JP2020010491A - Non-contact power transmission system - Google Patents

Abstract

To provide a non-contact power transmission system capable of detecting a phase coil angle at high accuracy using an imaging device in alignment of a primary coil and a secondary coil.SOLUTION: A non-contact power transmission system 10 comprises: a power transmission unit 100 containing a primary coil 101; and a power reception unit 200 containing a secondary coil 201. Power transmission is performed from the primary coil of the power transmission unit to the secondary coil to the power reception unit in a non-contact manner. At least one of the power transmission unit and the power reception unit includes at least one of an imaging device and a linear light emitter and two or more point-shaped light emitters. The non-contact power transmission system further comprises a correction unit (a power transmission ECU 150) that recognizes at least one of a line formed by the linear light emitter and the line connecting the two or more point-shaped light emitters by using the imaging device, and corrects a deviation of an attachment angle of the imaging device using the line recognized by the imaging device.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to a non-contact power transmission system, and more particularly, to a non-contact power transmission system in which power is transmitted in a non-contact manner from a primary coil of a power transmission unit to a secondary coil of a power reception unit.

  2. Description of the Related Art A non-contact power transmission system that transmits power from a primary coil of a power transmission unit to a secondary coil of a power reception unit in a non-contact manner is known (see Patent Documents 1 to 6).

  Japanese Patent Application Laid-Open No. 2015-230681 (Patent Document 6) discloses a primary coil in a non-contact power transmission system in which a secondary coil and an imaging device are provided in a vehicle and a primary coil is installed on the ground surface of a parking space. There is disclosed a technique in which a light-emitting body provided in the vicinity of the light-emitting element is imaged by the above-described imaging device, and a distance between a primary coil and a secondary coil is detected from the image of the light-emitting body.

JP 2013-154815 A JP 2013-146154 A JP 2013-146148 A JP 2013-110822 A JP 2013-126327 A JP 2015-230681 A

  By the way, in a non-contact power transmission system in which a power receiving unit (hence, a secondary coil) is installed on the lower surface of a vehicle and a power transmission unit (hence, a primary coil) is installed on the ground surface of a parking lot, the yaw angle of the vehicle is used. The relative orientation (hereinafter, also referred to as “relative coil angle”) between the primary coil and the secondary coil changes according to (the relative angle of the vehicle with respect to the road surface). If the relative coil angle shift amount (hereinafter, also referred to as “rotation shift amount”) in the alignment between the primary coil and the secondary coil is large, the power transmission efficiency (the ratio of the received power to the transmitted power) decreases. May occur. Note that the rotational displacement corresponds to a rotational displacement between the primary coil and the secondary coil.

  According to the method described in Patent Literature 1, the distance between the primary coil and the secondary coil can be detected with relatively high accuracy, but the relative coil angle (and, consequently, the rotational displacement amount) is detected with high accuracy. Difficult to do. If the detection accuracy of the rotational deviation is insufficient, it is difficult to reduce the rotational deviation in alignment. The inventor of the present application has repeatedly conducted experiments and studies on a method of detecting a relative coil angle using an imaging device in order to find a cause of a decrease in detection accuracy, and one of the causes is a shift in the mounting angle of the imaging device. I found that.

  If the mounting angle of the imaging device deviates from a normal angle (for example, a design angle) in assembling the imaging device, a deviation occurs between the relative coil angle recognized by the imaging device and the actual relative coil angle. For example, the assembling accuracy of the imaging device is often about ± 4 ° with respect to the regular angle, but is less than ± 3 ° with respect to the regular angle in the alignment between the primary coil and the secondary coil. Position accuracy may be required. Further, even after the image pickup device is assembled, an external force may be applied to the image pickup device to change the mounting angle of the image pickup device and deviate from a normal angle. For example, in a non-contact power transmission system in which a power receiving unit is installed on a lower surface of a vehicle and a power transmission unit is installed on a ground surface of a parking lot, when the power transmission unit includes an imaging device, the imaging device is used by the vehicle when the vehicle is parked. May be trampled.

  The present disclosure has been made in order to solve the above-described problem, and has as its object to provide a non-contact power supply capable of detecting a relative coil angle with high accuracy by using an imaging device in alignment between a primary coil and a secondary coil. Provide a transmission system.

  A wireless power transmission system according to the present disclosure includes a power transmission unit including a primary coil and a power reception unit including a secondary coil. Non-contact power transmission is performed from the primary coil of the power transmission unit to the secondary coil of the power reception unit. At least one of the power transmission unit and the power reception unit has an imaging device, and further has at least one of a linear light emitter and two or more dot light emitters. The non-contact power transmission system according to the present disclosure uses an imaging device to recognize at least one of a line formed of a linear light-emitting body and a line connecting two or more dot-shaped light-emitting bodies. And a correction unit that corrects the deviation of the mounting angle of the imaging device using the line recognized by the above.

  The above non-contact power transmission system includes a correction unit. The correction unit is configured to recognize the line of the illuminant using the imaging device, and correct the deviation of the mounting angle of the imaging device using the line of the illuminant recognized by the imaging device. In the above-described non-contact power transmission system, such a correction unit corrects the deviation of the mounting angle of the imaging device, so that the relative coil angle can be accurately determined using the imaging device in the alignment between the primary coil and the secondary coil. Can be detected.

  Note that the line formed by the luminous body is less susceptible to external light than the printed line, so that the line can be easily recognized by the imaging device.

  According to the present disclosure, it is possible to provide a non-contact power transmission system that can detect a relative coil angle with high accuracy using an imaging device in positioning a primary coil and a secondary coil.

