Antenna device, power supply system, power supply device, and power supply method

Abstract

To provide an antenna device which can suppress the spread of reflection of a signal that has been transmitted and reduce the influence of interference to another device that may exist in the periphery.SOLUTION: In a power supply apparatus 100, an antenna device 100A comprises: an array antenna 110; a phase shifter 120 which adjusts the phase of a power transmission signal supplied to a plurality of antenna elements 111; a camera 140 which acquires an image; and a control device 150. The control device 150 comprises: a position derivation unit which converts the position of the image into polar coordinates; an elevation angle acquisition unit which acquires an elevation angle of the image; a memory which stores plural sets of plural pieces of phase data according to the plurality of elevation angles; and a control unit which controls the phase shifter 120 that adjusts the direction of the beam emitted by the array antenna on the basis of the phase data.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an antenna device, a power feeding system, a power feeding device, and a power feeding method. [Background technology]

[0002] There has been a wireless power transmitting device having a beam transmitting unit that transmits an energy beam for power supply to a wireless power receiving device mounted on an aircraft, an information acquiring unit that acquires control information for increasing the power receiving efficiency of the wireless power receiving device, and a control unit that controls the energy beam based on the control information so as to increase the power receiving efficiency of the wireless power receiving device. It is described that an array antenna may be used as a power transmitting antenna (for example, see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-135900 A Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, when power is transmitted from multiple antenna elements of an array antenna and received by a wireless power receiving device, if the wireless power receiving device is mounted on an aircraft as in the case of a conventional wireless power transmitting device, there is a sufficient distance between the wireless power transmitting device (power supply device) and the wireless power receiving device (power receiving device). Therefore, the difference in distance between the multiple antenna elements and the power receiving device is negligible, and even if power is transmitted from the multiple antenna elements to the same target, the reception phase shift when the power receiving device receives power is small and hardly causes any problem.

[0005] However, when the distance between the power receiving device and the power supply device is short, such as a few meters, if power is transmitted from multiple antenna elements to the same target, the difference in transmission distance will be large when the power receiving device receives power, resulting in a large deviation in the received potential, which can cause a problem of reduced composite received power.

[0006] Therefore, an object of the present invention is to provide an antenna device, a power feeding system, a power feeding device, and a power feeding method that can suppress the spread of reflections of a transmitted signal and reduce the effect of interference on other devices that may exist in the vicinity. [Means for solving the problem]

[0007] An antenna device according to an embodiment of the present invention includes an array antenna having a plurality of antenna elements arranged two-dimensionally along a first axis and a second axis, a phase adjustment unit that adjusts a phase of a power transmission signal supplied to the plurality of antenna elements in the first axis direction, an image acquisition unit that acquires an image through a fisheye lens, a position derivation unit that converts a first position of a marker included in an image acquired by the image acquisition unit with respect to the image acquisition unit into a second position in polar coordinates on a first plane including the first axis and the second axis, an elevation angle acquisition unit that acquires an elevation angle with respect to the third axis in the second plane of a projection position obtained by projecting the first position onto a second plane including the first axis and a third axis based on the second position, and The present invention includes a storage unit that stores multiple sets of phase data representing multiple phases when transmitting the power transmission signal from multiple antenna elements to a power receiving device located at the marker position, the multiple phases being adjusted so that the phases at which the power receiving device receives the power transmission signal from the multiple antenna elements are aligned, corresponding to the multiple elevation angles, and a control unit that reads out the phase data corresponding to the elevation angle acquired by the elevation angle acquisition unit from the storage unit, and controls the phase adjustment unit based on the read phase data so that the direction of the beam radiated by the array antenna becomes the elevation angle within the second plane, wherein the phase data is phase data for the multiple elevation angles that fall within a predetermined range of angles. Effect of the Invention

[0008] It is possible to provide an antenna device, a power feeding system, a power feeding device, and a power feeding method that can suppress the spread of reflections of a transmitted signal and reduce the effect of interference on other devices that may exist in the vicinity. [Brief description of the drawings]

[0009] [Figure 1] 1 is a diagram illustrating a power supply device 100 according to an embodiment. [Diagram 2] 1 is a diagram illustrating a power supply device 100 according to an embodiment. [Diagram 3] FIG. 2 is a diagram showing a polar coordinate system of the array antenna 110. [Figure 4] FIG. 13 is a diagram for explaining how to obtain phase data. [Diagram 5] 3 is a diagram illustrating the antenna gain of the antenna device 100A and the power supply device 100. FIG. [Figure 6] FIG. 2 is a diagram for explaining how to reduce the side lobes of a beam radiated from an array antenna 110. [Figure 7] 11A and 11B are diagrams illustrating power transmission from an antenna device 100A to a power receiving device 50B successively performed multiple times within a narrow angle range. [Figure 8] FIG. 13 is a diagram showing a region 142B1 that an image processing unit 142B sets for image data by ROI control. [Figure 9] 10 is a diagram showing an example of a radiation angle pattern of a power transmission signal output by an antenna device 100A. FIG. [Figure 10] 10 is a diagram showing the amount of power received by a power receiving device 50B according to a radiation angle pattern of the embodiment and the amount of power received according to a comparative radiation angle pattern. FIG. [Figure 11] 1A to 1C are diagrams illustrating application examples of a power supply device 100. [Figure 12] 11 is a diagram showing an example of the characteristics of the reflection coefficient with respect to the incident angle of the beam on the radio wave absorber 52. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments to which an antenna device, a power supply system, a power supply device, and a power supply method according to the present invention are applied will be described.

[0011] <Embodiment> 1 is a diagram illustrating a power supply device 100 according to an embodiment. The power supply device 100 includes an array antenna 110, a phase shifter 120, a microwave generation source 130, a camera 140, and a control device 150. The antenna device 100A according to the embodiment is the power supply device 100 without the microwave generation source 130.

[0012] In the following, the XYZ coordinate system will be used for explanation. Planar view refers to XY planar view. The X axis is an example of the first axis, the Y axis is an example of the second axis, and the Z axis is an example of the third axis. The XY plane is an example of the first plane, and the XZ plane is an example of the second plane.

[0013] The array antenna 110 is grouped into N subarrays 110A, for example. The first (#1) to the Nth (#N) of the N subarrays 110A are shown. Here, N is an integer of 2 or more, but FIG. 1 shows an example in which N is an even number of 4 or more. The N subarrays 110A are arranged in the X-axis direction (first axis direction), and each subarray 110A includes, for example, four antenna elements 111. Therefore, the array antenna 110 includes, for example, 4N antenna elements 111. Each array antenna 110 extends in the Y-axis direction (second axis direction). The antenna element 111 is a patch antenna that is rectangular in plan view. The array antenna 110 may have a ground plate that is held at ground potential on the -Z-axis side of the antenna element 111. Note that, for example, the center of the positions of the 4N antenna elements 111 coincides with the origin of the XYZ coordinate system. Moreover, the number of antenna elements 111 included in each subarray 110A only needs to be two or more, and they only need to be arranged two-dimensionally.

[0014] In the following, a description will be given using FIG. 2 in addition to FIG. 1. FIG. 2 is a diagram showing a power supply device 100 according to an embodiment. In FIG. 2, the origin of the XYZ coordinate system is shifted in order to make the drawing easier to see, but in the following description, the origin of the XYZ coordinate system is assumed to coincide with the center of the positions of 4N antenna elements 111 as shown in FIG. 1. FIG. 2 also shows one antenna element 111 adjacent to the -Y axis side of the X axis for each subarray 110A. FIG. 2 also shows components included in the control device 150, a marker 50A, and a power receiving device 50B. The marker 50A and the power receiving device 50B are fixed to an inner wall 51 of a tunnel as an example. The inner wall 51 of the tunnel is an example of a wall portion, and the inside of the tunnel is an example of a space in which the marker 50A arranged along the inner wall 51 exists. As an example, the antenna device 100A and the power supply device 100 are mounted on a work vehicle and travel through a tunnel, detect a marker 50A attached to an inner wall 51 of the tunnel, and transmit power to a power receiving device 50B.

[0015] 2, the marker 50A exists in the direction of angle θb from the Z axis when viewed in the XZ plane. For convenience of explanation, the XYZ coordinate system is shifted in FIG. 2, but since the origin of the XYZ coordinate system coincides with the center of the positions of the 4N antenna elements 111, the angle θb is the angle between the Z axis and a straight line connecting the origin of the XYZ coordinate system and the marker 50A in the XZ plane. When the XZ plane is viewed from the +Y axis direction, the angle θb is indicated as a positive value when it is tilted toward the +X axis direction, and is indicated as a negative value when it is tilted toward the -X axis direction.

[0016] N phase shifters 120 are provided corresponding to the N subarrays 110A, and the N phase shifters 120 are connected to the antenna elements 111 of the N subarrays 110A, respectively. The phase shifters 120 are an example of a phase adjustment unit that adjusts the phase, and are an example of a phase shifter. In each subarray 110A, four antenna elements 111 are connected in parallel to one phase shifter 120. The phase shifter 120 is an example of a phase adjustment unit.

