Distance estimation device, antenna device, power supply system, power supply device, and power supply method

Abstract

The present application provides a distance estimation device capable of estimating the distance between a power receiving device and a power supplying device in real time. The distance estimation device includes: a position deriving section that converts a first position of a marker included in an image acquired by a fisheye lens with respect to an image acquisition section into a second position in polar coordinates on a first plane including a first axis and a second axis; and an elevation angle acquisition section that acquires a first elevation angle of a position on a second plane including the first axis and a third axis after the first position is projected onto the second plane with respect to the third axis based on the second position, wherein a distance in the direction of the first axis between the image acquisition section and the marker is estimated based on coordinates of an upper end of the marker included in the image with respect to the third axis and an azimuth angle with respect to the first axis, coordinates of a lower end of the marker included in the image with respect to the third axis and an azimuth angle with respect to the first axis, and a length between the upper end and the lower end, and a distance in the direction of the third axis between the image acquisition section and the marker is estimated based on the first elevation angle and the distance in the direction of the first axis.

Description

Technical Field

[0001] This invention relates to a distance estimation device, an antenna device, a power supply system, a power supply device, and a power supply method. Background Technology

[0002] A conventional wireless power transmission device includes: a beam transmitting unit for transmitting a power beam to a wireless power receiving device mounted on an aircraft; an information acquisition unit for acquiring control information for improving the power receiving efficiency of the wireless power receiving device; and a control unit for controlling the power beam based on the control information to improve the power receiving efficiency of the wireless power receiving device. It is described that an array antenna can be used as the power transmission antenna (for example, see Patent Document 1).

[0003] Patent Document 1: Japanese Patent Application Publication No. 2019-135900 Summary of the Invention

[0004] <Problem to be solved by this invention>

[0005] On the other hand, when power is supplied from multiple antenna elements of an array antenna and received by a wireless power receiving device, and the wireless power receiving device is mounted on an aircraft as with conventional wireless power supply devices, there is sufficient distance between the wireless power supply device (power supply unit) and the wireless power receiving device (power receiving device). Therefore, the angular difference between the multiple antenna elements and the power receiving device is negligible, and even if power is supplied from multiple antenna elements to the same target, the phase deviation received when the power receiving device is small and hardly becomes a problem.

[0006] However, when the distance between the receiving device and the power supply device is only a few meters, if power is transmitted from multiple antenna elements to the same target, the angle difference between each antenna element and the receiving device increases when the receiving device receives power, and the power receiving phase deviation increases. Therefore, the combined power received may be reduced.

[0007] To solve this problem, it is preferable to monitor the distance between the receiving device and the power supply device in real time, so as to adjust the phase of the power transmission signal transmitted from multiple antenna elements to make the receiving phase consistent.

[0008] Therefore, the object of the present invention is to provide a distance estimation device, an antenna device, a power supply system, a power supply device, and a power supply method capable of estimating the distance between a power receiving device and a power supply device in real time.

[0009] <Methods for solving problems>

[0010] A distance estimation apparatus according to an embodiment of the present invention includes: an image acquisition unit for acquiring an image using a fisheye lens; a position derivation unit for converting a first position of a marker contained in the image acquired by the image acquisition unit relative to the image acquisition unit into a second position in polar coordinates on a first plane including a first axis and a second axis; an elevation angle acquisition unit for acquiring, based on the second position, a first elevation angle of the projected position after projecting the first position onto the second plane including the first axis and a third axis, relative to the third axis in the second plane; and a distance estimation unit for estimating the distance between the image acquisition unit and the marker, wherein the distance estimation... The image acquisition unit estimates the distance between the image acquisition unit and the mark in the direction of the first axis based on the coordinates of the upper end of the mark contained in the image relative to the second elevation angle of the third axis and the azimuth angle of the upper end relative to the first axis, the coordinates of the lower end of the mark contained in the image relative to the third axis and the azimuth angle of the lower end relative to the first axis, and the length between the upper end and the lower end. Based on the first elevation angle obtained by the elevation angle acquisition unit and the estimated distance in the direction of the first axis, the image acquisition unit estimates the distance between the image acquisition unit and the mark in the direction of the third axis.

[0011] <The Effects of the Invention>

[0012] The invention provides a distance estimation device, an antenna device, a power supply system, a power supply device, and a power supply method capable of estimating the distance between a power receiving device and a power supply device in real time. Attached Figure Description

[0013] Figure 1 This is a diagram showing the power supply device 100 according to an embodiment.

[0014] Figure 2 This is a diagram showing the power supply device 100 according to an embodiment.

[0015] Figure 3 This is a diagram showing the polar coordinate system of the array antenna 110.

[0016] Figure 4 This is a diagram illustrating the method for obtaining phase data.

[0017] Figure 5 This is a diagram illustrating the antenna gain of antenna device 100A and power supply device 100.

[0018] Figure 6 This is a diagram showing the marking 50A.

[0019] Figure 7 This is a diagram showing the polar coordinate system of the array antenna 110.

[0020] Figure 8 This is a flowchart illustrating the estimation process for the relative distance Z.

[0021] Figure 9 This is a graph showing the simulation results of the received power.

[0022] Figure 10 This is a diagram illustrating an application example of the power supply device 100. Detailed Implementation

[0023] The following describes embodiments of the distance estimation device, antenna device, power supply system, power supply device, and power supply method that apply the present invention.

[0024] <Implementation Method>

[0025] Figure 1 This 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 generator 130, a camera 140, and a control device 150. The antenna device 100A according to the embodiment removes the microwave generator 130 from the power supply device 100.

[0026] The following explanation uses the XYZ coordinate system. The top view refers to the XY plane. Furthermore, 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, while the XZ plane is an example of the second plane.

[0027] As an example, the array antenna 110 is divided into N subarrays 110A. The first (#1) to the Nth (#N) of the N subarrays 110A are shown. #1 to #N represent the coordinates of the N subarrays 110A in the X-axis direction. Here, N is an integer greater than 2, but... Figure 1 The diagram illustrates an even number N, greater than 4, as an example. N subarrays 110A are arranged along the X-axis (first axis direction), and each subarray 110A includes four antenna elements 111, for example. Therefore, the array antenna 110 includes 4N antenna elements 111, for example. Each array antenna 110 extends along the Y-axis (second axis direction). The antenna elements 111 are rectangular patch antennas in the top view. The array antenna 110 may also have a ground plane on the -Z-axis side of the antenna elements 111 that is maintained at ground potential. Note that, for example, the center of the 4N antenna elements 111 coincides with the origin of the XYZ coordinate system. Furthermore, 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 in two dimensions.

[0028] Below, in Figure 1 In addition to using Figure 2 Please provide an explanation. Figure 2This is a diagram illustrating the power supply device 100 according to an embodiment. Figure 2 In, with Figure 1 Similarly, the structure surrounding phase shifter 120 is shown in a simplified manner. Figure 2 In the accompanying diagram, the origins of the XYZ coordinate system are shown offset to make them easier to view, but the following is as follows: Figure 1 The origin of the XYZ coordinate system shown is aligned with the center of the positions of the 4N antenna elements 111. Furthermore, Figure 2 Regarding each subarray 110A, one adjacent antenna element 111 is also shown on the -Y axis side of the X-axis. Furthermore, Figure 2 The structural elements, marker 50A, and power receiving device 50B included in the control device 150 are also shown. As an example, marker 50A and power receiving device 50B are fixed to the inner wall 51 of the tunnel. The inner wall 51 of the tunnel is an example of a wall, and the interior of the tunnel is an example of a space containing marker 50A arranged along the inner wall 51. As an example, the antenna device 100A and the power supply device 100, while mounted on a work vehicle and traveling inside the tunnel, detect the marker 50A installed on the inner wall 51 of the tunnel and supply power to the power receiving device 50B.

[0029] In addition, Figure 2 In the XZ plane diagram, the marker 50A exists in the direction of angle θb, starting from the Z-axis. Figure 2 For ease of explanation, the XYZ coordinate system is shown offset. However, 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 formed by the line connecting the origin of the XYZ coordinate system, the line marked 50A, and the Z-axis within the XZ plane. For angle θb, when viewing the XZ plane from the +Y-axis direction, a positive value represents the value when swinging towards the +X-axis direction, and a negative value represents the value when swinging towards the -X-axis direction.

[0030] Here, the distance estimation device 100B of the embodiment includes a camera 140, an elevation angle acquisition unit 152 of the control device 150, a position offset detection unit 153, and a distance estimation unit 154, and is a device for estimating the distance between the camera 140 and the marker 50A. Figure 2 In the distance estimation device 100B, the camera 140, the elevation angle acquisition unit 152, the position offset detection unit 153, and the distance estimation unit 154 are marked with brackets.

[0031] Furthermore, the power supply system of the embodiment includes an antenna device 100A, a microwave generator 130, a marker 50A, and a power receiving device 50B. It is a system that transmits a power signal composed of microwaves generated by the microwave generator 130 from the antenna device 100A to the power receiving device 50B. Reference will be made below. Figure 10The power supply system is described. Furthermore, the method by which the power supply device 100 supplies power to the power receiving device 50 is a power supply method according to the embodiment.

