated by the power transmitting device shown in FIG. [Figure 11] FIG. 11 is a diagram illustrating an example of a directivity pattern of radio waves from the power transmitting device according to the first embodiment. [Figure 12] FIG. 12 is a diagram illustrating an example of a configuration of a power transmitting device according to a modified example of the first embodiment. [Figure 13] FIG. 13 is a diagram illustrating an example of a configuration of a power transmitting device according to a modified example of the first embodiment. [Figure 14] FIG. 14 is a diagram illustrating an example of a configuration of a power transmitting device according to the second embodiment. [Figure 15] FIG. 15 is a diagram showing an example of an equivalent low-pass system analysis model of an adaptive array antenna. [Figure 16] FIG. 16 is a diagram showing an example of an adaptive array antenna and its directivity. [Figure 17] FIG. 17 is a diagram showing an example of vectorization when differential coefficients are constrained. [Figure 18] FIG. 18 is a diagram illustrating an example of the configuration of a power receiving device according to the second embodiment. [Figure 19] FIG. 19 is a diagram for explaining an example of a processing procedure of the power transmitting device in the system shown in FIG. [Figure 20] FIG. 20 is a diagram for explaining a data flow of the power transmitting device shown in FIG. [Figure 21] FIG. 21 is a diagram for explaining an operation example of the power transmitting device according to the second embodiment. [Figure 22] FIG. 22 is a diagram showing an example of the results of calculating, by computer simulation, the intensity distribution of radio waves radiated by the power transmitting device shown in FIG. [Figure 23] FIG. 23 is a diagram illustrating an example of a directivity pattern of radio waves from a power transmitting device. [Figure 24] FIG. 24 is a diagram illustrating an example of a configuration of a power transmitting device according to a modified example of the second embodiment. [Diagram 25] FIG. 25 is a diagram illustrating an example of another configuration of a power transmitting device according to a modification of the second embodiment. [Figure 26] FIG. 26 is a diagram illustrating a data flow in a power transmitting device according to a modification of the second embodiment. [Figure 27] FIG. 27 is a diagram illustrating an example of a configuration of a power transmitting device according to the third embodiment. [Figure 28] FIG. 28 is a diagram showing an example of an equivalent low-pass system analysis model of an adaptive array antenna. [Figure 29] FIG. 29 is a diagram showing an example of an adaptive array antenna and its directivity. [Diagram 30] FIG. 30 is a diagram showing an example of vectorization in the multi-point null constraint method. [Diagram 31] FIG. 31 is a diagram showing an example of vectorization in the differential coefficient constraint method. [Diagram 32] FIG. 32 is a diagram illustrating an example of null depth processing in the preprocessing unit. [Diagram 33] FIG. 33 is a diagram illustrating another example of processing of the null depth in the preprocessing unit. [Diagram 34]FIG. 34 is a diagram illustrating an example of the configuration of a power receiving device according to the third embodiment. [Diagram 35] FIG. 35 is a diagram for explaining an example of a processing procedure of the power transmitting device in the system shown in FIG. [Diagram 36] FIG. 36 is a diagram for explaining an example of a data flow in the power transmitting device illustrated in FIG. [Figure 37] FIG. 37 is a diagram for explaining another example of the data flow of the power transmitting device illustrated in FIG. [Figure 38] FIG. 38 is a diagram for explaining an operation example of the power transmitting device according to the third embodiment. [Figure 39] FIG. 39 is a diagram illustrating an example of a directivity pattern of radio waves from the power transmitting device according to the third embodiment. [Diagram 40] FIG. 40 is a diagram illustrating another example of the directivity pattern of radio waves from the power transmitting device according to the third embodiment. [Diagram 41] FIG. 41 is a diagram illustrating an example of a configuration of a power transmitting device according to a modification of the third embodiment. [Diagram 42] FIG. 42 is a diagram illustrating an example of a configuration of a power transmitting device according to a modification of the third embodiment. [Diagram 43] FIG. 43 is a diagram illustrating an example of a configuration of a power transmitting device according to a modification of the third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] A number of embodiments for implementing a power transmitting device, a wireless power transmission system, a control method, and the like according to the present application will be described in detail with reference to the drawings. Note that the following description does not limit the present invention. Furthermore, the components in the following description include those that a person skilled in the art can easily imagine, those that are substantially the same, and those that are within the so-called equivalent range. In the following description, similar components may be given the same reference numerals. Furthermore, duplicate descriptions may be omitted.

[0010] FIG. 1 is a diagram for explaining an outline of a wireless power transmission system according to an embodiment. The system 1 shown in FIG. 1 includes, for example, a wireless power transmission system capable of microwave transmission type (space transmission type) wireless power transmission. Wireless power transmission is a mechanism that allows power to be transmitted without using, for example, a cable or a plug. The microwave transmission type system 1 can use a retrodirective method. The microwave transmission type system 1 uses radio waves (microwaves) as energy transmission. A plurality of frequency bands are available for the frequency of radio waves used in the microwave transmission type system 1, and in Japan, for example, the 920 MHz band, the 2.4 GHz band, the 5.7 GHz band, and the like are included. In this embodiment, the system 1 makes it possible to simultaneously improve power supply efficiency appropriate to the situation and ensure safety. The system 1 can also be applied to, for example, space solar power generation, and the like.

[0011] In the example shown in FIG. 1, the system 1 uses a multipath retrodirective method. The system 1 includes a power transmitting device 10 and a power receiving device 20. The system 1 transmits power from the power transmitting device 10 to the power receiving device 20 using multiple paths (propagation channels). The power transmitting device 10 is a transmission device in the system 1 that transmits power wirelessly and is a device capable of transmitting radio waves for power supply. The power transmitting device 10 includes a sensor unit 15 that can detect an object such as a human body in the vicinity of the array antenna 11. In the following description, the power transmitting device 10 may be referred to as "own device".

[0012] The power receiving device 20 is a power-supplied device in the system 1 that receives radio waves for power supply to obtain power. Examples of the power receiving device 20 include a smartphone, a tablet terminal, an IoT (Internet of Things) sensor, a notebook personal computer, a drone, an electric car, an electric bicycle, a game machine, and the like. In this manner, the power receiving device of the present disclosure may be a mobile device.

[0013] In scene C1, the power receiving device 20 can transmit a prescribed signal 1000 determined between the power receiving device 20 and the power transmitting device 10. The prescribed signal 1000 includes, for example, a beacon, a pilot signal, and the like. The power receiving device 20 can transmit the prescribed signal 1000, for example, at a transmission period. The power receiving device 20 can transmit the prescribed signal 1000 by emitting radio waves including the prescribed signal 1000. On the other hand, when the power transmitting device 10 receives the prescribed signal 1000, it estimates characteristic values ​​(array response vectors) of multiple paths from the power receiving device 20 to the power transmitting device 10 based on the prescribed signal 1000. The power transmitting device 10 calculates a weighting coefficient for transmission using the estimated array response vector for the power receiving device 20.

[0014] In scene C2, the power transmitting device 10 performs directivity control by multiplying each antenna by a weighting coefficient, and radiates radio waves including a transmission signal 2000 for power supply. Directivity control means, for example, controlling the relationship between the radiation direction and radiation intensity of radio waves. If the frequencies of the prescribed signal 1000 and the transmission signal 2000 are the same and time fluctuations in the propagation path are ignored, the characteristics of the multiple paths from the power transmitting device 10 to the power receiving device 20 match the characteristics from the power receiving device 20 to the power transmitting device 10. As a result, the radio waves 2000W radiated from the power transmitting device 10 have a radiation pattern that makes use of not only paths toward the power receiving device 20, but also paths toward a direction different from the power receiving device 20.

[0015] FIG. 2 is a diagram showing an example of the result of calculating the intensity distribution of radio waves emitted by the reference power transmitting device 100A in the conventional retrodirective method by computer simulation. The intensity distribution 3000 shown in FIG. 2 shows the intensity distribution when the reference power transmitting device 100A and the power receiving device 20 are placed in a room 4000, an object 5000 whose physical properties are similar to a human body is placed, and radio waves 2000W including a transmission signal 2000 are emitted from the reference power transmitting device 100A in the retrodirective method. The reference power transmitting device 100A is configured to estimate the characteristic values ​​of multiple paths from the power receiving device 20 to the power transmitting device 10 based on the specified signal 1000, control the antenna directivity using the characteristic values, and transmit radio waves 2000W including a transmission signal 2000 for power supply, similar to the power transmitting device 10 according to the present embodiment. The room 4000 is a room of 3m×3m×3m with walls made of concrete. The object 5000 is disposed between the reference power transmitting device 100A and the power receiving device 20, at a position shifted to the left from a straight line connecting the reference power transmitting device 100A and the power receiving device 20. The object 5000 has physical properties such as a relative dielectric constant of 35.4 and a conductivity of 5.17, for example.

[0016] 2, the intensity distribution 3000 shows that the radio wave 2000W-1 traveling directly from the reference power transmitting device 100A to the power receiving device 20 and the radio wave 2000W-2 traveling from the reference power transmitting device 100A to the object 5000 have stronger intensities. That is, the intensity distribution 3000 is considered to indicate that the reference power transmitting device 100A receives the prescribed signal 1000 directly from the power receiving device 20 and also receives the prescribed signal 1000 reflected by the object 5000. In the present disclosure, the system 1 provides a technology for reducing the influence on the human body when the prescribed signal 1000 from the power receiving device 20 is reflected by the human body and reaches the power transmitting device 10, compared to the conventional multipath retrodirective method.

[0017] (Embodiment 1) [Configuration of power transmission device according to embodiment 1] Fig. 3 is a diagram illustrating an example of the configuration of the power transmitting device 10 according to the first embodiment. Fig. 4 is a diagram illustrating an example of an equivalent low-pass system analysis model of an adaptive array antenna. Fig. 5 is a diagram illustrating an example of an adaptive array antenna and its directivity.

[0018] As shown in FIG. 3, the power transmitting device 10 includes an array antenna 11, a transmission signal generating unit 12, a transmitting / receiving unit 13, an estimating unit 14, a sensor unit 15, a detecting unit 16, a weight generating unit 17, and a multiplying unit 18.

[0019] The array antenna 11 is configured to be capable of directivity control (beam forming). The array antenna 11 includes a plurality of antenna elements 11A. For example, the array antenna 11 is configured such that each of the plurality of antenna elements 11A radiates the same radio wave, and the phase and power intensity of each element are adjusted to strengthen the radio wave in a specific direction and to weaken the radio wave by canceling each other out in another direction. The array antenna 11 radiates a radio wave including a transmission signal 2000 and receives a radio wave including a prescribed signal 1000 from the power receiving device 20. The array antenna 11 supplies the received signal to the transmitting / receiving unit 13. In this embodiment, for the sake of simplicity, the array antenna 11 is described as including three or more antenna elements 11A, but the number of antenna elements 11A is not limited to this.

[0020] The transmission signal generating unit 12 generates a transmission signal 2000 for power supply to be transmitted to the power receiving device 20. The transmission signal 2000 is a signal for emitting radio waves 2000W capable of supplying power. For example, the transmission signal 2000 may be a baseband signal. The transmission signal 2000 may be, for example, an unmodulated signal or a modulated signal. In the case of an unmodulated signal, there is no time variation in the transmission signal 2000 during the transmission period. In the case of a modulated signal, the transmission signal generating unit 12 time-varies the transmission signal 2000 during the transmission period. The transmission signal generating unit 12 includes, for example, stopping the transmission signal 2000 at the timing of receiving the specified signal 1000. The transmission signal generating unit 12 is electrically connected to the multiplier unit 18 and supplies the generated transmission signal 2000 to the multiplier unit 18.

[0021] The transmitting / receiving unit 13 has a plurality of transmitting / receiving circuits 13A electrically connected to each of the plurality of antenna elements 11A of the array antenna 11. The transmitting / receiving circuit 13A is electrically connected to the estimation unit 14, the multiplication unit 18, and the like. The transmitting / receiving circuit 13A extracts a reception signal received by the antenna element 11A and supplies it to the estimation unit 14. The transmitting / receiving circuit 13A causes the antenna element 11A to radiate a transmission signal 2000 multiplied by a transmission weight in the multiplication unit 18. The transmission weight includes, for example, a weighting coefficient capable of adjusting the amplitude and phase. The transmitting / receiving unit 13 causes the plurality of antenna elements 11A to simultaneously radiate radio waves 2000W including the transmission signal 2000 multiplied by the transmission weight (complex amplitude), so that the power transmitting device 10 radiates radio waves 2000W with controlled directivity.

[0022] The estimation unit 14 estimates a propagation channel characteristic (impulse response) from a reference signal 1000 included in a received signal received by the plurality of antenna elements 11A. The propagation channel characteristic (impulse response) includes, for example, an amplitude characteristic and a phase characteristic. The array response vector indicates, for example, channel characteristics for the number of antennas. The array response vector includes, for example, a vector in which the propagation channel characteristic (impulse response) for each of the plurality of antenna elements 11A is arranged. The array response vector in the receiving process is also called a receiving response vector. The estimation unit 14 estimates the receiving response vector using a known algorithm, for example, as disclosed in Japanese Patent Application Laid-Open No. 2002-43995. The estimation unit 14 supplies vector data of the array response vector to a weight generation unit 17.

[0023] The sensor unit 15 can obtain information capable of detecting the presence or absence, direction, etc. of the object 5000 in the radio wave propagation environment of the power transmitting device 10. The radio wave propagation environment includes, for example, a space in which radio waves 2000W are propagated between the power transmitting device 10 and the power receiving device 20. The sensor unit 15 obtains information on the object 5000 present in the radio wave propagation environment using, for example, a camera, a radar such as a LIDAR (Laser Imaging Detection and Ranging) or millimeter wave radar, a ToF (Time of Flight) sensor, an infrared sensor, a human presence sensor, etc. The sensor unit 15 may be provided outside the power transmitting device 10. The sensor unit 15 is electrically connected to the detection unit 16, and supplies the detection unit 16 with sensor information capable of detecting the direction of the object 5000 in the radio wave propagation environment. The sensor information includes, for example, information on the presence or absence, distance, position, image, etc. of the object 5000.

[0024] The detection unit 16 detects information on the position of an object 5000 different from the power receiving device 20 in a radio wave propagation environment based on the sensor information from the sensor unit 15. The object 5000 includes, for example, a human being, an animal, a robot, a moving object, a plant, food, and a device that transmits or receives electromagnetic waves. The detection unit 16 detects the direction of the object 5000 from the array antenna 11. For example, the detection unit 16 detects the direction of the object 5000 from the array antenna 11 based on the direction, position, etc. of the object 5000 indicated by the sensor information and the relative positional relationship between the sensor unit 15 and the array antenna 11. When multiple objects 5000 exist, the detection unit 16 detects the positions of the multiple objects 5000. The detection unit 16 is electrically connected to the weight generation unit 17 and supplies directional information indicating the direction of the object 5000 from the array antenna 11 to the weight generation unit 17. The directional information includes, for example, information indicating the direction of the object 5000 from the array antenna 11. In this way, the detection unit 16 of the present disclosure detects information regarding the position of an object 5000 other than the power receiving device 20 in a radio wave propagation environment based on sensor information from the sensor unit 15, including position information such as GPS information of the object 5000, directional information, distance information, etc.

[0025] The weight generating unit 17 generates weights for power transmission based on the array response vector for the power receiving device 20, which is the estimation result of the estimating unit 14, and the direction information of the object 5000 from the detecting unit 16. For example, a ZF (Zero-Forcing) algorithm or an MMSE (Minimum Mean Square Error) algorithm used in MIMO can be used to generate the weights. The weight generating unit 17 is electrically connected to the multiplying unit 18, and supplies weight information indicating the weights for power transmission to the multiplying unit 18. In the following description, for the sake of simplicity, a case will be described in which a plurality of antenna elements 11A of the array antenna 11 are arranged at equal intervals in the horizontal direction.

[0026] As shown in FIG. 4, the adaptive array antenna transmits a complex amplitude w k Complex conjugate w of (weight) k * After multiplying by, radio waves of 2000 W are emitted simultaneously from K antenna elements 11A. * When a character has an asterisk (*) on its right side, it means the complex conjugate. Weight w k where k=0, ,K-1. At the receiving point 200P, a composite signal of 2000W of radio waves radiated from K antenna elements 11A is observed. At this time, the amplitude and phase change for each propagation channel. Therefore, the impulse response of the propagation channel between the antenna elements 11A #0 to #K-1 and the receiving point 200P is expressed as Z k (complex number), the analytical array antenna characteristics are given by the following (Equation 11).

number

[0027] In this disclosure, the analytical array antenna characteristic is referred to as the array response value AR. If the weight vector is W and the array response vector is V, then (Equation 11) can be expressed as the inner product of complex vectors as shown in the following (Equation 12). Note that in this disclosure, (·) HWhen an "H" is written on the right side of a letter, it means complex conjugate transpose (Hermitian transpose). AR=W H V...(Formula 12) When the weight vector W and the array response vector V are expressed by concrete elements, they are given by the following (Equation 13).

number

[0028] If the array response vector V is known, then the array response value AR at the receiving point 200P can be controlled by providing an appropriate weight vector W. When determining the weight vector W, it is necessary to ensure that the square of the norm of the weight vector W is 1 (||W|| 2 = 1).

[0029] In the retrodirective system 1, an array response vector V d and use this to find the optimal weight vector W opt If we ignore the time variation of the propagation channel, the array response vector V d can be regarded as an array response vector from the power transmitting device 10 to the power receiving device 20. However, the pilot signal has the same frequency as the radio wave used for power transmission. ||W|| 2 = 1, the magnitude of the array response value |W H V d The optimal weight vector W that maximizes | opt can be expressed as the following (Equation 14).

number

[0030] As described above, the optimal weight vector W for retrodirective transmission is opt is the array response vector V of the received pilot signal. dIt is sufficient, and information such as the direction of the receiving point 200P is unnecessary.

[0031] Next, the simultaneous realization of the retro-directive method and multiple (for example, M) null formations will be described.

[0032] A null means that the gain such as the direction or point becomes zero in the directivity of the array antenna 11. To form a null with the array antenna 11, for the array response vector V i (i = 1, ···, M), the magnitude |W H V i | should be set to zero. Under this condition, the magnitude |W d of the array response value of the array response vector V H V d | is maximized. This can be formulated as an optimization problem shown in the following (Equation 15). In the present disclosure, this is referred to as a retro-directive method with linear constraints. Here, K is the number of antenna elements 11A. M is the number of nulls. Since the degree of freedom is K - 1, M < K is assumed. argmax (argument of the maximum) means the set of values that achieve the maximum value. (Equation 15) is an equation for obtaining the optimal weight vector W H V d for which |W opt V

Equation

[0033] The optimization problem of (Equation 15) has a closed-form solution. If (Equation 16) is defined as follows, the optimal weight vector W opt is given by (Equation 17).

Equation

Equation

[0034] Here, A is a matrix shown in (Equation 18) formed by arranging M complex column vectors, namely the array response vectors V1, V2, ···, V M .

Number

[0035] The array response value corresponding to the null must satisfy W H V i = 0 (i = 1, ···, M < K). Therefore, considering these as a system of homogeneous linear equations, using the matrix A formed by arranging M complex column vectors, namely the array response vectors V1, V2, ···, V M , it can be expressed as the product of a matrix and a vector like A H W = 0. The general solution is given by using the Moore - Penrose generalized inverse matrix A + as W = (I - AA + ) H z = (I - AA + )z, where z is an arbitrary complex vector. Substituting W = (I - AA H V d ) + ) H z = (I - AA + )z into the magnitude of the array response value to be maximized, |W H V d |, we get |W H (I - AA+ )V d | is obtained. And, by the Cauchy-Schwarz inequality, |W H V d |=|z H (I-AA + )V d |≦||z||·||(I-AA + )V d || holds true. |W H V d | is maximized when the inequality is equal, and then z=α(I-AA + )V d where α is a complex constant.