[0017] In each subarray 110A, a power transmission signal of the same phase is supplied to the four antenna elements 111. The phases of the power transmission signals output from the N phase shifters 120 to the N subarrays 110A are different from each other. Therefore, the angle (elevation angle) of the beam formed by the radio waves radiated from the 4N antenna elements 111 can be controlled within the XZ plane.

[0018] The beam formed by the radio waves radiated from the 4N antenna elements 111 is synonymous with the beam output by the array antenna 110. In addition, the beam output by the array antenna 110 is synonymous with the beam output by the antenna device 100A and the power feeding device 100.

[0019] The microwave generating source 130 is connected to the N phase shifters 120, and supplies microwaves of a predetermined power. The microwave generating source 130 is an example of a radio wave generating source. The frequency of the microwaves is, for example, a frequency in the 920 MHz band. Note that, although a form in which the power supply device 100 includes the microwave generating source 130 will be described here, the microwaves are not limited to microwaves, and any radio waves of a predetermined frequency may be used.

[0020] The camera 140 is disposed between the N / 2-th subarray 110A and the N / 2+1-th subarray 110A in the X-axis direction, and is disposed between the second antenna element 111 and the third antenna element 111 from the +Y-axis direction side among the four antenna elements 111 included in each subarray in the Y-axis direction. The camera 140 has a fisheye lens 141 and a camera body 142. The camera 140 is an example of an image acquisition unit. In FIG. 2, the camera body 142 is shown divided into an imaging unit 142A and an image processing unit 142B.

[0021] The fisheye lens 141 is a lens that employs an equidistant projection method. For example, the center position of the fisheye lens 141 coincides with the center of the 4N antenna elements 111 and the origin of the XYZ coordinate system. The camera body 142 is a part of the camera 140 other than the fisheye lens 141, and may be a camera including a CMOS (Complementary Metal Oxide Semiconductor) image sensor or an infrared camera.

[0022] The camera 140 acquires an image including the marker 50A through the fisheye lens 141, and outputs the image data to the control device 150. The marker 50A is attached to the power receiving device 50B having a power receiving antenna, which is a target to be irradiated with the beam output by the antenna device 100A and the power feeding device 100. The antenna device 100A and the power feeding device 100 obtain the position of the marker 50A included in the image acquired by the camera 140, and irradiate the beam toward the power receiving device 50B.

[0023] The camera body 142 has an imaging section 142A and an image processing section 142B. The imaging section 142A includes an image sensor and is a section that acquires image data by capturing an image through the fisheye lens 141. The image processing section 142B performs image processing such as binarization processing on the image data acquired by the imaging section 142A, and outputs a pixel index to the control device 150. The pixel index is an XY coordinate value (address) that indicates the position of the marker 50A on the captured screen.

[0024] In addition, when the work vehicle equipped with the antenna device 100A is moving, the image processing unit 142B sets a region to be detected in the image data acquired by the imaging unit 142A by ROI (Region On Interest) control. The image processing unit 142B waits for the marker 50A to enter the region, and when the marker 50A enters the region, it tracks the marker 50A over a predetermined narrow angle range by ROI control, and waits again when tracking over the predetermined narrow angle range is completed. As an example, the predetermined narrow angle range is a range in which the angle θb is ±15 degrees with respect to the front direction of the fisheye lens 141. The front direction of the fisheye lens 141 is the +Z axis direction passing through the center of the fisheye lens 141 (the origin of the XYZ coordinate system), and is the front direction of the antenna device 100A.

[0025] The control device 150 has a position derivation unit 151, an elevation angle acquisition unit 152, a position deviation detection unit 153, a distance estimation unit 154, a control unit 155, and a memory 156. The control device 150 is realized by a computer including a CPU (Central Processing Unit) and a memory. The position derivation unit 151, the elevation angle acquisition unit 152, the position deviation detection unit 153, the distance estimation unit 154, and the control unit 155 are functional blocks showing the functions of a program executed by the control device 150. The memory 156 is a functional representation of the memory of the control device 150.

[0026] Here, the position derivation unit 151, the elevation angle acquisition unit 152, the position deviation detection unit 153, the distance estimation unit 154, the control unit 155, and the memory 156 will be described with reference to FIG. 3 in addition to FIG. 1 and FIG. 2. FIG. 3 is a diagram showing a polar coordinate system of the array antenna 110. FIG. 3 shows the subarrays 110A of the array antenna 110 in the power supply device 100, the antenna elements 111 included in each subarray 110A, and the beams 115 output from the array antenna 110, and omits other components. FIG. 3 also shows a polar coordinate system on a plane 1 parallel to the XY plane.

[0027] The position of the marker 50A in the XYZ coordinate system is P1, the elevation angle of the line segment connecting the origin O and the position P1 is θ, and the azimuth angle is φ. The elevation angle is the angle with respect to the +Z axis direction, and the azimuth angle is the angle with respect to the +X axis direction, and a clockwise value in a planar view seen from the +Z axis direction side is a positive value. The elevation angle of the line segment connecting the origin O and the position P1a projected onto the XZ plane of the position P1 is θa. The elevation angle θa is an angle approximately obtained by projecting the elevation angle θ onto the XZ plane when the position of the marker 50A is close to the XZ plane. As with the angle θb, the elevation angle θa is indicated as a positive value when it is tilted toward the +X axis direction when the XZ plane is viewed from the +Y axis direction side, and is indicated as a negative value when it is tilted toward the -X axis direction side.

[0028] The position P1 is an example of a first position, the position P1a is an example of a projected position, and the origin O is an example of a reference point of the XYZ coordinate system.

[0029] The antenna device 100A and the power supply device 100 control the elevation angle of the beam 115 output by the array antenna 110 only in the XZ plane. This is based on the assumption that the array antenna 110 performs in-phase power supply in the Y-axis direction, so that the beam is fixed in the Y-axis direction and can be swung in an elevation angle direction with the Z-axis at 0 degrees, and that the position of the power receiving device 50B does not deviate much from the XZ plane (for example, within about ±30 degrees in elevation angle with respect to the Z-axis in the YZ plane). If the power receiving device 50B is located in such a position, the beam 115 can be efficiently irradiated to the power receiving device 50B while suppressing the scale of the control unit of the array antenna 110 by simply controlling the elevation angle of the beam 115 in the XZ plane.

[0030] The position derivation unit 151 calculates the center of gravity of the image of the marker based on the pixel index output from the image processing unit 142B. The pixel index output from the image processing unit 142B represents an equidistant projection image obtained through the fisheye lens 141. By this image processing, the position P1 of the marker with respect to the array antenna 110, which is included in the image acquired by the camera 140, is converted to a position P2 in polar coordinates on the XY plane. In this manner, the position derivation unit 151 derives the position P2. The position P1 is the position of the center of gravity calculated by the position derivation unit 151. The position P2 is an example of a second position.

[0031] The position P2 is represented by a radius vector r and a deviation angle φ from the origin O. The radius vector r is expressed by the focal length of the fisheye lens 141 as f L Then, r=f L The position P2 is represented by θ. The deflection angle φ is the same as the azimuth angle φ. The position derivation unit 151 obtains r·cosφ by mapping the radius vector r onto the X-axis through the image processing described above. The position derivation unit 151 outputs data representing the position P2 to the elevation angle acquisition unit 152.

[0032] The elevation angle acquisition unit 152 calculates the X coordinate (r cosφ) of the mapping position P2a obtained by mapping the position P2 onto the X axis by the focal length f of the fisheye lens 141. L Divided by (r cosφ / f L ) is acquired (calculated) as the elevation angle θa. The reason why the elevation angle θa can be acquired in this manner will be described later. The elevation angle acquisition unit 152 outputs the elevation angle θa to the distance estimation unit 154 and the control unit 155.

[0033] The positional deviation detection unit 153 obtains the shape and center of gravity of the marker 50A based on the pixel index output from the image processing unit 142B, and detects the positional deviation between the camera 140 and the marker 50A in the Y-axis direction based on the position of the center of gravity within the range in which the marker 50A exists. As an example, the position of the center of the fisheye lens 141 coincides with the center of the 4N antenna elements 111 and the origin of the XYZ coordinate system, so that, for example, the position of the center of gravity in the Y-axis direction when there is no positional deviation between the camera 140 and the marker 50A may be set to Y=0. If the obtained position of the center of gravity in the Y-axis direction within the range in which the marker 50A exists is Y=0, the positional deviation detection unit 153 determines that there is no positional deviation between the camera 140 and the marker 50A. Furthermore, if the obtained position of the center of gravity in the Y-axis direction within the range in which the marker 50A exists is not Y=0, the positional deviation detection unit 153 determines that there is a positional deviation between the camera 140 and the marker 50A, and detects the positional deviation. The position shift detection unit 153 outputs the detection result to the distance estimation unit 154. The position of the center of gravity may be acquired from the position derivation unit 151.