[0032] N phase shifters 120 are provided corresponding to N subarrays 110A, and each of the N phase shifters 120 is connected to the antenna elements 111 of the N subarrays 110A. The phase shifter 120 is an example of a phase adjustment unit for adjusting the phase, and is an example of a phase shifter. In each subarray 110A, four antenna elements 111 are connected in parallel to one phase shifter 120.

[0033] In each subarray 110A, a transmission signal of the same phase is provided to four antenna elements 111. Furthermore, the phases of the transmission signals output by 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 emitted from the 4N antenna elements 111 can be controlled in the XZ plane.

[0034] The beam formed by the radio waves emitted from the 4N antenna elements 111 is the same as the beam output from the array antenna 110. Furthermore, the beam output from the array antenna 110 is the same as the beam output from the antenna device 100A and the power supply device 100.

[0035] Microwave source 130 is connected to N phase shifters 120 to provide microwaves with a specified power. Microwave source 130 is an example of an electromagnetic wave source. As an example, the frequency of the microwave is a frequency in the 920MHz band. Note that the description here refers to the power supply device 100 including microwave source 130, but it is not limited to microwaves; any electromagnetic wave of a specified frequency is acceptable.

[0036] Camera 140 is located between the N / 2th subarray 110A and the N / 2+1th subarray 110A in the X-axis direction, and between the second and third antenna elements 111 from the +Y-axis direction among the four antenna elements 111 included in each subarray in the Y-axis direction. Camera 140 includes a fisheye lens 141 and a camera body 142. Camera 140 is an example of an image acquisition unit. Figure 2 In the image, the camera body 142 is divided into a shooting unit 142A and an image processing unit 142B.

[0037] The fisheye lens 141 is a lens that uses equidistant projection. For example, 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. The camera body 142 is the part of the camera 140 excluding the fisheye lens 141, and can be a camera containing a CMOS (Complementary Metal Oxide Semiconductor) image sensor or an infrared camera.

[0038] Camera 140 acquires an image including marker 50A via fisheye lens 141 and outputs the image data to control device 150. Marker 50A is mounted on a powered device 50B, which has an antenna for receiving power, intended to illuminate the beam output by antenna device 100A and power supply device 100. Antenna device 100A and power supply device 100 determine the position of marker 50A contained in the image acquired by camera 140 and illuminate the beam of light onto powered device 50B.

[0039] The camera body 142 includes a capturing unit 142A and an image processing unit 142B. The capturing unit 142A includes a capturing element and is the part that acquires image data by capturing images through a fisheye lens 141. The image processing unit 142B performs image processing such as binarization on the image data acquired by the capturing unit 142A and outputs the pixel index to the control device 150. The pixel index is the XY coordinate value (address) representing the position of the marker 50A on the captured image screen.

[0040] In addition, the image processing unit 142B performs processing to obtain the outline of the mark 50A, processing to obtain the maximum outline, and processing to read the coordinates of the upper and lower ends of the mark 50A, and outputs the data representing the coordinates of the upper and lower ends of the mark 50A to the control device 150.

[0041] The process of extracting the contour of marker 50A is based on the distribution of pixel indices obtained by binarizing the image data acquired by the imaging unit 142A to extract one or more contours.

[0042] The process of finding the maximum contour involves selecting the largest contour from one or more contours extracted based on the distribution of pixel indices (maximum contour extraction based on the number of pixels within the contour). By finding the largest contour, the influence of noise and other factors can be eliminated.

[0043] The process of reading the coordinates of the upper and lower ends of mark 50A is a process of reading the coordinates of the upper and lower ends from the maximum contour obtained by the maximum contour calculation process. The image processing unit 142B outputs the read coordinates of the upper and lower ends of mark 50A to the control device 150.

[0044] The control device 150 includes a position derivation unit 151, an elevation angle acquisition unit 152, a position offset detection unit 153, a distance estimation unit 154, a control unit 155, and a memory 156. The control device 150 is implemented by a computer including a CPU (Central Processing Unit) and memory. The position derivation unit 151, elevation angle acquisition unit 152, position offset detection unit 153, distance estimation unit 154, and control unit 155 represent the functions of the program executed by the control device 150 as function blocks. The memory 156 functionally represents the memory of the control device 150.

[0045] exist Figure 1 and Figure 2 In addition, we will also refer to Figure 3 The unit includes a position derivation unit 151, an elevation angle acquisition unit 152, a position offset detection unit 153, a distance estimation unit 154, a control unit 155, and a memory 156. Figure 3 The polar coordinate system of the array antenna 110 is shown. Figure 3 The diagram shows a subarray 110A of the array antenna 110 in the power supply device 100, antenna elements 111 included in each subarray 110A, and a beam 115 output from the array antenna 110. Figure 3 A polar coordinate system is shown on plane 1, which is parallel to the XY plane. Plane 1 is the xy plane of the image data acquired by the imaging unit 142A, and is equal to the xy plane used for the pixel index output from the image processing unit 142B. The x-axis and y-axis are parallel to the X-axis and Y-axis of the XYZ coordinate system, respectively, and are also equal in direction.

[0046] Furthermore, let the position of marker 50A in the XYZ coordinate system be P1, and let the elevation angle of the line segment connecting the origin O and position P1 be θ, and the azimuth angle be φ. The elevation angle is the angle relative to the +Z axis direction, and the azimuth angle is the angle relative to the +X axis direction. In the planar view viewed from the +Z axis direction, clockwise is taken as a positive value. Additionally, let the elevation angle of the line segment connecting position P1a (after projecting position P1 onto the XZ plane) and the origin O be θa. The elevation angle θa is an approximation obtained by projecting the elevation angle θ onto the XZ plane when the position of marker 50A is close to the XZ plane. Similar to angle θb, when viewing the XZ plane from the +Y axis direction, the elevation angle θa is represented by a positive value when swinging towards the +X axis direction, and by a negative value when swinging towards the -X axis direction.

[0047] Position P1 is an example of the first position, and position P1a is an example of the projected position. Furthermore, the origin O is an example of the reference point of the XYZ coordinate system.

[0048] Antenna device 100A and power supply device 100 control the elevation angle of the beam 115 output by array antenna 110 only in the XZ plane. This is based on the assumption that since array antenna 110 is powered in phase in the Y-axis direction, it becomes a fixed beam in the Y-axis direction, and the beam can be swung in the elevation direction that makes the Z-axis 0 degrees; the position of receiving device 50B is almost not deviated from the XZ plane (for example, the elevation angle relative to the Z-axis in the YZ plane is approximately within ±30 degrees). This is because if receiving device 50B is located in such a position, the size of the control section of array antenna 110 can be suppressed by controlling the elevation angle of beam 115 only in the XZ plane, and beam 115 can be efficiently irradiated onto receiving device 50B.

[0049] The position derivation unit 151 calculates the centroid of the image of marker 50A based on the pixel index output from the image processing unit 142B. The pixel index output from the image processing unit 142B represents the equidistant projected image obtained through the fisheye lens 141. Through this image processing, the position P1 of marker 50A relative to the array antenna 110 contained in the image acquired by the camera 140 is converted into a position P2 in polar coordinates on plane 1. Thus, the position derivation unit 151 derives position P2. Position P2 is the position of the centroid calculated by the position derivation unit 151. Position P2 is an example of a second position.

[0050] Position P2 is represented by the radial direction r from the origin O and the deflection angle φ. Let the focal length of the fisheye lens 141 be f. L Then the radius r is determined by r = f L θ represents the position. The deflection angle φ is the same as the azimuth angle φ. The position derivation unit 151 calculates r·cosφ after mapping the radial vector r to the X-axis through the above image processing. The position derivation unit 151 outputs the data representing the position P2 to the elevation angle acquisition unit 152.

[0051] The elevation angle acquisition unit 152 acquires (calculates) the X coordinate (r·cosφ) of the mapped position P2a after mapping position P2 onto the X-axis, and divides it by the focal length f of the fisheye lens 141. L The obtained value is (r·cosφ / f) L The elevation angle θa is obtained by taking the elevation angle θa as an integer. The reason for obtaining the elevation angle θa will be explained later. The elevation angle acquisition unit 152 outputs the elevation angle θa to the distance estimation unit 154 and the control unit 155.

[0052] The position offset detection unit 153 calculates the shape and centroid of the marker 50A based on the pixel index output from the image processing unit 142B, and detects the position offset between the camera 140 and the marker 50A in the Y-axis direction based on the position of the centroid within the range where the marker 50A exists. For example, 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. Therefore, for example, the position of the centroid in the Y-axis direction when there is no position offset between the camera 140 and the marker 50A can be set to Y=0. If the calculated position of the centroid within the range where the marker 50A exists is Y=0, the position offset detection unit 153 determines that there is no position offset between the camera 140 and the marker 50A. Furthermore, if the calculated position of the centroid within the range where the marker 50A exists is not Y=0, the position offset detection unit 153 determines that a position offset has occurred between the camera 140 and the marker 50A, and detects the position offset. The position offset detection unit 153 outputs the detection result to the distance estimation unit 154. Note that the position of the center of gravity can also be obtained from the position derivation unit 151.