1 is an overall configuration diagram of a wireless power transmission system according to an embodiment of the present disclosure. It is the figure which looked at the power transmission unit shown in FIG. 1 from the top. 1 is a diagram for describing an outline of foreign object detection in a wireless power transmission system according to an embodiment of the present disclosure. 11 is a flowchart illustrating a processing procedure in the case of correcting a shift in the mounting angle of the imaging device when the power transmission unit is shipped in the non-contact power transmission system according to the embodiment of the present disclosure. 11 is a flowchart illustrating a processing procedure of mounting angle correction of an imaging device performed by a control device of a power transmission unit in the wireless power transmission system according to the embodiment of the present disclosure. FIG. 6 is a diagram illustrating an example of a light emission order of light emitters in the processing of FIG. 5. FIG. 6 is a diagram for explaining an angle of a luminous body line viewed from the imaging device, which is detected in the process of FIG. 10 is a flowchart illustrating a processing procedure when correcting a shift in the mounting angle of the imaging device at the end of power transmission from the power transmission unit to the power reception unit (at the end of charging) in the wireless power transmission system according to the embodiment of the present disclosure. . FIG. 6 is a diagram illustrating a first modification of the power transmission unit illustrated in FIG. 2. FIG. 9 is a diagram illustrating a second modification of the power transmission unit illustrated in FIG. 2. It is a figure which shows the 3rd modification of the power transmission unit shown in FIG. It is a figure for explaining a luminous body line which connects two or more dot-like luminous bodies. It is a figure which shows the 4th modification of the power transmission unit shown in FIG. FIG. 7 is a diagram illustrating a modification of the light emission order illustrated in FIG. 6.

  Embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding portions have the same reference characters allotted, and description thereof will not be repeated.

  Arrows F, B, R, L, U, and D in the drawings used below indicate directions based on the vehicle, where arrow F is “front”, arrow B is “rear”, and arrow R is “ Arrow L indicates “left”, arrow U indicates “up”, and arrow D indicates “down”. Hereinafter, the electronic control unit (Electronic Control Unit) is referred to as “ECU”.

  FIG. 1 is an overall configuration diagram of a wireless power transmission system according to an embodiment of the present disclosure. Referring to FIG. 1, this power transmission system 10 includes a charging facility 1 and a vehicle 2.

  Charging facility 1 includes power transmission unit 100 (ground unit) including primary coil 101, power transmission ECU 150 for controlling power transmission unit 100, and AC power supply 700 for supplying power to power transmission unit 100. The power transmission unit 100 is installed on the ground F10 (for example, the ground surface of a parking lot). An example of the AC power supply 700 is a household power supply (for example, an AC power supply having a voltage of 200 V and a frequency of 50 Hz).

  Vehicle 2 includes a power receiving unit 200 including a secondary coil 201, a power storage device 300 that is charged by power received by power receiving unit 200, and a vehicle ECU 500 that controls power receiving unit 200. Power receiving unit 200 is provided on the lower surface (road surface side) of power storage device 300 installed on lower surface F20 (under the floor) of vehicle 2.

  Power storage device 300 includes, for example, a secondary battery (such as a lithium ion battery or a nickel hydride battery), a charging relay that is ON / OFF controlled by vehicle ECU 500, and a monitoring unit that monitors the state of power storage device 300 (all shown in the drawing). Z). The monitoring unit includes various sensors that detect the state (temperature, current, voltage, and the like) of power storage device 300, and outputs a detection result to vehicle ECU 500. Vehicle ECU 500 acquires the state (SOC (State Of Charge) or the like) of power storage device 300 based on the output of the monitoring unit. The charging relay is turned on (conducting state) when the power receiving unit 200 charges the power storage device 300. Power storage device 300 supplies power to, for example, a vehicle drive device (such as an inverter and a drive motor) not shown. Vehicle 2 may be an electric vehicle that can run using only the power stored in power storage device 300, or may use both the power stored in power storage device 300 and the output of an engine (not shown). It may be a hybrid vehicle that can travel.

  Each of the ECUs (the power transmission ECU 150 and the vehicle ECU 500) includes an arithmetic device, a storage device, an input / output port, a communication port (all not shown), and the like. The arithmetic device is configured by a microprocessor including a CPU (Central Processing Unit), for example. The storage device includes a RAM (Random Access Memory) for temporarily storing data, and a storage (ROM (Read Only Memory), a rewritable nonvolatile memory, and the like) for storing programs and the like. Various controls are executed by the arithmetic device executing the program stored in the storage device. Power transmission ECU 150 according to the present embodiment includes “correction unit” according to the present disclosure. In power transmission ECU 150, for example, a correction unit is embodied by an arithmetic device and a program executed by the arithmetic device. Note that various controls are not limited to processing by software, but may be processed by dedicated hardware (electronic circuit).

  The charging facility 1 further includes a communication unit 160, and the vehicle 2 further includes a communication unit 600. Communication units 160 and 600 are communication interfaces for performing wireless communication between charging facility 1 and vehicle 2. By performing wireless communication between the communication unit 160 of the charging facility 1 and the communication unit 600 of the vehicle 2, information can be exchanged between the power transmission ECU 150 and the vehicle ECU 500.

  The charging facility 1 further includes an input unit 170, and the vehicle 2 further includes an input unit 410. The input units 170 and 410 are devices that receive instructions from the user. Input units 170 and 410 are operated by the user and output signals corresponding to the user's operation to power transmission ECU 150 and vehicle ECU 500, respectively. The communication system may be wired or wireless. As the input units 170 and 410, for example, a touch panel can be adopted. However, the present invention is not limited to this, and a keyboard, a mouse, and various switches (such as push button switches) may be employed as the input units 170 and 410. The input units 170 and 410 may be provided on a meter panel, or may be operation units of an on-vehicle car navigation system.

