JP2017127055A - Non-contact power transmission system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a non-contact power transmission system capable of grasping a position to be aligned with a power transmission device even when a part of a mark provided on the power transmission device is contaminated with mud or the like.SOLUTION: The non-contact power transmission system comprises: a vehicle including a power reception device; a power transmission device including a power transmission coil that transmits power to the power reception device in a non-contact manner; a circular mark 410 provided on the power transmission device, for indicating a position of the power transmission coil; a camera provided in the vehicle and imaging the circular mark; and a control unit. The control unit estimates a position of a center point O3 of the circular mark 410 from a circular arc of the circular mark 410 being imaged.SELECTED DRAWING: Figure 12

Description

  The present invention relates to a contactless power transmission system.

  Conventionally, various contactless power transmission systems that transmit power from a power transmission device to a power reception device in a contactless manner have been proposed. A contactless power transmission system described in Japanese Patent Application Laid-Open No. 2011-182608 includes a vehicle including a power reception device, a monitor, and an underfloor camera, and a power transmission device that transmits power to the power reception device in a contactless manner.

  The underfloor camera mounted on the vehicle images the power transmission device, and an image captured by the underfloor camera is displayed on the monitor. Specifically, the monitor displays a target mark that virtually indicates the position of the power receiving device and a horizontal displacement amount between the target mark and the center position of the power feeding coil. And a user implements position alignment with a power transmission apparatus and a power receiving apparatus based on the information displayed on the monitor.

JP2013-154815A JP2013-146154A JP2013-146148A JP 2013-110822 A JP 2013-126327 A JP 2011-182608 A

  In the non-contact power transmission system described in JP 2011-182608 A, in order for the underfloor camera to grasp the center position of the power feeding coil, it is necessary to provide a mark indicating the center position of the power feeding coil on the upper surface of the power transmission device. .

  However, when a part of the mark provided on the power transmission device is dirty with mud or the like, the mark may not be accurately grasped. As a result, the subject that alignment with a power transmission apparatus and a power receiving apparatus becomes difficult arises.

  The present invention has been made in view of the above problems, and its purpose is to position the mark relative to the power transmission device even when part of the mark provided on the power transmission device is dirty with mud or the like. It is to provide a non-contact power transmission system that can grasp a position to be aligned.

  A contactless power transmission system according to the present invention includes a vehicle including a power reception device, a power transmission device including a power transmission coil that transmits power to the power reception device in a contactless manner, and a circular shape that is provided in the power transmission device and indicates a position of the power transmission coil. The mark is provided in the vehicle, and includes a camera that captures an image of the circular mark, and a control unit. The control unit estimates the center position of the circular mark from the circular arc of the captured circular mark.

  According to the contactless power transmission system described above, even if the camera cannot capture the center position of the circular mark, the center of the circular mark can be set as long as a part of the circular mark can be captured. Thereby, alignment with a power receiving apparatus and a power transmission apparatus becomes easy.

  A contactless power transmission system according to the present invention includes a power transmission device, a power reception device including a power reception coil that receives power from the power transmission device in a contactless manner, a circular mark that is provided in the power reception device and indicates a position of the power reception coil, The power transmission apparatus includes a camera that captures an image of the circular mark and a control unit, and the control unit sets a virtual position of the center of the circular mark from the arc of the circular mark being imaged.

  Even in the above non-contact power transmission system, the center of the circular mark can be set even when the circular mark provided on the power receiving device is dirty with mud or the like and the center of the circular mark cannot be grasped by the camera. it can. Thereby, position alignment with a power receiving apparatus and a power transmission apparatus can be performed easily.

  According to the non-contact power transmission system according to the present invention, the position to be aligned with the power transmission device can be grasped even when a part of the mark provided on the power transmission device is dirty with mud or the like.