[0036] The optimal weight vector W opt is the above-mentioned W=(I-AA + ) H z=(I-AA + )z, z=α(I-AA + )V d By substituting, W opt =α(I-AA + )V d Here, V' is given as in (Equation 16). d =(I-AA + )V d Then, ||W opt || 2 = |α| 2 ||V' d || 2 = 1, α = 1 / ||V' d Therefore, the optimal weight vector W opt can be expressed as (Equation 17) above.

[0037] Next, an example of a method for calculating an array response vector corresponding to a null will be described. The array response vector between the power transmitting device 10 and the power receiving device 20 is estimated from the specified signal 1000. However, if it is assumed that the specified signal 1000 is not transmitted from the target to which the null is to be directed, it is necessary to calculate the array response vector by another method. In the present disclosure, the purpose is to avoid radio waves going directly from the power transmitting device 10 to the target to which the null is to be directed, and the array response vector is calculated from the direction of the object 5000, which is the null target, acquired by the sensor unit 15.

[0038] As shown in Fig. 5, in a linear array in which K antenna elements 11A are arranged at equal intervals, the array response vector in the far field radiated in a direction rotated clockwise by θ (-π / 2<θ<π / 2) from the broadside is given by the following (Equation 19). The broadside is a direction perpendicular to the direction in which the antenna elements 11A are arranged, and is the upward direction in Fig. 5. The inter-element distance from antenna element 11A #0 of reference point 200B to antenna element 11A #k is kd. The inter-element distance from antenna element 11A #0 of reference point 200B to antenna element 11A #K-1 is (K-1)d.

number

[0039] Here, the impulse response Z is expressed by (Equation 20).

number

number

number

[0040] The weight generating unit 17 calculates the direction θ of the null object. i Array response vector V corresponding to null from i is derived using (Equation 21) and (Equation 22), and then the matrix (I-AA + The weight generating unit 17 calculates the calculated matrix (I-AA + ) and the array response vector V corresponding to the power receiving device 20 d From this, the magnitude of the array response value |W H V d The optimal weight vector W that maximizes | opt Generally, the matrix (I-AA + ) and the array response vector V d Therefore, the weight generation unit 17 calculates the matrix (I-AA + ) can be stored in memory unit 17D.

[0041] The storage unit 17D may include any non-transient storage medium such as a semiconductor storage medium and a magnetic storage medium. The storage unit 17D may include a combination of a storage medium such as a memory card, an optical disk, or a magneto-optical disk, and a storage medium reader. The storage unit 17D may include a storage device used as a temporary storage area such as a RAM. The storage unit 17D may be provided outside the weight generation unit 17.

[0042] 3, the multiplier 18 multiplies the transmission signal 2000 from the transmission signal generator 12 by a weight for each of the antenna elements 11A based on the weight information from the weight generator 17. The multiplier 18 has, for example, a multiplier. The multiplier 18 supplies the transmission signal 2000 multiplied by the weight corresponding to the antenna element 11A to the transmission / reception circuit 13A of the antenna element 11A.

[0043] An example of the functional configuration of the power transmitting device 10 according to the present embodiment has been described above. Note that the above configuration described with reference to Fig. 3 is merely an example, and the functional configuration of the power transmitting device 10 according to the present embodiment is not limited to this example. The functional configuration of the power transmitting device 10 according to the present embodiment can be flexibly modified according to the specifications and operation.

[0044] [Power receiving device according to embodiment 1] FIG. 6 is a diagram showing an example of the configuration of the power receiving device 20 according to the first embodiment. As shown in FIG. 6, the power receiving device 20 includes an antenna 21, a transmitting / receiving unit 22, a signal generating unit 23, and a power receiving unit 24. The power receiving device 20 of the present disclosure may be a mobile device. For example, such a power receiving device 20 may be a mobile battery, a smartphone, a camera, a vibration sensor, a biosensor, a temperature sensor, an alarm, or other device mounted on a moving object such as a drone or a car, an autonomous vehicle, a vibration sensor, a biosensor, a temperature sensor, an alarm, or the like whose installation position is variable. In the present disclosure, since the power receiving device 20 is a mobile device, the characteristics of the propagation channel based on the prescribed signal may change depending on the position of the power receiving device 20.

[0045] The antenna 21 is electrically connected to the transmitting / receiving unit 22. The antenna 21 is a power receiving antenna capable of receiving radio waves 2000W from the power transmitting device 10. For example, a patch antenna, a dipole antenna, a parabolic antenna, or the like can be used as the antenna 21. For example, the antenna 21 emits radio waves including a specified signal 1000, and receives radio waves 2000W including a transmission signal 2000 from the power transmitting device 10. The antenna 21 supplies a reception signal of the received radio waves 2000W to the transmitting / receiving unit 22.

[0046] The transmitting / receiving unit 22 is electrically connected to the signal generating unit 23 and the power receiving unit 24. The transmitting / receiving unit 22 causes the antenna 21 to radiate radio waves including the specified signal 1000 from the signal generating unit 23. The transmitting / receiving unit 22 supplies the power receiving unit 24 with a reception signal of the radio waves received by the antenna 21.

[0047] The signal generating unit 23 generates a specified signal 1000. The signal generating unit 23 causes the antenna 21 to emit radio waves including the specified signal 1000 via the transmitting / receiving unit 22. The signal generating unit 23 can generate the specified signal 1000 based on a transmission period. The signal generating unit 23 may be configured to generate a signal different from the specified signal 1000.

[0048] The power receiving unit 24 converts the radio waves of 2000 W received by the antenna 21 into a direct current and receives power using this direct current. The power receiving unit 24 converts the radio waves into a direct current using, for example, a known rectifier circuit. The power receiving unit 24 supplies the received power to, for example, a battery or load compatible with Qi (an international standard for wireless power supply). The load includes, for example, mechanical equipment, an IoT (Internet of Things) sensor, electronic equipment, lighting equipment, and the like.

[0049] An example of the functional configuration of the power receiving device 20 according to the present embodiment has been described above. Note that the above configuration described with reference to Fig. 6 is merely an example, and the functional configuration of the power receiving device 20 according to the present embodiment is not limited to this example. The functional configuration of the power receiving device 20 according to the present embodiment can be flexibly modified according to the specifications and operation.

[0050] [Example of Processing Procedure of Power Transmission Device According to Embodiment 1] Fig. 7 is a diagram for explaining an example of a processing procedure of the power transmitting device 10 of the system 1 shown in Fig. 1. Fig. 8 is a diagram for explaining a data flow of the power transmitting device 10 shown in Fig. 7.

[0051] 7, in the system 1, the power receiving device 20 transmits a prescribed signal 1000. When the power transmitting device 10 receives radio waves including the prescribed signal 1000 at the array antenna 11, the power transmitting device 10 transmits an array response vector V d For example, as shown in FIG. 8, the power transmitting device 10 estimates the propagation channel characteristics of a reference signal 1000 included in the received signals received by the multiple antenna elements 11A in the estimation unit 14, and estimates an array response vector V dWhen the process of step S111 ends, the power transmitting device 10 advances the process to step S131.

[0052] In addition, the power transmitting device 10 detects the direction of the object 5000 different from the power receiving device 20 in the radio wave propagation environment based on the sensor information from the sensor unit 15 by using the detection unit 16 (step S121). For example, as shown in FIG. 8, when the detection unit 16 detects M objects 5000 as null targets, the power transmitting device 10 detects the directions θ1, θ2, . . . , θ M and supplies the weight to the weight generating unit 17. Returning to FIG. 7, when the power transmitting device 10 ends the process of step S121, the power transmitting device 10 advances the process to step S122.

[0053] The power transmitting device 10 performs array response vectorization and matrix calculation corresponding to null in the weight generating unit 17 (step S122). For example, as shown in FIG. 8, the power transmitting device 10 performs array response vectorization and matrix calculation corresponding to null in the weight generating unit 17 in the directions θ1, θ2, . . . , θ M Based on the above (Eq. 21) and (Eq. 22), the array response vectorization (V1, V2, . . . , V M ) (step S171). Then, the weight generating unit 17 of the power transmitting device 10 performs a matrix operation (step S172). In detail, the power transmitting device 10 calculates an array response vector V i = V1, V2, . . . , V M Using (I-AA + ), and the calculation result is stored in the storage unit 17D. M 7, when the process of step S122 ends, the power transmitting device 10 advances the process to step S131.

[0054] The power transmitting device 10 generates a transmission weight (step S131). For example, as shown in FIG. 8, the power transmitting device 10 performs a matrix-vector multiplication (step S173). In detail, in the power transmitting device 10, the weight generating unit 17 multiplies the array response vector V estimated by the estimating unit 14 by d and the matrix (I-AA+ ) to obtain the array response vector V d The power transmitting device 10 calculates the array response vector V d ' is normalized using (Equation 17) to obtain the optimal weight vector W opt (step S174). Returning to FIG. 7, when the process of step S131 ends, the power transmitting device 10 advances the process to step S132.

[0055] The power transmitting device 10 multiplies the transmission weight (step S132). For example, the power transmitting device 10 multiplies the transmission weight by the optimal weight vector W opt Based on weight information indicating the weight, the power transmitting device 10 multiplies the transmission signal 2000 for power supply from the transmission signal generating unit 12 by the weight for each of the plurality of antenna elements 11A and supplies the result to the transmitting / receiving circuit 13A. In this way, the power transmitting device 10 causes the plurality of antenna elements 11A to radiate radio waves 2000W including the transmission signal 2000 for power supply from the plurality of antenna elements 11A. In this case, since the power transmitting device 10 directs a null toward the object 5000, the radio waves 2000W are constructively combined in the power receiving device 20, but are destructively combined in the object 5000.

[0056] The power receiving device 20 converts the received radio waves for power supply (2000 W) into a direct current, and uses the direct current to charge a battery or to operate using the charged power. After that, the power receiving device 20 transmits a prescribed signal 1000.

[0057] When the power transmitting device 10 receives radio waves including the prescribed signal 1000 at the array antenna 11, the power transmitting device 10 repeats the above-mentioned processing procedure to obtain the weight vector W opt and radiates radio waves 2000W of the transmission signal 2000 from the array antenna 11. In this way, even if the power receiving device 20 or the object 5000 moves, the power transmitting device 10 can maintain the state in which the radio waves 2000W are combined constructively at the power receiving device 20 and combined destructively at the object 5000.

[0058] The processing procedure of the power transmitting device 10 shown in FIG. 7 is as follows: d (step S111) and the array response vector V according to the direction of the object 5000 i and the matrix calculation (step S122) do not need to be synchronized. For example, the period in which the prescribed signal 1000 is received may be different from the period in which the detection unit 16 provides information. In addition, for example, when there is no change in the direction of the object 5000, the power transmitting device 10 synchronizes the past array response vector V i may also be used.

[0059] Fig. 9 is a diagram for explaining an example of the operation of the power transmitting device 10 according to the embodiment 1. Fig. 10 is a diagram showing an example of the result of calculating, by computer simulation, the intensity distribution of radio waves radiated by the power transmitting device 10 shown in Fig. 9. Fig. 11 is a diagram showing an example of the directivity pattern of radio waves 2000 W from the power transmitting device 10 according to the embodiment 1.

[0060] 9 and 10, the system 1 places the power transmitting device 10 and the power receiving device 20 in a room 4000, and an object 5000 having the same physical properties as a human body is present. The room 4000 is a 3m x 3m x 3m room with concrete walls. The object 5000 is placed between the power transmitting device 10 and the power receiving device 20, at a position offset from the straight line connecting the power transmitting device 10 and the power receiving device 20. That is, the measurement environment shown in FIG. 10 is the same as the environment shown in FIG. 2.

[0061] 10, in the system 1, when an object 5000 is present in the vicinity between the power transmitting device 10 and the power receiving device 20, the power transmitting device 10 can detect the direction of the object 5000 based on the sensor information of the sensor unit 15. When the power receiving device 20 emits radio waves including a prescribed signal 1000, the main paths are a path that goes directly to the power transmitting device 10 and a path that is reflected by the object 5000 and goes back to the power transmitting device 10. In this case, the power transmitting device 10 estimates the propagation channel characteristics of the radio waves including the prescribed signal 1000 received by the array antenna 11, and calculates an array response vector V d The reference power transmission device 100A in FIG. 2 estimates this array response vector V dHowever, the power transmitting device 10 generates the transmission weights using only the directions θ1, θ2, . . . , θ of an object 5000 different from the power receiving device 20 based on the sensor information from the sensor unit 15. M The power transmitting device 10 detects an array response vector V corresponding to the null from the direction of the object 5000. i Calculate the array response vector V i and the array response vector V d and use it to find the optimal weight vector W opt The power transmitting device 10 generates an optimal weight vector W opt The radio wave 2000 W of the transmission signal 2000 multiplied by is radiated from the multiple antenna elements 11 A of the array antenna 11 .

[0062] 10, even if the power transmitting device 10 receives the specified signal 1000 from the direction of the object 5000, the power transmitting device 10 can direct the radiated radio waves 2000W toward the power receiving device 20 and suppress the radiation of the radio waves 2000W toward the object 5000. As a result, even in an environment where radio waves including the specified signal 1000 from the power receiving device 20 are reflected by the human body and reach the human body, the power transmitting device 10 can suppress the radio waves 2000W toward the human body, thereby realizing safe wireless power transmission.

[0063] Even if a plurality of objects 5000 are present in the propagation environment, the power transmitting device 10 detects the directions of the plurality of objects 5000 and calculates a weight vector W so as to direct a null to each of the plurality of objects 5000. opt In the present disclosure, the weight generating unit 17 may generate the transmission weights so that the gain in the direction of the object is within a predetermined gain range from null. For example, when the null is A [dB], the weight generating unit 17 may generate the transmission weights so that the gain in the direction of the object is within a gain range from null A [dB] to B [dB]. Here, the value of B may be a predetermined multiple of A, such as 0.9A, 0.8A, 0.7A, 0.98A, 0.99A, 1.1A, or 1.01A.

[0064] The graph shown in FIG. 11 shows, for example, a directivity pattern of radio waves 2000W emitted from the power transmitting device 10 according to the first embodiment in a case where two objects 5000 are present. In the graph shown in FIG. 11, the vertical axis shows the power (square of the absolute value) [dB] of the array response value, and the horizontal axis shows the radiation direction [°] of the radio waves 2000W. In the example shown in FIG. 11, the power transmitting device 10 has eight antenna elements 11A, the spacing between adjacent antenna elements 11A is λ / 2, and the antenna arrangement is an equally spaced linear array. λ represents the wavelength. The power transmitting device 10 estimates that the direction of 30° is the radiation direction of the radio waves 2000W to the power receiving device 20, and detects that −10° and −45° in the radiation direction are the directions of the two objects 5000. The power transmitting device 10 calculates an array response vector V corresponding to the power receiving device 20 in the direction of 30°. d Based on the array response vector V1 corresponding to the null in the -10° direction and the array response vector V2 corresponding to the null in the -45° direction, a weight vector W opt The power transmitting device 10 generates an optimal weight vector W opt 2000W of the transmission signal 2000 multiplied by is radiated from the multiple antenna elements 11A of the array antenna 11. In the example shown in FIG. 11, the power of the array response value of the power transmitting device 10 is large near the radiation direction of 30°, and the power of the array response value is small near the direction D1 of -10° and the direction D2 of -45°. As a result, even if the power transmitting device 10 detects multiple objects 5000, it can direct the radiated radio waves 2000W in the direction of the power receiving device 20 and can suppress the radiation of the radio waves 2000W toward the multiple objects 5000. Generally, the array response vector V d does not correspond to a specific direction in the directivity pattern, but in the example of FIG. 11, it is set as an array response vector in the direction of 30° for ease of understanding.

[0065] In the above-described first embodiment, the power transmitting device 10 has been described as including a linear array in which the antenna elements 11A of the array antenna 11 are equally spaced from one another. However, the present invention is not limited to this. The power transmitting device 10 receives an array response vector V iAs long as it is possible to calculate the above, the arrangement of the multiple antenna elements 11A does not need to be an equally spaced linear array.

[0066] [Modification of the power transmitting device according to the first embodiment] 12 and 13 are diagrams showing an example of the configuration of the power transmitting device 10 according to a modification of the first embodiment. As shown in FIG. 12, the power transmitting device 10 may have the sensor unit 15 and the detection unit 16 provided in the electronic device 30 outside the power transmitting device 10. In this case, the power transmitting device 10 may be configured to be able to receive data from the electronic device 30 and may acquire a detection result of the object 5000 from the electronic device 30. As shown in FIG. 13, the power transmitting device 10 may have only the sensor unit 15 provided outside the device. In this case, the power transmitting device 10 may be configured to be able to acquire sensor information and the like from the external sensor unit 15 and the detection unit 16 may detect the object 5000 based on the sensor information and the like from the sensor unit 15.

[0067] (Embodiment 2) [Configuration of power transmission device according to embodiment 2] Fig. 14 is a diagram showing an example of the configuration of a power transmitting device 10 according to the second embodiment. Fig. 15 is a diagram showing an example of an equivalent low-pass system analysis model of an adaptive array antenna. Fig. 16 is a diagram showing an example of an adaptive array antenna and directivity. Fig. 17 is a diagram showing an example of vectorization when differential coefficients are constrained.

[0068] As shown in FIG. 14, the power transmitting device 10 includes an array antenna 11, a transmission signal generating unit 12, a transmitting / receiving unit 13, an estimating unit 14, a sensor unit 15, a detecting unit 16, a weight generating unit 17, and a multiplying unit 18.

[0069] The array antenna 11 is configured to be capable of directivity control (beam forming). The array antenna 11 includes a plurality of antenna elements 11A. For example, the array antenna 11 is configured such that each of the plurality of antenna elements 11A radiates the same radio wave, and the phase and power intensity of each element are adjusted to strengthen the radio wave in a specific direction and to weaken the radio wave by canceling each other out in another direction. The array antenna 11 radiates a radio wave including a transmission signal 2000 and receives a radio wave including a prescribed signal 1000 from the power receiving device 20. The array antenna 11 supplies the received signal to the transmitting / receiving unit 13. In this embodiment, for the sake of simplicity, the array antenna 11 is described as including three or more antenna elements 11A, but the number of antenna elements 11A is not limited to this.

[0070] The transmission signal generating unit 12 generates a transmission signal 2000 for power supply to be transmitted to the power receiving device 20. The transmission signal 2000 is a signal for emitting radio waves 2000W capable of supplying power. For example, the transmission signal 2000 may be a baseband signal. The transmission signal 2000 may be, for example, an unmodulated signal or a modulated signal. In the case of an unmodulated signal, there is no time variation in the transmission signal 2000 during the transmission period. In the case of a modulated signal, the transmission signal generating unit 12 time-varies the transmission signal 2000 during the transmission period. The transmission signal generating unit 12 includes, for example, stopping the transmission signal 2000 at the timing of receiving the specified signal 1000. The transmission signal generating unit 12 is electrically connected to the multiplier unit 18 and supplies the generated transmission signal 2000 to the multiplier unit 18.