  The charging facility 1 further includes a notification unit 180, and the vehicle 2 further includes a notification unit 420. The notification units 180 and 420 are configured to perform predetermined notification processing to a user (for example, a driver of the vehicle 2) when requested by the power transmission ECU 150 and the vehicle ECU 500, respectively. Examples of the notification units 180 and 420 include a display device, a speaker, and a lamp. The notification process to the user is optional, and may be notified by display (characters, images, etc.) on the display device, may be notified by sound (including sound) by a speaker, or a predetermined lamp may be turned on (blinking) May be included).

  Hereinafter, the configuration of the power transmission unit 100 will be described with reference to FIG. 2 together with FIG. FIG. 2 is a diagram of the power transmission unit 100 shown in FIG. 1 as viewed from above.

  Referring to FIGS. 1 and 2, power transmission unit 100 includes a housing 102 that houses primary coil 101. In FIG. 2, the reference plane P11 is a plane (LR-UD plane) orthogonal to the axis in the front-rear direction (FB direction) and includes the coil center axis P10. The reference plane P12 is a plane (FB-UD plane) orthogonal to the axis in the left-right direction (LR direction) and includes the coil center axis P10. The coil center axis P10 is the center axis of the primary coil 101, and corresponds to the line of intersection between the reference plane P11 and the reference plane P12.

  The housing 102 has a rectangular outer shape in plan view. The power transmission unit 100 further includes an imaging device 103 and linear light emitters 104a to 104d on the upper surface F1 of the housing 102. The imaging device 103 includes a camera 103a, and is attached to a central portion of the upper surface F1 of the housing 102 by fastening members S1 to S4 (for example, screws). The camera 103a is fixed, for example, so as to be located at the coil center axis P10. The light emitters 104a to 104d are arranged on the edge of the upper surface F1 of the housing 102 so as to surround the camera 103a. In this embodiment, the number of imaging devices included in the power transmission unit 100 is one, but a plurality of imaging devices may be provided in the power transmission unit 100.

  Each of the light emitters 104a to 104d has a linear outer shape, and is provided along the contour (four sides) of the power transmission unit 100. Of the light-emitting members 104a to 104d, the light-emitting member 104a has a long shape long in the FB direction by being provided along one side (left side) of the housing 102. The luminous body 104b has a long shape elongated in the LR direction by being provided along another side (front side) of the housing 102. The luminous body 104c has a long shape long in the FB direction by being provided along another side (right side) of the housing 102. The light emitter 104d has a long shape elongated in the LR direction by being provided along another side (back side) of the housing 102. As described above, in the power transmission unit 100, the imaging device 103 and the light emitters 104a to 104d are provided on the same surface (upper surface F1) of the power transmission unit 100.

  The camera 103a includes a lens and an image sensor. The image sensor is disposed on the image plane, and light passing through the lens is converted into an electric signal by the image sensor. As an image sensor of the camera 103a, for example, a CMOS (Complementary Metal Oxide Semiconductor) image sensor or a CCD (Charge-Coupled Device) image sensor can be adopted. In this embodiment, a fisheye lens is used as the lens of the camera 103a. Thereby, a wide area (wide angle) space can be photographed by the camera 103a. The camera 103a captures an image of the surrounding space to obtain image data (hereinafter, referred to as a “photographed image”), and outputs the captured image to the power transmission ECU 150.

  Each of the light-emitting members 104a to 104d is a light-emitting member that can be turned on and off, and the state (light-on / light-off) of each light-emitting member is controlled by the power transmission ECU 150. In the lighting state, light emitted from each of the light emitters 104a to 104d is detected by the camera 103a. The camera 103a can recognize the lighted illuminant among the illuminants 104a to 104d. In this embodiment, an LED (light emitting diode) is employed as each of the light emitters 104a to 104d. However, the invention is not limited to this, and another light emitting body (such as an incandescent light bulb) may be employed.

  The primary coil 101 forms a resonance circuit that resonates at a transmission frequency (frequency of transmitted power). The Q value indicating the resonance intensity of the resonance circuit is preferably 100 or more. In the housing 102, in addition to the primary coil 101, a ferrite plate (core of the primary coil 101), a metal plate for electromagnetic shielding, a circuit board, a monitoring unit, and the like (all not shown) are further housed. ing. The circuit board includes a power conversion unit (AC / DC converter, inverter, filter circuit, and the like) that performs a predetermined power conversion process on the power received from AC power supply 700. Further, the monitoring unit includes various sensors for detecting the state (temperature, current, voltage, etc.) of the circuit board, and outputs a detection result to power transmission ECU 150. When the power transmission ECU 150 controls the power converter, AC power having a predetermined magnitude and frequency is supplied to the primary coil 101.

  On the other hand, the power receiving unit 200 of the vehicle 2 includes a secondary coil 201 in a housing as shown in FIG. The secondary coil 201 forms a resonance circuit that resonates at a transmission frequency. The Q value indicating the resonance intensity of the resonance circuit is preferably 100 or more. In the housing of the secondary coil 201, in addition to the secondary coil 201, a ferrite plate (core of the secondary coil 201), a metal plate for electromagnetic shielding, a circuit board, a monitoring unit, and the like (all not shown). It is further housed. The circuit board includes a filter circuit, a rectifier circuit, a smoothing capacitor, and the like. Further, the monitoring unit includes various sensors for detecting the state (temperature, current, voltage, etc.) of the circuit board, and outputs a detection result to vehicle ECU 500. The AC power received by the secondary coil 201 is converted into DC power by the circuit board. Thereby, DC power is supplied to power storage device 300 as output power of power receiving unit 200.