1 is a schematic diagram schematically showing a non-contact power transmission system 1 according to a first embodiment. 3 is a bottom view illustrating a power receiving device 110. FIG. FIG. 3 is a schematic cross-sectional view of the power receiving device 110 and the power transmitting device 200 in a cross-sectional view taken along line III-III shown in FIG. 2. It is a top view when the power transmission apparatus 200 is planarly viewed from above the power transmission apparatus 200. It is a figure which shows an example when the image imaged by the fisheye camera 120 is displayed on the display part 150. FIG. It is a flowchart which shows the control flow at the time of aligning with the power receiving apparatus 110 and the power transmission apparatus 200. FIG. It is a figure which shows the state in which a part of circular marker 410 is covered with foreign materials, such as mud 500. FIG. It is a flowchart which shows the detailed flow of an image correction process (step 40). It is the schematic diagram which displayed the imaged outer periphery circle mark 417 as a plane image. It is a figure which shows the state which set the point 414 on the circular arc of the imaged outer periphery circle mark 417. FIG. It is a figure which shows the state which set the line segment 412 on the circular arc of the imaged outer periphery circle mark 417. FIG. It is a figure which shows the state which set the intersection 415 on the circular arc of the imaged outer periphery circle mark 417. FIG. It is a figure which shows the state which displayed the part hidden by foreign materials, such as mud 500, on the display part 150 among the circular markers 410. FIG. It is a figure which shows the imaged outer periphery circle mark 417. FIG. It is a figure which shows the part with the longest arc length from the imaged outer periphery circle mark 417. FIG. It is a figure which derives | leads-out a center point from the part with the longest arc length from the imaged outer periphery circle mark 417. FIG. It is a schematic diagram which shows typically the non-contact power transmission system 1A which concerns on Embodiment 2. FIG. It is a bottom view showing a lower surface of the power receiving apparatus 110A.

(Embodiment 1)
FIG. 1 is a schematic diagram schematically showing a contactless power transmission system 1 according to the first embodiment. As shown in FIG. 1, the non-contact power transmission system 1 includes a vehicle 100 and a power transmission device 200.

  Vehicle 100 includes a power receiving device 110, a communication unit 130, an ECU 140, and a display unit 150. The power receiving apparatus 110 includes a case 111, a power receiving coil 115 accommodated in the case 111, and a fisheye camera 120 provided on the lower surface of the case 111.

  The fisheye camera 120 images the state of the lower surface side of the vehicle 100 and transmits the captured image data to the ECU 140. The ECU 140 corrects the received fisheye image data to a flat image and displays it on the display unit 150.

  The power transmission device 200 includes a case 201, a power transmission coil 210 accommodated in the case 201, a transmitted power generation unit 220 connected to the power transmission coil 210, a communication unit 230, and a control device 240.

  The transmitted power generation unit 220 adjusts the frequency and voltage of AC power supplied from the power supply 300 and supplies the adjusted power to the power transmission coil 210. When an alternating current flows through the power transmission coil 210, a magnetic flux is formed around the power transmission coil 210. When this magnetic flux is linked to the power receiving coil 115, a current flows through the power receiving coil 115. In this way, power is transmitted from the power transmission coil 210 to the power reception coil 115 in a contactless manner.

  FIG. 2 is a bottom view showing the power receiving device 110. As shown in FIG. 2, when the power receiving device 110 is viewed from below the power receiving device 110, the power receiving coil 115 is formed to surround the winding center line O1 extending in the vertical direction. As the power receiving coil 115, a spiral coil is employed.

  A hole 113 is formed at the center of the lower surface 112 of the case 111. A fisheye camera 120 is arranged in the hole 113. When the power receiving device 110 is viewed from below the power receiving device 110, the fisheye camera 120 is provided at a position overlapping the winding center line O1.

  FIG. 3 is a schematic cross-sectional view of the power receiving device 110 and the power transmitting device 200 taken along a line III-III shown in FIG. As shown in FIG. 3, when the power transmission device 200 is located below the fisheye camera 120, the fisheye camera 120 can capture images including the power transmission device 200 and the periphery of the power transmission device 200. That is, the area of the imaging range A of the fisheye camera 120 is wider than the area of the upper surface of the power transmission device 200.

  The power transmission coil 210 is formed so as to surround the winding center line O2 extending in the vertical direction. The power transmission coil 210 is a spiral coil.