[0071] The transmitting / receiving unit 13 has a plurality of transmitting / receiving circuits 13A electrically connected to each of the plurality of antenna elements 11A of the array antenna 11. The transmitting / receiving circuit 13A is electrically connected to the estimation unit 14, the multiplication unit 18, and the like. The transmitting / receiving circuit 13A extracts a reception signal received by the antenna element 11A and supplies it to the estimation unit 14. The transmitting / receiving circuit 13A causes the antenna element 11A to radiate a transmission signal 2000 multiplied by a transmission weight in the multiplication unit 18. The transmission weight includes, for example, a weighting coefficient capable of adjusting the amplitude and phase. The transmitting / receiving unit 13 causes the plurality of antenna elements 11A to simultaneously radiate radio waves 2000W including the transmission signal 2000 multiplied by the transmission weight (complex amplitude), so that the power transmitting device 10 radiates radio waves 2000W with controlled directivity.

[0072] The estimation unit 14 estimates a propagation channel characteristic (impulse response) from a reference signal 1000 included in a received signal received by the plurality of antenna elements 11A. The propagation channel characteristic (impulse response) includes, for example, an amplitude characteristic and a phase characteristic. The array response vector indicates, for example, channel characteristics for the number of antennas. The array response vector includes, for example, a vector in which the propagation channel characteristic (impulse response) for each of the plurality of antenna elements 11A is arranged. The array response vector in the receiving process is also called a receiving response vector. The estimation unit 14 estimates the receiving response vector using a known algorithm, for example, as disclosed in Japanese Patent Application Laid-Open No. 2002-43995. The estimation unit 14 supplies vector data of the array response vector to a weight generation unit 17.

[0073] The sensor unit 15 can obtain information capable of detecting the presence, direction, area, etc. of the object 5000 in the radio wave propagation environment of the power transmitting device 10. The radio wave propagation environment includes, for example, a space in which radio waves 2000W are propagated between the power transmitting device 10 and the power receiving device 20. The area of ​​the object 5000 includes, for example, information on the area of ​​the object 5000 in the radio wave propagation environment and the angular spread of the object 5000 from the own device. The sensor unit 15 obtains information on the object 5000 present in the radio wave propagation environment using, for example, a camera, a radar such as a millimeter wave radar, a LIDAR (Laser Imaging Detection and Ranging), a ToF (Time of Flight) sensor, an infrared sensor, a human sensor, a depth sensor, etc. The sensor unit 15 may be provided outside the power transmitting device 10. The sensor unit 15 is electrically connected to the detection unit 16 and supplies the detection unit 16 with sensor information capable of detecting the direction and area of ​​the object 5000 in the radio wave propagation environment. The sensor information includes, for example, information on the presence or absence of the object 5000, distance, position, images, etc.

[0074] The detection unit 16 detects information on the position and area of ​​an object 5000 different from the power receiving device 20 in a radio wave propagation environment based on the sensor information from the sensor unit 15. The object 5000 includes, for example, a human being, an animal, a robot, a moving object, a plant, food, and a device that transmits or receives electromagnetic waves. The detection unit 16 executes a publicly known object recognition process on an image indicated by the sensor information, and detects the area and shape of the object 5000, the area in which the object exists in the radio wave propagation environment, the direction and area of ​​the object 5000 from the own device, and the like. For example, the detection unit 16 detects the direction, area, and the like of the object 5000 from the array antenna 11 based on the direction, position, area, and the like of the object 5000 indicated by the sensor information and the relative positional relationship between the sensor unit 15 and the array antenna 11. When multiple objects 5000 exist, the detection unit 16 detects the positions and areas of the multiple objects 5000. The detection unit 16 is electrically connected to the weight generation unit 17, and supplies the weight generation unit 17 with identifiable direction information indicating the direction, area, and the like of the object 5000 from the array antenna 11. In this manner, the detection unit 16 of the present disclosure detects information regarding the position of the object 5000 different from the power receiving device 20 in the radio wave propagation environment, based on sensor information from the sensor unit 15 including position information such as GPS information of the object 5000, direction information, distance information, and the like.

[0075] The directional information includes, for example, information indicating the direction, area, etc. of the object 5000 from the array antenna 11. For example, as shown in FIG. 14, the directional information includes identifiable information such as an area 151 including the object 5000 and a size 152. The directional information can be information that identifies the size of the object 5000 set according to the arrangement of the multiple antenna elements 11A. For example, when the multiple antenna elements 11A are arranged in a matrix, the area 151 of the object 5000 can set the length and width, the position, the shape of the object 5000, etc. For example, when the multiple antenna elements 11A are arranged in one direction, the size 152 of the object 5000 can set the length and distance in one direction such as width and height, the angle range from the own aircraft, etc. The area 151 of the object 5000 may be a spatial area according to the outer shape of the object 5000, etc.

[0076] The weight generating unit 17 generates weights for power transmission based on the array response vector for the power receiving device 20, which is the estimation result of the estimating unit 14, and the direction information of the object 5000 from the detecting unit 16. For example, a ZF (Zero-Forcing) algorithm or an MMSE (Minimum Mean Square Error) algorithm used in MIMO can be used to generate the weights. The weight generating unit 17 is electrically connected to the multiplying unit 18, and supplies weight information indicating the weights for power transmission to the multiplying unit 18. In the following description, for the sake of simplicity, a case will be described in which a plurality of antenna elements 11A of the array antenna 11 are arranged at equal intervals in the horizontal direction.

[0077] As shown in FIG. 15, the adaptive array antenna transmits a complex amplitude w k Complex conjugate w of (weight) k * After multiplying by , radio waves of 2000 W are emitted simultaneously from K antenna elements 11A. * When a character has an asterisk (*) on its right side, it means the complex conjugate. Weight w k where k=0, ,K-1. At the receiving point 200P, a composite signal of 2000W of radio waves radiated from K antenna elements 11A is observed. At this time, the amplitude and phase change for each propagation channel. Therefore, the impulse response of the propagation channel between the antenna elements 11A #0 to #K-1 and the receiving point 200P is expressed as Z k (complex number), the analytical array antenna characteristics are given by the following (Equation 211).

number

[0078] In this disclosure, the analytical array antenna characteristic is referred to as the array response value AR. If the weight vector is W and the array response vector is V, then (Equation 211) can be expressed as the inner product of complex vectors as shown in the following (Equation 212). Note that in this disclosure, (·) HWhen an "H" is written on the right side of a letter, it means complex conjugate transpose (Hermitian transpose). AR=W H V...(Formula 212) When the weight vector W and the array response vector V are expressed by concrete elements, they are given by the following (Equation 213).

number

[0079] If the array response vector V is known, then the array response value AR at the receiving point 200P can be controlled by providing an appropriate weight vector W. When determining the weight vector W, it is necessary to ensure that the square of the norm of the weight vector W is 1 (||W|| 2 = 1).

[0080] In the retrodirective system 1, an array response vector V d and use this to find the optimal weight vector W opt If we ignore the time variation of the propagation channel, the array response vector V d can be regarded as an array response vector from the power transmitting device 10 to the power receiving device 20. However, the pilot signal has the same frequency as the radio wave used for power transmission. ||W|| 2 The magnitude of the array response value under the condition |W H V d The optimal weight vector W that maximizes | opt can be expressed as the following (Equation 214).

number

[0081] As described above, the optimal weight vector W for retrodirective transmission is opt is the array response vector V of the received pilot signal. dIt is sufficient, and information such as the direction of the receiving point 200P is unnecessary.

[0082] Next, the simultaneous realization of the retro-directive method and multiple (for example, M) null formations will be described.

[0083] A null means that the gain such as the direction or point becomes zero in the directivity of the array antenna 11. To form a null with the array antenna 11, for the array response vector V i (i = 1, ···, M), the magnitude |W H V i | may be set to zero. Under this condition, the magnitude |W d of the array response value of the array response vector V H V d | is maximized. This can be formulated as an optimization problem shown in the following (Equation 215). In the present disclosure, this is referred to as a retro-directive method with linear constraints. Here, K is the number of antenna elements 11A. M is the number of nulls. Since the degree of freedom is K - 1, M < K. argmax (argument of the maximum) means the set of values that achieve the maximum value. (Equation 215) is a conditional expression for obtaining the optimal weight vector W H V d such that |W opt V

Number

[0084] The optimization problem of (Equation 215) has a closed-form solution. When (Equation 216) is defined as follows, the optimal weight vector W opt is given by (Equation 217).

Number

Number

[0085] Here, A is a matrix shown in (Equation 218) formed by arranging the M complex column vectors, i.e., the array response vectors V1, V2, ···, V M .

Number

[0086] The array response value corresponding to the null must satisfy W H V i = 0 (i = 1, ···, M < K). Therefore, considering these as a system of homogeneous linear equations, it can be expressed as the product of a matrix and a vector using the matrix A formed by arranging the M complex column vectors, i.e., the array response vectors V1, V2, ···, V, such that A M W = 0. The general solution is given by W=(I - AA H ) + z=(I - AA + ) H z=(I - AA + )z, where z is an arbitrary complex vector. Substituting W=(I - AA H V d ) + ) H z=(I - AA + )z into the magnitude of the array response value to be maximized, |W H V d |, we get |W H (I - AA+ )V d | is obtained. And, by the Cauchy-Schwarz inequality, |W H V d |=|z H (I-AA + )V d |≦||z||·||(I-AA + )V d || holds true. |W H V d | is maximized when the inequality is equal, and then z=α(I-AA + )V d where α is an arbitrary complex constant.

[0087] The optimal weight vector W opt is the above-mentioned W=(I-AA + ) H z=(I-AA + )z, z=α(I-AA + )V d By substituting, W opt =α(I-AA + )V d Here, V' is given as in (Eq. 216). d =(I-AA + )V d Then, ||W opt || 2 = |α| 2 ||V' d || 2 = 1, α = 1 / ||V' d Therefore, the optimal weight vector W opt can be expressed as (Equation 217) above.

[0088] Next, an example of a method for calculating an array response vector corresponding to a null will be described. The array response vector between the power transmitting device 10 and the power receiving device 20 is estimated from the specified signal 1000. However, if it is assumed that the specified signal 1000 is not transmitted from the target to which the null is to be directed, it is necessary to calculate the array response vector by another method. In the present disclosure, the purpose is to avoid radio waves going directly from the power transmitting device 10 to the target to which the null is to be directed, and the array response vector is calculated from the direction of the object 5000, which is the null target, acquired by the sensor unit 15.

[0089] As shown in Fig. 16, in a linear array in which K antenna elements 11A are arranged at equal intervals, the array response vector in the far field radiated in a direction rotated clockwise by θ (-π / 2<θ<π / 2) from the broadside is given by the following (Equation 219). The broadside is a direction perpendicular to the direction in which the antenna elements 11A are arranged, and is the upward direction in Fig. 16. The inter-element distance from antenna element 11A #0 to antenna element 11A #K of reference point 200B is kd. The inter-element distance from antenna element 11A #0 to antenna element 11A #K-1 of reference point 200B is (K-1)d.

number

[0090] Here, the impulse response Z is expressed as (Equation 220).

number

number

number

[0091] The weight generating unit 17 calculates the direction θ of the null object. i Array response vector V corresponding to null from i is derived using (Eq. 221) and (Eq. 222), and then the matrix (I-AA + The weight generating unit 17 calculates the calculated matrix (I-AA + ) and the array response vector V corresponding to the power receiving device 20 d From the magnitude of the array response value |W H V d The optimal weight vector W that maximizes | opt Generally, the matrix (I-AA + ) and the array response vector V d Therefore, the weight generation unit 17 calculates the matrix (I-AA + ) can be stored in the memory unit 17D.

[0092] The storage unit 17D may include any non-transient storage medium such as a semiconductor storage medium and a magnetic storage medium. The storage unit 17D may include a combination of a storage medium such as a memory card, an optical disk, or a magneto-optical disk, and a storage medium reader. The storage unit 17D may include a storage device used as a temporary storage area such as a RAM. The storage unit 17D may be provided outside the weight generation unit 17.

[0093] Next, an example of widening the null will be described. The object 5000 to be the null has an extension, and it is desirable to widen the null depending on the area of ​​the object 5000. A number of methods can be used to widen the null. In this disclosure, a case where derivative constraints are used will be described. By substituting (Equation 219) and (Equation 220) into the above-mentioned (Equation 211) and (Equation 212), the array response value of the K-element equally spaced linear array in the θ direction can be obtained by (Equation 223).

number

[0094] W H Let V = D(θ). D(θ) is called the array response function or array factor. D(θ) is a continuous function of θ and can be differentiated with respect to θ. Also, a graph of this absolute value |D(θ)| will show the directional pattern of the array antenna.

[0095] In (Eq. 223), θ = θ i (i=1, ,M) is substituted into D(θ i ) is θ i is the array response value in the direction. Also, since (Eq. 223) is differentiable, θ = θ i θ=θ i +Δθ array response value D(θ i +Δθ) is L i Using the next approximation formula, this can be expressed as (Equation 224) below.

number

[0096] In (Eq. 224), the derivative D (l) (θ i )(l=1,...,L i ) is zero, then D(θ i +Δθ) ≒ D(θ i ) and θ i Neighborhood θ i +Δθ can make the array response values ​​similar. This is called null (D(θ i )=0) is the broadening of the null by the derivative constraint, and the order of the approximation formula is L i In this disclosure, the superscript (l) of each character indicates the order of differentiation.

[0097] Derivative constraint D (l) (θ i )=0(l=1, ,L i ) is equivalent to the following (Equation 225).

number

[0098] So, the diagonal matrix Q l If we express (Equation 225) as (Equation 226) below, then (Equation 225) can be expressed as (Equation 227) below. Note that (Equation 226) and (Equation 227) are for l=1, ,L i It is. Q l =diag[0 l 1 l (K-1) l ]...(Formula 226) W H (Q l V i )=0...(Formula 227)

[0099] When the following (Equation 228) and (Equation 229) are summarized, the constraint condition for the l-th derivative is given by the following (Equation 230). Note that (Equation 229) is for l=1, ,L i In (Equation 230), l=0, ,L i It is. i (l) Although V is different from the array response vector, it can be treated in the same way as the constraint condition of (Equation 215) from (Equation 230). i (l) is called the constraint vector. V i (0) =V i ...(Formula 228) V i (l) =Q l V i ...(Formula 229) W H V i (l) =0...(Formula 230)

[0100] Under the constraints of (Eq. 230), the array response vector V d Magnitude of the array response value of |W H V d The optimization problem to maximize | can be formulated as follows (Equation 231). [Number]

[0101] Here, K is the number of antenna elements 11A, and M is the number of nulls. The number of nulls is the number of objects 5000 detected by the detection unit 16. L1, L2, ···, L M is a number that determines the degree of broadening of each null, and in the present disclosure, this is referred to as the wide angle. The wide angle is determined according to the region of the object 5000 detected by the detection unit 16, and a constraint vector is added by the wide angle. Since the degree of freedom is K - 1, M + L1 + L2 + ··· + L M <is set as K. Also, the array response vector V i (l) (l = 0, ···, K - 1) is linearly independent.

[0102] As can be seen from the comparison between the above (Equation 215) and (Equation 231), it is possible to broaden the null while following the algorithm of the linearly constrained retro - directive method. In the present disclosure, this is referred to as the micro - coefficient constrained retro - directive method.

[0103] The weight generation unit 17 generates a transmission weight so that the nulls face the direction and region of the object 5000 based on the propagation channel characteristics of the specified signal 1000 and the detection results of the direction and region of the object 5000 detected by the detection unit 16. In order to generate the transmission weight, for example, the weight generation unit 17 determines the wide angle L i .

[0104] For example, the weight generation unit 17 calculates the array response vector V i from the direction θ i using (Equation 221) and (Equation 222). For example, as shown in FIG. 17, the weight generation unit 17 applies the information indicating the direction θ i and the region δ i of the null target to the table 170 to obtain the wide angle L i . The region δ i includes information regarding the region, size, etc. of the object 5000. The wide angle L iis a wide-angle parameter, and the area δ of the object 5000 i Not only the direction θ i Since the direction θ also depends on the direction θ, the direction θ may be calculated using the table 170 or may be calculated using machine learning or the like. In this embodiment, the table 170 is stored in the storage unit 17D. i and the region δ i From wide angle L i This is a lookup table that derives the

[0105] The weight generating unit 17 calculates the wide angle L i and the array response vector V i Therefore, by vectorizing using the above (equation 226), (equation 228), and (equation 229), the constraint vector V i (l) (l=0,...,L i The weight generating unit 17 calculates the constraint vector V i (l) Using the above, the magnitude of the array response value |W H V d The optimal weight vector W that maximizes | opt is determined by the above-mentioned (Equation 231). i can be set for each null target. The power transmitting device 10 can calculate the matrix calculated from the direction and region to which the null is directed and the propagation channel characteristics of the prescribed signal 1000 independently.

[0106] 14, the multiplier 18 multiplies the transmission signal 2000 from the transmission signal generator 12 by a weight for each of the antenna elements 11A based on the weight information from the weight generator 17. The multiplier 18 has, for example, a multiplier. The multiplier 18 supplies the transmission signal 2000 multiplied by the weight corresponding to the antenna element 11A to the transmission / reception circuit 13A of the antenna element 11A.

[0107] An example of the functional configuration of the power transmitting device 10 according to the present embodiment has been described above. Note that the above configuration described with reference to Fig. 14 is merely an example, and the functional configuration of the power transmitting device 10 according to the present embodiment is not limited to this example. The functional configuration of the power transmitting device 10 according to the present embodiment can be flexibly modified according to the specifications and operation.

[0108] [Power receiving device according to embodiment 2] FIG. 18 is a diagram showing an example of the configuration of the power receiving device 20 according to the second embodiment. As shown in FIG. 18, the power receiving device 20 includes an antenna 21, a transmitting / receiving unit 22, a signal generating unit 23, and a power receiving unit 24. The power receiving device 20 of the present disclosure may be a mobile device. For example, such a power receiving device 20 may be a mobile battery, a smartphone, a camera, a vibration sensor, a biosensor, a temperature sensor, an alarm, or other device mounted on a moving object such as a drone or a car, an autonomous vehicle, a vibration sensor, a biosensor, a temperature sensor, an alarm, or the like whose installation position is variable. In the present disclosure, since the power receiving device 20 is a mobile device, the characteristics of the propagation channel based on the prescribed signal may change depending on the position of the power receiving device 20.

[0109] The antenna 21 is electrically connected to the transmitting / receiving unit 22. The antenna 21 is a power receiving antenna capable of receiving radio waves 2000W from the power transmitting device 10. For example, a patch antenna, a dipole antenna, a parabolic antenna, or the like can be used as the antenna 21. For example, the antenna 21 emits radio waves including a specified signal 1000, and receives radio waves 2000W including a transmission signal 2000 from the power transmitting device 10. The antenna 21 supplies a reception signal of the received radio waves 2000W to the transmitting / receiving unit 22.

[0110] The transmitting / receiving unit 22 is electrically connected to the signal generating unit 23 and the power receiving unit 24. The transmitting / receiving unit 22 causes the antenna 21 to radiate radio waves including the specified signal 1000 from the signal generating unit 23. The transmitting / receiving unit 22 supplies the power receiving unit 24 with a reception signal of the radio waves received by the antenna 21.

[0111] The signal generating unit 23 generates a specified signal 1000. The signal generating unit 23 causes the antenna 21 to emit radio waves including the specified signal 1000 via the transmitting / receiving unit 22. The signal generating unit 23 can generate the specified signal 1000 based on a transmission period. The signal generating unit 23 may be configured to generate a signal different from the specified signal 1000.