  The power transmitting unit 100 is configured to transmit power to the power receiving unit 200 in a non-contact manner through a magnetic field in a state where the vehicle 2 is positioned so that the secondary coil 201 faces the primary coil 101. Secondary coil 201 receives electric power from primary coil 101 in a non-contact manner. The non-contact (wireless) power transmission method is, for example, a magnetic field resonance method. However, the invention is not limited to this, and another system (such as an electromagnetic induction system) may be adopted.

  In this embodiment, the illuminants 104a to 104d arranged around the camera 103a are used in foreign substance detection described below. The power transmission unit 100 uses the imaging device 103 and the light emitters 104a to 104d to determine whether or not a foreign substance exists in a space between the primary coil 101 and the secondary coil 201 (hereinafter, also referred to as “between coils”). (That is, foreign object detection). Hereinafter, an outline of foreign object detection in the power transmission system 10 will be described with reference to FIG. FIG. 3 is a diagram of the power transmission unit 100 as viewed from the side (right), but the light emitters 104a and 104c are omitted for convenience of explanation.

  Referring to FIGS. 2 and 3, in this embodiment, light-emitting bodies 104 a to 104 d are formed in a ring shape (more specifically, along the outer periphery of power transmission unit 100 on the upper surface of power transmission unit 100 (upper surface F <b> 1 of housing 102)). Specifically, it is provided in a rectangular shape in a plan view). The light emitters 104 a to 104 d emit light so that the emitted light is detected by the imaging device 103. The captured image captured by the imaging device 103 is output to the power transmission ECU 150.

  The power transmission ECU 150 can detect the foreign matter X existing between the coils (for example, the upper surface of the power transmission unit 100) based on the output of the imaging device 103. The foreign matter X should not be present between the coils, and may be, for example, a beverage can, coins, snow, dead leaves, animals, and the like.

  When performing foreign object detection, power transmission ECU 150 turns on (or blinks) light emitters 104a to 104d. When the foreign matter X exists between the coils, a part of the light emitted from the light emitters 104a to 104d is blocked by the foreign matter X. Therefore, there is a difference in the captured image of the imaging device 103 between the case where the foreign matter X does not exist between the coils and the case where the foreign matter X exists between the coils. The power transmission ECU 150 can determine whether or not the foreign matter X exists between the coils based on the difference between the captured images.

  By the way, if power transmission is performed in a state where the positions of the primary coil 101 and the secondary coil 201 are shifted, the power transmission efficiency tends to decrease. For this reason, in power transmission system 10, the position of primary coil 101 and the position of secondary coil 201 are adjusted before power is transmitted. By this alignment, for example, the relative position of the primary coil 101 and the secondary coil 201 on a plane (FB-LR plane) orthogonal to the axis in the vertical direction (UD direction) (hereinafter, “relative coil position”) ) (Hereinafter, also simply referred to as “position shift amount”). For example, alignment (position correction) is performed so that the center axis of the primary coil 101 and the center axis of the secondary coil 201 match. As will be described in detail later, in this embodiment, the relative coil position (and, consequently, the amount of displacement) is detected using a positioning mark (not shown). However, the present invention is not limited to this, and the relative coil position (and thus the amount of displacement) may be detected based on the three-dimensional distance between the center position of the primary coil 101 and the center position of the secondary coil 201.

  In addition, not only the above-described displacement of the relative coil position, but also the displacement of the relative direction (relative coil angle) between the primary coil 101 and the secondary coil 201 can reduce the power transmission efficiency. The relative coil angle changes according to the direction of the vehicle 2 when the vehicle 2 is parked above the power transmission unit 100 (that is, the yaw angle of the vehicle 2). If the changing relative coil angle cannot be detected with high accuracy, it is difficult to sufficiently reduce the rotational deviation amount (that is, the rotational amount deviation between the primary coil 101 and the secondary coil 201) in alignment. Become. The inventor of the present application has repeatedly conducted experiments and studies on a method of detecting a relative coil angle using the imaging device 103 in order to find a cause of a decrease in detection accuracy, and one of the causes is a displacement of the mounting angle of the imaging device 103. Was found.

  For example, when assembling the imaging device 103 to the housing 102 by the fastening members S1 to S4, the imaging device 103 may be installed in an inclined manner in a rotation direction about the vertical direction (UD direction). When the mounting angle of the imaging device 103 is deviated from a normal angle (for example, a design angle) in assembling the imaging device 103, the relative coil angle recognized by the imaging device 103 and the actual relative coil angle are deviated. Occurs. For example, the assembling accuracy of the imaging device 103 is often about ± 4 ° with respect to the regular angle, but ± 3 ° with respect to the regular angle in the alignment between the primary coil 101 and the secondary coil 201. ° or less position accuracy may be required. Further, even after the image pickup device 103 is assembled, the mounting angle of the image pickup device 103 may change due to an external force applied to the image pickup device 103 and may deviate from the normal angle. For example, the imaging device 103 may be stepped on by the vehicle 2 when the vehicle 2 is parked.

  Therefore, in power transmission system 10 according to the present embodiment, power transmission unit 100 includes power transmission ECU 150. The power transmission ECU 150 is configured to recognize a line composed of the linear light-emitting bodies 104 a to 104 d using the imaging device 103 and to correct a shift in the mounting angle of the imaging device 103 using the line recognized by the imaging device 103. Is done. By correcting the deviation of the mounting angle of the imaging device 103 by the power transmission ECU 150, the relative coil angle (and, consequently, the rotational deviation amount) can be detected with high accuracy using the imaging device 103.