  FIG. 4 is a plan view when the power transmission device 200 is viewed from above the power transmission device 200. As shown in FIG. 4, a marker 400 is drawn on the upper surface 250 of the case 201 of the power transmission device 200.

  The marker 400 includes a circular marker 410 and a direction determination marker 420. The circular marker 410 includes a plurality of concentric circle marks. When the power transmission device 200 is viewed from above, the center point O3 of each circle mark coincides with the winding center line O2. The radius ratio of each circle mark is determined in advance. The circular marker 410 includes a center circle mark 411 that surrounds the periphery of the center point O3 at a position closest to the center point O3, and an outer peripheral circle mark 417 that forms the outer shape of the circular marker 410.

  The orientation determination marker 420 includes a square mark 421 and a corner mark 422 drawn at a corner of the square mark 421. The center point O3 of the circular marker 410 is located in the square mark 421. The corner mark 422 is provided at three corners of the four corners of the square mark 421. ECU 140 determines the traveling direction of vehicle 100 relative to power transmission device 200 based on the arrangement relationship of square marks 421.

  FIG. 5 is a diagram illustrating an example when an image captured by the fisheye camera 120 is corrected to a planar image and displayed on the display unit 150. As shown in FIG. 5, the display unit 150 displays a power reception marker 600 schematically showing the position of the power reception device 110 in addition to the image captured by the fisheye camera 120. When the center point O4 of the power receiving marker 600 and the center point O3 of the circular marker 410 coincide, the winding center line O1 of the power receiving coil 115 and the winding center line O2 of the power transmitting coil 210 are arranged in the vertical direction. .

  In the contactless power transmission system 1 described above, in order to transmit power from the power transmission device 200 to the power reception device 110 in a contactless manner, the vehicle 100 needs to be stopped so that the power reception device 110 is positioned above the power transmission device 200.

  In the first embodiment, the driver performs alignment between the power receiving apparatus 110 and the power transmitting apparatus 200 while viewing the image displayed on the display unit 150.

  FIG. 6 is a flowchart showing a control flow when the power receiving apparatus 110 and the power transmitting apparatus 200 are aligned. The flow shown in FIG. 6 is started when communication is established between the communication unit 130 of the vehicle 100 and the communication unit 230 of the power transmission device 200 when the non-contact charging button provided on the vehicle 100 is ON. The ECU 140 converts the image captured by the fisheye camera 120 into a normal plane image and displays it on the display unit 150 (step 10).

  Next, based on the image data transmitted from the fisheye camera 120, the ECU 140 determines whether or not there are three corner marks 422 within the imaging range A captured by the fisheye camera 120 (step 20). ).

  When ECU 140 determines that three corner marks 422 are within imaging range A (YES in step 20), the position of center point O3 of circular marker 410 from the circular arc of circular marker 410 in the converted image data corrected to a planar image. And an image correction process for displaying the estimated position of the center point O3 on the display unit 150 is performed (step 40).

  Here, as shown in FIG. 5, not only when the marker 400 is completely visible, but as shown in FIG. 7, when a part of the circular marker 410 is covered with foreign matter such as mud 500. There is. In this case, it is difficult for the user to accurately align the power receiving apparatus 110 and the power transmitting apparatus 200. On the other hand, in the non-contact power transmission system 1 according to the first embodiment, as will be described later, the position of the center point O3 is estimated from the arc of the circular marker 410 being imaged, and the position of the estimated center point O3 is estimated. Is displayed on the display unit 150. As a result, the user easily aligns the power transmission device 200 and the power reception device 110 by operating the vehicle 100 so that the position of the displayed center point O3 and the center point O4 of the power reception marker 600 overlap each other. be able to.

  FIG. 8 is a flowchart showing a detailed flow of the image correction process (step 40). As shown in FIG. 8, the image correction process (step 40) includes a process (step 49) for estimating the position of the center point O3 from the circular arc of the circular marker 410 being picked up, and a circular marker 410 hidden by a foreign object. A process (step 47) of estimating a hidden portion, an estimated image of a hidden part of the circular marker 410, and a process of displaying an image virtually indicating the center point O3 at the estimated position coordinates of the center point O3 (step 47). Step 48).