[0053] When the elevation angle θa calculated by the elevation angle acquisition unit 152 is zero degrees (0 degrees), the distance estimation unit 154 estimates the distance from the center of the fisheye lens 141 to the mark 50A based on the pixel index number output from the image processing unit 142B of the camera 140. An elevation angle θa of 0 degrees means that, in the Z-axis direction, the mark 50A exists on the front of the fisheye lens 141 (the center of gravity of the mark 50A exists on the Z-axis).

[0054] The distance estimation unit 154 estimates the relative distance r from the center of the fisheye lens 141 to the mark 50A when the elevation angle θa is 0 degrees. FD An elevation angle θa of 0 degrees is an example of an elevation angle θa being included within a specified angular range that includes 0 degrees. Relative distance r FD It is the distance of marker 50A relative to camera 140 on the Z-axis.

[0055] For example, when the camera 140 and the marker 50A are separated by multiple distances along the Z-axis, the multiple binarized pixel indexes acquired by the image processing unit 142B are pre-stored in the memory 156. Furthermore, the distance estimation unit 154 counts the pixel indexes output from the image processing unit 142B of the camera 140 when the elevation angle θa is zero degrees (0 degrees), and compares them with the multiple relative distances r stored in the memory 156. FD By comparing multiple reference data, the relative distance r from the center of the fisheye lens 141 to mark 50A when the elevation angle θa is 0 degrees can be estimated. FD Since the pixel index number depends on the relative distance r FDThe relative distance r varies depending on the pixel index, therefore it can be estimated based on the pixel index number. FD .

[0056] Note that when the elevation angle θa is zero degrees (0 degrees), the image processing unit 142B of the camera 140 outputs pixel indices multiple times, and the relative distance r is estimated based on the average of the multiple pixel indexes. FD That's all.

[0057] Furthermore, because the fisheye lens 141 is used, even when a positional shift occurs between the camera 140 and the marker 50A, compared to the case where no positional shift occurs between the camera 140 and the marker 50A, the relative distance r is [not specified]. FD The pixel index number also decreases. Therefore, when the position offset detection unit 153 determines that a position offset has occurred between the camera 140 and the marker 50A in the Y-axis direction, the distance estimation unit 154 can estimate the relative distance r by storing data representing the degree of change in the position offset of the pixel index number relative to the Y-axis direction in the memory 156 in advance. FD That's all.

[0058] Note that when the elevation angle θa is included in a specified angle range including 0 degrees, the distance estimation unit 154 estimates the relative distance r using the above estimation method. FD However, when the elevation angle θa is not included in the specified angle range containing 0 degrees, a different estimation method is used to estimate the distance X and relative distance Z in real time. Distance X and relative distance Z are the X and Z components of the distance from the center of the fisheye lens 141 to the mark 50A. Real-time estimation of distance X and relative distance Z means estimating the distance X and relative distance Z in real time based on the current elevation angle θa when the elevation angle θa is not included in the specified angle range containing 0 degrees. The aforementioned relative distance r... FD It can only be estimated when the elevation angle θa is zero degrees (0 degrees), while the distance X and relative distance Z can be estimated in real time because the elevation angle θa is not included in the specified angle range containing 0 degrees. See below for further details. Figure 7 Explain the methods for estimating distance X and relative distance Z.

[0059] The control unit 155 controls the phase shift amount (adjustment amount) in the phase shifter 120 so that the direction of the beam 115 emitted by the array antenna 110 is an elevation angle θa in the XZ plane. The elevation angle θa is acquired by the elevation angle acquisition unit 152. In addition, the control unit 155 performs output control of the microwave generator 130 and shooting control of the camera 140, etc.

[0060] The control unit 155 specifically controls the phase shift amount in the phase shifter 120 as follows: The control unit 155 reads the relative distance r estimated by the distance estimation unit 154 from the memory 156. FD The phase data corresponding to the elevation angle θa acquired by the elevation angle acquisition unit 152 is used to control the phase displacement of the N phase shifters 120 based on the read phase data. The relative distance r estimated by the distance estimation unit 154 is... FD The relative distance r is estimated by the distance estimation unit 154 when the elevation angle θa is included in the specified angle range containing 0 degrees and when the elevation angle θa is not included in the specified angle range containing 0 degrees. FD .

[0061] Here, in order to ensure efficient power reception by the receiving antenna of the power receiving device, ideally, the phases of the transmission signals received by the receiving antenna from the N subarrays 110A should be equal. On the other hand, the antenna device 100A and the power supply device 100 transmit the transmission signals to the power receiving device 50B, located at a close distance of approximately 3m to 7m from the array antenna 110. When power is transmitted to the power receiving device 50B installed on the inner wall 51 of the tunnel, with the angle θb at 0 degrees, the distance from the array antenna 110 to the power receiving device 50B is approximately 3m to approximately 5m.

[0062] Because of this assumption of short-distance power transmission, the relative difference in distance from each of the N subarrays 110A to the receiving antenna of the power receiving device is relatively large. When the N subarrays 110A transmit power to the same target, the phase of the transmission signals received by the receiving antenna of the power receiving device from the N subarrays 110A is inconsistent, and the power receiving device 50B cannot receive power efficiently. The difference in distance from each of the N subarrays 110A to the receiving antenna of the power receiving device varies depending on the angle θb and the distance from the N subarrays 110A to the receiving antenna of the power receiving device along the Z-axis.

[0063] Therefore, the antenna device 100A and the power supply device 100 use phase data to adjust the phase of each of the N subarrays 110A during power transmission, so that the phase of the power transmission signal received by the receiving antenna of the power receiving device from the N subarrays 110A is consistent. The phase data represents the amount of phase displacement (adjustment). Here, as an example, assuming power transmission occurs when the elevation angle θa changes from +70 degrees to -70 degrees as the antenna device 100A and the power supply device 100 move, multiple sets of phase data are prepared that can adjust the phase displacement of the N subarrays 110A in 1-degree steps. Each set of phase data includes the N phase displacements set for the N phase shifters 120 connected to the N subarrays 110A respectively, corresponding to a certain elevation angle θa. For the range of +70 degrees to -70 degrees of angle θa, 141 sets of such phase data are prepared in 1-degree steps, for a certain relative distance r.FD Multiple sets of phase data. Furthermore, in order to be able to obtain phase data based on multiple relative distances r FD Each of these is used to adjust the phase displacement of the N subarrays 110A, preparing them for interaction with multiple relative distances r. FD The corresponding phase data for multiple sets of quantities. Note that since the phase data is created based on the angle θb, therefore... Figure 2 The phase data ψ3(θb) to ψ7(θb) of multiple sets of quantities are represented by θb. The control unit 155 only needs to use the phase data of multiple sets of quantities with respect to the angle θb, which is equal to the elevation angle θa. Furthermore, each of the phase data ψ3(θb) to ψ7(θb) has a displacement amount θs#1 to θs#N corresponding to the coordinates (#1 to #N) of the N subarrays 110A. For example, the displacement amount θs#1 of the displacement amounts θs#1 to θs#N contained in the phase data ψ3(θb) is used for the antenna element 111 of the subarray 110A at coordinate #1, and the displacement amount θs#N is used for the antenna element 111 of the subarray 110A at coordinate #N. Note that, hereinafter, without distinguishing between the displacement amounts θs#1 to θs#N, they are referred to as the displacement amount θs.

[0064] The control unit 155 uses the relative distance r estimated by the distance estimation unit 154. FD The phase data of the corresponding multiple sets of quantities, and the phase data of the angle θb that is equal to the elevation angle θa obtained by the elevation angle acquisition unit 152, are used to control the displacement of the phase in the N phase shifters 120.

[0065] Note that here, the control unit 155 uses the relative distance r estimated by the distance estimation unit 154. FD The phase data of the corresponding multiple sets of quantities, and the phase data of the angle θb that is equal to the elevation angle θa obtained by the elevation angle acquisition unit 152, are used to control the phase displacement of the N phase shifters 120.

[0066] The memory 156 is an example of a storage unit, storing programs executed during processing by the position export unit 151, the elevation angle acquisition unit 152, and the control unit 155, data used during program execution, data generated by program execution, and image data acquired by the camera 140. Furthermore, the memory 156 stores data for multiple relative distances r. FD Each of these stores phase data for multiple sets of quantities. For example, this applies to five relative distances r: 3m, 4m, ..., 7m. FD For an angle θa ranging from +70 degrees to -70 degrees, 141 sets of phase data are stored in 1-degree increments. Additionally, memory 156 stores length data representing the length between the upper and lower ends of marker 50A.

[0067] Next, the method for determining the elevation angle θa will be explained.

[0068] If the azimuth angle φ and the elevation angle θ are used, the elevation angle θa can be obtained from the following equation (1) based on the geometric relationship between position P1 and position P1a.

[0069] (number 1)

[0070]

[0071] If we expand equation (1), we get equation (2).