[0112] The power receiving unit 24 converts the radio waves of 2000 W received by the antenna 21 into a direct current and receives power using this direct current. The power receiving unit 24 converts the radio waves into a direct current using, for example, a known rectifier circuit. The power receiving unit 24 supplies the received power to, for example, a battery or load compatible with Qi (an international standard for wireless power supply). The load includes, for example, mechanical equipment, an IoT (Internet of Things) sensor, electronic equipment, lighting equipment, and the like.

[0113] An example of the functional configuration of the power receiving device 20 according to the present embodiment has been described above. Note that the above configuration described with reference to Fig. 18 is merely an example, and the functional configuration of the power receiving device 20 according to the present embodiment is not limited to this example. The functional configuration of the power receiving device 20 according to the present embodiment can be flexibly modified according to the specifications and operation.

[0114] [Example of Processing Procedure of Power Transmission Device According to Second Embodiment] Fig. 19 is a diagram for explaining an example of a processing procedure of the power transmitting device 10 of the system 1 shown in Fig. 1. Fig. 20 is a diagram for explaining a data flow of the power transmitting device 10 shown in Fig. 19.

[0115] 19, in the system 1, the power receiving device 20 transmits a prescribed signal 1000. When the power transmitting device 10 receives radio waves including the prescribed signal 1000 at the array antenna 11, the power transmitting device 10 transmits an array response vector V d For example, as shown in FIG. 20, the power transmitting device 10 estimates the propagation channel characteristics of a reference signal 1000 included in the received signals received by the multiple antenna elements 11A in the estimation unit 14, and estimates an array response vector V dReturning to Fig. 19, when the process of step S111 ends, the power transmitting device 10 advances the process to step S131.

[0116] In addition, the power transmitting device 10 detects the direction and area of ​​the object 5000 different from the power receiving device 20 in the radio wave propagation environment based on the sensor information from the sensor unit 15 by using the detection unit 16 (step S121). For example, as shown in FIG. 20, when the detection unit 16 detects M objects 5000 as null targets, the power transmitting device 10 detects the directions θ1, θ2, . . . , θ M Then, the power transmitting device 10 detects the regions δ1, δ2, . . . , δ of the plurality of objects 5000. M The power transmitting device 10 detects the directions θ1, θ2, . . . , θ M and areas δ1,δ2,...,δ M to the weight generating unit 17. Returning to FIG. 19, when the process of step S121 ends, the power transmitting device 10 advances the process to step S122.

[0117] The power transmitting device 10 performs constraint vectorization and matrix calculation corresponding to null in the weight generating unit 17 (step S122). For example, as shown in FIG. 20, the power transmitting device 10 performs constraint vectorization and matrix calculation corresponding to null in the direction θ i and the region δ i The information shown in Table 170 is applied to the wide-angle L i Search for wide angle L i and the array response vector V i Therefore, by vectorizing using the above (equation 226), (equation 228), and (equation 229), the constraint vector V corresponding to the null is obtained. i (l) (l=0,...,L i ) is calculated (step S171). The weight generating unit 17 of the power transmitting device 10 then performs a matrix calculation (step S172). In detail, the power transmitting device 10 calculates a constraint vector V i (l) Using (I-AA + ) matrix operation, and the operation result is stored in the storage unit 17D. (0) ,···,V1 (L1),V2 (0) ,···,V2 (L2) ,···,V M (0) ,···,V M (LM) 19, when the process of step S122 ends, the power transmitting device 10 advances the process to step S131.

[0118] The power transmitting device 10 generates a transmission weight (step S131). For example, as shown in FIG. 20, the power transmitting device 10 performs a matrix-vector multiplication (step S173). In detail, in the power transmitting device 10, the weight generating unit 17 multiplies the array response vector V d and (I-AA + ) to obtain the array response vector V d Then, the power transmitting device 10 performs normalization (step S174). In detail, the power transmitting device 10 calculates the array response vector V d ' is normalized using (Equation 217) to obtain the optimal weight vector W opt Returning to Fig. 19, when the process of step S131 ends, the power transmitting device 10 advances the process to step S132.

[0119] The power transmitting device 10 multiplies the transmission weight (step S132). For example, the power transmitting device 10 multiplies the transmission weight by the optimal weight vector W opt Based on weight information indicating the weight, the power transmitting device 10 multiplies the transmission signal 2000 for power supply from the transmission signal generating unit 12 by the weight for each of the plurality of antenna elements 11A and supplies the result to the transmitting / receiving circuit 13A. In this way, the power transmitting device 10 causes the plurality of antenna elements 11A to radiate radio waves 2000W including the transmission signal 2000 for power supply from the plurality of antenna elements 11A. In this case, since the power transmitting device 10 directs a null toward the area of ​​the object 5000, the radio waves 2000W are constructively combined in the power receiving device 20, but are destructively combined in the object 5000.

[0120] The power receiving device 20 converts the received radio waves for power supply (2000 W) into a direct current, and uses the direct current to charge a battery or to operate using the charged power. After that, the power receiving device 20 transmits a prescribed signal 1000.

[0121] When the power transmitting device 10 receives radio waves including the prescribed signal 1000 at the array antenna 11, the power transmitting device 10 repeats the above-mentioned processing procedure to obtain the weight vector W opt and radiates radio waves 2000W of the transmission signal 2000 from the array antenna 11. In this way, even if the power receiving device 20 or the object 5000 moves, the power transmitting device 10 can maintain the state in which the radio waves 2000W are combined constructively at the power receiving device 20 and combined destructively at the object 5000.

[0122] The processing procedure of the power transmitting device 10 shown in FIG. 19 is to calculate the array response vector V d (step S111) and the constraint vector V according to the direction and area of ​​the object 5000 i (l) The calculation of and the matrix calculation (step S122) do not need to be synchronized. Therefore, for example, the period in which the regulation signal 1000 is received may be different from the period in which the detection unit 16 provides information. In addition, for example, when there is no change in the direction and area of ​​the object 5000, the power transmitting device 10 uses the past constraint vector V i (l) may also be used.

[0123] Fig. 21 is a diagram for explaining an example of the operation of the power transmitting device 10 according to the second embodiment. Fig. 22 is a diagram showing an example of the result of calculating, by computer simulation, the intensity distribution of radio waves radiated by the power transmitting device 10 shown in Fig. 21. Fig. 23 is a diagram showing an example of the directivity pattern of radio waves 2000 W from the power transmitting device 10 according to the second embodiment.

[0124] 21 and 22, the system 1 places the power transmitting device 10 and the power receiving device 20 in a room 4000, and an object 5000 having the same physical properties as a human body is present. The room 4000 is a 3m x 3m x 3m room with walls made of concrete. The object 5000 is placed between the power transmitting device 10 and the power receiving device 20, at a position offset from the straight line connecting the power transmitting device 10 and the power receiving device 20. That is, the measurement environment shown in FIG. 22 is the same as the environment shown in FIG. 2.

[0125] 22, in the system 1, when an object 5000 is present in the vicinity between the power transmitting device 10 and the power receiving device 20, the power transmitting device 10 can detect the direction of the object 5000 based on the sensor information of the sensor unit 15. When the power receiving device 20 emits radio waves including a prescribed signal 1000, the main paths are a path that goes directly to the power transmitting device 10 and a path that is reflected by the object 5000 and goes back to the power transmitting device 10. In this case, the power transmitting device 10 estimates the propagation channel characteristics of the radio waves including the prescribed signal 1000 received by the array antenna 11, and calculates an array response vector V d The power transmitting device 10 detects the direction and area of ​​the object 5000 different from the power receiving device 20 in the radio wave propagation environment based on the sensor information from the sensor unit 15, and estimates the directions θ1, θ2, . . . , θ M and areas δ1,δ2,...,δ M 22, M=1. The power transmitting device 10 detects the array response vector V i and calculate the constraint vector V based on the area of ​​the object 5000. i (l) The constraint vector V i (l) and the array response vector V d and use it to find the optimal weight vector W opt The power transmitting device 10 generates an optimal weight vector W opt The radio wave 2000 W of the transmission signal 2000 multiplied by is radiated from the multiple antenna elements 11 A of the array antenna 11 .

[0126] 22, even if the power transmitting device 10 receives the prescribed signal 1000 from the direction of the object 5000, the power transmitting device 10 can direct the radiated radio waves 2000W toward the power receiving device 20, and can suppress the radiation of the radio waves 2000W toward the object 5000 by forming a wide-angle null in the area of ​​the object 5000. As a result, even in an environment where the prescribed signal 1000 from the power receiving device 20 is reflected off the human body and reaches the human body, the power transmitting device 10 can suppress the radio waves 2000W toward the human body, thereby realizing safe wireless power transmission.

[0127] Even if a plurality of objects 5000 are present in the propagation environment, the power transmitting device 10 detects the directions and regions of the plurality of objects 5000 and calculates a weight vector W so as to direct a null to each of the plurality of objects 5000. opt can be generated.

[0128] The graph shown in FIG. 23 shows an example of a directivity pattern of radio waves 2000W emitted from the power transmitting device 10 according to the second embodiment in the case where two objects 5000 are present. In the graph shown in FIG. 23, the vertical axis shows the power (square of the absolute value) [dB] of the array response value, and the horizontal axis shows the radiation direction [°] of the radio waves 2000W. In the example shown in FIG. 23, the power transmitting device 10 has eight antenna elements 11A, the spacing between adjacent antenna elements 11A is λ / 2, and the antenna arrangement is an equally spaced linear array. λ represents the wavelength. The power transmitting device 10 estimates that the direction of 30° is the radiation direction of the radio waves 2000W to the power receiving device 20, and detects that −10° and −45° in the radiation direction are the directions of the two objects 5000. The power transmitting device 10 calculates an array response vector V corresponding to the power receiving device 20 in the direction of 30°. d The array response vector V1 corresponding to the null in the -10° direction, the array response vector V2 corresponding to the null in the -45° direction, and the weight vector W based on the respective null width angles are opt The power transmitting device 10 generates an optimal weight vector W opt23, the power of the array response value of the power transmitting device 10 is large near the radiation direction of 30°, and the power of the array response value is small near the direction D1 of -10° and the direction D2 of -45°. As a result, even if the power transmitting device 10 detects multiple objects 5000, it can direct the radiated radio waves 2000W in the direction of the power receiving device 20 and can suppress the radiation of the radio waves 2000W toward the multiple objects 5000. Generally, the array response vector V d does not correspond to a specific direction in the directivity pattern, but in the example of FIG. 23, it is set as an array response vector in a 30° direction for ease of understanding.

[0129] In the above-described second embodiment, the power transmitting device 10 has been described as including a linear array in which the antenna elements 11A of the array antenna 11 are equally spaced, but the power transmitting device 10 is not limited to this. i As long as it is possible to calculate the above, the arrangement of the multiple antenna elements 11A does not need to be an equally spaced linear array.

[0130] [Modification of the power transmitting device according to the second embodiment] FIG. 24 is a diagram showing an example of the configuration of the power transmitting device 10 according to a modification of the second embodiment. FIG. 25 is a diagram showing another example of the configuration of the power transmitting device 10 according to a modification of the second embodiment. As shown in FIG. 24, the power transmitting device 10 may have the sensor unit 15 and the detection unit 16 provided in the electronic device 30 outside the power transmitting device 10. In this case, the power transmitting device 10 may be configured to be able to receive data from the electronic device 30 and may acquire a detection result of the object 5000 from the electronic device 30. As shown in FIG. 25, the power transmitting device 10 may have only the sensor unit 15 provided outside the device. In this case, the power transmitting device 10 may be configured to be able to acquire sensor information and the like from the external sensor unit 15 and the detection unit 16 may detect the object 5000 based on the sensor information and the like from the sensor unit 15.

[0131] [Example of applying derivative constraint to weights generated under arbitrary conditions in embodiment 2] In the derivative-constrained retrodirective method, V d is in the same direction as the optimal weight in the retrodirective method, and the matrix (I-AA + ) is the projection matrix of the subspace spanned by the column vectors of matrix A onto the orthogonal subspace. The elements of the subspace spanned by the column vectors of matrix A are given by Ax. Matrix (I-AA + ) multiplied by vector Ax from the right, (I-AA + )Ax=(I-AA + A)x = (AA)x = 0. This means that by multiplying any vector by this matrix from the left, the components parallel to the subspace spanned by the column vectors of matrix A become zero, and only the orthogonal components remain. Therefore, this is the projection matrix of the subspace spanned by the column vectors of matrix A onto the orthogonal subspace.

[0132] That is, the power transmitting device 10 calculates the matrix (I-AA + ) can remove radiation components toward the null direction. This means that it can be applied to any transmission weight calculated under a certain condition. FIG. 26 is a diagram for explaining a data flow of a power transmitting device according to a modification of the second embodiment. Note that the certain condition includes a plurality of conditions generalized based on the direction and area of ​​the object 5000.

[0133] The power transmission device 10 shown in FIG. 26 uses the weight vector W generated by the weight generation unit 17 under certain conditions and (I-AA + ) to calculate a weight vector W′ (step S175). Then, the power transmitting device 10 normalizes the weight vector W′ calculated by the weight generating unit 17 to obtain an optimal weight vector W opt (=W' / ||W'||) is generated (step S176), where A=[V1 (0) ,···,V1 (L1) ,V2 (0) ,···,V2 (L2) ,···,V M (0) ,···,VM (LM) The power transmitting device 10 multiplies the transmission weights in step S132 described above. For example, the power transmitting device 10 multiplies the transmission weights in step S132 by the multiplier 18, which multiplies the optimum weight vector W opt Based on the weight information indicating the weight, the power transmitting device 10 multiplies the transmission signal 2000 for power supply from the transmission signal generating unit 12 by the weight for each of the plurality of antenna elements 11A and supplies the result to the transmitting / receiving circuit 13A. In this way, the power transmitting device 10 causes the plurality of antenna elements 11A to radiate radio waves 2000W including the transmission signal 2000 for power supply. As a result, since the power transmitting device 10 directs a null toward the area of ​​the object 5000, the radio waves 2000W are directed toward the power receiving device 20, but the radiation toward the object 5000 can be reduced. In this way, the power transmitting device 10 can obtain the above-mentioned operational effects even if the configuration is changed.

[0134] [Example of application of multi-point null constraint method to wide-angle null in embodiment 2] Another example of widening the null angle will be described. In order to widen the null angle, for example, a plurality of null points may be arranged in the area of ​​the object 5000. For example, the weight generation unit 17 may generate a null image in the direction θ i and the region δ i to the minimum value θ in that direction min i and the maximum value θ max i The weight generating unit 17 determines θ min From θ max Covering direction θ i (0) ,θ i (1) , ,θ i (Li) The step size is determined by the direction θ i Regardless of the direction θ of the object 5000, the i The weight generating unit 17 uses (Equation 221) and (Equation 222) to calculate θ i (l) from the array response vector V i (l) (l=0,...,L i) and convert them into the constraint vector V i (l) In the present disclosure, the method of setting nulls over the area of ​​the object 5000 is referred to as a multi-point null constraint retrodirective method. Both the multi-point null constraint retrodirective method and the differential coefficient constraint retrodirective method use (Equation 231). Therefore, in null widening, the multi-point null constraint retrodirective method that sets multiple nulls and the differential coefficient constraint retrodirective method that sets multiple constraint vectors according to the wide angle may be combined.

[0135] [Example of limiting the direction and area of ​​an object according to the second embodiment] The direction and area of ​​the object 5000 may be limited under specific conditions. For example, if the object is a human, the detection unit 16 may limit the direction and area of ​​the human to the head by a publicly known object recognition process for the image indicated by the sensor information. Also, for example, the direction and area of ​​the object 5000 may be limited to the direction and area from which the regulated signal 1000 arrives by a publicly known arrival direction estimation process for the regulated signal 1000 received by the power transmitting device 10. Also, for example, the area of ​​the object 5000 may be divided, and the null target area may be limited to the divided area. In this case, the divided areas may be switched over time.

[0136] [Conversion of differential coefficient constraint conditions according to the second embodiment] Derivative constraint D (l) (θ i )=0(l=1, ,L i We prove below that (equation 225) above is equivalent to (equation 225).

[0137] First, we show that the following formula (2C1) holds true. ln (θ) is a function of θ.

number

[0138] [2-1]Consider the case where l=1. By differentiating both sides of the following (equation 2C1a) with respect to θ, we obtain (equation 2C1b).

number

number

number

[0139] By using the following (Equation 2C2a) and (Equation 2C2b), we obtain (Equation 2C3).

number

number

number

[0140] [2-2]When l=p, suppose that (equation 2C1) holds as the following (equation 2C4).

number

[0141] By differentiating both sides of (Equation 2C4) with respect to θ, we obtain the following (Equation 2C5).

number

[0142] By differentiating both sides of (equation 2C2b) with respect to θ, we obtain the following (equation 2C6).

number

[0143] By substituting (equation 2C5) into (equation 2C6), we obtain the following (equation 2C61).

number

[0144] Dividing both sides of (equation 2C61) by (j2πd / λ)cosθ gives the following (equation 2C7).

number

[0145] Here, we use the following (Formula 2C8), (Formula 2C9), and (Formula 2C10), where n=2, . . . , p in (Formula 2C9).

number

number

number

[0146] From (equation 2C8), (equation 2C9), and (equation 2C10), (equation 2C7) becomes the following (equation 2C11).

number

[0147] In (Equation 2C1), θ = θ i and Z i =Z(θ i ) to obtain the following (Equation 2C12).

number

[0148] From (Equation 2C12), D (l) (θ i )=0(l=1, ,L i ), the following (Equation 2C12a) is obtained. However, in (Equation 2C12a), l=1, ,L i It is.

number

[0149] Conversely, from (Equation 2C12), if the following (Equation 2C12b) holds, then the following (Equation 2C12c) holds. However, in (Equation 2C12c), l=1, ,L i It is.

number

number

[0150] So, if we use the following formula (2C12d), then D (l) (θ i )=0(l=1, ,L i ) is shown.

number

[0151] Consider the case where [2-A]l=1. F 11 (θ i )·D'(θ i )=0, then F 11 (θ i )=λ / (j2πd·cosθ)≠0, so D'(θ i )=0.

[0152] [2-B]l=p( <L i ) when D (l) (θ i )=0(l=1, ,p), we obtain the following (Equation 2C12e).

number

[0153] From the above (Equation 2C10), the following (Equation 2C12f) is obtained, so D (p+1) (θ i )=0.

number

[0154] Therefore, D (l) (θ i )=0(l=1,···,p+1). From the above [2-A] and [2-B], if the following (Formula 2C12g) is true, then D (l) (θ i )=0(l=1,···,p+1).

number

[0155] Therefore, in the following (equation 2C12h), D (l) (θ i )=0(l=1, ,L). Thus, the idea behind the problem has been answered.

number

[0156] [Independence of Differential Coefficient Constraint Vectors in the Second Embodiment] Array response vector V i (l) Prove that (l=0, ,K-1) are linearly independent.

[0157] First, the array response vector V i (l) For (l=0, ,K-1) to be linearly independent, if we set the following (equation 2D1), this holds true if a l = 0(l = 0, , K-1).

number

[0158] Here, if we use the following (Equation 2D2), (Equation 2D1) becomes A i a=0, and "a=0 is the only solution" and "A i "There exists an inverse matrix of A" is equivalent. i It is sufficient to show that the determinant of is not zero.

number

[0159] From the above (equation 221), (equation 226), (equation 228), and (equation 229), we obtain the following (equation 2D3), so the determinant |A i | becomes the following (equation 2D4).

number

number

[0160] When cofactor expansion is performed on the first line of (equation 2D4), we obtain the following (equation 2D5).

number

[0161] Furthermore, since (equation 2D51) generally holds, (equation 2D5) becomes the following (equation 2D6).

number

number

[0162] Furthermore, (equation 2D6) contains the Vandermonde determinant, and the Vandermonde determinant is the following (equation 2D61), which results in the following (equation 2D62).

number

number

[0163] Therefore, |A i |≠0. The above proves the point of the question.