  FIG. 4 is a flowchart illustrating a processing procedure when correcting a shift in the mounting angle of the imaging device 103 at the time of shipping the power transmission unit 100 (for example, before inspection before shipping). The processing shown in this flowchart includes steps S11 to S13 (hereinafter, simply referred to as “S11” to “S13”).

  Referring to FIG. 4, in S <b> 11, the worker attaches various components such as the imaging device 103 and the light emitters 104 a to 104 d to the housing 102 of the power transmission unit 100. Subsequently, in S12, the worker energizes the power transmission unit 100, and checks whether the components assembled in S11 operate normally. If any part does not operate normally, the operator investigates the cause and repairs it. When each part starts operating normally, the process proceeds to S13.

  In S13, power transmission ECU 150 executes a series of processes shown in FIG. 5 based on a request from the worker. FIG. 5 is a flowchart showing a processing procedure for correcting the mounting angle of the imaging device 103 performed by the power transmission ECU 150. The process shown in this flowchart includes steps S21 to S26 (hereinafter, simply referred to as “S21” to “S26”).

  Referring to FIG. 5, in S21, power transmission ECU 150 starts light emission of light emitters 104a to 104d. Power transmission ECU 150 causes light emitters 104a to 104d to emit light in a predetermined order. FIG. 6 is a diagram illustrating an example of a light emission order of the light emitters 104a to 104d.

  Referring to FIG. 6, for example, like pattern A, light emitter 104a (left side), light emitter 104b (front side), light emitter 104c (right side), light emitter 104d (rear side). In this order, the light emitters may emit light one by one. The light-emitting time of each light-emitting body may be set, and after the light-emitting time of a certain light-emitting body has elapsed, the light-emitting body may be turned off and the next light-emitting body may emit light. Further, when the light-emitting time of the last light-emitting body (light-emitting body 104d) has elapsed, the first light-emitting body (light-emitting body 104a) is made to emit light again, and the light-emitting bodies 104a to 104d are repeatedly made to emit light until the light emission ends in S24 described later. You may do so. Alternatively, the light emission of the light emitter may be terminated at the timing when the recognition of the light emitter line is completed in S22 without setting the light emission time. For example, when the recognition of the line of the light emitting body 104a is completed in S22, the light emitting body 104a may be turned off and the next light emitting body 104b may emit light.

  In this embodiment, the light-emitting bodies 104a to 104d emit light in the order of the pattern A. However, the present invention is not limited to this, and pattern B may be employed instead of pattern A. As shown in FIG. 6, in the pattern B, the light emitters emit light two by two. More specifically, the light emitters 104a and 104b emit light at the same time, and after a predetermined light emission time elapses, the light emitters 104a and 104b are turned off and the light emitters 104c and 104d emit light at the same time. If four light emitters 104a to 104d emit light at the same time, it becomes difficult for the imaging device 103 to recognize the direction of each light emitter line, and it tends to be difficult to find the angle of the light emitter line in S25 described later.

  Referring again to FIG. 5, after light emission is started in S21, the process proceeds to S22. The process of S22 is executed in a situation where the light emitters 104a to 104d emit light in a predetermined order (for example, pattern A) as described above.

  In S22, the power transmission ECU 150 captures an image of the luminous body that emits light among the luminous bodies 104a to 104d using the imaging device 103, and outputs the luminous body based on each pixel information of the captured image obtained by the imaging device 103. (Hereinafter, also referred to as a “light emitter line”). Then, power transmission ECU 150 stores the information on the recognized light emitting body line in the storage device. For example, when the linear light emitting body 104a along the left side of the power transmission unit 100 emits light, a line along the left side of the power transmission unit 100 is recognized as the light emitting line, and the recognized light emitting body is recognized. Line information (for example, image data) is stored in the storage device.

  Note that the process of S22 is preferably performed in an environment where the power transmission ECU 150 can easily recognize the luminous body line (that is, the line of light emitted from the luminous body). For example, the presence of light other than the light of the light emitter may make it difficult for power transmission ECU 150 to recognize the light emitter line. In consideration of such circumstances, the process of S22 may be performed in a dark place.

  In S23, power transmission ECU 150 determines whether or not the recognition of all the light emitter lines (each of light emitters 104a to 104d) has been completed. While it is determined that the recognition of any of the illuminant lines is not completed (NO in S23), the process of S22 is repeated, and the recognition of all the illuminant lines is completed (YES in S23). , The process proceeds to S24.

  In S24, all the light emitters (all of the light emitters 104a to 104d) are turned off, and the light emission started in S21 is ended.

  Subsequently, in S25, the power transmission ECU 150 obtains the angle of the illuminant line recognized in S22 (that is, the angle of the illuminant line viewed from the imaging device 103). The angle of the illuminant line can be represented, for example, based on the angle of the illuminant line recognized by the imaging device 103 when the mounting angle of the imaging device 103 is a regular angle (0 °). Such a reference for each illuminant line is obtained in advance by an experiment or the like, for example, and stored in the storage device of power transmission ECU 150.