[0072] (Number 2)

[0073] tanθa=cosφtanθ (2)

[0074] Here, when the elevation angle θ is small enough, tanθ≈θ; when the azimuth angle φ is small enough, cosφ≈1; and when the azimuth angle φ is close to 90 degrees, cosφ≈0. Therefore, equation (2) can be transformed into equation (3).

[0075] (Number 3)

[0076] θa=θcosφ (3)

[0077] That is, when the position of the power receiving device 50B is almost not deviated from the XZ plane, the elevation angle θa can be approximated as in equation (3).

[0078] Furthermore, as mentioned above, if the focal length of the fisheye lens 141 is set to f... L Then the radial direction r is represented by the following equation (4).

[0079] (Number 4)

[0080] r = f L θ (4)

[0081] According to equations (3) and (4), the elevation angle θa can be expressed by equation (5).

[0082] (number 5)

[0083] θa=r·cosφ / f L (5)

[0084] Thus, the elevation angle θa can be approximately obtained using equation (5).

[0085] Next, the method for obtaining phase data will be explained. Figure 4 This is a diagram illustrating the method for obtaining phase data. Figure 4The image shows a fisheye lens 141 of 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 the N subarrays 110A. The position of marker 50A is equal to the position of power receiving device 50B.

[0086] like Figure 4 As shown, the distances from the N subarrays 110A to the marker 50A are denoted as r1 to rN. For simplicity, it is assumed that the camera 140 and the marker 50A have no positional offset in the Y-axis direction. The centers of the 4N antenna elements 111 coincide with the origin of the XYZ coordinate system; therefore, the coordinates of the centers of the 4N antenna elements 111 are (X, Y, Z) = (0, 0, 0). Furthermore, the camera 140 and the marker 50A have no positional offset in the Y-axis direction, and their relative distance is r. FD The angle of the receiving device 50B as observed from the fisheye lens 141 is θb. Therefore, the position of the receiving device 50B can be expressed as (X, Y, Z) = (r FD ·tanθb,0,r FD Here, let r be the distance from the fisheye lens 141 to the power receiving device 50B. ref Then the distance r ref It can be represented by the following formula (6).

[0087] (number 6)

[0088]

[0089] If we let the position of the i-th antenna element 111 among N antenna elements 111 be (X, Y, Z) = (d i If (0, 0), then the distance r from the i-th antenna element 111 to the power receiving device 50B is... i It can be represented by the following formula (7).

[0090] (number 7)

[0091]

[0092] Therefore, the distance r from the fisheye lens 141 to the power receiving device 50B ref and the distance r from the i-th antenna element 111 to the power receiving device 50B i Path difference τ i It can be represented by the following formula (8).

[0093] (number 8)

[0094] τ i =r i -r ref (8)

[0095] Due to path difference τ i It is measured in meters, so if we convert it to the wavelength λ of the microwave used to calculate the phase difference ψ... i Then it can be represented by the following formula (9).

[0096] (number 9)

[0097]

[0098] As long as the sign of the phase difference represented by equation (9) is reversed, -ψr FD,i (θb) is the phase set for the phase shifter 120 when the i-th antenna element 111 is powered on. For the N subarrays 110A, multiple sets of phase data corresponding to multiple elevation angles θa are prepared and stored in the memory 156. Furthermore, it is only necessary to prepare phase data for multiple relative distances r... FD The phase data of multiple sets of quantities can be stored in memory 156. By using such phase data of multiple sets of quantities, the power transmission signals transmitted from the N subarrays 110A can reach the power receiving device 50B with the same phase. The phase data of multiple sets of quantities corresponding to multiple angles θb is represented by the following formula (10).

[0099] (number 10)

[0100]

[0101] The control unit 155 only needs to use the phase data of the angle θb corresponding to the elevation angle θa to set the displacement of the N phase shifters 120 connected to the N subarrays 110A respectively.

[0102] Figure 5 This diagram illustrates the effects of the antenna device 100A and the power supply device 100. Figure 5 This shows the relative distance r FD This is a graph showing the antenna gain of the receiving antenna of a vehicle with a height of 4m, equipped with antenna device 100A and power supply device 100, at a speed of 80km / h. The horizontal axis represents time; 0 seconds represents the moment when the elevation angle θa reaches 0 degrees, -300 seconds represents the moment when the elevation angle θa reaches +70 degrees, and +300 seconds represents the moment when the elevation angle θa reaches -70 degrees. That is, the time on the horizontal axis corresponds to the elevation angle θa.

[0103] In addition, Figure 5In the diagram, the solid line represents the antenna gain when the displacement in the phase shifter 120 is adjusted using phase data based on relative distance and elevation angle in the antenna device 100A and power supply device 100, while the dashed line represents the antenna gain used for comparison when phase data based solely on elevation angle is used. The antenna gain using phase data based solely on elevation angle is the antenna gain obtained by the power receiving device 50B when the displacement in the N phase shifters 120 connected to the N subarrays 110A is set to a value corresponding to the elevation angle θa.

[0104] like Figure 5 As shown, the antenna gain when using phase data based on relative distance and elevation angle is greater than or equal to the antenna gain when using phase data based solely on elevation angle. The closer the time period is to 0 seconds (the smaller the absolute value of the elevation angle θa), the greater the difference between the antenna gain when using phase data based on relative distance and elevation angle and the antenna gain when using phase data based solely on elevation angle. It can be considered that the closer the elevation angle θa is to 0 degrees, the shorter the distance between the N subarrays 110A and the receiving device 50B, and the more significant the effect of individual phase control of the N subarrays 110A using phase data based on relative distance and elevation angle.

[0105] <Structure marked 50A>

[0106] Figure 6 This is a diagram showing the marking 50A. Figure 6 The vertical direction in the text indicates the vertical direction when the mark 50A is set. For example... Figure 6 As shown in (A), the mark 50A has an upper end 50AU, a lower end 50AL, and a wide portion 50AW. As an example, the mark 50A includes a reflector that reflects infrared light by retroreflection, which is capable of reflecting infrared light across the entire surface of the mark 50A.

[0107] Marker 50A has a cylindrical shape that is longer vertically than its base. The widest portion 50AW is the thickest, while the upper end 50AU and lower end 50AL are narrower than the widest portion 50AW. Furthermore, as an example, the vertical length of the portion above the wide end 50AU is equal to the vertical length of the portion below the wide end 50AL. Note that marker 50A only needs to be able to reflect infrared or visible light, and the coordinates of the upper end 50AU, lower end 50AL, and center of gravity can be obtained through image processing by camera 140; the structure shown here is an example.

[0108] also, Figure 6 (B) represents an example of a pixel index obtained by the image processing unit 142B through image processing such as binarization of the image data acquired by the imaging unit 142A. Figure 6 In (B), the horizontal axis is the x-axis, and the vertical axis is the y-axis. The x-axis, y-axis, and... Figure 3 The x-axis and y-axis of the plane 1 shown are equal, and the origin is also equal.

[0109] The pixel index contains the outline marked 50A, and the coordinates of the upper 50AU are set to (x... U y U Set the coordinates of the lower 50AL to (x L y L ), set the coordinates of the centroid of marker 50A to (x C y C The contour of marker 50A is obtained by the image processing unit 142B through contour extraction based on pixel index distribution. In actual pixel indices, in addition to the contour of marker 50A, there may sometimes be small contours generated by noise, etc. Therefore, the contour of marker 50A is obtained by performing a process of obtaining the largest contour from multiple contours extracted based on pixel index distribution, i.e., obtaining the largest contour. Furthermore, the image processing unit 142B obtains the coordinates of the upper end 50AU and the lower end 50AL based on the contour of marker 50A obtained as the largest contour. The coordinates of the centroid are obtained by the position derivation unit 151.

[0110] The marker 50A has the above-described structure in order to minimize the positional offset of the center of gravity relative to the center of the marker 50A (the vertical center and the center when viewed from above) when the position derivation unit 151 calculates the center of gravity of the image of the marker 50A based on the pixel index output from the image processing unit 142B. Ideally, the center of the marker 50A is derived by the position derivation unit 151 as the center of gravity of the marker 50A.

[0111] The reason for minimizing the deviation of the center of gravity from the center of the mark 50A is that, Figure 3 In the polar coordinate system shown, by minimizing the height deviation between the centroid of mark 50A and the origin O in the Y-axis direction, the elevation angle θa can be calculated with high precision in the XZ plane, and phase control can be performed with high precision.

[0112] Furthermore, using the coordinates of the upper end 50AU, lower end 50AL, and center of gravity of marker 50A, as well as length data representing the vertical length of marker 50A, the relative distance Z from the origin O to marker 50A along the Z-axis can be estimated in real time. Regarding the ability to estimate the relative distance Z, [the following is used]. Figure 7 The explanation will follow.

[0113] Note that here, the method by which the image processing unit 142B obtains the coordinates of the upper end 50AU and the lower end 50AL of the mark 50A is described, but it does not necessarily have to be the upper end 50AU and the lower end 50AL of the mark 50A. For example, if the reflector is set to a position offset downwards from the upper end of the mark 50A, it could be the coordinates of the upper end of the upper portion of the mark 50A where the reflector exists. Similarly, if the reflector is set to a position offset upwards from the lower end of the mark 50A, it could be the coordinates of the lower end of the lower portion of the mark 50A where the reflector exists. Furthermore, as length data representing the vertical length of the mark 50A, length data representing the length between the upper and lower ends could be used.