[0164] [Change of diagonal matrix according to the second embodiment] Q shown in (Eq. 226) above l =diag[0 l 1 l (K-1) l ] is Q l '=diag[q l,0 q l,1 q l,K-1 ] can be substituted. This is proved below.

[0165] Here, q l,k Let be the following (Equation 2E1), where k = 0, , K-1.

number

[0166] (Equation 2E1) to Q l '=diag[q l,0 q l,1 q l,K-1 ] becomes the following (Equation 2E2).

number

[0167] Now, if we put the following (equation 2E3), Q l ' can be expressed by the following formula (2E4). l,1 ,···,c l,l is a constant.

number

number

[0168] Multiplying both sides of (equation 2E4) by Vi from the right, the following (equation 2E7) is given by the following (equation 2E5) and (equation 2E6).

number

number

number

[0169] If we rearrange (equation 2E7), we get the following (equation 2E8), so V i (l) (l=0,...,L j ) arranged horizontally as a matrix A i =[V i (0) V i (1) V i (Ll) ] and V' i (l) (l=0,...,L j ) arranged horizontally to form a matrix A' i =[V' i (0) V' i (1) V' i (Ll) ] is calculated by using the following formula (2E9) to find A' i =A i B i However, V' i (0) =V i =V i (0) Also, C r,r ≠0(r=1, ,L j ) to the matrix B i is regular.

number

number

[0170] Matrix A shown in the following (equation 2E10) and matrix A' shown in the following (equation 2E11) can be expressed as A'=AB using matrix B shown in the following (equation 2E12).

number

number

number

[0171] The above matrix B i is regular, so AB=AA + AB=ABB -1 A + AB=AB(B -1 A + )AB, and (AB) + =B -1 A + Therefore, A'A' + =AB(AB) + =ABB -1 A + =AA + Matrix A is the operation AA + Used for Q l AA when using + The result of the calculation and Q' l A'A' when using + Since the results of the calculations are equal, Q l Instead of Q' l This shows that the problem can be solved by using the above.

[0172] [Calculation of the generalized Moore-Penrose inverse matrix according to the second embodiment] The Moore-Penrose generalized inverse of A + can be calculated by singular value decomposition. Also, complex column vectors V1, V2, . . . , V MIf are linearly independent, then A + =(A H A) -1 A H where matrix A=[V1V2··· V M On the other hand, complex column vectors V1, V2, . . . , V M If the linear independence of is not guaranteed, A is calculated using a known regularization parameter α. + =(αI+A H A) -1 A H For example, in the matrix calculation of the weight generating unit 17 (step S172), a calculation using a regularization parameter may be performed.

[0173] (Embodiment 3) [Configuration of power transmission device according to embodiment 3] Fig. 27 is a diagram illustrating an example of a configuration of a power transmitting device 10 according to embodiment 3. Fig. 28 is a diagram illustrating an example of an equivalent low-pass system analysis model of an adaptive array antenna. Fig. 29 is a diagram illustrating an example of an adaptive array antenna and its directivity.

[0174] As shown in FIG. 27, the power transmission device 10 includes an array antenna 11, a transmission signal generating unit 12, a transmission / reception unit 13, an estimation unit 14, a sensor unit 15, a detection unit 16, a weight generation unit 17, a multiplication unit 18, and a pre-processing unit 19.

[0175] The array antenna 11 is configured to be capable of directivity control (beam forming). The array antenna 11 includes a plurality of antenna elements 11A. The array antenna 11 is configured such that, for example, each of the plurality of antenna elements 11A radiates the same radio wave, and the phase and power intensity of each element are adjusted to strengthen the radio wave in a specific direction and to weaken the radio wave by canceling each other out in another direction. The array antenna 11 radiates a radio wave including a transmission signal 2000 and receives a radio wave including a prescribed signal 1000 from the power receiving device 20. The array antenna 11 supplies the received signal to the transmitting / receiving unit 13. In this embodiment, for the sake of simplicity, the array antenna 11 includes three or more antenna elements 11A, but the number of antenna elements 11A is not limited to this. The array antenna 11 is an example of an antenna.

[0176] The transmission signal generating unit 12 generates a transmission signal 2000 for power supply to be transmitted to the power receiving device 20. The transmission signal 2000 is a signal for emitting radio waves 2000W capable of supplying power. For example, the transmission signal 2000 may be a baseband signal. The transmission signal 2000 may be, for example, an unmodulated signal or a modulated signal. In the case of an unmodulated signal, there is no time variation in the transmission signal 2000 during the transmission period. In the case of a modulated signal, the transmission signal generating unit 12 time-varies the transmission signal 2000 during the transmission period. The transmission signal generating unit 12 includes, for example, stopping the transmission signal 2000 at the timing of receiving the specified signal 1000. The transmission signal generating unit 12 is electrically connected to the multiplier unit 18 and supplies the generated transmission signal 2000 to the multiplier unit 18.

[0177] The transmitting / receiving unit 13 has a plurality of transmitting / receiving circuits 13A electrically connected to each of the plurality of antenna elements 11A of the array antenna 11. The transmitting / receiving circuit 13A is electrically connected to the estimating unit 14, the multiplying unit 18, and the like. The transmitting / receiving circuit 13A extracts a reception signal received by the antenna element 11A and supplies it to the estimating unit 14. The transmitting / receiving circuit 13A causes the antenna element 11A to radiate a transmission signal 2000 multiplied by a transmission weight in the multiplying unit 18. The transmission weight includes, for example, a weighting coefficient capable of adjusting the amplitude and phase. The transmitting / receiving unit 13 causes the plurality of antenna elements 11A to simultaneously radiate radio waves including the transmission signal 2000 multiplied by the transmission weight (complex amplitude), so that the power transmitting device 10 radiates radio waves 2000W with controlled directivity. Note that the power transmitting device 10 may not require the multiplying unit 18 when the transmission signal is an unmodulated wave.

[0178] The estimation unit 14 estimates a propagation channel characteristic (impulse response) from a reference signal 1000 included in a received signal received by the plurality of antenna elements 11A. The propagation channel characteristic (impulse response) includes, for example, an amplitude characteristic and a phase characteristic. The array response vector indicates, for example, channel characteristics for the number of antennas. The array response vector includes, for example, a vector in which the propagation channel characteristic (impulse response) for each of the plurality of antenna elements 11A is arranged. The array response vector in the receiving process is also called a receiving response vector. The estimation unit 14 estimates the receiving response vector using a known algorithm, for example, as disclosed in Japanese Patent Application Laid-Open No. 2002-43995. The estimation unit 14 supplies vector data of the array response vector to a weight generation unit 17.

[0179] The sensor unit 15 can acquire information capable of detecting the presence, position, area, distance (depth), and the like of the object 5000 in the radio wave propagation environment of the power transmitting device 10. The radio wave propagation environment includes, for example, a space in which radio waves 2000W are propagated between the power transmitting device 10 and the power receiving device 20. The area of ​​the object 5000 includes, for example, information on the area of ​​the object 5000 in the radio wave propagation environment, the angle of the object 5000 from the own device, and the angular spread. The sensor unit 15 acquires information on the object 5000 present in the radio wave propagation environment using, for example, a camera, a LIDAR (Laser Imaging Detection and Ranging), a radar such as a millimeter wave radar, a ToF (Time of Flight) sensor, an infrared sensor, a human sensor, a depth sensor, and the like. The sensor unit 15 may be provided outside the power transmitting device 10. The sensor unit 15 is electrically connected to the detection unit 16, and supplies the detection unit 16 with sensor information capable of detecting at least the direction and distance of the object 5000 in the radio wave propagation environment. The sensor information includes, for example, information on the presence or absence, distance, position, and image of the object 5000. In this manner, the detection unit 16 of the present disclosure detects information on the position of the object 5000 different from the power receiving device 20 in the radio wave propagation environment based on the sensor information from the sensor unit 15 including position information such as GPS information of the object 5000, direction information, distance information, and the like.

[0180] The detection unit 16 detects, for example, information on the position, area, and distance of an object 5000 different from the power receiving device 20 in a radio wave propagation environment based on the sensor information from the sensor unit 15. The object 5000 includes, for example, a human being, an animal, a robot, a moving object, a plant, food, and a device that transmits or receives electromagnetic waves. The detection unit 16 executes a publicly known object recognition process on an image indicated by the sensor information, and detects the presence or absence of the object 5000, its shape, the area in which the object exists in the radio wave propagation environment, and the direction and distance of the object 5000 from the own device. For example, the detection unit 16 detects the direction, area, position, distance, etc. of the object 5000 from the array antenna 11 based on the direction, position, area, etc. of the object 5000 indicated by the sensor information and the relative positional relationship between the sensor unit 15 and the array antenna 11. When multiple objects 5000 exist, the detection unit 16 detects the position, distance, etc. of each of the multiple objects 5000. The detection unit 16 is electrically connected to the pre-processing unit 19, and supplies the pre-processing unit 19 with identifiable direction information indicating the direction, area, distance, etc. of the object 5000 from the array antenna 11.

[0181] The directional information includes, for example, information indicating the direction, area, distance, etc. of the object 5000 from the array antenna 11. For example, as shown in FIG. 27, the directional information includes identifiable information such as an area 151 including the object 5000, a size 152, and a distance 153. The directional information can be information that identifies the size of the object 5000 set according to the arrangement of the multiple antenna elements 11A. For example, when the multiple antenna elements 11A are arranged in a matrix, the area 151 of the object 5000 can set the length and width, the position, the shape of the object 5000, etc. For example, when the multiple antenna elements 11A are arranged in one direction, the size 152 of the object 5000 can set the length and distance in one direction such as width and height, the angle range from the own device, etc. The distance 153 of the object 5000 can set the shortest, longest, average, etc. distance from the sensor unit 15 to the object 5000, the depth, etc. The region 151 of the object 5000 may be a spatial region according to the outer shape of the object 5000 or the like.

[0182] The pre-processing unit 19 performs a process of vectorization and generating the magnitude of the null depth as identifiable information based on the direction information from the detection unit 16. When widening the null in accordance with the size of the object 5000, the pre-processing unit 19 can perform vectorization using, for example, at least one of a multi-point null constraint method and a differential coefficient constraint method. The processing of the pre-processing unit 19 will be described later. The pre-processing unit 19 performs pre-processing related to the generation of weights and supplies the processing result to the weight generation unit 17.

[0183] The weight generating unit 17 generates weights for power transmission from the results of calculation in the preprocessing unit 19 based on the array response vector for the power receiving device 20, which is the estimation result of the estimating unit 14, and the direction information of the detecting unit 16. For example, a ZF (Zero-Forcing) algorithm or an MMSE (Minimum Mean Square Error) algorithm used in MIMO can be used as a method for generating the weights. The weight generating unit 17 is electrically connected to the multiplying unit 18, and supplies weight information indicating the weights for power transmission to the multiplying unit 18. In the following description, for the sake of simplicity, a case will be described in which a plurality of antenna elements 11A of the array antenna 11 are arranged at equal intervals in the horizontal direction.

[0184] As shown in FIG. 28, the adaptive array antenna transmits a transmission signal 2000 with a complex amplitude (weight w k ) complex conjugate w k * After multiplying by, radio waves of 2000 W are emitted simultaneously from K antenna elements 11A. * When a character has an asterisk (*) on its right side, it means the complex conjugate. Weight w k where k=0, ,K-1. At the receiving point 200P, a composite signal of 2000W of radio waves radiated from K antenna elements 11A is observed. At this time, the amplitude and phase change for each propagation channel. Therefore, the impulse response of the propagation channel between the antenna elements 11A #0 to #K-1 and the receiving point 200P is expressed as Z k(complex number), the analytical array antenna characteristics are given by the following (Equation 311).

number

[0185] In this disclosure, the analytical array antenna characteristic is referred to as the array response value AR. If the weight vector is W and the array response vector is V, then (Equation 311) can be expressed as the inner product of complex vectors as shown in the following (Equation 312). Note that in this disclosure, (·) H When an "H" is written on the right side of a letter, it means complex conjugate transpose (Hermitian transpose). AR=W H V...(Formula 312) When the weight vector W and the array response vector V are expressed by concrete elements, they are given by the following (Equation 313).

number

[0186] If the array response vector V is known, then the array response value AR at the receiving point 200P can be controlled by providing an appropriate weight vector W. When determining the weight vector W, it is necessary to ensure that the square of the norm of the weight vector W is 1 (||W|| 2 = 1).

[0187] In the retrodirective system 1, an array response vector V d and use this to find the optimal weight vector W opt If we ignore the time variation of the propagation channel, the array response vector V d can be regarded as the array response vector during transmission from the power transmitting device 10 to the power receiving device 20. However, the pilot signal during reception has the same frequency as the radio wave during power transmission. ||W|| 2Magnitude of the array response value |W under the condition of = 1 H V d Optimal weight vector W that maximizes | opt can be the following (Equation 314).

Equation

[0188] As described above, the optimal weight vector W for retro - directive transmission opt only needs the array response vector V of the received pilot signal d and information such as the direction of the receiving point 200P is unnecessary.

[0189] Next, the simultaneous realization of the retro - directive method and multiple (for example, M) null formations will be described.

[0190] A null means that the gain such as direction or point becomes zero in the directivity of the array antenna 11. To form a null with the array antenna 11, for the array response vector V i (i = 1, ···, M), the magnitude of the array response value |W H V i | should be set to zero. Under this condition, maximize the magnitude of the array response value |W d of the array response vector V H V d |. This can be formulated as an optimization problem shown in the following (Equation 315). In the present disclosure, this is referred to as a retro - directive method with linear constraints. Here, K is the number of antenna elements 11A. M is the number of nulls. Since the degree of freedom is K - 1, M < K. argmax (argument of the maximum) means the set of values that achieve the maximum value. (Equation 315) is an equation for obtaining the optimal weight vector W for which |W H V d | becomes maximum opt .

Equation

[0191] The optimization problem of (Equation 315) has a closed-form solution. Defining (Equation 316), the optimal weight vector W opt is given by (Equation 317).

Number

Number

[0192] Here, A is the matrix shown in (Equation 318) formed by arranging the array response vectors V1, V2, ···, V M which are M complex column vectors.

Number

[0193] A + is the Moore-Penrose generalized inverse of A. The Moore-Penrose generalized inverse A + satisfies AA + A = A, A + AA + = A + , (AA + ) H = AA + , (A + A) H = A + When the array response vectors V1, V2, ···, V which are complex column vectors are linearly independent, A M = (A + A) H A -1 A H holds.

[0194] The array response values corresponding to the null must satisfy W H V i = 0 (i = 1, ·····, M < K). Therefore, considering these as a system of homogeneous linear equations, the array response vectors V1, V2, ···, V which are M complex column vectorsM Using the matrix A arranged in H It is expressed as a product of a matrix and a vector, such that W=0. The general solution is the general Moore-Penrose inverse matrix A + Using this, W=(I-AA + ) H z=(I-AA + )z, where z is an arbitrary complex vector. The magnitude of the array response we wish to maximize is |W H V d |W=(I-AA + ) H z=(I-AA + )z, |W H V d |=|z H (I-AA + )V d |And by the Cauchy-Schwarz inequality, |W H V d |=|z H (I-AA + )V d |≦||z||·||(I-AA + )V d || holds true. |W H V d | is maximized when the inequality is equal, and then z=α(I-AA + )V d where α is an arbitrary complex constant.

[0195] The optimal weight vector W opt is the above-mentioned W=(I-AA + ) H z=(I-AA + )z, z=α(I-AA + )V d By substituting, W opt =α(I-AA + )V d Here, V' is given as in (Eq. 316). d =(I-AA + )V d Then, ||W opt || 2 = |α| 2 ||V' d ||2 = 1, α = 1 / ||V' d Therefore, the optimal weight vector W opt can be expressed as (Equation 317) above.

[0196] Next, an example of a method for calculating an array response vector corresponding to a null will be described. The array response vector between the power transmitting device 10 and the power receiving device 20 is estimated from the specified signal 1000. However, if it is assumed that the specified signal 1000 is not transmitted from the target to which the null is to be directed, it is necessary to calculate the array response vector by another method. In the present disclosure, the purpose is to set the path directly from the power transmitting device 10 to the target to which the null is to be directed as the null target, and the array response vector is calculated from the direction of the object 5000, which is the null target, acquired using the sensor unit 15.

[0197] As shown in Fig. 29, in a linear array in which K antenna elements 11A are arranged at equal intervals, the array response vector in the far field radiated in a direction rotated clockwise by θ (-π / 2<θ<π / 2) from the broadside is given by the following (Equation 319). The broadside is a direction perpendicular to the direction in which the antenna elements 11A are arranged, and is the upward direction in Fig. 29. The inter-element distance from antenna element 11A #0 to antenna element 11A #k of reference point 200B is kd. The inter-element distance from antenna element 11A #0 to antenna element 11A #K-1 is (K-1)d.

number

[0198] Here, the impulse response Z is given by the following (Equation 320).

number

number

number

[0199] The weight generating unit 17 calculates the direction θ of the null object. i Array response vector V corresponding to null from i is derived using (Eq. 321) and (Eq. 322), and then the matrix (I-AA + The weight generating unit 17 calculates the calculated matrix (I-AA + ) and the array response vector V corresponding to the power receiving device 20 d From this, the magnitude of the array response value |W H V d The optimal weight vector W that maximizes | opt Determine.

[0200] The storage unit 17D may include any non-transient storage medium such as a semiconductor storage medium and a magnetic storage medium. The storage unit 17D may include a combination of a storage medium such as a memory card, an optical disk, or a magneto-optical disk, and a storage medium reader. The storage unit 17D may include a storage device used as a temporary storage area such as a RAM. The storage unit 17D may be provided outside the weight generation unit 17.

[0201] Next, an example of widening the null will be described. The object 5000 that is the null target has an expanse, and it is desirable to widen the null in accordance with the area of ​​the object 5000. A number of methods can be used to widen the null. For example, the multiple null constraints method, the derivative constraints method, etc. can be used to widen the null.

[0202] The multi-point null constraint method is a method for widening the null angle by forming nulls in multiple directions in the vicinity of the null target, rather than in one direction, according to the size of the null target. For example, the array response vector V i is the orientation of the null object, θ i It is calculated using (Equation 321) and (Equation 322) from the above, but a wide angle is achieved by giving multiple directions near the null as the directions of the null target according to the size of the null target.

[0203] The differential coefficient constraint method is a method for smoothing the differential coefficients by using the continuity of the array response value in the θ direction. The differential coefficient constraint method will be described in detail below.

[0204] The array response value of an equally spaced linear array of K antenna elements 11A in the θ direction for an array response vector V(θ) is a function of θ, and is represented as D(θ). By substituting (Equation 319) and (Equation 320) into (Equation 311) and (Equation 312) above, D(θ) is given by the following (Equation 323).

number

[0205] D(θ) is called the array response function or array factor. D(θ) is a continuous function of θ and can be differentiated with respect to θ. The absolute value |D(θ)| shown in a graph represents the directional pattern of the array antenna.