  FIG. 7 is a diagram for explaining the angle of the luminous body line (for example, the line of the luminous body 104a) viewed from the imaging device 103. Referring to FIG. 7, line L0 is a line indicating a reference (0 °), and line L1 is a line of luminous body 104a viewed from image pickup device 103 (a luminous body line formed of linear luminous body 104a). is there. The angle θ1 indicates the angle of the line L1. Each of the lines L0 and L1 is a straight line, and the angle θ1 corresponds to an angle between the line L0 and the line L1. In S25 of FIG. 5, the angle θ1 is obtained as the angle of the luminous body line. When a curve (for example, an arc) is recognized as the luminous body line in S22 of FIG. 5, it can be converted into a straight line by image processing in power transmission ECU 150. In this embodiment, the angle θ1 is obtained for each of the four luminous body lines (lines of the luminous bodies 104a to 104d) along the four sides of the power transmission unit 100, and the average value of the obtained four angles θ1 is calculated as Adopted as the angle of the luminous body line However, in the case where an insufficiently recognized luminous body line is present among the four luminous body lines, only the luminous body line that has been sufficiently recognized (a luminous body line having a predetermined recognition level or higher) is used to form the luminous body The angle of the line may be obtained.

  In this embodiment, light-emitting bodies 104a to 104d are arranged at the edge of power transmission unit 100 (more specifically, at the edge of upper surface F1 of housing 102). The presence of the light emitters 104a to 104d at a position distant from the camera 103a makes it possible to detect the angle of the light emitter line with higher accuracy in S25 than when the light emitters 104a to 104d exist at a position closer to the camera 103a. Becomes possible.

  The method for determining the angle of the luminous body line is not limited to the above. For example, correspondence information (e.g., a mathematical expression) indicating the relationship between the luminous body line (i.e., the image of the luminous body line) and the angle of the luminous body line seen from the imaging device 103 is obtained in advance by experiment or the like and stored in the storage device of the power transmission ECU 150. The angle of the illuminant line may be directly obtained from the image data of the illuminant line obtained by the imaging device 103 by referring to such correspondence information. When a plurality of adjacent luminous bodies (for example, the luminous bodies 104a and 104b) emit light at the same time, the line of the luminous bodies may be recognized as one arc in the imaging device 103. Also in this case, the angle of the arc (light emitter line) can be obtained based on the arc (that is, the image of the arc) seen from the imaging device 103.

  Referring to FIG. 5 again, the angle of the luminous body line obtained in S25 correlates with the mounting angle of the imaging device 103. For example, in the case where the angle of the illuminant line is represented based on the angle of the illuminant line recognized by the imaging device 103 when the mounting angle of the imaging device 103 is a regular angle (0 °), the illuminant line It means that the larger the angle is, the larger the amount of deviation of the mounting angle of the imaging device 103 from the regular angle is. Therefore, the mounting angle of the imaging device 103 (and, consequently, the amount of deviation from the normal angle) can be obtained from the angle of the luminous body line obtained in S25.

  After the processing in S25, the power transmission ECU 150 determines in S26 a correction coefficient (hereinafter, also referred to as a “rotation correction coefficient”) for compensating for a shift in the mounting angle of the imaging device 103 based on the angle of the illuminant line obtained in S25. Update. The rotation correction coefficient is stored in, for example, a storage device of power transmission ECU 150 and is used in predetermined software (such as an alignment program described later). The power transmission ECU 150 is configured to correct the captured image of the imaging device 103 (or information obtained from the captured image) using such a rotation correction coefficient.

  The series of processing in FIG. 5 (and, consequently, S13 in FIG. 4) ends with S26. Then, the series of processing in FIG. 4 ends when S13 ends. By performing the processing in FIG. 4 at the time of shipping the power transmission unit 100, it is possible to correct a shift (rotational shift) in the mounting angle of the imaging device 103 caused by assembling the imaging device 103.

  In addition, after the power transmission unit 100 is shipped, for example, by performing the processing in FIG. 8, it is possible to correct a shift (rotational shift) in the mounting angle of the imaging device 103 that occurs after the imaging device 103 is assembled. .

  FIG. 8 is a flowchart illustrating a processing procedure for correcting a shift in the mounting angle of the imaging device 103 when power transmission from the power transmission unit 100 to the power receiving unit 200 is completed (and when charging of the power storage device 300 is completed). The processing shown in this flowchart includes steps S31 to S34 (hereinafter, simply referred to as “S31” to “S34”).

  First, how power transmission from power transmission unit 100 to power reception unit 200 is performed will be described. In power transmission system 10 according to this embodiment, before starting power transmission, connection of wireless communication between communication unit 160 of charging facility 1 and communication unit 600 of vehicle 2 (for example, connection to wireless LAN) ) Is established. Thereafter, based on the relative coil position and the relative coil angle detected by power transmission ECU 150, position adjustment (position correction) is performed so that the amount of deviation between the relative coil position and the relative coil angle becomes smaller.

  In this embodiment, the relative coil position and the relative coil angle are detected using an image captured by the imaging device 103. In the power transmission system 10 according to the present embodiment, the deviation (rotational deviation) of the mounting angle of the imaging device 103 caused by the assembling of the imaging device 103 is corrected when the power transmission unit 100 is shipped (see FIG. 4). The yaw angle of the vehicle 2 (and, consequently, the relative coil angle) can be detected with high accuracy. For example, a positioning mark (alignment mark) recognizable by the imaging device 103 may be provided on the surface of the power receiving unit 200. Then, the relative coil position and the relative coil angle may be detected based on the position and the angle of the alignment mark in the field of view of the camera. Such detection of the position and angle can be performed using a known image recognition technique. The alignment mark may be a mark printed on a label or the like, or may be a mark formed by a light-emitting body (eg, an LED).