[0114] <Methods for Real-Time Estimation of Relative Distance Z>

[0115] Figure 7 This is a diagram showing the polar coordinate system of the array antenna 110. The process of estimating the relative distance Z is performed by the control device 150. The method of estimating the relative distance Z is realized by performing the process of estimating the relative distance Z.

[0116] exist Figure 7 In, with Figure 3 Similarly, subarrays 110A of the array antenna 110, antenna elements 111 included in each subarray 110A, and beam 115 output from the array antenna 110 are shown. Furthermore, in Figure 7 In addition to these, mark 50A is also shown. Mark 50A is configured such that center 50AC1 and centroid 50AC2 are aligned, but due to the existence of a maximum contour based on pixel index, the centroid 50AC2 derived by position derivation unit 151 deviates from center 50AC1, therefore... Figure 7 In the diagram, the center 50AC1 and the centroid 50AC2 are represented separately.

[0117] The Y-coordinate of the center 50AC1 of marker 50A is Y = 0. That is, the height of the center 50AC1 of marker 50A along the Y-axis is the same as the height of the origin O of the XYZ coordinate system. Furthermore, the coordinates of the upper end 50AU, lower end 50AL, and centroid 50AC2 of marker 50A in the XYZ coordinate system are (X, Y) respectively. U (Z), (X, Y) L (Z), (X, Y) C (Z). Since marker 50A extends parallel to the Y-axis, the X and Z coordinates of the upper end 50AU, the lower end 50AL, and the centroid 50AC2 are the same. Note that in Figure 7 In the diagram, the mark 50A is simplified and shown as a cylinder.

[0118] Furthermore, the polar coordinates of the upper 50 AU are the elevation angle θ. Uand azimuth φ U The polar coordinates of the lower 50AL are the elevation angle θ. L Azimuth φ L The polar coordinates of the centroid 50AC2 are the elevation angle θ. C Azimuth φ C Elevation angle θ U This is an example of the second elevation angle, θ. L This is an example of the third elevation angle. Furthermore, let P3 be the point on plane 1 where the upper end 50AU, the lower end 50AL, and the center of gravity 50AC2 are projected onto plane 1. U P3 L P3 C Point P3 U P3 L P3 C The x and y coordinates in plane 1 are respectively (x U y U ), (x L y L ) and (x C y C In addition, point P3 U P3 L P3 C The moving diameters are respectively r U r L r C .

[0119] If using a fisheye lens with a focal length of 141 f L The angle of elevation θ between the center of gravity and 50AC2 C Then by r C =f L θ C The radius r representing the centroid 50AC2 C Furthermore, if the radial vector r is used... C and azimuth φ C Then the xy coordinates of the centroid 50AC2 (x C y C ) is x C =r C cosφ C y C =r C sinφ C Therefore, the coordinates of the centroid 50AC2 are (x... C y C ) can be represented by the following formulas (11) and (12).

[0120] (number 11)

[0121] x C =f L θ Ccosφ C (11)

[0122] (Number 12)

[0123] y C =f L θ C sinφ C (12)

[0124] If we substitute the elevation angle θa shown in equation (3) into the centroid 50AC2, then equation (13) holds. Here, θa = x C / f L It is established because for the center of gravity 50AC2, r C =f L θ C This is true. The elevation angle θa is an example of the first elevation angle.

[0125] (Number 13)

[0126]

[0127] If we use the XYZ coordinates (X, Y) of the upper 50AU, U If Z), then the elevation angle θ of the upper 50AU is... U Azimuth φ U It can be represented by the following formulas (14) and (15).

[0128] (Number 14)

[0129]

[0130] (number 15)

[0131]

[0132] If using a fisheye lens with a focal length of 141 f L The elevation angle θ at the top 50 AU U Then the radial distance r at the upper end of 50AU U By r U =f L θ U This indicates that... Furthermore, if the radius r is used... U and azimuth φ U Then the xy coordinates (x, y) in plane 1 at the upper 50AU U y U ) is x U =r U cosφ U y U =r U sinφ U Therefore, the coordinates (x, y) of the upper 50AU are... Uy U It can be represented by the following formulas (16) and (17).

[0133] (Number 16)

[0134] x U =f L θ U cosφ U (16)

[0135] (Number 17)

[0136] y U =f L θ U sinφ U (17)

[0137] Furthermore, similar to the upper 50AU, if the lower 50AL's XYZ coordinates (X, Y) are used... L If Z), then the elevation angle θ of the lower end 50AL is... L Azimuth φ L It can be represented by the following formulas (18) and (19).

[0138] (Number 18)

[0139]

[0140] (Number 19)

[0141]

[0142] If using a fisheye lens with a focal length of 141 f L The elevation angle θ of the lower end 50AL L Then the radial distance r at the lower end 50AL L By r L =f L θ L This indicates that... Furthermore, if the radius r is used... L and azimuth φ L Then the xy coordinates (xy) in plane 1 at the lower end 50AL L y L ) is x L =r L cosφ L y L =r L sinφ L Therefore, the coordinates (x, y) of the lower 50AL are... L y L It can be represented by the following formulas (20) and (21).

[0143] (Number 20)

[0144] x L =f L θ L cosφ L (20)

[0145] (Number 21)

[0146] y L =f L θ L sinφ L (twenty one)

[0147] If equations (15) and (19) are transformed, we can obtain equations (22) and (23) respectively.

[0148] (Number 22)

[0149] Y U =X·tanφ U (twenty two)

[0150] (Number 23)

[0151] Y L =X·tamφ L (twenty three)

[0152] If we take the difference between equation (22) and equation (23), we can obtain equation (24).

[0153] (Number 24)

[0154] Y U -Y L =X·{tanφ U -tanφ L} (twenty four)

[0155] Therefore, the distance X in the X-axis direction between the origin O of the XYZ coordinate system, i.e., the center of the fisheye lens 141, and the centroid 50AC2 of the mark 50A, can be estimated according to equation (24) as shown in equation (25). The distance X^ is an estimated value. The distance X is the X-axis component of the distance between the origin O of the XYZ coordinate system, i.e., the center of the fisheye lens 141, and the centroid 50AC2 of the mark 50A.

[0156] (Number 25)

[0157]

[0158] Furthermore, the center 50AC1 of marker 50A has the same height as the origin O of the XYZ coordinate system, i.e., the center of the fisheye lens 141, and the Y coordinate (y...) of the centroid 50AC2... C ), y C ≈0 is true. Furthermore, if... Figure 3If the Y-coordinate of point P1, which represents the elevation angle θ, is set to 0 (Y = 0), then the elevation angle θ can be considered as the elevation angle θa obtained by projecting the elevation angle θ onto the XZ plane. Therefore, the relative distance Z along the Z-axis between the origin O of the XYZ coordinate system, i.e., the center of the fisheye lens 141, and the centroid 50AC2 of the mark 50A, can be expressed by the following formula (26). The relative distance Z^ is an estimated value.

[0159] (Number 26)

[0160]

[0161] Here, due to the length L between the upper end 50AU and the lower end 50AL of the mark 50A PM For Y U -Y L Therefore, we can obtain equation (27) from equation (26).

[0162] (Number 27)

[0163]

[0164] Note that due to Y U -Y L It is also included in the numerator of equation (25) for the estimated distance X, so the length L can also be substituted into the numerator of equation (25). PM To estimate the distance X, use the estimated distance X^ and elevation angle θa to calculate the relative distance Z^ according to equation (26).

[0165] Since the distance estimation unit 154 uses image data to estimate the relative distance Z, the relative distance Z^ is an estimated value. This relative distance Z, when the elevation angle θa is 0, is determined by x... U x L The value of tanθa is 0 and cannot be calculated, but it can be calculated in real time when it is outside 0 degrees. The relative distance Z is the Z component (distance in the Z-axis direction) of the distance between the center of the array antenna 110 (origin O of the XYZ coordinate system) and the centroid 50AC2 of the mark 50A. The center of the array antenna 110 (origin O of the XYZ coordinate system) is the center of the fisheye lens 141.

[0166] When the power supply unit 100 mounted on the vehicle moves relative to the marker 50A and the power receiving device 50B, the relative position of the marker 50A as observed from the power supply unit 100 changes constantly. Therefore, the center of gravity 50AC2 of the marker 50A can be detected and tracked using the image data of the marker 50A. However, since the relative distance Z^ is a roughly constant value, the relative distance Z can also be estimated at discrete angles with a specified elevation angle θa (e.g., 60 degrees, 50 degrees, 40 degrees, 30 degrees, 20 degrees). The average of the relative distances Z^ estimated at multiple discrete angles is then used for phase control.

[0167] The distance Rref between the center of the array antenna 110 (origin O of the XYZ coordinate system) and the receiving antenna of the receiving device can be obtained by the following formula (28).