[0206] In (Eq. 323), θ = θ i (i=1, ,M) is substituted into D(θ i ) is θ i is the array response value in the direction. Also, since (Eq. 323) is differentiable, θ = θ i θ=θ i +Δθ array response value D(θ i +Δθ) is L i Using the next approximation formula, this can be expressed as (Equation 324) below.

number

[0207] In (Equation 324), the derivative D (l) (θ i )(l=1,...,L i ) is zero, then D(θ i +Δθ) ≒ D(θ i ) and θ i Neighborhood θ i +Δθ can make the array response values ​​similar. This is called null (D(θ i )=0) is the broadening of the null by the derivative constraint, and the order of the approximation formula is L i In this disclosure, the degree of widening can be controlled by L i is referred to as the wide angle. In this disclosure, the derivative D (l) (θ i The (l) on the right side of the square indicates the order of differentiation.

[0208] The null direction is θ i (i=1, ,M), the order of the approximation is L i Then, the differential coefficient constraint condition is expressed as follows (Equation 325). However, (Equation 325) is for l=1, ,L i In addition, V i (l) The (l) on the right hand side is not the order of differentiation, but merely an index. D (l) (θ i )=W H V (l) (θ i )=0...(Formula 325)

[0209] (Equation 325) is equivalent to the following (Equation 326). However, (Equation 326) is for l=1, ,L i Here, Q l is a diagonal matrix and is given by the following (Equation 327). Note that the conversion of the differential coefficient constraint condition will be described later. W H (Q l V i )=W H (Q l V(θi ))=0 ···(Formula 326) Q l =diag[0 l 1 l (K-1) l ]...(Formula 327)

[0210] Therefore, the array response vector V i As V i (l) =Q l V i By adding the following, the null can be made wider by the differential coefficient constraint. Here, l=1, ,L i It is. i (l) is not actually an array response vector, but V in (Eq. 315) in this case. i It is inappropriate to call V in (Eq. 315) an array response vector. Therefore, in the following, we will use V in (Eq. 315) as a vector that gives the constraint condition. i is sometimes called the constraint vector.

[0211] As described above, in order to widen the angle of the null, the number of constraint vectors must be increased. This makes the constraints on the weight vector W stricter, and the array response value |W H V d | may become smaller. On the other hand, when the distance between the power transmitting device 10 and the object 5000 is large, it is not necessary to form a deep null, and it is expected that the power supply to the power receiving device 20 can be improved by controlling the null depth. An example of a method for controlling the null depth will be described below.

[0212] The optimization problem in which some of the constraints of the above-mentioned (Equation 315) are changed can be formulated as the following conditional equation (Equation 328). In detail, (Equation 328) is the W H V i = 0, |W H V i | 2 =|ε i | 2 has been changed to.

number

[0213] Here, K is the number of antenna elements 11A, and M is the number of nulls. The number M of nulls corresponds to the area of ​​the object 5000 detected by the detection unit 16.

[0214] The optimal weight vector W in (Eq. 328) opt is given by the following (Equation 329) using the above (Equation 316).

number

[0215] Here, V' d =(I-AA + )V d , V ε =(A + ) H ε. A is a set of M complex sequence constraint vectors V1, V2, . . . , V M A is a matrix of + is the generalized Moore-Penrose inverse of A. Also, ε=[ε1ε2 ε M ] T and ε i Absolute value of |ε i | is given by (Equation 328). In this disclosure, (·) T When a letter has a superscript "T" like this, it means transposition. i The argument of the vector (A + V d ) to obtain the array response value |W H V d | can be maximized. Note that α in (Equation 329) is given by the following (Equation 330).

number

[0216] The weight vector W and the constraint vector V are calculated by (Eq. 329) and (Eq. 330). i The magnitude of the dot product of |WH V i | to |ε i |, but compared to the above (Eq. 316) and (Eq. 317), V ε This becomes more complicated because it requires the calculation of α.

[0217] The above-mentioned (Equation 328) can be simplified by making it into an approximate solution. An example of how to find the approximate solution will be described below.

[0218] The square of the norm of the weight vector W is 1 (||W||=1), and ||V d Since || is known, |W H V d Maximizing | is |W H V d | / (||W||·||V d This is equivalent to making W / ||W||≒V d / ||V d That is, W ≒ γV d γ is a proportionality constant. H V i | 2 =|ε i | 2 W H V i ≒ 0. As a result, the optimization problem of (Equation 328) can be approximately thought of as the following conditional equation (Equation 331). In (Equation 331), ≒ means that the value on the left side and the value on the right side should be as close as possible.

number

[0219] The optimal weight vector W in (Eq. 331) opt When the following (Equation 332) is defined, it is given by the following (Equation 333). Note that the null depth control using an approximate solution will be described later.

number

number

[0220] where A' is a set of M complex column vectors α1V1,α2V2,...,α M V M The matrix A'=[α1V1α2V2··· α M V M α i (i=1, ,M) is V i The weighting coefficient for the absolute value |ε i α instead of | i By using the above, the null depth can be controlled. In this way, the algorithm for controlling the null depth may be obtained from an exact solution or may use an approximate solution. In addition, the algorithm for controlling the null depth can be used to widen the null angle whether it is obtained from an exact solution or using an approximate solution.

[0221] The weight generating unit 17 generates a transmission weight so that the null is directed to the area of ​​the object 5000, based on the propagation channel characteristics of the prescribed signal 1000 and the results of calculations performed in the preprocessing unit 19 based on directional information that can identify the direction, area, and distance of the object 5000 detected by the detection unit 16. When directing the null to the area, the constraint vector V i is V i (l) (l=0,...,L i )

[0222] 30 is a diagram showing an example of vectorization in the multi-point null constraint method. When the multi-point null constraint method is used, the pre-processing unit 19 calculates a direction θ i and the region δ i Using (Eq. 321) and (Eq. 322), the array response vector V i (l) (l=0,...,L i In detail, the preprocessing unit 19 calculates the direction θ i and the region δ i to the minimum value θ in that direction min i and the maximum value θ max iThe weight generating unit 17 determines θ min From θ max Covering direction θ (0) i , ,θ (Li) i The step size is determined by the direction θ i It may be constant regardless of the direction θ of the object 5000. i The pre-processing unit 19 may change the direction θ (0) i , ,θ (Li) i Using (Eq. 321) and (Eq. 322), the constraint vector V i (l) (l=0,...,L i In this disclosure, the order of the approximation formula L i is called the wide angle as a measure of the degree of widening, but the above L i Also sometimes called wide angle.

[0223] 31 is a diagram showing an example of vectorization in the differential coefficient constraint method. When the differential coefficient constraint method is used, the pre-processing unit 19 calculates a vector in a direction θ i and the region δ i Using (Eq. 321) and (Eq. 322), etc., we obtain the array response vector V i (l) (l=0,...,L i In detail, the pre-processing unit 19 calculates the direction θ i and the area δ of object 500 i From wide angle L i Find the wide angle L i is the area δ i Not only the direction θ i Therefore, the preprocessing unit 19 determines the wide angle L i By using tables and machine learning to derive the wide-angle L i Request.

[0224] In the example shown in FIG. 31, the pre-processing unit 19 detects a direction θ i and the region δ iThe information shown in Table 170 is applied to the wide-angle L i Find the area δ i For example, the table 170 includes information on the area, distance, etc. of the object 5000. i and the region δ i From wide angle L i The preprocessing unit 19 calculates the wide angle L i and the array response vector V i Therefore, by vectorizing using the above (Equation 325), (Equation 326), and (Equation 327), the constraint vector V i (l) (l=0,...,L i ) where V i (0) =V i Let us assume that.

[0225] FIG. 32 is a diagram showing an example of processing of the null depth by the pre-processing unit 19. The example shown in FIG. 32 shows a processing example in which the pre-processing unit 19 uses the above-mentioned (Equation 328). As shown in FIG. 32, the pre-processing unit 19 can perform processing regarding the magnitude of the null depth. In the case of the above-mentioned (Equation 328), the distance d i The pre-processing unit 19 estimates the attenuation of the intensity of the radio wave of 2000 W based on the results of the previous measurement. i and absolute value |ε i Using the table of |, the absolute value |ε i Calculate the absolute value of |ε i For example, taking into account the directivity of the antenna element itself, the direction θ of the object 5000 i It may be changed every time.

[0226] In the case of the multi-point null constraint method shown in 19A of FIG. 32, the preprocessing unit 19 calculates the distances d1, d2, . . . , d M and wide angles L1, L2, . . ., L MFor example, a process is performed to obtain a vector P1 that indicates the magnitude of the null depth for the same null object with the same value by using the vectors [|ε1|,|ε1|,...,|ε1|,|ε2|,|ε2|,...,|ε2|,....|ε M |,|ε M |,...,|ε M |] T It is.

[0227] In the case of the differential coefficient constraint method shown in 19B of FIG. 32, the preprocessing unit 19 calculates the distances d1, d2, . . . , d M and wide angles L1, L2, . . ., L M Using V i (0) The magnitude of the null depth corresponding to |ε i | and V i (l) (l=1,...,L i ), the magnitude of the null depth corresponding to the vector P2 is set to zero, and a process is performed to obtain a vector P2 indicating the magnitude of the null depth. For example, the vector P2 is [|ε1|,0,···,0,|ε2|,0,···,0,···.|ε M |,0,···,0] T It is.

[0228] When the power transmission device 10 uses the above-mentioned (Equation 328), the preprocessing unit 19 calculates the obtained constraint vector V i (l) Using (I-AA + ), A + The above matrix operations are performed to calculate vectors P1 and P2 indicating the magnitude of the null depth, and the operation results are stored in the storage unit 17D and supplied to the weight generation unit 17.

[0229] FIG. 33 is a diagram showing another example of processing of the null depth by the pre-processing unit 19. The example shown in FIG. 33 shows a processing example in which the pre-processing unit 19 uses the above-mentioned (Equation 331). As shown in FIG. 33, the pre-processing unit 19 can process the magnitude of the null depth. In the case of the above-mentioned (Equation 331), the pre-processing unit 19 calculates the distance d i and weighting factor α iUsing the table, the weighting coefficient α i The weighting coefficient α i For example, taking into account the directivity of the antenna element itself, the direction θ of the object 5000 i It may be changed every time.

[0230] In the case of the multi-point null constraint method shown in 19C of FIG. 33, the preprocessing unit 19 calculates the distances d1, d2, . . . , d M and wide angles L1, L2, . . ., L M A process is performed to obtain a vector P3 that indicates the magnitude of the null depth with the same value for the same null object using the vector P3. For example, the vector P3 is expressed as [α1,α1,···,α1,α2,α2,···,α2,···.α M ,α M ,...,α M ] T It is.

[0231] In the case of the derivative constraint method shown in 19D of FIG. 33, the preprocessing unit 19 calculates the distances d1, d2, . . . , d M and wide angles L1, L2, . . ., L M Using V i (0) The size of the null depth corresponding to i And V i (l) (l=1,...,L i ), the magnitude of the null depth corresponding to the vector P4 is set to a fixed value (α0>>1), and a process is performed to obtain a vector P4 indicating the magnitude of the null depth. M ,α0,···,α0] T It is.

[0232] When the power transmission device 10 uses the above-mentioned (Equation 331), the preprocessing unit 19 calculates the obtained constraint vector V i (l) Using vectors P3 and P4, which indicate the magnitude of the null depth, (I-A'(I+A' H A') -1 A' H ) and stores the calculation results in storage unit 17D and supplies them to weight generating unit 17.

[0233] The weight generating unit 17 generates an array response vector V d Using the information stored in the storage unit 17D, the optimal weight vector W opt is calculated using the above-mentioned (Equation 329) or (Equation 333).

[0234] The weight generating unit 17 can store weight information capable of identifying a weight vector suitable for the generated direction, area, and distance in the storage unit 17D. i can be set for each null target. The power transmitting device 10 can calculate a matrix or vector calculated from the direction, area, and distance to which the null is directed, and the propagation channel characteristics of the prescribed signal 1000, independently.

[0235] 27, the multiplier 18 multiplies the transmission signal 2000 from the transmission signal generator 12 by a weight for each of the antenna elements 11A based on the weight information from the weight generator 17. The multiplier 18 has, for example, a multiplier. The multiplier 18 supplies the transmission signal 2000 multiplied by the weight corresponding to the antenna element 11A to the transmission / reception circuit 13A of the antenna element 11A.

[0236] An example of the functional configuration of the power transmitting device 10 according to the present embodiment has been described above. Note that the above configuration described with reference to Fig. 27 is merely an example, and the functional configuration of the power transmitting device 10 according to the present embodiment is not limited to this example. The functional configuration of the power transmitting device 10 according to the present embodiment can be flexibly modified according to the specifications and operation.

[0237] [Power receiving device according to embodiment 3] FIG. 34 is a diagram showing an example of the configuration of the power receiving device 20 according to the third embodiment. As shown in FIG. 34, the power receiving device 20 includes an antenna 21, a transmitting / receiving unit 22, a signal generating unit 23, and a power receiving unit 24. The power receiving device 20 of the present disclosure may be a mobile device. For example, such a power receiving device 20 may be a mobile battery, a smartphone, a camera, a vibration sensor, a biosensor, a temperature sensor, an alarm, or other device mounted on a moving object such as a drone or a car, an autonomous vehicle, a vibration sensor, a biosensor, a temperature sensor, an alarm, or the like whose installation position is variable. In the present disclosure, since the power receiving device 20 is a mobile device, the characteristics of the propagation channel based on the prescribed signal may change depending on the position of the power receiving device 20.

[0238] The antenna 21 is electrically connected to the transmitting / receiving unit 22. The antenna 21 is a power receiving antenna capable of receiving radio waves 2000W from the power transmitting device 10. For example, a patch antenna, a dipole antenna, a parabolic antenna, or the like can be used as the antenna 21. For example, the antenna 21 emits radio waves including a specified signal 1000, and receives radio waves 2000W including a transmission signal 2000 from the power transmitting device 10. The antenna 21 supplies a reception signal of the received radio waves 2000W to the transmitting / receiving unit 22.

[0239] The transmitting / receiving unit 22 is electrically connected to the signal generating unit 23 and the power receiving unit 24. The transmitting / receiving unit 22 causes the antenna 21 to radiate radio waves including the specified signal 1000 from the signal generating unit 23. The transmitting / receiving unit 22 supplies the power receiving unit 24 with a reception signal of the radio waves received by the antenna 21.

[0240] The signal generating unit 23 generates a specified signal 1000. The signal generating unit 23 causes the antenna 21 to emit radio waves including the specified signal 1000 via the transmitting / receiving unit 22. The signal generating unit 23 can generate the specified signal 1000 based on a transmission period. The signal generating unit 23 may be configured to generate a signal different from the specified signal 1000.

[0241] The power receiving unit 24 converts the radio waves of 2000 W received by the antenna 21 into a direct current and receives power using this direct current. The power receiving unit 24 converts the radio waves into a direct current using, for example, a known rectifier circuit. The power receiving unit 24 supplies the received power to, for example, a battery or load compatible with Qi (an international standard for wireless power supply). The load includes, for example, mechanical equipment, an IoT (Internet of Things) sensor, electronic equipment, lighting equipment, and the like.

[0242] An example of the functional configuration of the power receiving device 20 according to the present embodiment has been described above. Note that the above configuration described with reference to Fig. 34 is merely an example, and the functional configuration of the power receiving device 20 according to the present embodiment is not limited to this example. The functional configuration of the power receiving device 20 according to the present embodiment can be flexibly modified according to the specifications and operation.

[0243] [Example of Processing Procedure of Power Transmission Device According to Third Embodiment] Fig. 35 is a diagram for explaining an example of a processing procedure of the power transmission device 10 of the system 1 shown in Fig. 1. Fig. 36 is a diagram for explaining an example of a data flow of the power transmission device 10 shown in Fig. 35. Fig. 36 shows a case where the power transmission device 10 uses the above-mentioned (Equation 328).

[0244] 35, in the system 1, the power receiving device 20 emits radio waves including a prescribed signal 1000. When the power transmitting device 10 receives the radio waves including the prescribed signal 1000 at the array antenna 11, the power transmitting device 10 outputs an array response vector V d For example, as shown in FIG. 36, the power transmitting device 10 estimates the propagation channel characteristics of a reference signal 1000 included in the received signals received by the multiple antenna elements 11A in the estimation unit 14, and estimates an array response vector V d Returning to Fig. 35, when the process of step S111 ends, the power transmitting device 10 advances the process to step S131.

[0245] In addition, the power transmitting device 10 detects the direction, area, and distance of the object 5000 different from the power receiving device 20 in the radio wave propagation environment based on the sensor information from the sensor unit 15 by using the detection unit 16 (step S121). For example, as shown in FIG. 36, when the detection unit 16 detects M objects 5000 as null targets, the power transmitting device 10 detects the directions θ1, θ2, . . . , θ of the multiple objects 5000. M The power transmitting device 10 detects the regions δ1, δ2, . . . , δ of the multiple objects 5000. M The power transmitting device 10 detects distances d1, d2, . . . , d M The power transmitting device 10 detects the directions θ1, θ2, . . . , θ M , the regions δ1, δ2, , δ M and distances d1, d2, . . . , d M to the preprocessing unit 19. Returning to FIG. 35, when the process of step S121 ends, the power transmitting device 10 advances the process to step S122.

[0246] The power transmitting device 10 executes pre-processing (step S122). For example, when the differential coefficient constraint method is used, as shown in FIG. 36, the power transmitting device 10 performs vectorization in the pre-processing unit 19 (step S191). For example, the power transmitting device 10 performs vectorization in a direction θ i and the region δ i The information shown in Table 170 is applied to the wide-angle L i Search for wide angle L i and the array response vector V i By vectorizing from and, the constraint vector V corresponding to the null is obtained. i (l) (l=0,...,L i ) is required.

[0247] In the power transmitting device 10, the pre-processing unit 19 performs a matrix operation (step S192). i (l) Using (I-AA + ), A + The matrix calculation is performed and the calculation result is stored in the storage unit 17D. (0)1,...,V (L1) 1,V (0) 2,...,V (L2) 2,...,V (0) M ,···,V (LM) M ].

[0248] In the power transmitting device 10, the pre-processing unit 19 calculates the magnitude of the null depth (step S193). i and the wide angle L calculated in step S191. i Based on this, the portion corresponding to the differential coefficient constraint is set to zero, and a vector P2 indicating the magnitude of the null depth is obtained and stored in the storage unit 17D. Returning to FIG. 35, when the process of step S122 is completed, the power transmitting device 10 advances the process to step S131.

[0249] The power transmitting device 10 generates a transmission weight (step S131). For example, as shown in FIG. 36, the weight generating unit 17 of the power transmitting device 10 multiplies a matrix and a vector (step S171). In detail, the weight generating unit 17 of the power transmitting device 10 multiplies a calculation result (I-AA + ) and the array response vector V d For example, the power transmitting device 10 accumulates (I-AA + ) and the array response vector V d Add up the vector V d ' is required.

[0250] In the power transmitting device 10, the weight generating unit 17 multiplies a matrix by a vector (step S172). + ) and the array response vector V d For example, the power transmitting device 10 accumulates the (A + ) and the array response vector V d Multiplying the vector (A + V dIn the power transmitting device 10, the weight generating unit 17 generates the vector ε (step S173). For example, the power transmitting device 10 calculates the vector P2 indicating the magnitude of the null depth in the storage unit 17D and the vector (A + V d ) and generate a vector ε.

[0251] In the power transmission device 10, the weight generation unit 17 calculates the vector V ε For example, the power transmitting device 10 generates (A + ) and the vector ε in step S173, the vector V ε In the power transmitting device 10, the weight generating unit 17 performs coefficient calculation (step S175). For example, the power transmitting device 10 generates the vector V d ' and vector V in step S174 ε The coefficient α is calculated based on the above.