[0034] Distance estimation unit 154 estimates the distance from the center of fisheye lens 141 to marker 50A based on the number of pixel indexes output from image processing unit 142B of camera 140 when elevation angle θa calculated by elevation angle acquisition unit 152 is zero degrees (0 degrees). An elevation angle θa of 0 degrees means that marker 50A is located in front of fisheye lens 141 in the Z-axis direction (the center of gravity of marker 50A is located on the Z-axis).

[0035] The distance estimation unit 154 calculates the facing distance r from the center of the fisheye lens 141 to the marker 50A when the elevation angle θa is 0 degrees. FD Estimate the facing distance r FD is the distance when marker 50A faces camera 140 on the Z axis.

[0036] For example, the number of multiple binarized pixel indexes acquired by the image processing unit 142B when the camera 140 and the marker 50A are separated by multiple distances on the Z axis is stored in advance in the memory 156. Then, the distance estimation unit 154 counts the number of pixel indexes output from the image processing unit 142B of the camera 140 when the elevation angle θa is zero degrees (0 degrees), and estimates the multiple opposing distances r FD By comparing with a plurality of reference data corresponding to the elevation angle θa, the facing distance r FD Estimate the facing distance r FD Since the number of pixel indices varies depending on FD can be estimated.

[0037] In addition, when the elevation angle θa is zero degrees (0 degrees), if the image processing unit 142B of the camera 140 outputs pixel indices multiple times, the facing distance r FD can be estimated.

[0038] In addition, since the fisheye lens 141 is used, when there is a positional deviation between the camera 140 and the marker 50A, the distance r FD Therefore, when the positional deviation detection unit 153 determines that a positional deviation occurs between the camera 140 and the marker 50A in the Y-axis direction, the distance estimation unit 154 stores in advance in the memory 156 data indicating the degree of change in the pixel index number with respect to the positional deviation in the Y-axis direction, and calculates the facing distance r FD can be estimated.

[0039] The control unit 155 controls the amount of phase shift in the phase shifter 120 so that the direction of the beam 115 radiated by the array antenna 110 has an elevation angle θa in the XZ plane. The elevation angle θa is acquired by the elevation angle acquisition unit 152. The control unit 155 also controls the output of the microwave generation source 130, and controls the shooting of the camera 140, etc.

[0040] Specifically, the control unit 155 controls the amount of phase shift in the phase shifter 120 as follows. FD and the elevation angle θa acquired by the elevation angle acquisition unit 152, and reads out from the memory 156 phase data corresponding to the elevation angle θa, and controls the amount of phase shift in the N phase shifters 120 based on the read out phase data.

[0041] Here, in order for the antenna of the power receiving device 50B to efficiently receive power, it is ideal that the phase of the power transmission signal when the antenna of the power receiving device 50B receives power from the N subarrays 110A is equal. Meanwhile, the antenna device 100A and the power feeding device 100 transmit the power transmission signal to the power receiving device 50B located at a short distance, for example, about 3 m to 7 m from the array antenna 110. When transmitting power to the power receiving device 50B attached to the inner wall 51 of a tunnel, the distance from the array antenna 110 to the power receiving device 50B is about 3 m to about 5 m when the angle θb is 0 degrees.

[0042] Since such short-distance power transmission is assumed, the relative difference in distance from each of the N subarrays 110A to the antenna of the power receiving device 50B is relatively large, and when the N subarrays 110A transmit power to the same target, the phases of the power transmission signals received by the antenna of the power receiving device 50B from the N subarrays 110A are not aligned, and the power receiving device 50B cannot receive power efficiently. The difference in distance from each of the N subarrays 110A to the antenna of the power receiving device 50B varies depending on the angle θb and the distance in the Z-axis direction from the N subarrays 110A to the antenna of the power receiving device 50B.

[0043] Therefore, the antenna device 100A and the power supply device 100 use phase data for adjusting the phase of each of the N subarrays 110A when transmitting power so that the phases of the power transmission signals received by the antenna of the power receiving device 50B from the N subarrays 110A are aligned. In addition, in order to reduce the influence of the power transmission signal on other devices that may be present around the antenna device 100A and the power supply device 100, multiple sets of phase data are prepared that can adjust the amount of phase shift of the N subarrays 110A in increments of 1 degree, assuming that power transmission is performed when the angle θb at which the marker 50A exists relative to the antenna device 100A and the power supply device 100 is within a range of ±15 degrees as the antenna device 100A and the power supply device 100 move. Power transmission within a range of ±15 degrees is an example of power transmission within a predetermined narrow angle range. Each phase data includes N phase shift amounts to be set in N phase shifters 120 connected to N subarrays 110A, respectively, corresponding to one elevation angle θa. Thirty-one sets of such phase data are prepared in 1 degree increments for the range of angle θb from +15 degrees to -15 degrees, and are arranged at a certain facing distance r FD In addition, the phase data is obtained by dividing the phase data by the distance r FD In order to adjust the phase shift amount of the N subarrays 110A according to each of the plurality of opposing distances r FD Since the phase data is data created based on the angle θb, multiple sets of phase data ψ3(θb) to ψ7(θb) are shown using θb in Fig. 2. The control unit 155 may use multiple sets of phase data for the angle θb that is equal to the elevation angle θa.

[0044] The control unit 155 detects the facing distance r FD and controls the phase shift amounts in the N phase shifters 120 using phase data for an angle θb that is equal to the elevation angle θa acquired by the elevation angle acquisition unit 152 from among the multiple sets of phase data.

[0045] Furthermore, the control unit 155 controls the transmission power of the power transmission signal to be equal to or lower than a predetermined power. This is to reduce interference caused by the power transmission signal on other devices that may be present around the power receiving device 50B. The predetermined power is an upper limit power that does not affect (interfere with) other devices. In order to ensure that the effect of the power transmission signal on other devices, such as mobile phones, smartphones, or portable mobile stations such as transceivers, is equal to or lower than a predetermined power that is limited by restrictions on the power reception of other devices, the control unit 155 reads out the transmission power data stored in the memory 156 and sets the transmission power of the power transmission signal. Also, as an example, five types of opposing distances r of 3 m, 4 m, . . . , and 7 m are set. FD The transmission power of the power transmission signal may be set according to the above.

[0046] The memory 156 is an example of a storage unit, and stores the programs executed by the position derivation unit 151, the elevation angle acquisition unit 152, and the control unit 155 when they perform processing, data used in conjunction with the execution of the programs, data generated by the execution of the programs, image data acquired by the camera 140, and the like. FD For each of the above, multiple sets of phase data and transmission power data are stored. As an example, five types of opposing distances r FD For the angle θb, 31 sets of phase data are stored in 1 degree increments for a range of +15 degrees to -15 degrees. The memory 156 also stores transmission power data that reduces interference with other devices that may be present around the power receiving device 50B, i.e., transmission power data that represents an upper limit value of the transmission power limited by constraints on the power received by other devices. The upper limit value of the transmission power is an example of a predetermined power. As an example, five types of opposing distances r of 3 m, 4 m, . . . , and 7 m are stored. FD For each of the above, five types of upper limit values ​​for transmission power may be stored.

[0047] Next, a method for determining the elevation angle θa will be described.

[0048] The elevation angle θa can be calculated from the geometric relationship between the positions P1 and P1a by using the azimuth angle φ and the elevation angle θ, using the following equation (1).

[0049]

number

[0050]

number

[0051]

number

[0052] As described above, the focal length of the fisheye lens 141 is f L Then, the radius vector r is expressed by the following equation (4).

[0053]

number

[0054]

number

[0055] Next, a method of obtaining phase data will be described. Fig. 4 is a diagram for explaining the method of obtaining phase data. Fig. 4 shows a fisheye lens 141 of a camera 140, a marker 50A, a power receiving device 50B, and N antenna elements 111. Each antenna element 111 is one of four antenna elements 111 included in N subarrays 110A. The position of the marker 50A is equal to the position of the power receiving device 50B.

[0056] As shown in FIG. 4, the distances from the N subarrays 110A to the marker 50A are denoted by r1 to rN. Here, for the sake of simplicity, it is assumed that there is no positional deviation between the camera 140 and the marker 50A in the Y-axis direction. Since the centers of the 4N antenna elements 111 coincide with the origin of the XYZ coordinate system, the coordinates of the centers of the 4N antenna elements 111 are (X, Y, Z) = (0, 0, 0). In addition, there is no positional deviation between the camera 140 and the marker 50A in the Y-axis direction, and the facing distance is r FD Since the angle of the power receiving device 50B as viewed from the fisheye lens 141 is θb, the position of the power receiving device 50B is expressed as (X, Y, Z)=(r FD tanθb,0,r FD ) where the distance from the fisheye lens 141 to the power receiving device 50B is r ref Then, the distance r ref can be expressed by the following equation (6).