[0168] (Number 28)

[0169]

[0170] Here, the height of the center 50AC1 of the marker 50A is the same as the height of the origin O of the XYZ coordinate system, so Y can be considered to be 0 in equation (28). The distance Ri between the antenna element 111 included in the i-th subarray 110A of the N subarrays 110A and the receiving antenna of the receiving device can be expressed by equation (29) using equation (28).

[0171] (Number 29)

[0172]

[0173] Here, (d) i,x d i,y ) represents the XY coordinates of the antenna elements 111 included in the i-th subarray 110A in the XYZ coordinate system. In each subarray 110A, a transmission signal of the same phase is provided to multiple antenna elements 111 arranged in the Y-axis direction. Since no phase difference is set, it is set as d. i,y =0. The path length difference τi between the distance Rref from the center of the array antenna 110 to the receiving antenna of the receiving device and the distance Ri between the antenna element 111 included in the i-th subarray 110A and the receiving antenna of the receiving device can be obtained by the following formula (30).

[0174] (number 30)

[0175] τ i =R i -R ref (30)

[0176] When the relative distance Z^ and elevation angle θa are given, in order to make the phase of the power transmission signal supplied to the antenna element 111 of the i-th subarray 110A consistent with the phase of the power transmission signal supplied to the antenna element 111 of the N subarray 110A, the phase of the power transmission signal is as shown in the following formula (31).

[0177] (Number 31)

[0178]

[0179] Here, λ is the wavelength of the microwaves used for power transmission.

[0180] The phase shown in Equation (31) is based on the same idea as the phase data described above and can be used instead of the phase data. The phase shown in Equation (31) can be calculated in real time, so phase control can also be performed in real time. When calculating the phase using Equation (31), for example, it can be performed by the control unit 155. In addition, real-time calculation is not necessarily required. It is also possible to obtain and store the phase corresponding to several discrete relative distances Z^ and elevation angles θa in the memory 156, and read the phase corresponding to the real-time estimated relative distances Z^ and elevation angles θa to perform phase control.

[0181] <Processing for Real-Time Estimation of Relative Distance Z>

[0182] Figure 8 This is a flowchart illustrating the estimation process for the relative distance Z. When the process begins, the image processing unit 142B reads the brightness values ​​of each pixel in the image data acquired by the imaging unit 142A (step S1).

[0183] The image processing unit 142B binarizes the image data acquired by the imaging unit 142A and calculates the distribution of pixel indices (step S2).

[0184] The image processing unit 142B extracts one or more contours based on the distribution of pixel indices (step S3).

[0185] The image processing unit 142B performs a process to find the largest contour (maximum contour) from one or more contours extracted from the distribution based on pixel index (step S4).

[0186] The position derivation unit 151 calculates the centroid of the largest contour contained in the pixel index obtained by the image processing unit 142B (step S5A). From this, the coordinates of the centroid 50AC2 of marker 50A are derived. The position derivation unit 151 processes the coordinates of the centroid 50AC2 as the centroid of the largest contour.

[0187] The image processing unit 142B reads the coordinates of the upper and lower ends of the maximum contour obtained by the image processing unit 142B (step S5B). From this, the coordinates of the upper end 50AU and the lower end 50AL of the mark 50A are obtained. The processing in step S5B is performed in parallel with step S5A. The image processing unit 142B outputs the read coordinates of the upper and lower ends of the maximum contour as the coordinates of the upper end 50AU and the lower end 50AL of the mark 50A to the control device 150.

[0188] Elevation angle acquisition unit 152 utilizes the elevation angle θ of the center of gravity 50AC2. C and azimuth φ C The elevation angle θa is obtained according to equation (13) (step S6A). The elevation angle θa of the center of gravity 50AC2 C and azimuth φ C Based on the coordinates (x) of the centroid 50AC2 C y C ) Please obtain.

[0189] Distance estimation unit 154 reads the length L from memory 156 PM The data is used to estimate the distance X using equation (25) (step S6B).

[0190] The distance estimation unit 154 estimates the relative distance Z based on the distance X^ and the elevation angle θa using equation (26) (step S7).

[0191] <Simulation results of charge received>

[0192] Figure 9 This is a graph showing the simulation results of the received power. These simulation results were obtained with the relative distance Z set to 3m. Figure 9 In the diagram, the horizontal axis represents time (ms), the left vertical axis represents the elevation angle θa (degrees), and the right vertical axis represents the amount of electricity received by the receiving device 50B (mJ). The amount of electricity received is the amount of power received by the receiving device 50 from the power supply device 100. Furthermore, in... Figure 9 In the diagram, the dashed line represents the time change of the elevation angle θa. The solid line represents the time change of the amount of electricity received by the receiving device 50B, which receives power from the power supply device 100. The dashed line represents the time change of the amount of electricity received by the receiving device 50B, which receives power from the power supply device used for comparison.

[0193] Here, in the power supply device used for comparison, the phase of the transmission signals supplied to the antenna elements 111 of all subarrays 110A from #1 to #N is equal, and they are supplied to the power receiving device 50B located in the direction of the elevation angle θa. Therefore, the phase of the transmission signals supplied to the receiving antenna of the power receiving device from the antenna elements 111 of the N subarrays 110A of the power supply device used for comparison is inconsistent.

[0194] Assuming the power supply device 100 moves relative to the power receiving device 50B along the X-axis, such as Figure 9 As shown, when the elevation angle θa changes from +30 degrees to -30 degrees, the amount of power received from the power supply device 100 is approximately 50% greater than the amount of power received from the power supply device used for comparison. Therefore, it can be confirmed that by performing phase control, while simultaneously estimating the relative distance Z in real time by the power supply device 100, and ensuring that the phase of the transmission signal transmitted from the antenna elements 111 of all subarrays 110A from #1 to #N is consistent on the receiving antenna of the receiving device located in the direction of the elevation angle θa, the amount of power received by the receiving device 50B can be significantly increased.

[0195] If equations (25) and (26), or equations (25) to (27) are used, the distance estimation unit 154 can use the length L between the upper end 50AU and the lower end 50AL of the mark 50A. PM The relative distance Z between the origin O of the XYZ coordinate system (i.e., the center of the fisheye lens 141) and the centroid 50AC2 of the mark 50A is estimated in real time. The relative distance Z represents the estimated Z coordinate of the centroid 50AC2 of the mark 50A as observed from the origin O.

[0196] Therefore, it is possible to provide a distance estimation device 100B, an antenna device 100A, a power supply system, a power supply device 100, and a power supply method that can estimate the relative distance Z^ between the power receiving device 50B and the power supply device 100 in real time.

[0197] When the elevation angle θa is not included in the specified angle range including 0 degrees, the distance estimation unit 154 can estimate the relative distance Z in real time. As an example, the specified angle range is the range in which the distance estimation unit 154 is not suitable to use formula (27) to calculate the relative distance Z^, and is the specified range before and after the elevation angle θa becomes 0 degrees.

[0198] Furthermore, as shown in formula (25), when the elevation angle θa is not included in the specified angle range including 0 degrees, the distance estimation unit 154 can also estimate the distance X in the X-axis direction in real time. This is because the Y of the molecule of formula (25) U -Y L It is the length L between the upper end 50AU and the lower end 50AL of the mark 50A. PM tanφ in the denominator U , tanφ L As shown in equation (27), point P3 can be used U P3 L xy coordinates (x U y U ), (x L y LThe distance estimation unit 154 can estimate the distance X when the elevation angle θa is not included in the specified angle range including 0 degrees. Similar to the relative distance Z^, the distance estimation unit 154 can estimate the distance X when the elevation angle θa is not included in the specified angle range including 0 degrees.

[0199] Furthermore, since the vertical length of marker 50A is longer than its horizontal length, the center of gravity of marker 50A derived by the position derivation unit 151 based on the contour contained in the pixel index easily coincides with the center of marker 50A in the vertical direction, reducing the positional offset between the center of gravity and the center. As a result, the elevation angle θa can be calculated with high precision, enabling phase control to be performed with high precision.

[0200] Furthermore, since the marker 50A has a wide portion 50AW in the central part in the vertical direction, the position of the center of gravity of the marker 50A, derived by the position derivation unit 151 based on the contour contained in the pixel index, can be guided to the center of the marker 50A. As a result, the elevation angle θa can be calculated with high precision, and phase control can be performed with high precision.

[0201] Furthermore, since the wide portion 50AW is located at the center of the vertical direction of the mark 50A, the position of the centroid of the mark 50A derived by the position derivation unit 151 based on the contour contained in the pixel index can be guided to the center of the mark 50A. As a result, the elevation angle θa can be calculated with higher precision, and phase control can be performed with higher precision.

[0202] Furthermore, since the length data representing the length between the upper end 50AU and the lower end 50AL of the mark 50A is stored in the memory 156, the distance X^ or the relative distance Z^ can be easily calculated.

[0203] Furthermore, the upper and lower ends of mark 50A are the upper and lower ends of mark 50A, respectively, so the pixel index can be easily obtained.