  In the above-described positioning, the driver of the vehicle 2 is notified of how to move the vehicle 2 to reduce the amount of deviation between the relative coil position and the relative coil angle. For example, the notification is performed by power transmission ECU 150 controlling notification unit 180 or by vehicle ECU 500 controlling notification unit 420 based on information transmitted from power transmission ECU 150. The driver of the vehicle 2 operates the steering wheel, the accelerator, the brake (none of which is shown), and the like in accordance with the notified information so that the deviation amount between the relative coil position and the relative coil angle is reduced. The vehicle 2 can be moved. By repeating the detection of the relative coil position and the relative coil angle and the movement of the vehicle 2, each deviation amount between the relative coil position and the relative coil angle can be set within an allowable range. The movement of the vehicle 2 may be performed by automatic driving.

  When the amount of deviation between the relative coil position and the relative coil angle falls within the allowable range, power transmission is started by power transmission ECU 150. Power transmission (that is, power transmission from the power transmitting unit 100 to the power receiving unit 200) is performed in a state where the vehicle 2 exists above the power transmitting unit 100. Therefore, external light (sunlight or the like) is blocked by the vehicle 2 and hardly enters between the coils.

  After the start of power transmission, power transmission ECU 150 determines whether or not a predetermined completion condition is satisfied. If the completion condition is satisfied during power transmission (that is, if power transmission is normally completed), power transmission ECU 150 performs power transmission during execution. Stop and end power transmission. The completion condition can be set arbitrarily. The completion condition may be satisfied when the SOC of power storage device 300 becomes equal to or higher than a predetermined SOC value during power transmission, or may be satisfied when a user gives an instruction to stop power transmission during power transmission.

  Further, during the transmission of the electric power, the above-described detection of the relative coil position and the above-described foreign object detection (see FIG. 3) are performed. In the detection of the relative coil position, when it is determined that the vehicle 2 has moved during the transmission of the power and the deviation amount of the relative coil position has exceeded the allowable range, the power transmission ECU 150 forcibly transmits the power without waiting for the completion. Stop. Also, in the foreign object detection, even when the presence of a foreign object (metal, animal, or the like) between the coils is detected, the power transmission ECU 150 forcibly stops the power transmission without waiting for the completion.

  The process in FIG. 8 is executed by power transmission ECU 150, for example, at the timing when the above-described power transmission is normally completed (that is, when the predetermined completion condition is satisfied). If power transmission is forcibly stopped during power transmission (that is, power transmission is not completed normally), the processing in FIG. 8 is not executed.

  Referring to FIG. 8, in S31, power transmission ECU 150 performs the above-described foreign object detection (see FIG. 3) to determine whether or not a foreign object exists between the coils. In S32, power transmission ECU 150 determines whether or not the wireless communication connected at the time of starting the power transmission has not been disconnected.

  If there is no foreign object between the coils and the connection of the wireless communication is maintained (YES in both S31 and S32), the process proceeds to S33, and the presence of the foreign object between the coils or the wireless communication Is disconnected (NO in either S31 or S32), the series of processes in FIG. 8 ends.

In S33, similarly to S13 in FIG. 4, the power transmission ECU 150 executes a series of processes in FIG.
Referring to FIG. 5 together with FIG. 8, in the present embodiment, the process of FIG. 5 is performed in the above-described state at the time of power transmission (that is, state in which vehicle 2 is present above power transmission unit 100). Since the light (sunlight or the like) radiating between the coils is blocked by the vehicle 2, the power transmission ECU 150 can easily recognize the luminous body line in S22 of FIG.

  In S33 in FIG. 8, the power transmission ECU 150 monitors the state of the vehicle 2 through wireless communication with the vehicle 2 while executing the processing in FIG. Then, when it is detected that the vehicle 2 is likely to move or that the vehicle 2 has moved, the power transmission ECU 150 stops the processing in FIG. 5 and executes a series of processing in FIG. finish. For example, when the shift range of vehicle 2 is changed, or when the wireless communication between power transmission unit 100 and vehicle 2 is cut off, it is determined that vehicle 2 is likely to move. You may make it. Further, when an accelerator operation is performed on the vehicle 2 or when the vehicle speed changes, it may be determined that the vehicle 2 has moved. In the power transmission system 10, since the user (the driver of the vehicle 2) can freely move the vehicle 2 even during the execution of the processing in FIG. 5, the convenience of the user is high.

  In S25 of FIG. 5 executed in S33 of FIG. 8, the angle of the luminous body line (current angle) is calculated based on the angle of the luminous body line (previous angle) obtained in the previous S25. You may. In this case, the calculated angle of the luminous body line (current angle) indicates the amount of change from the previous time. The current angle may be compared with the previous angle, and the rotation correction coefficient may be updated (S26 in FIG. 5) only when the current angle is different from the previous angle.

  However, the present invention is not limited to this, and in S25 in FIG. 5 executed in S33 in FIG. 8, similarly to S13 in FIG. 4, the light-emitting body recognized by the imaging device 103 when the mounting angle of the imaging device 103 is a regular angle. The angle of the illuminant line recognized by the imaging device 103 in the current state may be determined based on the line angle as a reference (0 °).

  Referring to FIG. 8 again, after the processing of S33, power transmission ECU 150 terminates the wireless communication with vehicle 2 in S34. Thereby, the wireless communication between the power transmission unit 100 and the vehicle 2 is disconnected. The series of processing in FIG. 8 ends with this S34.

  In the power transmission system 10 according to the present embodiment, each time the power transmission by the power transmission unit 100 (and the charging of the vehicle-mounted battery) is completed, it is determined whether the predetermined execution condition is satisfied in S31 and S32 in FIG. When the execution condition is satisfied (YES in both S31 and S32), the rotation correction coefficient is updated (S26 in FIG. 5) by performing the series of processes in FIG. 5 in S33 in FIG. . By repeatedly updating the rotation correction coefficient, even when the mounting angle of the imaging device 103 is displaced (rotational deviation) after the imaging device 103 is assembled, the deviation of the angle is corrected by the rotation correction coefficient. Becomes possible. The timing at which the processing in FIG. 8 is performed can be changed as appropriate. For example, the processing in FIG. 8 may be executed immediately before the power transmission by the power transmission unit 100 is started (for example, after the above-described positioning is completed).