[0057]

number

[0058] The position of the i-th antenna element 111 among the N antenna elements 111 is defined as (X, Y, Z) = (d i , 0, 0), the distance r from the i-th antenna element 111 to the power receiving device 50B is i can be expressed by the following equation (7).

[0059]

number

[0060] Therefore, the distance r from the fisheye lens 141 to the power receiving device 50B ref and the path difference τ between the distance ri from the i-th antenna element 111 to the power receiving device 50B. i can be expressed by the following equation (8).

[0061]

number

[0062] Path difference τ i Since the unit is meters, convert it to the wavelength λ of the microwave used to obtain the phase difference ψ i When calculated, it can be expressed as the following equation (9).

[0063]

number

[0064] The sign of the phase difference expressed by equation (9) is inverted to -ψr FDi (θb) is set as the phase to be set in the phase shifter 120 when the i-th antenna element 111 transmits power, and multiple sets of phase data corresponding to multiple elevation angles θa for the N subarrays 110A are prepared and stored in the memory 156. FD A plurality of sets of phase data for the angles θb may be prepared and stored in the memory 156. By using such a plurality of sets of phase data, it is possible to make the power transmission signals transmitted from the N subarrays 110A reach the power receiving device 50B in the same phase. The plurality of sets of phase data corresponding to the plurality of angles θb are expressed by the following formula (10).

[0065]

number

[0066] The control unit 155 may use phase data of the angle θb corresponding to the elevation angle θa to set the shift amounts in the N phase shifters 120 connected to the N subarrays 110A, respectively.

[0067] 5 is a diagram illustrating the antenna gain of the antenna device 100A and the power supply device 100. FD 13 is a diagram showing the antenna gain of power received by the antenna of the power receiving device 50B when the distance is 4 m and the speed of the vehicle equipped with the antenna device 100A and the power supply device 100 is 80 km / h. The horizontal axis represents time, with 0 ms (milliseconds) representing the time when the elevation angle θa becomes 0 degrees, -300 ms representing the time when the elevation angle θa becomes +70 degrees, and +300 ms representing the time when the elevation angle θa becomes -70 degrees. That is, the time on the horizontal axis corresponds to the elevation angle θa. Note that the time when the elevation angle θa becomes +15 degrees is approximately -65 ms, and the time when the elevation angle θa becomes -15 degrees is approximately +65 ms.

[0068] 5, the antenna gain when the shift amount in the phase shifter 120 is adjusted using phase data based on the facing distance and elevation angle in the antenna device 100A and the power feeding device 100 is indicated by a solid line, and the antenna gain when phase data based only on the elevation angle is indicated by a dashed line for comparison. The antenna gain when phase data based only on the elevation angle is the antenna gain obtained in the power receiving device 50B when the shift amount in the N phase shifters 120 connected to the N subarrays 110A is set to a value corresponding to the elevation angle θa.

[0069] As shown in Fig. 5, the antenna gain when using phase data based on the facing distance and the elevation angle is larger or equal to the antenna gain when using phase data based only on the elevation angle, and the difference between the antenna gain when using phase data based on the facing distance and the elevation angle and the antenna gain when using phase data based only on the elevation angle becomes larger as the time period approaches 0 ms (as the absolute value of the elevation angle θa becomes smaller). It is considered that the closer the elevation angle θa is to 0 degrees, the shorter the distance between the N subarrays 110A and the power receiving device 50B becomes, and the effect of individual phase control of the N subarrays 110A using the phase data based on the facing distance and the elevation angle becomes more prominent.

[0070] Therefore, in the range of about -65ms to about +65ms where the elevation angle θa is within the range of ±15 degrees, the antenna gain is the largest, the power transmission efficiency is the highest, and the difference from the antenna gain for comparison is the largest. In addition, by transmitting the power transmission signal within the range of about -65ms to about +65ms, the power transmission time can be shortened compared to the case of transmitting the power transmission signal within the range of -300ms to +300ms. Since the high power transmission efficiency of the antenna device 100A corresponds to the large amount of power received by the power receiving device 50B, by transmitting the power transmission signal in a short time within the range of high power transmission efficiency, it is possible to realize efficient power reception at the power receiving device 50B, shortening of the power receiving time, and reduction of the influence of the power transmission signal on other devices that may be present around the power receiving device 50B.

[0071] In addition, in the simulation, it was confirmed that there is a lot of reflection when transmitting power in a region in a tunnel where the absolute value of the elevation angle θa is large (for example, a region of 30 degrees or more), but there is little reflection within the range of ±15 degrees. Therefore, transmitting power within a narrow angle range such as within the range of ±15 degrees can reduce the influence of reflected waves on other devices that may be present around the power receiving device 50B.

[0072] <Low side lobe beam> 6A and 6B are diagrams for explaining the reduction of the side lobes of the beam 115 radiated from the array antenna 110. In Fig. 6A and Fig. 6B, the horizontal axis indicates the angle (degrees) and the vertical axis indicates the gain (dB). From the viewpoint of achieving both efficient power reception at the power receiving device 50B and reducing the influence of the power transmission signal on other devices that may be present around the power receiving device 50B, the side lobes of the beam 115 radiated from the array antenna 110 are reduced.

[0073] In Fig. 6(A), the horizontal directivity when beam 115 is emitted from array antenna 110 in the horizontal 0 degree direction (+Z axis direction) is shown by a solid line, and the vertical directivity is shown by a dashed line. As can be seen from the horizontal directivity shown in Fig. 6(A), the gain of the side lobes on both sides is lower than the main lobe located in the 0 degree direction. Note that the vertical directivity is evenly distributed with respect to 0 degrees.

[0074] In addition, in Fig. 6(B), the horizontal directivity when beam 115 is emitted from array antenna 110 in the horizontal +15 degree direction (the direction in which angle θb is +15 degrees with respect to the +Z axis direction) is shown by a solid line, and the vertical directivity is shown by a dashed line. As can be seen from the horizontal directivity shown in Fig. 6(B), the gain of the side lobes on both sides is reduced compared to the main lobe located at about +15 degrees. Note that the vertical directivity is evenly distributed with respect to 0 degrees.

[0075] Such a reduction in side lobes of the beam 115 can be achieved, for example, by weighting the amplitude or power of the transmission signals transmitted from the N subarrays 110A using a Taylor distribution (window function).

[0076] <Continuous multiple power transmissions within a narrow angle range> FIG. 7 is a diagram for explaining power transmission from the antenna device 100A to the power receiving device 50B continuously multiple times within a narrow angle range. In FIG. 7, the +X axis direction is the direction in which a work vehicle (power transmitting vehicle) equipped with the antenna device 100A travels through a tunnel. The antenna device 100A starts transmitting a power transmission signal at a power transmission start position, and ends transmitting the power transmission signal at a power transmission end position. Here, as an example, a case will be described in which power transmission is continuously performed three times within a narrow angle range between the power transmission start position and the power transmission end position. FIG. 7 shows the antenna device 100A at the power transmission start position and the power transmission end position.

[0077] 7 also shows three power receiving antennas 50B1, 50B2, and 50B3 of the power receiving device 50B. Here, the power receiving device 50B has three power receiving antennas 50B1, 50B2, and 50B3, and each of the three power receiving antennas 50B1, 50B2, and 50B3 is provided with one marker 50A. Note that the marker 50A is omitted in FIG. 7.

[0078] A battery or the like is charged with power received by three power receiving antennas 50B1-50B3 of the power receiving device 50B. The power receiving antennas 50B1-50B3 are arranged at equal intervals in this order from the -X-axis direction side to the +X-axis direction side. The interval between the power receiving antennas 50B1-50B3 is d1+d2.

[0079] The facing distance from the antenna device 100A to the three power receiving antennas 50B1 to 50B3 of the power receiving device 50B is r (m). The facing distance r (m) is, for example, 3 to 7 m. The position that is a distance d2 past the power receiving antenna 50B1 is a position that is a distance d1 before the power receiving antenna 50B2, and the position that is a distance d2 past the power receiving antenna 50B2 is a position that is a distance d1 before the power receiving antenna 50B3. The power receiving antennas 50B1 to 50B3 are arranged in this manner to enable power transmission within three consecutive narrow angle ranges.

[0080] The distance D between the power transmission start position and the power transmission end position is D=3(d1+d2), and here, as an example, d1>d2. Therefore, at a position where the antenna device 100A starts transmission on the front side of each of the power receiving antennas 50B1-50B3 in the X-axis direction, each of the power receiving antennas 50B1-50B3 is located in the direction of angle +θ1. The angle +θ1 is an example of a first angle range on the first side in the +Z-axis direction. The +Z-axis direction is the front direction of the antenna device 100A. Furthermore, at a position where the antenna device 100A ends transmission to each of the power receiving antennas 50B1-50B3, each of the power receiving antennas 50B1-50B3 is located in the direction of angle -θ2. The angle -θ2 is an example of a second angle range on the second side in the +Z-axis direction. The angles +θ1 and -θ2 correspond to the above-mentioned angle θb, and the angles +θ1 and -θ2 are within a predetermined range of angles. Focal length of fisheye lens 141 f L Using this, d1=f L θ1, d2=f L θ2.