[0204] Furthermore, since multiple sets of phase data are stored in memory 156 with multiple relative distances r FD The corresponding quantity, and the distance estimated by the distance estimation section 154 is the estimated relative distance r. FD Therefore, it is possible to use relative distance r FD The phase data of multiple sets of quantities are used to set the displacement of the N phase shifters 120, which are respectively connected to the N subarrays 110A. Therefore, by using the phase data of multiple sets of quantities corresponding to the distance to the power receiving device 50B in the Z-axis direction, it is possible to provide an antenna device 100A and a power supply device 100 that can transmit power in a manner that enables the power receiving device 50B to receive power efficiently even at close range, based on the distance to the power receiving device 50B in the Z-axis direction. Note, for example, in the absence of a relative distance r FDIn the case of phase data of multiple corresponding quantities, as long as the closest estimated relative distance r is used... FD relative distance r FD The corresponding phase data is sufficient.

[0205] Furthermore, the multiple antenna elements 111 are divided into multiple subarrays 110A extending along the Y-axis. The phase shifter 120 is connected to each of the multiple subarrays 110A and adjusts the phase of the transmission signal for each subarray 110A. Therefore, a phase-consistent transmission signal can be delivered to the power receiving device 50B through phase control in the X-axis direction. In addition, since phase control is performed only through phase control in the X-axis direction, phase control can be simplified.

[0206] Furthermore, when the elevation angle θa is included within a specified angle range containing 0 degrees, such as Figure 3 As shown, the distance estimation unit 154 converts the position P1 obtained by equidistant projection into polar coordinates on plane 1 parallel to the XY plane to obtain the position P2. Then, it divides the X coordinate (r·cosφ) of the mapped position P2a after mapping position P2 to the X-axis by the focal length f of the fisheye lens 141. L Therefore, the elevation angle θa (=r·cosφ / f) can be calculated. L ).

[0207] Then, the control unit 155 uses phase data of the angle θb corresponding to the elevation angle θa to set the displacement of the N phase shifters 120 connected to the N subarrays 110A respectively. If the displacement of the N phase shifters 120 is controlled using phase data corresponding to the change in elevation angle θa that accompanies the movement of the antenna device 100A and the power supply device 100, it is possible to transmit a power receiving antenna that always arrives at the power receiving device from the N subarrays 110A with the same phase while moving the antenna device 100A and the power supply device 100.

[0208] Furthermore, when the elevation angle θa is included within a specified angle range including 0 degrees, the position offset detection unit 153 detects the position offset of the camera 140 and the marker 50A in the Y-axis direction. In the event of a position offset, the distance estimation unit 154 reads data from the memory 156 indicating the degree of change in the position offset of the pixel index number relative to the Y-axis direction, and uses the pixel index number corrected according to the degree of position offset relative to the Y-axis direction to estimate the relative distance r. FD Therefore, when the elevation angle θa is included within a specified angle range including 0 degrees, in the case of a positional shift between the camera 140 and the marker 50A in the Y-axis direction, the control unit 155 uses the relative distance r estimated using the corrected pixel index number. FDThe corresponding multiple sets of phase data can provide an antenna device 100A and a power supply device 100, wherein even if the camera 140 and the marker 50A are offset in the Y-axis direction, power can be transmitted in a way that enables the power receiving device 50B to receive power efficiently even at close range, based on the distance to the power receiving device 50B in the Z-axis direction.

[0209] Furthermore, since the antenna device 100A and the power supply device 100 only control the elevation angle of the beam 115 output by the array antenna 110 in the XZ plane, the number of phase shifters 120 is only 1 / 4 compared to the case where the elevation angle is controlled in both the XZ and YZ planes. Therefore, the antenna device 100A and the power supply device 100 can be implemented in a cost-effective manner.

[0210] Note that the above description illustrates an embodiment where the center of the fisheye lens 141 coincides with the centers of the 4N antenna elements 111. However, the center of the fisheye lens 141 may also deviate from the centers of the 4N antenna elements 111. In this case, simply offset the origin of the coordinate system used for calculating the phase of the array antenna by the amount of position offset. Alternatively, the mark 50A and the receiving antenna may be set separately by this position offset amount.

[0211] Furthermore, the above describes the control device 150 having a position offset detection unit 153. However, for example, if it is known that the camera 140 and the marker 50A will not experience position offset, the control device 150 may not include a position offset detection unit 153, and the distance estimation unit 154 may not perform corrections corresponding to position offset.

[0212] <Application Examples of Power Supply Device 100 and Power Supply System 10>

[0213] Figure 10 This diagram illustrates an application example of the power supply device 100. As an example, the power supply device 100 is mounted on a vehicle 60, and a receiving antenna 50C, serving as a target, is installed on the inner wall 51 of the tunnel. A marker 50A and a receiving device 50B are mounted on the receiving antenna 50C. Marker 50A is... Figure 6 As shown in (A), the receiving antenna 50C is positioned next to the wide portion 50AW of the marking 50A. This is because, since the power supply unit 100 radiates a beam of power transmission signal to the centroid 50AC2 obtained from the image data of the marking 50A, the receiving antenna 50C can efficiently receive power. The distance between the tunnel inner wall 51 and the vehicle 60 is different for each tunnel it passes through. Furthermore, when the vehicle 60 is traveling, if the vehicle 60 is traveling diagonally relative to the driving lane, the distance between the inner wall 51 and the vehicle 60 changes constantly.

[0214] Here, the system including the power supply device 100, the marker 50A, the power receiving device 50B, and the power receiving antenna 50C is the power supply system 10 of the embodiment. Because the power supply device 100 includes the antenna device 100A and the microwave generating source 130, the power supply system 10 includes the antenna device 100A, the microwave generating source 130, the marker 50A, the power receiving device 50B, and the power receiving antenna 50C.

[0215] When vehicle 60 travels along the +X axis, power supply unit 100 uses camera 140 to convert the position of mark 50A into polar coordinates on a plane parallel to the XY plane, and then divides the X coordinate (r·cosφ) of the mapped position on the X axis (equivalent to the mapped position of P2a) by the focal length f of fisheye lens 141. L Find the elevation angle θa (=r·cosφ / f) L Furthermore, as long as the power supply device 100 is based on the image data of mark 50A and the vertical length L of mark 50A... PM By calculating the relative distance Z^ in real time and reading the phase data corresponding to the relative distance Z^ and elevation angle θa from the memory 156, the displacement of the N phase shifters 120 can be controlled. This allows the power supply device 100 to move while simultaneously transmitting a power signal of the same phase from the N subarrays 110A to the receiving antenna 50C of the receiving device 50B. The power signal of the same phase illuminates the receiving antenna 50C as a beam. Alternatively, the power supply device 100 can use the above equation (9) to set the phase of the power signal transmitted in real time from the N subarrays 110A, instead of reading the phase data from the memory 156.

[0216] Furthermore, when the elevation angle θa is included within a specified angle range including 0 degrees, the distance estimation unit 154 can estimate the relative distance r from the center of the fisheye lens 141 to the mark 50A based on the pixel index number obtained by the image processing unit 142B. FD In addition, the power supply device 100 can also estimate the relative distance Z according to the elevation angle θa as a specified discrete angle (e.g., 60 degrees, 50 degrees, 40 degrees, 30 degrees, 20 degrees), and take the average of the estimated relative distance Z^ in multiple discrete angles, and use the average value of the relative distance Z^ for phase control.

[0217] For example, when fixing infrastructure structures such as jet fans or signs installed on the inner wall 51 of the tunnel to the fixing part on the inner wall 51, a receiving antenna 50C, a sensor for monitoring the loosening of bolts on the fixing part, a rectifier, and a wireless communication module are pre-installed. When a beam is emitted from the power supply unit 100 to the receiving antenna 50C while the vehicle 60 is traveling, the rectifier connected to the receiving antenna 50C generates power to activate the wireless communication module. The wireless communication module emits a signal indicating the output of the sensor, which is received on the vehicle 60 side. This allows the fixing status of the infrastructure structures to be checked while the vehicle is traveling.

[0218] In this configuration, the wireless communication module can receive a signal representing the sensor's output at the array antenna 110.

[0219] Furthermore, the X-coordinate (r·cosφ) of the mapped position on the X-axis (equivalent to the mapped position of P2a) is obtained based on the position of the receiving antenna 50C offset from the XZ plane, and the X-coordinate (r·cosφ) is divided by the focal length f of the fisheye lens 141. L The obtained value is (r·cosφ / f) L The elevation angle θa is used to control the beam, so even if the vehicle 60 traveling along the X-axis deviates from either the positive or negative Y-axis, the positional deviation can be absorbed to obtain the elevation angle θa.

[0220] Furthermore, although this uses Figure 10 The description illustrates the communication mode between the power supply device 100 (antenna device 100A) and the wireless communication module installed on the inner wall 51 of the tunnel. However, the wireless communication module is not limited to the module installed on the inner wall 51 of the tunnel, but can be installed in various locations. In this way, the power supply device 100 (antenna device 100A) can be used as a communication device.