[0252] In the power transmission device 10, the weight generation unit 17 generates a weight vector W opt For example, the power transmitting device 10 generates V d ' and V in step S174 ε Based on the α in step S175, the optimal weight vector W is calculated using (Equation 328). opt = αV d '+V ε Returning to Fig. 35, when the process of step S131 ends, the power transmitting device 10 advances the process to step S132.

[0253] The power transmitting device 10 multiplies the transmission weight (step S132). For example, the power transmitting device 10 multiplies the transmission weight by the optimal weight vector W optBased on the weight information indicating the weight, the power transmission signal 2000 for power supply from the transmission signal generating unit 12 is multiplied by the weight for each of the plurality of antenna elements 11A and supplied to the transmission / reception circuit 13A. In this way, the power transmission device 10 causes the plurality of antenna elements 11A to radiate radio waves 2000W including the power supply transmission signal 2000. In this case, the power transmission device 10 calculates the distance d i Since a null is directed toward the area of ​​the object 5000 taking into consideration the attenuation of the intensity of the radio waves 2000 W, the radio waves 2000 W are combined constructively in the power receiving device 20 but are combined destructively in the object 5000.

[0254] The power receiving device 20 converts the received radio waves for power supply (2000 W) into a direct current, and uses the direct current to charge a battery or to operate using the charged power. After that, the power receiving device 20 transmits a prescribed signal 1000.

[0255] When the power transmitting device 10 receives radio waves including the prescribed signal 1000 at the array antenna 11, the power transmitting device 10 repeats the above-mentioned processing procedure to obtain the weight vector W opt and radiates radio waves 2000W of the transmission signal 2000 from the array antenna 11. In this way, even if the power receiving device 20 or the object 5000 moves, the power transmitting device 10 can maintain the state in which the radio waves 2000W are combined constructively at the power receiving device 20 and combined destructively at the object 5000.

[0256] [Another example of the processing procedure of the power transmitting device according to the third embodiment] Fig. 37 is a diagram for explaining another example of the data flow of the power transmitting device 10 shown in Fig. 35. Fig. 37 shows a case where the power transmitting device 10 uses the above-mentioned (Equation 331). Note that the power transmitting device 10 executes the same processing procedure as the processing procedure shown in Fig. 35.

[0257] 35, in the system 1, the power receiving device 20 emits radio waves including a prescribed signal 1000. When the power transmitting device 10 receives the radio waves including the prescribed signal 1000 at the array antenna 11, the power transmitting device 10 outputs an array response vector V d For example, as shown in FIG. 37, the power transmitting device 10 estimates the propagation channel characteristics of the reference signal 1000 included in the received signals received by the multiple antenna elements 11A in the estimation unit 14, and estimates the array response vector V d Returning to Fig. 35, when the process of step S111 ends, the power transmitting device 10 advances the process to step S131.

[0258] In addition, the power transmitting device 10 detects the direction, area, and distance of the object 5000 different from the power receiving device 20 in the radio wave propagation environment based on the sensor information from the sensor unit 15 by using the detection unit 16 (step S121). For example, as shown in FIG. 37, when the detection unit 16 detects M objects 5000 as null targets, the power transmitting device 10 detects the directions θ1, θ2, . . . , θ of the multiple objects 5000. M The power transmitting device 10 detects the regions δ1, δ2, . . . , δ of the multiple objects 5000. M The power transmitting device 10 detects distances d1, d2, . . . , d M The power transmitting device 10 detects the directions θ1, θ2, . . . , θ M , the regions δ1, δ2, , δ M and distances d1, d2, . . . , d M to the preprocessing unit 19. Returning to FIG. 35, when the process of step S121 ends, the power transmitting device 10 advances the process to step S122.

[0259] The power transmitting device 10 executes pre-processing (step S122). For example, when the differential coefficient constraint method is used, as shown in FIG. 37, the power transmitting device 10 performs vectorization in the pre-processing unit 19 (step S194). For example, the power transmitting device 10 performs vectorization in a direction θ i and the region δ i The information shown in Table 170 is applied to the wide-angle L i Search for wide angle Li and the array response vector V i By vectorizing from and, the constraint vector V corresponding to the null is obtained. i (l) (l=0,...,L i ) is required.

[0260] In the power transmitting device 10, the pre-processing unit 19 calculates the magnitude of the null depth (step S195). i and the wide angle L calculated in step S194. i Based on the above, a vector P4 indicating the magnitude of the null depth as a fixed value for the differential coefficient constraint is obtained.

[0261] In the power transmitting device 10, the pre-processing unit 19 performs a matrix operation (step S196). i (l) Using vector P4 from step S195, (I-A'(I+A' H A') -1 A' H ) matrix operation, and the operation result is stored in the storage unit 17D. (0) 1α0V (1) 1···α0V (L1) 1α2V (0) 1α0V (1) 2...α0V (L2) 2 α M V (0) M α0V (1) M α0V (LM) M 35, when the process of step S122 ends, the power transmitting device 10 advances the process to step S131.

[0262] The power transmitting device 10 generates a transmission weight (step S131). For example, as shown in FIG. 37, the weight generating unit 17 of the power transmitting device 10 multiplies a matrix and a vector (step S177). In detail, the weight generating unit 17 of the power transmitting device 10 multiplies a calculation result (I-A'(I+A' H A') -1A' H ) and the array response vector V d For example, the power transmitting device 10 accumulates (I-A'(I+A' H A') -1 A' H ) and the array response vector V d The array response vector V d ''=(I-A'(I+A' H A') -1 A' H )V d Request.

[0263] The power transmitting device 10 calculates the array response vector V d For example, the power transmitting device 10 normalizes the optimal weight vector W′′ using (Equation 333). opt Returning to Fig. 35, when the process of step S131 ends, the power transmitting device 10 advances the process to step S132.

[0264] The power transmitting device 10 multiplies the transmission weight (step S132). For example, the power transmitting device 10 multiplies the transmission weight by the optimal weight vector W opt Based on the weight information indicating the weight, the power transmission signal 2000 for power supply from the transmission signal generating unit 12 is multiplied by the weight for each of the plurality of antenna elements 11A and supplied to the transmission / reception circuit 13A. In this way, the power transmission device 10 causes the plurality of antenna elements 11A to radiate radio waves 2000W including the power supply transmission signal 2000. In this case, the power transmission device 10 calculates the distance d i Since a null is directed toward the area of ​​the object 5000 taking into consideration the attenuation of the intensity of the radio waves 2000 W, the radio waves 2000 W are combined constructively in the power receiving device 20 but are combined destructively in the object 5000.

[0265] The power receiving device 20 converts the received radio waves for power supply (2000 W) into a direct current, and uses the direct current to charge a battery or to operate using the charged power. After that, the power receiving device 20 transmits a prescribed signal 1000.

[0266] When the power transmitting device 10 receives radio waves including the prescribed signal 1000 at the array antenna 11, the power transmitting device 10 repeats the above-mentioned processing procedure to obtain the weight vector W opt and radiates radio waves 2000W of the transmission signal 2000 from the array antenna 11. In this way, even if the power receiving device 20 or the object 5000 moves, the power transmitting device 10 can maintain the state in which the radio waves 2000W are combined constructively at the power receiving device 20 and combined destructively at the object 5000.

[0267] The processing procedure of the power transmitting device 10 shown in FIG. 35 is to calculate the array response vector V d The estimation of the constraint vector V (step S111) and the pre-processing according to the direction, area, and distance of the object 5000 (step S122) do not need to be synchronized. Therefore, for example, the period in which the prescribed signal 1000 is received and the period in which the detection unit 16 provides information may be different. Also, for example, when there is no change in the direction, area, and distance of the object 5000, the power transmitting device 10 estimates the constraint vector V i (l) , the past constraint vector V under similar environment i (l) etc. may also be used.

[0268] Fig. 38 is a diagram for explaining an example of the operation of the power transmitting device 10 according to the embodiment 3. Fig. 39 is a diagram showing an example of a result of calculating, by computer simulation, the directivity pattern of radio waves 2000W of the power transmitting device 10 according to the embodiment 3. Fig. 40 is a diagram showing another example of a result of calculating, by computer simulation, the directivity pattern of radio waves 2000W of the power transmitting device 10 according to the embodiment 3.

[0269] 38, in the system 1, when an object 5000 is present in the vicinity between the power transmitting device 10 and the power receiving device 20, the power transmitting device 10 can detect the direction of the object 5000 based on the sensor information of the sensor unit 15. The radio wave including the specified signal 1000 radiated by the power receiving device 20 has a path that goes directly to the power transmitting device 10 and a path that goes back to the power transmitting device 10 after being reflected by the object 5000. The power transmitting device 10 estimates the propagation channel characteristics of the radio wave including the specified signal 1000 received by the array antenna 11, and calculates the array response vector V d is estimated, but the array response vector V d includes characteristics of a path directly to the power receiving device 20 and a path toward the object 5000.

[0270] The power transmitting device 10 detects the direction, area, and distance of an object 5000 different from the power receiving device 20 in the radio wave propagation environment based on sensor information from the sensor unit 15, and calculates directions θ1, θ2, . . . , θ M , the regions δ1, δ2, , δ M and distances d1, d2, . . . , d M The power transmitting device 10 detects the direction of the object 5000, i.e., the array response vector V corresponding to the null target. i and calculates the constraint vector V based on the area and distance of the object 5000. i (l) Calculate the constraint vector V i (l) and the array response vector V d The optimal weight vector W that reduces the radio wave intensity in the direction of the object 5000 is opt The power transmitting device 10 generates an optimal weight vector W opt The radio wave 2000 W of the transmission signal 2000 multiplied by is radiated from the multiple antenna elements 11 A of the array antenna 11 .

[0271] As a result, even if the power transmitting device 10 receives the specified signal 1000 from the direction of the object 5000, the radiated radio waves 2000W can be made to reinforce each other at the power receiving device 20, and the radiation of the radio waves 2000W toward the object 5000 can be suppressed by forming a null with a wide angle and a controlled null depth according to the area and distance of the object 5000. As a result, even in an environment where the specified signal 1000 from the power receiving device 20 is reflected by a human body or the like and reaches the object 5000, the power transmitting device 10 can suppress the radio waves 2000W toward the human body or the like, thereby realizing safe wireless power transmission.

[0272] Even if a plurality of objects 5000 are present in the propagation environment, the power transmitting device 10 detects the directions, regions, and distances of the plurality of objects 5000, and calculates a weight vector W so as to direct a null to each of the plurality of objects 5000. opt can be generated.

[0273] The graph shown in FIG. 39 shows an example of a directivity pattern of radio waves 2000W emitted from the power transmitting device 10 according to the third embodiment when a multipoint null constraint method is used for the power transmitting device 10 according to the third embodiment in the case where two objects 5000 exist. In the graph shown in FIG. 39, the vertical axis shows the power (square of absolute value) [dB] of the array response value, and the horizontal axis shows the radiation direction [°] of the radio waves 2000W. In the example shown in FIG. 39, the power transmitting device 10 has eight antenna elements 11A, the spacing between adjacent antenna elements 11A is λ / 2, and the antenna arrangement is an equidistant linear array. λ represents the wavelength. The power transmitting device 10 estimates that the direction of 30° is the radiation direction of the radio waves 2000W to the power receiving device 20, and detects that −10° and −45° in the radiation direction are the directions of the two objects 5000. The power transmitting device 10 calculates the null depth in the direction of -10° to be 0.001 and the null depth in the direction of -45° to be 0.01. The power transmitting device 10 calculates the array response vector V d Based on the array response vector V1 corresponding to the null in the -10° direction and the array response vector V2 corresponding to the null in the -45° direction, a weight vector W opt The power transmitting device 10 generates an optimal weight vector W optThe radio wave 2000 W of the transmission signal 2000 multiplied by is radiated from the multiple antenna elements 11 A of the array antenna 11 .

[0274] 39, the power transmitting device 10 has a high array response value near the radiation direction of 30°, a low array response value near the direction D1 of -10° and the direction D2 of -45°, and a null depth of -60 dB in the direction D1 and -40 dB in the direction D2. As a result, even if the power transmitting device 10 receives a specified signal 1000 from the directions of multiple objects 5000, it can direct the radiated radio waves 2000 W in the direction of the power receiving device 20 and can suppress the radiation of the radio waves 2000 W toward the multiple objects 5000.

[0275] The graph shown in FIG. 40 shows an example of a directivity pattern of radio waves 2000W emitted from the power transmitting device 10 when the differential coefficient constraint method is used for the power transmitting device 10 according to the third embodiment in the case where two objects 5000 exist. In the graph shown in FIG. 40, the vertical axis shows the power (square of the absolute value) [dB] of the array response value, and the horizontal axis shows the radiation direction [°] of the radio waves 2000W. The graph shown in FIG. 40 is under the same measurement conditions as those shown in FIG. 39. The power transmitting device 10 estimates that the direction of 30° is the radiation direction of the radio waves 2000W to the power receiving device 20, and detects that −10° and −45° in the radiation direction are the directions of the two objects 5000. The power transmitting device 10 calculates the null depth in the −10° direction to be 0.001, and the null depth in the −45° direction to be 0.01. The power transmitting device 10 detects an array response vector V d Based on the array response vector V1 corresponding to the null in the -10° direction and the array response vector V2 corresponding to the null in the -45° direction, a weight vector W opt The power transmitting device 10 generates an optimal weight vector W opt The radio wave 2000 W of the transmission signal 2000 multiplied by is radiated from the multiple antenna elements 11 A of the array antenna 11 .

[0276] 40, the power transmitting device 10 has a high array response value near the radiation direction of 30°, a low array response value near the direction D1 of -10° and the direction D2 of -45°, and a null depth of -60 dB in the direction D3 and -40 dB in the direction D4. As a result, even if the power transmitting device 10 receives a specified signal 1000 from the directions of multiple objects 5000, it can direct the radiated radio waves 2000 W in the direction of the power receiving device 20 and can suppress the radiation of the radio waves 2000 W toward the multiple objects 5000.

[0277] As described above, the power transmitting device 10 can obtain the same effect whether it uses the multipoint null constraint method or the differential coefficient constraint method. As a result, in the system 1, the power transmitting device 10 can improve safety even if it controls the antenna directivity based on the result of identifying the radio wave propagation channel of the specified signal 1000 from the power receiving device 20. Generally, the array response vector V d does not correspond to a specific direction in the directivity pattern, but in the examples of Figs. 39 and 40, the array response vector is set to a direction of 30° for ease of understanding.

[0278] In the above-described third embodiment, the power transmitting device 10 has been described as including a linear array in which the antenna elements 11A of the array antenna 11 are equally spaced from one another. However, the power transmitting device 10 is not limited to this. i If it is possible to calculate, the arrangement of the multiple antenna elements 11A does not need to be an equally spaced linear array.

[0279] [Modification of the power transmission device according to the third embodiment] 41 and 42 are diagrams showing an example of the configuration of the power transmitting device 10 according to a modified example of the third embodiment. As shown in FIG. 41, the power transmitting device 10 may have the sensor unit 15, the detection unit 16, and the preprocessing unit 19 provided in the electronic device 30 outside the power transmitting device 10. In this case, the power transmitting device 10 may be configured to be able to receive data from the electronic device 30 and may acquire a detection result of the object 5000 from the electronic device 30. As shown in FIG. 42, the power transmitting device 10 may have only the sensor unit 15 provided outside the device. In this case, the power transmitting device 10 may be configured to be able to acquire sensor information and the like from the external sensor unit 15 and the detection unit 16 may detect the object 5000 based on the sensor information and the like from the sensor unit 15.

[0280] The above-mentioned power transmitting device 10 may combine the multi-point null constraint method and the differential coefficient constraint method for the null widening. The above-mentioned power transmitting device 10 may be configured to use at least one of the multi-point null constraint method and the differential coefficient constraint method for the null widening. The above-mentioned power transmitting device 10 may combine the method of setting multiple nulls over the null target area and the method using differential coefficient constraint for the null widening.

[0281] In the above-described power transmission device 10, in the case of (Equation 331), W ≒ γV d may be replaced with W≈W0. In other words, this means that it can also be applied to a transmission weight W0 derived under certain conditions. The transmission weight W0 derived under certain conditions includes a plurality of weights, such as weights that do not form nulls. In this case, the above-mentioned (Equation 332) can be replaced with the following (Equation 334). This allows the power transmitting device 10 to reduce the impact on the human body with a weight close to the transmission weight W0.

number

[0282] Fig. 43 is a diagram showing an example of a configuration of a power transmitting device 10 according to a modification of embodiment 3. As shown in Fig. 43, the power transmitting device 10 includes an array antenna 11, a transmission signal generating unit 12, a transmitting / receiving unit 13, a sensor unit 15, a detecting unit 16, a weight generating unit 17, a multiplying unit 18, a preprocessing unit 19, and a generating unit 10A.

[0283] The generation unit 10A generates a transmission weight W0 under a certain condition. The generation unit 10A supplies the generated transmission weight W0 to the weight generation unit 17. For example, the transmission weight W0 under a certain condition may be a weight stored in the storage unit 17D. The weight generation unit 17 applies the transmission weight W0 to (Equation 334) to generate a weight vector W opt Thus, the power transmitting device 10 radiates radio waves 2000W including a transmission signal 2000 for power supply from the multiple antenna elements 11A. As a result, the power transmitting device 10 can reduce radiation toward the object 5000 because the radio waves 2000W are not directed toward the area of ​​the object 5000. In this way, the power transmitting device 10 can obtain the above-mentioned advantageous effects even if the configuration is changed to one that uses the transmission weight W0.

[0284] The above-described power transmitting device 10 may be configured to adjust the null depth for each category by categorizing the detected object 5000, for example, a human body, an animal, a plant, etc. The power transmitting device 10 may control so that the null depth is deepened when the object 5000 is a human body, an animal, etc., and the null depth is shallowed when the object 5000 is a plant, etc.

[0285] [Conversion of differential coefficient constraint conditions according to the third embodiment] D in the above (Equation 325) (l) (θ i )=W H V (l) (θ i )=0 is the W H (Q l V i )=W H (Q l V(θ i))=0. However, (325) and (326) are equivalent to l=1, ,L i Here, Q l =diag[0 l 1 l (K-1) l ].

[0286] First, we use the function F of θ as follows (Equation 3C1) and (Equation 3C2): l,n It shows that (θ) exists. If (Equation 3C1) is satisfied, the following (Equation 3C3) is obtained.

number

number

[0287] In (Eq. 3C3) and (Eq. 3C2), θ = θ i Substituting the above, we obtain the following (Equation 3C31) and (Equation 3C32).

number

[0288] Using these, the following (Equation 3C33) can be shown by mathematical induction.

number

[0289] [3-1]Consider the case where l=1. Differentiating (Equation 320) with respect to θ results in the following (Equation 3C4).

number

[0290] Here, if we define the following (Equation 3C5), then (Equation 3C5) satisfies (Equation 3C2).

number

[0291] And, (Equation 3C4) can be expressed as (Equation 3C6) below.

number

[0292] By differentiating (Equation 319) with respect to θ, it can be expressed as the following (Equation 3C7) using (Equation 3C6). Therefore, when l = 1, (Equation 3C1) is satisfied.

number

[0293] Here, in (Equation 3C7), θ = θ i Substituting V'(θ i )=F 1.1 (θ i )·Q1V(θ i ) Therefore, D'(θ i )=W H V'(θ i )=F 1.1 (θ i )·W H Q1V(θ i From (Equation 3C5), F1.1(θ i ) ≠ 0, the following (equation 3C71) holds.

number

[0294] [3-2]l=p( <L i ), it is assumed that (Equation 3C1) and (Equation 3C2) hold as the following (Equation 3C8) and (Equation 3C9).

number

[0295] By differentiating (equation 3C8) with respect to θ and using (equation 3C7), we obtain the following (equation 3C81).

number

[0296] By definition, Q n Q1=Q n+1 Therefore, we obtain the following (Equation 3C82).

number

[0297] Here, if we use the following (Equation 3C83), then from (Equation 3C5) and (Equation 3C9), we obtain the following (Equation 3C10). F p+1,1 (θ)=F' p,1 (θ) F p+1,n (θ)=F' p,n (θ)+F p,n-1 (θ)F 1,1 (θ) (n=2, ,p) F p+1,p+1 (θ)=F p,p (θ)F 1,1 (θ)...(Formula 3C83) F p+1,p+1 (θ)≠0...(Formula 3C10)

[0298] Therefore, (equation 3C2) is satisfied even when l = p + 1. Furthermore, (equation 3C82) becomes the following (equation 3C11) from (equation 3C83), and therefore (equation 3C1) is satisfied even when l = p + 1.

number

[0299] Here, in (Equation 3C11), θ = θ i Substituting this, we obtain the following (Equation 3C12).

number

[0300] From (Equation 3C12), W H Q l V i = 0(l = 1, , p + 1), then D (p+1) (θ i )=0. This means that W H Q l V i = 0(l = 1, , p) then D (l) (θ i )=0(l=1, ,p) holds, then W H Q l V i = 0(l = 1, , p + 1) then D (l) (θ i ) = 0(l = 1, , p + 1).