[0081] In FIG. 7, as an example, since d1>d2, the absolute value of angle +θ1 is greater than the absolute value of angle -θ2, but angles +θ1 and -θ2 may be equal, or may be ±15 degrees as described above.

[0082] The antenna device 100A starts power transmission by setting the angle of the beam 115 to +θ1 at a power transmission start position that is a distance d1 before the power receiving antenna 50B1 in the X-axis direction, and ends power transmission to the power receiving antenna 50B1 at a position that has passed the power receiving antenna 50B1 by a distance d2 while continuously changing the angle of the beam 115 toward -θ2. Since the position that has passed the power receiving antenna 50B1 by the distance d2 is a position that is a distance d1 before the power receiving antenna 50B2, the antenna device 100A sets the angle of the beam 115 to +θ1 without stopping power transmission at the position where power transmission to the power receiving antenna 50B1 is to be ended, and directs the beam 115 to the power receiving antenna 50B2 to transmit power to the power receiving antenna 50B2.

[0083] The antenna device 100A ends power transmission to the power receiving antenna 50B2 at a position where the power receiving antenna 50B2 has passed by a distance d2 while continuously changing the angle of the beam 115 from +θ1 to -θ2. Since the position where the power receiving antenna 50B2 has passed by a distance d2 is a position that is a distance d1 before the power receiving antenna 50B3, the antenna device 100A sets the angle of the beam 115 to +θ1 without stopping power transmission at the position where power transmission to the power receiving antenna 50B2 ends, and transmits power to the power receiving antenna 50B3 by directing the beam 115 to the power receiving antenna 50B3. The antenna device 100A ends power transmission at a power transmission end position where the power receiving antenna 50B3 has passed by a distance d2 while continuously changing the angle of the beam 115 from +θ1 to -θ2.

[0084] In this way, between the power transmission start position and the power transmission end position, the angle of the beam 115 is changed in accordance with the running of the power transmitting vehicle, and power is transmitted three times consecutively to the power receiving antennas 50B1 to 50B3 in a narrow angle range. Such three power transmissions are performed consecutively without any time gap. Note that the beam 115 may be temporarily turned off when changing the angle of the beam 115 from -θ2 to +θ1 in order to transmit power to the power receiving antenna 50B2 after the power transmission to the power receiving antenna 50B1 is completed, and when changing the angle of the beam 115 from -θ2 to +θ1 in order to transmit power to the power receiving antenna 50B3 after the power transmission to the power receiving antenna 50B2 is completed. Even in this case, the three power transmissions are performed consecutively without any time gap, and the beam 115 is radiated continuously multiple times over the narrow angle range.

[0085] In order to enable the continuous emission of the beam 115 within such a clamping angle range over multiple times, the three power receiving antennas 50B1 to 50B3 of the three power receiving devices 50B may be arranged along the X-axis so that the emission of the beam 115 over the clamping angle range can be continuously performed multiple times. More specifically, the control unit 155 may set the intervals between the three power receiving antennas 50B1 to 50B3, the moving speed of the antenna device 100A, and the clamping angle range so that the phase shifter 120 can be continuously controlled three times based on the phase data according to the three power receiving antennas 50B1 to 50B3.

[0086] <ROI Control> FIG. 8 is a diagram showing the region 142B1 set by the image processing unit 142B for the image data by ROI control. FIG. 8 shows the inner wall 51 of the tunnel and the three markers 50A in the image data acquired by the imaging unit 142A. Here, the power receiving device 50B has three power receiving antennas, and one marker 50A is provided for each power receiving antenna. The image processing unit 142B sets, by ROI control, the region 142B1 to be the detection target for the image data acquired by the imaging unit 142A within a predetermined clamping angle range where the angle θb is ±15 degrees with respect to the front direction (+Z-axis direction) of the antenna device 100A.

[0087] When the work vehicle equipped with the antenna device 100A is moving, the image processing unit 142B sets the region 142B1 in the +15-degree direction and waits. When the marker 50A enters the region 142B1, the image processing unit 142B makes the region 142B1 follow the marker 50A and moves it in the -X-axis direction to the -15-degree range. Then, when the region 142B1 reaches the -15-degree direction, the tracking stops, and the region 142B1 is set in the +15-degree direction and waits. The image processing unit 142B repeatedly performs the process of following the marker 50A in the region 142B1 in this way. While the marker 50A is captured within the region 142B1, the image processing unit 142B outputs a capture signal indicating that the capture is being performed to the control unit 155.

[0088] The control unit 155 transmits the power transmission signal while the capture signal is being input from the image processing unit 142B, and stops the power transmission when the capture signal is no longer input. Therefore, the position where the angle θb is +15 degrees with respect to the direction of the front of the antenna device 100A is the position where the image processing unit 142B starts capturing the marker 50A, and is the power transmission start position where the control unit 155 starts transmitting power. The distance on the inner wall 51 of the tunnel between the front of the antenna device 100A and the position where the angle θb is +15 degrees is d1. Also, the position where the angle θb is -15 degrees with respect to the front of the antenna device 100A is the position where the image processing unit 142B ends capturing the marker 50A, and is the power transmission end position where the control unit 155 ends transmitting power. The distance on the inner wall 51 of the tunnel between the front of the antenna device 100A and the position where the angle θb is -15 degrees is d2.

[0089] <Radiation angle pattern> Fig. 9 is a diagram showing an example of a radiation angle pattern of a power transmission signal output by antenna device 100A. In Fig. 9, the horizontal axis represents time (ms) and the vertical axis on the left represents the angle (degrees) of beam 115. The time on the horizontal axis is set to 0 (ms) when the angle of beam 115 becomes 0 degrees. Also, the right side of Fig. 9 shows the power transmission efficiency versus the angle of beam 115.

[0090] 9, the radiation angle pattern of the power transmission signal output by the antenna device 100A is shown by a solid line, and a comparative radiation angle pattern is shown by a dashed line. The comparative radiation angle pattern is a radiation angle pattern in which power is transmitted from -400 ms to +400 ms so that the angle of the beam 115 for one power receiving antenna is from +70 degrees to -70 degrees.

[0091] The radiation angle pattern of the power transmission signal output by the antenna device 100A is a radiation angle pattern for continuous power transmission when three power receiving antennas 50B1-50B3 are provided on the inner wall 51 of a tunnel as shown in Fig. 7. Three markers 50A are provided on each of the three power receiving antennas 50B1-50B3 as shown in Fig. 8.

[0092] The power receiving antennas 50B1 to 50B3 are arranged so that +θ1 is +15 degrees and −θ2 is −15 degrees in Fig. 7. This corresponds to the arrangement of the three markers 50A described in Fig. 8.

[0093] The control unit 155 repeats the operation of outputting the power transmission signal to each of the power receiving antennas 50B1 to 50B3 in the order of the power receiving antennas 50B1 to 50B3 within the angle range of +15 degrees to -15 degrees three times. Therefore, the radiation angle pattern in which the antenna device 100A transmits the power transmission signal to the power receiving antennas 50B1 to 50B3 is a radiation angle pattern in which the power transmission is continuously repeated three times within the angle range of +15 degrees to -15 degrees from about -140 ms to about 140 ms, as shown in Fig. 9. Such a radiation angle pattern is realized by ROI control.

[0094] As shown on the right side of Fig. 9, the power transmission efficiency is low when the angle of the beam 115 is large, and is highest when the angle of the beam 115 is 0 degrees. Within the range of the included angle from +15 degrees to -15 degrees, which corresponds to the range of the double-headed arrow A, the power transmission efficiency is very high. The included angle range is a highly efficient range in which the power transmission efficiency is equal to or higher than a predetermined value. In addition, the power transmission time is very short in the included angle range compared to the comparative radiation angle pattern.

[0095] By transmitting power using a radiation angle pattern in which power transmission is repeated three times consecutively within an angle range of +15 degrees to -15 degrees, power transmission is repeated within a range where power transmission efficiency is high and power can be transmitted in a short period of time.

[0096] <Amount of power received> Fig. 10 is a diagram showing the amount of power received by the power receiving device 50B according to the radiation angle pattern of the embodiment and the amount of power received according to the radiation angle pattern for comparison. In Fig. 10, the horizontal axis represents time (ms) and the vertical axis represents the amount of power received (mJ). Fig. 10 shows the amount of power received by the first, second, and third power transmissions according to the radiation angle pattern of the embodiment, the total amount of power received by the first, second, and third power transmissions, and the amount of power received according to the radiation angle pattern for comparison. The transmission power of the radiation angle pattern of the embodiment and the radiation angle pattern for comparison is equal and is maintained at a constant value over time.