  In the image correction process, the ECU 140 first acquires and extracts image data of the circular marker 410 captured by the fisheye camera 120 (step 41). The ECU 140 extracts image data indicating the circular marker 410 from the image data transmitted from the fisheye camera 120. In the first embodiment, image data indicating the outer circumference circle mark 417 is extracted from the circular marker 410.

  FIG. 9 is a schematic diagram showing the captured outer circle mark 417 as a planar image. As shown in FIG. 9, since a part of the circular marker 410 is not imaged by the mud 500, a part of the outer circumference circle mark 417 is broken.

  Next, as shown in FIG. 10, the ECU 140 sets a point 414 located on the arc of the outer circumference circle mark 417, and sets a tangent line 416 at this point 414 (step 42). Next, as shown in FIG. 11, a line segment 412 extending from the point 414 in a direction perpendicular to the tangent line 416 is set (step 43).

  Next, as shown in FIG. 12, the ECU 140 sets an intersection 415 between the outer circumference circle mark 417 (circular marker 410) being imaged and the line segment 412 (step 44). Then, the radius of the outer circumference circle mark 417 is calculated from the half length of the line connecting the point 414 and the intersection point 415 (step 45).

  Then, the position coordinate of the center point O3 is estimated from the calculated radius and the coordinates of the point 414 (step 46).

  Next, the ECU 140 performs a complementing process for estimating a portion hidden by the foreign matter in the circular marker 410 (step 47). First, the ECU 140 estimates a portion of the outer circle mark 417 that is hidden by a foreign object from the position coordinate of the center point O3 of the circular marker 410 and the radius of the outer circle mark 417.

  The ECU 140 stores the radius ratio of each circle mark of the circular marker 410, and is hidden by a foreign object among the circle marks from the radius ratio, the position coordinate of the center point O3, and the radius of the outer circumference circle mark 417. Estimate the part.

  Next, as shown in FIG. 13, in the circular marker 410, a display that complements a portion hidden by a foreign substance such as the mud 500 and a center mark are displayed at a position where the center point O3 is estimated to be located (step 48). . In this step 48, when the complementary image of the circular marker 410 or the center mark indicating the center point O3 is already displayed, the already displayed complementary image or the like is deleted, and a new complementary image or the like is deleted. Is displayed.

  Thus, in the non-contact power transmission system 1 according to the first embodiment, even if the circular marker 410 is hidden by foreign matter such as the mud 500, the ECU 140 complements the hidden portion and displays it on the display unit 150. Therefore, alignment of the power receiving device 110 and the power transmitting device 200 can be easily performed.

  Next, as shown in FIG. 6, ECU 140 determines whether or not center point O3 of circular marker 410 and center point O4 of power reception marker 600 match. “The center point O3 and the center point O4 coincide with each other” is not limited to the case where the center point O3 and the center point O4 completely coincide with each other. That is, as a condition for determining that “the center point O3 and the center point O4 coincide”, the center point O4 can be appropriately set in advance such that the center point O4 enters the center circle mark 411.

  When ECU 140 determines that center point O3 and center point O4 do not match (NO in step 50), if the alignment completion display is displayed, the alignment completion display is turned off (step 52). The ECU 140 displays an image on the display unit 150 based on the image data transmitted from the fisheye camera 120 (step 10), and performs an image correction process and the like.

  On the other hand, when ECU 140 determines that center point O3 and center point O4 match (YES in step 50), ECU 140 displays a notification that alignment has been made on display unit 150 (step 50). 60). At this time, the ECU 140 may notify the user to stop.

  In the first embodiment described above, the example using the tangent line of the arc portion of the acquired circular marker 410 as the technique for estimating the position coordinate of the center point O3 has been described. However, the position coordinate of the center point O3 is estimated. Various methods can be adopted as the method.

  Another method for estimating the center point O3 of the circular marker 410 will be described with reference to FIGS.