[0301] Conversely, D (l) (θ i )=0(l=1, ,p), then W H Q l V i If =0(l=1, ,p) holds, then D (l) (θ i )=0(l=1, ,p+1), then from (Equation 3C12), we obtain the following (Equation 3C13).

number

[0302] From formula 3C10, F p+1,p+1 (θ i )≠0 to W H Q p+1 V(θ i )=0. This gives us the following (Equation 3C14):

number

[0303] From the above [3-1] and [3-2], it has been proven that the following (Equation 3C15) holds.

Number

[0304] [Optimal Weight for Null Depth Control According to Embodiment 3] The magnitude |W H V i | of the inner product of the weight vector W and the null constraint vector Vi (i = 1, ···, M < K) is constrained to |ε i | 2 . It will be proven below that the optimal weight for the optimization problem can be expressed as the following (Equation N1).

Number

[0305] Here, V’ d =(I - AA + )V d , V ε =(A + ) H ε. A is a matrix formed by arranging M complex column constraint vectors V1, V2, ···, V M , and A + is the Moore-Penrose generalized inverse matrix of A. Also, ε = [ε1 ε2 ··· ε M T , and the argument of ε i is set to the same value as each element of A + V d . α satisfies the above-mentioned (Equation 330).

[0306] First, let the Lagrange multiplier for the condition |W H V i | 2 = |ε i | 2 be λ i , and the multiplier for ||W|| 2 = 1 be μ, and set the following (Equation N2). Note that λ i , μ are real numbers.

Number

[0307] Using the Lagrange multiplier method, the following (Equation D1), (Equation D2), and (Equation D3) can be obtained from (Equation N3) below, where i=1, ,M.

number

number

number

[0308] V H d W and V H i Since W is a complex scalar, α, β i Using V H d W = μα, λ i V H i W=μβ i Then, (Equation D1) becomes the following (Equation D4).

number

[0309] Here, (Equation D4) is A=[V1V2··· V M ] and b = [β1β2··· β M ] T Using this, it can be rewritten as the following (Equation D5). W = αV d -Ab...(Formula D5)

[0310] Substituting (D5) into (D2), we obtain the following (D51). Therefore, (D51) is αV H i V d -V H i Ab=εi It is also possible to use the following.

number

[0311] This means that A=[V1V2... V M ] and ε = [ε1ε2 ε M ] T Using this, we can express it as the following (Equation D6). Therefore, we can obtain the following (Equation D7). αA H V d -A H Ab = ε (Eq. D6) A H Ab=αA H V d -ε (Eq. D7)

[0312] From (Equation D7), the general solution for b is given by (Equation D71). Note that z is an arbitrary complex vector, I is a unit matrix, () + is the generalized Moore-Penrose inverse.

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[0313] In general, A + =(A H A) + A H Therefore, we get the following (Equation D8). Substituting (Equation D8) into (Equation D7), we get the following (Equation D81). A H =A H (A H ) + A H =A H A(A H A) + A H =A H AA + From A H A(A H A) + It is necessary to satisfy ε = ε. Therefore, A H (A H ) + ε = ε.

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[0314] This means that ε=A H This holds true when x. That is, ε i =V H i There must exist a complex vector x that satisfies x. V i If are linearly dependent, the equation ε=A H x may not be satisfied, which means that no solution exists.

[0315] By the way, by substituting (Equation D8) into (Equation D5), we obtain the following (Equation D9).

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[0316] Substituting (D9) into (D3), W H W = |α| 2 V H d (I-AA + )V d +ε H A + (A + ) H Since ε=1, we obtain the following (Equation D91).

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[0317] The following (Equation D10) may be selected as α that satisfies (Equation D91).

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[0318] By the way, W H V dSubstituting (Equation D9) into (Equation D11), we obtain the following (Equation D11).

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[0319] From the trigonometric inequality of complex numbers, the following relationship (Equation D11a) holds.

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[0320] The equality sign is ε H A + V d is αV H d (I-AA + )V d This holds true when α is a positive real number multiple of α. From (Equation D10), α is a non-negative real number, and (I-AA + ) is a Hermitian matrix, so V H d (I-AA + )V d is also a non-negative real number. Therefore, ε H A + V d The argument of each element of the complex vector ε should be adjusted so that A is a non-negative real number. + V d The argument of each element of is made to match.

[0321] Here, V' d =(I-AA + )V d , V ε =(A + ) H If we use ε, then (Equation D9) gives us the following (Equation D12). W opt =αV' d +V ε ...(Formula D12)

[0322] Moreover, (Equation D10) becomes the following (Equation D13).

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[0323] The weight calculation procedure is organized as follows. (PC1) Obtain A from A + Find. (PC2) Find the declination angle of each element from A + V d and create ε from this declination angle and |ε i |. (PC3) V’ d =(I - AA + )V d and V ε =(A + ) H Calculate ε and find α according to (Equation D13). (PC4) Use (Equation D12) to calculate W d from α, V’ ε and V opt .

[0324] [Null Depth Control by Approximate Solution According to Embodiment 3] W ≈ γV d and W H V i ≈ 0 (i = 1, ···, M < K) The optimal weight vector W opt is given by the following (Equation E2) as shown below when the following (Equation E1) is used. However, ||W|| 2 = 1.

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[0325] Here, A’ is the following (Equation E3) formed by arranging M complex column vectors α1V1, α2V2, ···, α M V M and the following (Equation E4) is the weight coefficient.

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[0326] First, consider minimizing the evaluation function J(W) shown in the following (Equation E5).

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[0327] The following (Equation E6) leads to the following (Equation E7), which gives the following (Equation E8).

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[0328] Using (Equation E3), we obtain the following (Equation E9). (I+A'A' H )W=γV d ...(Formula E9)

[0329] (I+A'A' H ) is a positive definite matrix, and an inverse matrix exists, so the optimal weight vector W opt Then, the following equation (Equation E10) is obtained.

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[0330] Here, V'' d =(I-A'(I+A' H A') -1 A' H )V d Then, we get the following (Equation E11).

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[0331] Finally ||W|| 2 = |γ| 2 ||V'' d Let γ satisfy ||=1, then γ=1 / ||V'' d Therefore, (Equation E11) becomes (Equation E2) mentioned above.

[0332] Characteristic embodiments have been described in order to fully and clearly disclose the technology according to the attached claims. However, the attached claims should not be limited to the above-mentioned embodiments, but should be configured to embody all modifications and alternative configurations that a person skilled in the art can create within the scope of the basic matters shown in this specification. The contents of this disclosure can be modified and amended by a person skilled in the art based on this disclosure. Therefore, these modifications and amendments are included in the scope of this disclosure. For example, in each embodiment, each functional unit, each means, each step, etc. can be added to other embodiments so as not to be logically contradictory, or can be replaced with each functional unit, each means, each step, etc. of other embodiments. In each embodiment, multiple functional units, each means, each step, etc. can be combined into one or divided. In addition, each embodiment of the present disclosure described above is not limited to being faithfully implemented to each of the embodiments described respectively, and can be implemented by combining each feature or omitting a part as appropriate. [Explanation of symbols]

[0333] 1 System 10 Power transmission equipment 10A generator 11 Array Antenna 11A Antenna element 12 Transmission signal generator 13 Transmitter / receiver 14 Estimation part 15 Sensor section 16 Detection section 17 Weight Generation Unit 17D Storage section 18 Multiplication section 19 Pretreatment section 20 Power receiving device 21 Antenna 22 Transmitter / receiver 23 Signal Generator 24 Power receiving section 100A Reference power transmission device using conventional retrodirective method 200B Reference point 200P receiving point 1000 regulation signal 2000 Transmitted signal 2000W radio wave 3000 Radio wave strength distribution when using a reference power transmission device 4000 rooms 5000 objects V i Array response vector corresponding to null V d Array response vector corresponding to the receiving device W opt Weight Vector

Claims

1. A receiving unit that receives a reception signal transmitted from a power receiving device; A transmitting unit that transmits a transmission signal to the power receiving device by an antenna; a weight generating unit that controls the directivity of the antenna based on a size of an object so that the strength of the radio wave that transmits the transmission signal in an area where an object other than the power receiving device is present is equal to or less than a predetermined value; a sensor unit for detecting a direction and an area of ​​the object different from the power receiving device; Equipped with The weight generation unit a power transmitting device that generates a transmission weight that maximizes the magnitude of the inner product of the array response vector and the weight vector under conditions that an inner product of the constraint vector and a weight vector is set to zero and a norm of the weight vector is kept constant, based on an array response vector generated by a specified signal transmitted from the power receiving device and a constraint vector for the direction and region of the object.

2. A receiving unit that receives a reception signal transmitted from a power receiving device; A transmitting unit that transmits a transmission signal to the power receiving device by an antenna; a weight generating unit that controls the directivity of the antenna based on a size of an object so that the strength of the radio wave that transmits the transmission signal in an area where an object other than the power receiving device is present is equal to or less than a predetermined value; a sensor unit for detecting a direction and an area of ​​the object different from the power receiving device; Equipped with The weight generation unit The array response vector generated by the specified signal transmitted from the power receiving device is denoted by V ｄ Let K be the number of antenna elements of the antenna, M be the number of the objects, W be a weight vector, and W be the complex conjugate transpose (Hermitian transpose) of the weight vector. Ｈ The constraint vector calculated based on the direction of the object is V ｉ （0） (i=1, . . . , M), and the constraint vector V ｉ （ｌ） (l=1,...,L ｉ ), the array response vector V ｄ and the magnitude of the inner product of the weight vector |W Ｈ V ｄ The weight vector W that maximizes | ｏｐｔ is determined by the following conditional expression (Equation 1), and the weight vector W ｏｐｔ A power transmitting device that generates the transmission weight. [Number 136]

3. A receiving unit that receives a reception signal transmitted from a power receiving device; A transmitting unit that transmits a transmission signal to the power receiving device by an antenna; a weight generating unit that controls the directivity of the antenna based on a size of an object so that the strength of the radio wave that transmits the transmission signal in an area where an object other than the power receiving device is present is equal to or less than a predetermined value; a sensor unit for detecting a direction and an area of ​​the object different from the power receiving device; Equipped with The weight generation unit generates a transmission weight so that a null is directed toward the area of ​​the object based on the propagation channel characteristics of a specified signal, the detection results of the direction and area of ​​the object detected by the detection unit, and wide-angle parameters corresponding to the detection results.

4. The weight generation unit The power transmitting device according to claim 1 , wherein a weight is determined in accordance with a width of a region in which the object exists.

5. The weight generation unit The power transmitting device according to claim 1 , further comprising: a weight that generates a transmission signal having a plurality of portions with reduced radio wave intensity in an area where the object is present.

6. A power receiving device; a receiving unit that receives a reception signal transmitted from the power receiving device; a transmitting unit that transmits a transmission signal to the power receiving device by an antenna; a weight generating unit that controls the directivity of the antenna based on a size of an object so that the strength of the radio wave that transmits the transmission signal in an area where an object other than the power receiving device is present is equal to or less than a predetermined value; and a power transmitting device having a sensor unit for detecting a direction and an area of ​​the object different from the power receiving device; Equipped with The weight generation unit a transmission weight that maximizes the magnitude of the inner product of the array response vector and the weight vector under conditions that the inner product of the array response vector and the weight vector is set to zero and the norm of the weight vector is kept constant, based on an array response vector generated by a specified signal transmitted from the power receiving device and a constraint vector for the direction and area of ​​the object.

7. A power receiving device; a receiving unit that receives a reception signal transmitted from the power receiving device; a transmitting unit that transmits a transmission signal to the power receiving device by an antenna; a weight generating unit that controls the directivity of the antenna based on a size of an object so that the strength of the radio wave that transmits the transmission signal in an area where an object other than the power receiving device is present is equal to or less than a predetermined value; and a power transmitting device having a sensor unit for detecting a direction and an area of ​​the object different from the power receiving device; Equipped with The weight generation unit The array response vector generated by the specified signal transmitted from the power receiving device is denoted by V ｄ Let K be the number of antenna elements of the antenna, M be the number of the objects, W be a weight vector, and W be the complex conjugate transpose (Hermitian transpose) of the weight vector. Ｈ The constraint vector calculated based on the direction of the object is V ｉ （0） (i=1, . . . , M), and the constraint vector V ｉ （ｌ） (l=1,...,L ｉ ), the array response vector V ｄ and the magnitude of the inner product of the weight vector |W Ｈ V ｄ The weight vector W that maximizes | ｏｐｔ is determined by the following conditional expression (Equation 1), and the weight vector W ｏｐｔ A wireless power transmission system that generates the above as a transmission weight. [Number 136]

8. A power receiving device; a receiving unit that receives a reception signal transmitted from the power receiving device; a transmitting unit that transmits a transmission signal to the power receiving device by an antenna; a weight generating unit that controls the directivity of the antenna based on a size of an object so that the strength of the radio wave that transmits the transmission signal in an area where an object other than the power receiving device is present is equal to or less than a predetermined value; and a power transmitting device having a sensor unit for detecting a direction and an area of ​​the object different from the power receiving device; Equipped with A wireless power transmission system in which the weight generation unit generates a transmission weight so that a null is directed toward the area of ​​the object based on the propagation channel characteristics of a specified signal, the detection results of the direction and area of ​​the object detected by the detection unit, and wide-angle parameters corresponding to the detection results.

9. a receiving step of receiving a reception signal transmitted from a power receiving device; a transmitting step of transmitting a transmission signal to the power receiving device by an antenna; a control step of controlling a directivity of the antenna based on a size of an object so that an intensity of radio waves transmitting the transmission signal in an area where an object other than the power receiving device is present is equal to or less than a predetermined value; detecting a direction and an area of ​​the object different from the power receiving device by a sensor unit; Equipped with a control method for generating a transmission weight that maximizes the magnitude of the inner product of the array response vector and the weight vector under conditions that an inner product of the constraint vector and a weight vector is set to zero and a norm of the weight vector is kept constant, based on an array response vector generated by a specified signal transmitted from the power receiving device and a constraint vector for the direction and region of the object.

10. a receiving step of receiving a reception signal transmitted from a power receiving device; a transmitting step of transmitting a transmission signal to the power receiving device by an antenna; a control step of controlling a directivity of the antenna based on a size of an object so that an intensity of radio waves transmitting the transmission signal in an area where an object other than the power receiving device is present is equal to or less than a predetermined value; detecting a direction and an area of ​​the object different from the power receiving device by a sensor unit; Equipped with The array response vector generated by the specified signal transmitted from the power receiving device is denoted by V ｄ Let K be the number of antenna elements of the antenna, M be the number of the objects, W be a weight vector, and W be the complex conjugate transpose (Hermitian transpose) of the weight vector. Ｈ The constraint vector calculated based on the direction of the object is V ｉ （0） (i=1, . . . , M), and the constraint vector V ｉ （ｌ） (l=1,...,L ｉ ), the array response vector V ｄ and the magnitude of the inner product of the weight vector |W Ｈ V ｄ The weight vector W that maximizes | ｏｐｔ is determined by the following conditional expression (Equation 1), and the weight vector W ｏｐｔ A control method for generating a transmission weight. [Number 136]

11. a receiving step of receiving a reception signal transmitted from a power receiving device; a transmitting step of transmitting a transmission signal to the power receiving device by an antenna; a control step of controlling a directivity of the antenna based on a size of an object so that an intensity of radio waves transmitting the transmission signal in an area where an object other than the power receiving device is present is equal to or less than a predetermined value; detecting a direction and an area of ​​the object different from the power receiving device by a sensor unit; Equipped with A control method for generating a transmission weight so that a null is directed toward the area of ​​the object based on the propagation channel characteristics of a specified signal, the detection results of the direction and area of ​​the object detected by a detection unit, and wide-angle parameters corresponding to the detection results.

12. On the computer, a receiving step of receiving a reception signal transmitted from a power receiving device; a transmitting step of transmitting a transmission signal to the power receiving device by an antenna; a control step of controlling a directivity of the antenna based on a size of an object so that an intensity of radio waves transmitting the transmission signal in an area where an object other than the power receiving device is present is equal to or less than a predetermined value; detecting a direction and an area of ​​the object different from the power receiving device by a sensor unit; Run the command, a control program for generating a transmission weight that maximizes the magnitude of the inner product of the array response vector and the weight vector under conditions that an inner product of the constraint vector and a weight vector is set to zero and a norm of the weight vector is kept constant, based on an array response vector generated by a specified signal transmitted from the power receiving device and a constraint vector for the direction and region of the object.

13. On the computer, a receiving step of receiving a reception signal transmitted from a power receiving device; a transmitting step of transmitting a transmission signal to the power receiving device by an antenna; a control step of controlling a directivity of the antenna based on a size of an object so that an intensity of radio waves transmitting the transmission signal in an area where an object other than the power receiving device is present is equal to or less than a predetermined value; detecting a direction and an area of ​​the object different from the power receiving device by a sensor unit; Run the command, The array response vector generated by the specified signal transmitted from the power receiving device is denoted by V ｄ Let K be the number of antenna elements of the antenna, M be the number of the objects, W be a weight vector, and W be the complex conjugate transpose (Hermitian transpose) of the weight vector. Ｈ The constraint vector calculated based on the direction of the object is V ｉ （0） (i=1, . . . , M), and the constraint vector V ｉ （ｌ） (l=1,...,L ｉ ), the array response vector V ｄ and the magnitude of the inner product of the weight vector |W Ｈ V ｄ The weight vector W that maximizes | ｏｐｔ is determined by the following conditional expression (Equation 1), and the weight vector W ｏｐｔ A control program that generates the above as a transmission wait. [Number 136]

14. On the computer, a receiving step of receiving a reception signal transmitted from a power receiving device; a transmitting step of transmitting a transmission signal to the power receiving device by an antenna; a control step of controlling a directivity of the antenna based on a size of an object so that an intensity of radio waves transmitting the transmission signal in an area where an object other than the power receiving device is present is equal to or less than a predetermined value; detecting a direction and an area of ​​the object different from the power receiving device by a sensor unit; Run the command, A control program that generates a transmission weight so that a null is directed toward the area of ​​the object based on the propagation channel characteristics of a specified signal, the detection results of the direction and area of ​​the object detected by the detection unit, and wide-angle parameters corresponding to the detection results.

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