[0097] The first, second, and third power transmissions are to the power receiving antennas 50B1, 50B2, and 50B3, respectively, and the total amount of received power represents the total power received by the three power receiving antennas 50B1 to 50B3 of the power receiving device 50B. Note that the amount of received power according to the comparative radiation angle pattern is the power received by one power receiving antenna placed in the same position as the power receiving antenna 50B2.

[0098] As shown in Figure 10, the amount of power received by the comparative radiation angle pattern is very small in the range from -400ms to -200ms where the power transmission efficiency is low, and increases rapidly in the range from about -100ms to about 100ms where the power transmission efficiency is high. Also, after 200ms where the power transmission efficiency becomes low again, the amount of power received is saturated. Thus, the comparative radiation angle pattern has many ranges where the power transmission efficiency is low, and it takes a long time to transmit power. The final amount of power received is about 16.5mJ.

[0099] In contrast, in the radiation angle pattern of the embodiment, the first power transmission starts at about -140 ms, the first power transmission switches to the second power transmission at about -45 ms, the second power transmission switches to the third power transmission at about 45 ms, and the third power transmission ends at about 140 ms. The power reception amount of the three power transmissions is approximately the same, about 8 mJ. The total power reception amount of the three transmissions is about 24 mJ.

[0100] In this way, the radiation angle pattern of the embodiment realizes a larger amount of received power in a shorter time than the radiation angle pattern for comparison. One power transmission takes about 90 mS, and the amount of received power is about 8 mJ. Two power transmissions result in a received power amount of about 16 mJ, which is equivalent to the amount of received power (about 16.5 mJ) by the radiation angle pattern for comparison. Furthermore, three power transmissions in the radiation angle pattern of the embodiment result in a received power amount of about 24 mJ, which is about 1.5 times the amount of received power (about 16.5 mJ) by the radiation angle pattern for comparison. The time required for power transmission is about 280 ms, which is about one-third of the 800 ms required by the radiation angle pattern for comparison.

[0101] As described above, when controlling the elevation angle of the beam 115 of the array antenna 110 only within the XZ plane, the position P1 obtained by the equidistant projection is converted into polar coordinates on a plane parallel to the XY plane to obtain the position P2, and the X coordinate (r cosφ) of the mapped position P2a obtained by mapping the position P2 onto the X axis is calculated by dividing the focal length f of the fisheye lens 141 by the X coordinate (r cosφ). L By dividing by this, the elevation angle θa (=r cosφ / f L ) is required.

[0102] Then, the control unit 155 may use phase data of the angle θb corresponding to the elevation angle θa to set the shift amounts in the N phase shifters 120 connected to the N subarrays 110A, respectively. If the shift amounts in the N phase shifters 120 are controlled using phase data corresponding to the change in the elevation angle θa accompanying the movement of the antenna device 100A and the power feeding device 100, it is possible to transmit power transmission signals that always arrive at the antenna of the power receiving device 50B from the N subarrays 110A with the same phase while the antenna device 100A and the power feeding device 100 are moving.

[0103] Furthermore, by transmitting power within a range of angles including the direction in front of the antenna device 100A, it is possible to transmit power efficiently in a short time within a range where power transmission efficiency is high. Also, the power receiving device 50B can receive power efficiently in a short time within a range where power reception efficiency is high.

[0104] Therefore, it is possible to provide the antenna device 100A and the power feeding device 100 that are capable of transmitting power so that the power receiver can efficiently receive power even in a short distance.

[0105] In addition, multiple sets of phase data are stored for multiple opposing distances r FD are stored in the memory 156, and the distance estimation unit 154 estimates the facing distance r FD Therefore, the facing distance r FD It is possible to set the shift amounts in the N phase shifters 120 connected to the N subarrays 110A, respectively, by using a plurality of sets of phase data corresponding to the distance to the power receiving device 50B in the Z-axis direction. Therefore, it is possible to provide the antenna device 100A and the power feeding device 100 that can transmit power so that the power receiver can efficiently receive power even at a short distance according to the distance to the power receiving device 50B in the Z-axis direction. FD If there are no sets of phase data corresponding to the estimated facing distance r FD The closest facing distance r FD It is only necessary to use phase data according to the above.

[0106] Furthermore, the positional deviation detection unit 153 detects the positional deviation between the camera 140 and the marker 50A in the Y-axis direction. If a positional deviation occurs, the distance estimation unit 154 reads out data indicating the degree of change in the pixel index number with respect to the positional deviation in the Y-axis direction from the memory 156, and calculates the facing distance r FD Therefore, when there is a positional deviation between the camera 140 and the marker 50A in the Y-axis direction, the control unit 155 estimates the facing distance r FD By using multiple sets of phase data according to the above, it is possible to provide an antenna device 100A and a power supply device 100 that can transmit power so that the power receiver can efficiently receive power even at a short distance depending on the distance to the power receiving device 50B in the Z axis direction, even if there is a positional misalignment between the camera 140 and the marker 50A in the Y axis direction.

[0107] Furthermore, since the antenna device 100A and the power supply device 100 control the elevation angle of the beam 115 output by the array antenna 110 only in the XZ plane, the number of phase shifters 120 required is only one-fourth compared to when the elevation angle is controlled both in the XZ plane and the YZ plane. This allows the antenna device 100A and the power supply device 100 to be realized at low cost.

[0108] Moreover, by transmitting power within a range of angles with high power transmission efficiency, it is possible to reduce the transmission power of the beam 115 radiated from the antenna device 100A to a predetermined power or less limited by the constraints on the received power, and it is possible to reduce the influence of the transmission signal on other devices that may be present around the power receiving device 50B. Furthermore, power transmission within a range of angles such as ±15 degrees reduces the spread of reflections in the tunnel, and therefore it is possible to reduce the influence of reflected waves on other devices that may be present around the power receiving device 50B.

[0109] In addition, since the included angle range is an angle range having a predetermined included angle spread between the front of the antenna device 100A and the front of the antenna device 100A, efficient power transmission is possible in the included angle range including the front of the antenna device 100A, where power transmission efficiency is high. In addition, when power is transmitted within the included angle range between the front of the antenna device 100A, the spread of reflected waves caused by reflection on the inner wall 51 of the tunnel, etc. can be suppressed, and the influence of the power transmission signal on other devices that may be present around the power receiving device 50B can be reduced.

[0110] Furthermore, if the angle +θ1 on the first side of the included angle range relative to the front direction of the antenna device 100A and the angle -θ2 on the second side of the included angle range relative to the front direction of the antenna device 100A are made equal, efficient power transmission is possible in symmetrical ranges when the antenna device 100A moves in the X-axis direction relative to the power receiving device 50B and when it moves closer to the power receiving device 50B and when it moves away from the power receiving device 50B. Furthermore, if the absolute values ​​of the angle +θ1 and the angle -θ2 are equal, it is easy to control the angle of the beam 115.

[0111] The power receiving device 50B is provided along the X-axis and has a plurality of power receiving antennas 50B1-50B3 that receive power transmission signals, and each of the plurality of power receiving antennas 50B1-50B3 is provided with a marker 50A. The antenna device 100A moves along the X-axis relative to the plurality of power receiving antennas 50B1-50B3, and the control unit 155 controls the phase shifter 120 multiple times based on the phase data according to the plurality of power receiving antennas 50B1-50B3. Therefore, power can be efficiently transmitted to each of the plurality of power receiving antennas 50B1-50B3 within a narrow angle range, and one power receiving device 50B can efficiently charge the battery in a short time with the power efficiently received by the plurality of power receiving antennas 50B1-50B3.

[0112] In addition, the multiple power receiving antennas 50B1-50B3 are arranged along the X-axis so that the beam 115 is continuously radiated multiple times over a range of a narrow angle, so that power can be transmitted to the multiple power receiving antennas 50B1-50B3 continuously in a radiation angle pattern as shown in Fig. 9, and power can be transmitted efficiently in a short time. The power receiving device 50B can receive power efficiently in a short time in a narrow angle range where power receiving efficiency is high. Furthermore, by completing power transmission in a short time, the probability that other devices that may be present around the power receiving device 50B will be subjected to radio wave interference can be reduced.

[0113] The power receiving device 50B is provided along the X-axis and has a plurality of power receiving antennas 50B1-50B3 that receive power transmission signals, and each of the plurality of power receiving antennas 50B1-50B3 is provided with a marker 50A. The intervals between the plurality of power receiving antennas 50B1-50B3, the moving speed of the antenna device 100A, and the range of the included angle are set so that the control unit 155 can control the phase shifter 120 continuously multiple times based on the phase data according to the plurality of power receiving antennas 50B1-50B3. Therefore, power can be transmitted to the plurality of power receiving antennas 50B1-50B3 continuously with the radiation angle pattern shown in FIG. 9, and power can be transmitted efficiently in a short time. The power receiving device 50B can also receive power efficiently in a short time within the range of the included angle with high power receiving efficiency.