[0221] The distance estimation device, antenna device, power supply system, power supply device, and power supply method of the present invention have been described above according to exemplary embodiments. However, the present invention is not limited to the specific disclosed embodiments, and various modifications and alterations can be made without departing from the scope of the claims.

[0222] Note that this international application claims priority based on Japanese Patent Application 2021-126776, filed on August 2, 2021, the entire contents of which are incorporated herein by reference.

[0223] Explanation of reference numerals in the attached figures

[0224] 50A Mark

[0225] 50B Power receiving device

[0226] 50C receiving antenna

[0227] 100 power supply unit

[0228] 100A Antenna Device

[0229] 100B Distance Estimation Device

[0230] 110 array antenna

[0231] 110A subarray

[0232] 111 Antenna Components

[0233] 120 phase shifter

[0234] 130 Microwave Generator

[0235] 140 cameras

[0236] 141 Fisheye Lens

[0237] 150 Control device

[0238] 151 Location Export Section

[0239] 152 Elevation Angle Acquisition Unit

[0240] 153 Position Offset Detection Unit

[0241] 154 Distance Estimation Section

[0242] 155 Control Department

[0243] 156. Memory.

Claims

1. A distance estimation device, comprising: The image acquisition unit acquires images through a fisheye lens; The position derivation unit converts the first position of the marker contained in the image acquired by the image acquisition unit relative to the image acquisition unit into a second position in polar coordinates on a first plane containing a first axis and a second axis; The elevation angle acquisition unit, based on the second position, acquires the first elevation angle of the projected position (after projecting the first position onto a second plane including the first and third axes) relative to the third axis within the second plane; and The distance estimation unit estimates the distance between the image acquisition unit and the marker. The distance estimation unit estimates the distance in the first-axis direction between the image acquisition unit and the mark based on the coordinates of the upper end of the mark included in the image, obtained from the second elevation angle relative to the third axis and the azimuth angle relative to the first axis, the coordinates of the lower end of the mark included in the image, obtained from the third elevation angle relative to the third axis and the azimuth angle relative to the first axis, and the length between the upper end and the lower end. Based on the first elevation angle acquired by the elevation angle acquisition unit and the estimated distance in the first axis direction, the distance in the third axis direction between the image acquisition unit and the mark is estimated.

2. The distance estimation device according to claim 1, wherein, When the first elevation angle acquired by the elevation angle acquisition unit is not included in a predetermined angle range including zero degrees, the distance estimation unit estimates the distance in the first axis direction between the image acquisition unit and the mark, and based on the first elevation angle acquired by the elevation angle acquisition unit and the estimated distance in the first axis direction, estimates the distance in the third axis direction between the image acquisition unit and the mark.

3. The distance estimation device according to claim 2, wherein, When the first elevation angle acquired by the elevation angle acquisition unit is included in the predetermined angle range including zero degrees, the distance estimation unit estimates the distance from the image acquisition unit to the third axis direction of the mark based on the image acquired by the image acquisition unit.

4. The distance estimation device according to claim 3, wherein, It also includes: a position offset detection unit, which detects the position offset between the image acquisition unit and the mark in the second axis direction based on the position of the centroid of the mark contained in the image acquired by the image acquisition unit. When the first elevation angle acquired by the elevation angle acquisition unit is included in the predetermined angle range including zero degrees, the distance estimation unit estimates the distance from the image acquisition unit to the third axis direction of the mark based on the image after correction according to the degree of position offset detected by the position offset detection unit.

5. The distance estimation device according to any one of claims 1 to 4, wherein, The first axis and the second axis are orthogonal to each other, and the third axis is orthogonal to the first plane. The upper end and the lower end are the upper and lower ends of the mark, respectively.

6. The distance estimation device according to any one of claims 1 to 4, wherein, The elevation angle acquisition unit calculates the value obtained by dividing the coordinate of the mapped position of the second position onto the first axis by the focal length of the fisheye lens, and uses it as the first elevation angle.

7. The distance estimation device according to claim 6, wherein, The coordinates of the mapped position are represented by the value obtained by multiplying the radial distance of the polar coordinates by the cosine of the deflection angle.

8. An antenna device, comprising: Distance estimation device according to any one of claims 1 to 7; An array antenna having a plurality of antenna elements arranged in a two-dimensional manner along the first axis and the second axis; The phase adjustment unit adjusts the phase of the power transmission signal supplied to the plurality of antenna elements in the first axis direction; as well as The control unit controls the phase adjustment unit based on the first elevation angle obtained by the elevation angle acquisition unit and the distance in the third axis direction estimated by the distance estimation unit.

9. The antenna device according to claim 8, wherein, The plurality of antenna elements are divided into a plurality of subarrays extending along the second axis. The phase adjustment unit consists of multiple phase shifters that are connected to the multiple subarrays respectively and adjust the phase of the transmission signal for each subarray.

10. The antenna device according to claim 8 or 9, wherein, It also includes a storage unit that stores length data representing the length between the upper end and the lower end of the mark.

11. The antenna device according to claim 8 or 9, wherein, It also includes: a storage unit that stores phase data representing multiple phases corresponding to multiple sets of quantities corresponding to multiple first elevation angles, wherein the multiple phases are multiple phases from which the power transmission signals are transmitted from the multiple antenna elements to the power receiving device located at the marked position, and are adjusted so that the phases of the power receiving device receiving the power transmission signals from the multiple antenna elements are consistent. The storage unit stores phase data of multiple sets of quantities corresponding to multiple distances from the image acquisition unit to the marker. The control unit reads the phase data from the storage unit corresponding to the distance in the third axis direction estimated by the distance estimation unit and the first elevation angle obtained by the elevation angle acquisition unit, and controls the phase adjustment unit based on the read phase data.

12. A power supply system, comprising: Antenna device according to any one of claims 8 to 11; The radio wave generator provides the power transmission signal to the plurality of antenna elements; The power receiving device is located at the marked position; as well as The marker is installed on the power receiving device. The vertical length of the mark is longer than its horizontal length.

13. The power supply system according to claim 12, wherein, The mark has a wide portion in the center in the vertical direction.

14. The power supply system according to claim 13, wherein, The wide portion is located at the center in the vertical direction.

15. A power supply device, comprising: An array antenna having multiple antenna elements arranged in a two-dimensional configuration along a first axis and a second axis; Source of radio waves; A phase adjustment unit is disposed between the array antenna and the radio wave generating source, and adjusts the phase of the power transmission signal provided from the radio wave generating source to the plurality of antenna elements in the first axis direction; The image acquisition unit acquires images through a fisheye lens; The position derivation unit converts the first position of the marker contained in the image acquired by the image acquisition unit relative to the image acquisition unit into a second position in polar coordinates on a first plane containing a first axis and a second axis; The elevation angle acquisition unit, based on the second position, acquires the first elevation angle of the projected position, after projecting the first position onto a second plane including the first axis and the third axis, relative to the third axis within the second plane; The distance estimation unit estimates the distance between the image acquisition unit and the marker; as well as The control unit controls the phase adjustment unit based on the first elevation angle obtained by the elevation angle acquisition unit and the distance in the third axis direction estimated by the distance estimation unit. The distance estimation unit estimates the distance in the first-axis direction between the image acquisition unit and the mark based on the coordinates of the upper end of the mark included in the image, obtained from the second elevation angle relative to the third axis and the azimuth angle relative to the first axis, the coordinates of the lower end of the mark included in the image, obtained from the third elevation angle relative to the third axis and the azimuth angle relative to the first axis, and the length between the upper end and the lower end. Based on the first elevation angle acquired by the elevation angle acquisition unit and the estimated distance in the first axis direction, the distance in the third axis direction between the image acquisition unit and the mark is estimated.

16. A power supply method for a power supply device, The power supply device includes: An array antenna having multiple antenna elements arranged in a two-dimensional configuration along a first axis and a second axis; Source of radio waves; A phase adjustment unit is disposed between the array antenna and the radio wave generating source, and adjusts the phase of the power transmission signal provided from the radio wave generating source to the plurality of antenna elements in the first axis direction; The image acquisition unit acquires images through a fisheye lens; The position derivation unit converts the first position of the marker contained in the image acquired by the image acquisition unit relative to the image acquisition unit into a second position in polar coordinates on a first plane containing a first axis and a second axis; as well as The elevation angle acquisition unit, based on the second position, acquires the first elevation angle of the projected position (after projecting the first position onto a second plane including the first and third axes) relative to the third axis within the second plane. In the power supply method, Based on the coordinates of the upper end of the mark contained in the image, obtained according to the second elevation angle relative to the third axis and the azimuth angle relative to the first axis, the coordinates of the lower end of the mark contained in the image, obtained according to the third elevation angle relative to the third axis and the azimuth angle relative to the first axis, and the length between the upper end and the lower end, the distance between the image acquisition unit and the mark in the first axis direction is estimated. Based on the first elevation angle obtained by the elevation angle acquisition unit and the estimated distance along the first axis, the distance along the third axis between the image acquisition unit and the mark is estimated. The phase adjustment unit is controlled based on the first elevation angle obtained by the elevation angle acquisition unit and the estimated distance in the third axis direction.

Images