  ECU140 acquires the image data of the outer periphery circle mark 417 which the fisheye camera 120 imaged, and correct | amends the acquired image data to a plane image, as shown in FIG. In FIG. 14, the broken line portion is a portion hidden by foreign matter.

  Next, as shown in FIG. 15, the ECU 140 selects the arc having the longest length among the outer circumference circle marks 417 being imaged. If it is determined that the acquired outer circumference circle mark 417 is not hidden by a foreign object, an arc portion having a predetermined length is selected. A line segment 501 passing through both end points 418 and 419 of the selected arc is calculated. Next, a straight line 502 that is orthogonal to the line segment 501 and passes through the midpoint of the line segment 501 is calculated. Then, an intersection 503 between the straight line 502 and the outer circumference circle mark 417 is calculated.

  Next, the ECU 140 calculates a line segment 504 that passes through the end point 418 and the intersection point 503, as shown in FIG. Next, a straight line 506 that is orthogonal to the line segment 504 and passes through the midpoint of the line segment 504 is calculated. Then, the center point O3 is estimated at the intersection 505 between the straight line 506 and the straight line 502. Next, the distance between the intersection point 505 and the end point 418 is calculated, and this distance is set as the radius of the outer circumference circle mark 417. Thus, even using the above method, the position and radius of the center point O3 of the outer circle mark 417 can be calculated.

In the first embodiment, the reason for estimating the position of the center point O3 based on the outer circumference circle mark 417 is that the outer circumference circle mark 417 has the longest length among the circular markers 410. This is because the ratio of the portion hidden by foreign matter such as mud 500 is likely to be smaller than other circular marks. As a result, relatively accurate coordinates of the center point O3 can be calculated.
(Embodiment 2)
In the first embodiment, the circular mark is provided in the power transmission device and the fisheye camera is provided in the power reception device. However, the circular mark is provided in the power reception device and the fisheye camera is provided in the power transmission device. You may do it.

  Therefore, a non-contact power transmission system 1A according to the second embodiment will be described with reference to FIGS. 17 and 18 and FIGS.

  FIG. 17 is a schematic diagram schematically showing a contactless power transmission system 1A according to the second embodiment. As shown in FIG. 17, a fisheye camera 120A is disposed on the upper surface of the power transmission device 200A. The fisheye camera 120 </ b> A is provided at a position where the winding center line of the power transmission coil 210 passes.

  FIG. 18 is a bottom view showing the lower surface of the power receiving apparatus 110A. As shown in FIG. 18, a marker 700 is provided on the lower surface of the case 111A of the power receiving apparatus 110A. The marker 700 is formed in the same manner as the marker 400 shown in FIG. 4, and the marker 700 includes a circular marker 710 and an orientation determination marker 720.

  The control device 240A of the power transmission device 200A transmits the image data captured by the fisheye camera 120A to the communication unit 130A through the communication unit 230. ECU 140A executes control similar to the control shown in FIGS. 6 and 8 using the image data acquired from communication unit 130A.

  It should be understood that the embodiment disclosed this time is illustrative in all respects and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The present invention can be applied to a non-contact power transmission system.

  1, 1A contactless power transmission system, 100 vehicle, 110, 110A power receiving device, 111, 111A, 201 case, 112 lower surface, 113 hole, 115 power receiving coil, 120, 120A fisheye camera, 130, 130A, 230 communication unit, 150 display unit, 200, 200A power transmission device, 210 power transmission coil, 220 transmission power generation unit, 240, 240A control device, 250 top surface, 300 power source, 400, 700 marker, 410, 710 circular marker, 411 center circle mark, 412, 413, 501 line segment, 414 points, 415, 503, 505 intersection, 416 tangent, 417 outer circle mark.

Claims (1)

A vehicle including a power receiving device;
A power transmission device including a power transmission coil for transmitting power to the power reception device in a contactless manner;
A circular mark provided in the power transmission device and indicating a position of the power transmission coil;
A camera provided in the vehicle for imaging the circular mark;
A control unit,
The non-contact power transmission system, wherein the control unit estimates a center position of the circular mark from an arc of the circular mark being imaged.

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