[0114] In the above, a configuration has been described in which the center of the fisheye lens 141 coincides with the center of the 4N antenna elements 111. However, the center of the fisheye lens 141 may be offset from the center of the 4N antenna elements 111. In this case, the coordinate origin of the array antenna control phase calculation may be shifted by the amount of the positional offset. Alternatively, the marker 50A and the power receiving antenna may be installed apart by the amount of the positional offset.

[0115] Further, in the above, a configuration has been described in which the control device 150 has a position shift detection unit 153. However, for example, in a case where it is known that no position shift will occur between the camera 140 and the marker 50A, the control device 150 does not need to include the position shift detection unit 153, and the distance estimation unit 154 does not need to perform correction corresponding to the position shift.

[0116] In the above, the control device 150 has been described as having the distance estimation unit 154. For example, FD In an application where it is known that is constant, the control device 150 does not include the distance estimation unit 154 and the position deviation detection unit 153, and it is sufficient to store multiple sets of phase data corresponding to one type of opposing distance rFD in the memory 156.

[0117] In the above, the power receiving device 50B has three power receiving antennas 50B1-50B3, and the marker 50A is provided on each of the power receiving antennas 50B1-50B3. The number of power receiving antennas provided on the power receiving device 50B may be one, two, or four or more. The number of power receiving antennas may be appropriately determined depending on the purpose of the power receiving device 50B and restrictions on the output of other devices that may be present around the power receiving device 50B.

[0118] In the above, the range of the included angle is from -15 degrees to ±15 degrees with respect to the front direction of the antenna device 100A, but the range of the included angle is not limited to ±15 degrees and may be set appropriately depending on the use of the power receiving device 50B and restrictions on the output of other devices that may exist around the power receiving device 50B. The range of the included angle may be set as a high-efficiency range in which the power transmission efficiency is equal to or higher than a predetermined value.

[0119] <Application examples and power supply systems> FIG. 11 is a diagram showing an application example of the power supply device 100. The power supply device 100 is mounted on a vehicle as an example, and the inner wall 51 of a tunnel is provided with power receiving antennas 50B1-50B3 as targets and a radio wave absorber 52. Each of the power receiving antennas 50B1-50B3 is provided with a marker 50A, and one power receiving device 50B is connected to each of the power receiving antennas 50B1-50B3. The marker 50A is a retroreflector, a mirror ball, or the like. The distance between the inner wall 51 of the tunnel and the vehicle differs for each tunnel that the vehicle passes through. However, within the same tunnel, the distance between the inner wall of the tunnel and the vehicle can be considered to be approximately constant. The radio wave absorber 52 is provided on the inner wall 51 of the tunnel so as to be located around the power receiving antennas 50B1-50B3. As an example, the radio wave absorber 52 is configured in the shape of a single sheet. The radio wave absorber 52 is positioned around the power receiving antennas 50B1 to 50B3, and therefore around the power receiving device 50B.

[0120] Here, a system including the power supply device 100, the marker 50A, the power receiving device 50B, and the radio wave absorber 52 is the power supply system 10 of the embodiment. The power receiving device 50B has three power receiving antennas 50B1, 50B2, and 50B3. Since the power supply device 100 includes the antenna device 100A (see FIG. 1 ) and the microwave generation source 130, the power supply system 10 includes the antenna device 100A, the microwave generation source 130, the marker 50A, the power receiving device 50B, and the radio wave absorber 52.

[0121] When the vehicle travels in the +X-axis direction, the position of the marker 50A is converted by the camera 140 into polar coordinates on a plane parallel to the XY plane, and the X-coordinate (r cosφ) of the mapping position (the mapping position corresponding to P2a) mapped onto the X-axis is calculated by the focal length f of the fisheye lens 141. L Divide by the elevation angle θa (=r cosφ / f L ) can be obtained. Then, by reading out phase data according to the change in the elevation angle θa from the memory 156 and controlling the shift amount in the N phase shifters 120, it is possible to transmit power transmission signals that always reach the power receiving antennas 50B1-50B3 in sequence in the range of a narrow angle from the N subarrays 110A while the antenna device 100A and the power feeding device 100 are moving. The power transmission signals that arrive in the same phase are irradiated as beams to the power receiving antennas 50B1-50B3 in sequence. At this time, among the beams 115 radiated from the antenna device 100A toward the power receiving antennas 50B1-50B3, the beams that are directly radiated to the inner walls 51 around the power receiving antennas 50B1-50B3 and the beams that are reflected and radiated to the inner walls 51 around the power receiving antennas 50B1-50B3 can be absorbed by the radio wave absorber 52. This makes it possible to suppress interference with other devices that may be present around the power receiving device 50B.

[0122] Also, for example, when the elevation angle θa of the marker 50A #1 is zero degrees (0°), the facing distance from the center of the fisheye lens 141 of the camera 140 to the marker 50A can be estimated. Then, when transmitting a power transmission signal to the power receiving antenna 50B2 of the power receiving device 50B of the marker 50A #2, by reading out phase data based on the facing distance and the elevation angle from the memory 156 and controlling the shift amount in the N phase shifters 120, the antenna gain can be further improved.

[0123] For example, if receiving antennas 50B1-50B3, a sensor that monitors for loosening of bolts or the like at the fixing parts, a rectenna, and a wireless communication module are provided at fixing parts that fix infrastructure structures such as jet fans and signs attached to the inner wall 51 of a tunnel to the inner wall 51, and when a beam 115 is radiated from power supply device 100 to receiving antennas 50B1-50B3 while the vehicle is traveling, the rectenna connected to receiving antennas 50B1-50B3 generates power and activates the wireless communication module, which then radiates a signal representing the output of the sensor, which is received by the vehicle, the fixing state of the infrastructure structure can be inspected while traveling.

[0124] In this case, the wireless communication module may receive a signal representing the output of the sensor via the array antenna 110 .

[0125] In addition, the X coordinate (r·cosφ) of the mapping position (the mapping position corresponding to P2a) on the X axis from the positions of the power receiving antennas 50B1 to 50B3 that are shifted from the XZ plane is calculated, and the X coordinate (r·cosφ) is calculated by multiplying the focal length f of the fisheye lens 141 by the X coordinate (r·cosφ). L Divided by (r cosφ / f L ) is used as the elevation angle θa to control the beam 115, so even if a vehicle traveling in the X-axis direction shifts in either the plus or minus direction of the Y-axis, the positional deviation can be absorbed to determine the elevation angle θa.

[0126] 11, the power supply device 100 (antenna device 100A) communicates with the wireless communication module provided on the inner wall 51 of the tunnel, but the wireless communication module is not limited to being provided on the inner wall 51 of the tunnel and may be provided in various locations. In this way, the power supply device 100 (antenna device 100A) can be used as a communication device.

[0127] <Angle characteristics of radio wave absorber 52> 12 is a diagram showing an example of the characteristic of the reflection coefficient versus the incident angle of the beam 115 to the radio wave absorber 52. In Fig. 12, the horizontal axis represents the incident angle of the beam 115 to the radio wave absorber 52. The incident angle is the incident angle of the beam 115 with respect to the normal to the surface of the radio wave absorber 52.

[0128] 12, when the incident angle is 0 degrees, the reflection coefficient is the lowest, about -20 dB, and increases as the incident angle increases from 0 degrees to 90 degrees. A low reflection coefficient corresponds to a large amount of radio waves being absorbed by the radio wave absorber 52, and a high reflection coefficient corresponds to a small amount of radio waves being absorbed by the radio wave absorber 52. When the incident angle is in the range of about 0 degrees to 15 degrees or 0 degrees to 20 degrees, a sufficiently low reflection coefficient is obtained.

[0129] For example, when beam 115 is radiated from antenna device 100A with the included angle range set to ±15 degrees, the incident angle to radio wave absorber 52 falls within the range of ±15 degrees. Therefore, even if a state occurs in which part of beam 115 radiated from antenna device 100A is not received by power receiving antennas 50B1-50B3, the reflected waves can be absorbed by radio wave absorber 52, thereby suppressing interference with other devices that may be present around power receiving device 50B.

[0130] Furthermore, power transmission within an angle range such as within ±15 degrees causes little spread of reflection, and is therefore compatible with radio wave absorber 52, which has high absorption efficiency within an angle range. Therefore, even if reflection occurs during power transmission within an angle range such as within ±15 degrees, it can be efficiently absorbed by radio wave absorber 52, and the impact of reflected waves on other devices that may be present around power receiving device 50B can be reduced.

[0131] The above describes exemplary embodiments of the antenna device, power supply system, power supply device, and power supply method of the present invention. However, the present invention is not limited to the specifically disclosed embodiments, and various modifications and changes are possible without departing from the scope of the claims. [Explanation of symbols]

[0132] 10 Power Supply System 50B Power receiving device 50B1~50B3 Receiving antenna 52 Radio wave absorber 100 Power supply device 110 Array Antenna 110A Subarray 111 Antenna element 120 Phase Shifter 130 Microwave Source 140 Camera 141 Fisheye Lens 150 Control device 151 Position derivation part 152 Elevation angle acquisition part 153 Position deviation detection unit 154 Distance Estimation Unit 155 Control Unit 156 Memory

Claims

1. an array antenna having a plurality of antenna elements arranged two-dimensionally along a first axis and a second axis; a phase adjusting unit that adjusts a phase of a power transmission signal supplied to the plurality of antenna elements in the first axial direction; an image acquisition unit that acquires an image through a fisheye lens; a position derivation unit that converts a first position of a marker included in an image acquired by the image acquisition unit with respect to the image acquisition unit into a second position in polar coordinates on a first plane including the first axis and the second axis; an elevation angle acquisition unit that acquires an elevation angle of a projection position, obtained by projecting the first position onto a second plane including the first axis and a third axis, with respect to the third axis within the second plane based on the second position; a storage unit configured to store a plurality of sets of phase data representing a plurality of phases when the power transmission signals are transmitted from the plurality of antenna elements to the power receiving devices at the positions of the markers, the plurality of phases being adjusted so that the phases at which the power receiving devices receive the power transmission signals from the plurality of antenna elements are aligned, the plurality of sets of phase data corresponding to the plurality of elevation angles; a control unit that reads out the phase data corresponding to the elevation angle acquired by the elevation angle acquisition unit from the storage unit, and controls the phase adjustment unit based on the read out phase data so that the direction of the beam radiated by the array antenna becomes the elevation angle in the second plane; Including, the phase data is phase data for the plurality of elevation angles falling within a predetermined included angle range, the power receiving device includes a plurality of power receiving antennas that are provided along the first axis and receive the power transmission signal, and the marker is provided on each of the plurality of power receiving antennas; the array antenna moves relative to the plurality of receiving antennas along the first axis; The control unit controls the phase adjustment unit a plurality of times based on the phase data in accordance with the plurality of power receiving antennas.

2. the storage unit stores a plurality of sets of the phase data corresponding to a plurality of the elevation angles, and stores power data representing a transmission power of the power transmission signal; The control unit controls the phase adjustment unit based on the phase data, and controls the transmission power of the power transmission signal in accordance with the read power data. The antenna device according to claim 1 , wherein the power data represents a transmission power equal to or less than a predetermined power that is limited by a constraint on the receiving power of devices other than the power receiving device within a space in which the marker arranged along a wall portion exists.

3. 3. The antenna device according to claim 1, wherein the predetermined range of included angles is an angle range that includes a direction in which an elevation angle with respect to the third axis is zero degrees and has a spread of the predetermined included angle.

4. 4. The antenna device according to claim 3, wherein a first angle range on a first side of the predetermined included angle range in a direction in which the elevation angle relative to the third axis is zero degrees is equal to a second angle range on a second side of the predetermined included angle range in a direction in which the elevation angle relative to the third axis is zero degrees.

5. 5. The antenna device according to claim 1, wherein the plurality of receiving antennas are arranged such that radiation of beams covering the predetermined range of included angles is performed consecutively a plurality of times along the first axis.

6. the power receiving device includes a plurality of power receiving antennas that are provided along the first axis and receive the power transmission signal, and the marker is provided on each of the plurality of power receiving antennas; 5. The antenna device according to claim 1, wherein the distance between the plurality of receiving antennas, the moving speed of the antenna device, and the predetermined range of the included angle are set so that the control unit can control the phase adjustment unit continuously multiple times based on the phase data in accordance with the plurality of receiving antennas.

7. a distance estimation unit that estimates a distance from the image acquisition unit to the marker based on an image acquired by the image acquisition unit when the elevation angle acquired by the elevation angle acquisition unit is zero degrees; the storage unit stores the plurality of sets of the phase data in accordance with a plurality of distances from the image acquisition unit to the marker, 7. The antenna device according to claim 1, wherein the control unit reads out from the storage unit the phase data corresponding to the distance estimated by the distance estimation unit and the elevation angle acquired by the elevation angle acquisition unit, and controls the phase adjustment unit based on the read out phase data.

8. a positional deviation detection unit that detects a positional deviation between the image acquisition unit and the marker in the second axis direction based on a position of a center of gravity of the marker included in an image acquired by the image acquisition unit, The antenna device according to claim 7 , wherein the distance estimation unit estimates the distance from the image acquisition unit to the marker based on the image corrected in accordance with the degree of positional deviation detected by the positional deviation detection unit.

9. 9. The antenna device according to claim 1, wherein the elevation angle acquisition unit obtains, as the elevation angle, a value obtained by dividing coordinates of a mapping position obtained by mapping the second position onto the first axis by a focal length of the fisheye lens.

10. 10. The antenna device according to claim 9, wherein the coordinates of the mapping position are expressed by a value obtained by multiplying a radius in the polar coordinate system by a cosine of an angle of deviation.

11. The antenna elements are grouped into subarrays extending along the second axis; The antenna device according to claim 1 , wherein the phase adjustment unit is a plurality of phase shifters connected to the plurality of subarrays, respectively, and configured to adjust a phase of the power transmission signal for each of the subarrays.

12. 12. The antenna device according to claim 1, wherein the transmission signals supplied to the plurality of antenna elements are weighted to reduce side lobes of the beam radiated by the array antenna.

13. 13. The antenna device according to claim 1, wherein the image acquisition unit sets a region in the image in which the marker is to be detected within the predetermined angular range, and tracks the marker within the region by ROI (Region On Interest) control.

14. An antenna device according to any one of claims 1 to 13, a radio wave generating source that supplies the power transmission signal to the plurality of antenna elements; The power receiving device; The marker is attached to the power receiving device; and a radio wave absorber disposed around the power receiving device; A power supply system including:

15. an array antenna having a plurality of antenna elements arranged two-dimensionally along a first axis and a second axis; A radio wave source, a phase adjustment unit provided between the array antenna and the radio wave generation source and configured to adjust a phase of a power transmission signal supplied from the radio wave generation source to the plurality of antenna elements in the first axial direction; an image acquisition unit that acquires an image through a fisheye lens; a position derivation unit that converts a first position of a marker included in an image acquired by the image acquisition unit with respect to the image acquisition unit into a second position in polar coordinates on a first plane including the first axis and the second axis; an elevation angle acquisition unit that acquires an elevation angle of a projection position, obtained by projecting the first position onto a second plane including the first axis and a third axis, with respect to the third axis within the second plane based on the second position; a storage unit configured to store a plurality of sets of phase data representing a plurality of phases when transmitting power from the plurality of antenna elements to a power receiving device at the position of the marker, the plurality of phases being adjusted so that the phases at which the power receiving device receives the power transmission signals from the plurality of antenna elements are aligned, the plurality of sets corresponding to the plurality of elevation angles; a control unit that reads out the phase data corresponding to the elevation angle acquired by the elevation angle acquisition unit from the storage unit, and controls the phase adjustment unit based on the read phase data so that the direction of the beam radiated by the array antenna becomes the elevation angle in the second plane, the phase data is phase data for the plurality of elevation angles falling within a predetermined included angle range, the power receiving device includes a plurality of power receiving antennas that are provided along the first axis and receive the power transmission signal, and the marker is provided on each of the plurality of power receiving antennas; the array antenna moves relative to the plurality of receiving antennas along the first axis; The control unit controls the phase adjustment unit a plurality of times based on the phase data in accordance with the plurality of power receiving antennas.

16. an array antenna having a plurality of antenna elements arranged two-dimensionally along a first axis and a second axis; A radio wave source, a phase adjustment unit provided between the array antenna and the radio wave generation source and configured to adjust a phase of a power transmission signal supplied from the radio wave generation source to the plurality of antenna elements in the first axial direction; an image acquisition unit that acquires an image through a fisheye lens; a position derivation unit that converts a first position of a marker included in an image acquired by the image acquisition unit with respect to the image acquisition unit into a second position in polar coordinates on a first plane including the first axis and the second axis; an elevation angle acquisition unit that acquires an elevation angle of a projection position, obtained by projecting the first position onto a second plane including the first axis and a third axis, with respect to the third axis within the second plane based on the second position; a storage unit that stores a plurality of sets of phase data representing a plurality of phases when transmitting power from the plurality of antenna elements to a power receiving device at the position of the marker, the plurality of phases being adjusted so that the phases at which the power receiving device receives the transmission power signals from the plurality of antenna elements are aligned, corresponding to a plurality of the elevation angles; wherein the phase data is phase data for the plurality of elevation angles within a predetermined range of angles, reading out the phase data corresponding to the elevation angle acquired by the elevation angle acquisition unit from the storage unit, and controlling the phase adjustment unit based on the read out phase data so that the direction of the beam radiated by the array antenna becomes the elevation angle within the second plane; the power receiving device includes a plurality of power receiving antennas that are provided along the first axis and receive the power transmission signal, and the marker is provided on each of the plurality of power receiving antennas; the array antenna moves relative to the plurality of receiving antennas along the first axis; The power supply method further comprises controlling the phase adjustment unit a plurality of times based on the phase data in accordance with the plurality of power receiving antennas.

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