  In the power transmission system 10 according to the present embodiment, the deviation of the mounting angle of the imaging device 103 is corrected (more specifically, the rotation is performed) both at the time of shipment of the power transmission unit 100 and after shipment (in use). The correction coefficient is updated (see FIGS. 4 and 8). This makes it possible to detect the relative coil angle with high accuracy using the imaging device 103 in the alignment between the primary coil 101 and the secondary coil 201.

  In the above embodiment, the deviation of the mounting angle of the imaging device 103 is corrected at both the time of shipment of the power transmission unit 100 and the time after shipment (in use). The shift of the mounting angle of the image pickup device 103 may be corrected only at one of the timings of “after shipping” and “after use”.

  In the above embodiment, four light emitter lines along four sides of the power transmission unit 100 are formed by the linear light emitters 104a to 104d. However, the present invention is not limited to this, and it is sufficient that at least one illuminant line is formed in order to obtain the angle of the illuminant line in S25 of FIG.

  FIG. 9 is a diagram illustrating a first modification of the power transmission unit 100. Referring to FIG. 9, the number of light emitters may be two by omitting light emitters 104c and 104d in power transmission unit 100 shown in FIG. The power transmission unit shown in FIG. 9 includes linear light-emitting bodies 104a and 104b provided along two orthogonal sides.

  In the above embodiment, the luminous body lines are formed by the linear luminous bodies 104a to 104d. However, the present invention is not limited to this, and the luminous body line may be a line connecting two or more dot-like luminous bodies. The luminous body line may be a straight line connecting two point-like luminous bodies, or an approximate line connecting three or more point-like luminous bodies.

  FIG. 10 is a diagram illustrating a second modification of the power transmission unit 100. Referring to FIG. 10, this power transmission unit includes point-like light emitters 105a to 105c. The three light emitters 105a to 105c are provided along two orthogonal sides of the power transmission unit. In such a power transmission unit, a line connecting the point-like light emitters 105a and 105b and a line connecting the point-like light emitters 105b and 105c are recognized as light emitter lines.

  FIG. 11 is a diagram illustrating a third modification of the power transmission unit 100. Referring to FIG. 11, this power transmission unit includes point-like light emitters 105a and 105b. The two luminous bodies 105a and 105b are provided along one side of the power transmission unit. In such a power transmission unit, a line connecting the dot-like light emitters 105a and 105b is recognized as a light emitter line.

  FIG. 12 is a diagram for explaining a luminous body line connecting two or more dot-like luminous bodies. Referring to FIG. 12, for example, power transmission ECU 150 of each power transmission unit shown in FIG. 10 and FIG. 11, based on each pixel information of the captured image obtained by imaging device 103, illuminant line (see S22 in FIG. 5) ), The line L2 connecting the light emitters 105a and 105b can be recognized. The angle θ2 indicates the angle of the line L2. Each of the lines L0 and L2 is a straight line, and the angle θ2 corresponds to an angle formed between the line L0 (a line indicating a reference) and the line L2. Each of the power transmission units shown in FIGS. 10 and 11 can determine the angle θ2 as the angle of the luminous body line (see S25 in FIG. 5).

  Furthermore, a light-emitting body group in which a plurality of dot-shaped light-emitting bodies are linearly arranged may be employed. FIG. 13 is a diagram illustrating a fourth modification of the power transmission unit 100. Referring to FIG. 13, this power transmission unit includes illuminant groups 106 a to 106 d and 107 a to 107 d which are an aggregate of a plurality of point-like illuminants arranged in a line. Each of the light emitter groups 106a-106d and 107a-107d may form a light emitter line.

  When the power transmission ECU 150 includes a plurality of control boards for controlling the light emitters, the light emitters may emit light for each control board. For example, the power transmission ECU 150 of the power transmission unit shown in FIG. 13 controls a control board A that controls the light emitter groups 106a and 107a, a control board B that controls the light emitter groups 106b and 107b, and a light emitter group 106c and 107c. When a control board C to be controlled and a control board D to control the illuminant groups 106d and 107d are provided, each illuminant group may emit light in the order shown in FIG.

  FIG. 14 is a diagram showing a modification of the light emission order of the light emitters. Referring to FIG. 14, for example, as in pattern C, light emitters (first light emission) included in light emitter groups 106a and 107a controlled by control substrate A, light emitter group 106b controlled by control substrate B (A second light emission) included in the light emitters 107b and 107b, a light emitter (a third light emission) included in the light emitter groups 106c and 107c controlled by the control substrate C, and a light emitter group 106d controlled by the control substrate D The light-emitting body may emit light in the order of the light-emitting bodies (fourth light-emission) included in 107d and 107d. Further, like the pattern D, the light emitters (first light emission) included in the light emitter groups 106a, 107a, 106b, and 107b controlled by the control substrates A and B, and the light emission controlled by the control substrates C and D The light emitters may emit light in the order of the light emitters (second light emission) included in the body groups 106c, 107c, 106d, and 107d.

  In the above-described embodiment and the modification, the power transmission unit 100 includes the imaging device 103, the illuminant recognized by the imaging device 103, and the correction unit (power transmission ECU 150) that corrects a shift in the mounting angle of the imaging device 103. An example is shown. However, the present invention is not limited to this, and the power receiving unit 200 may include the above-described imaging device and the luminous body instead of or in addition to the power transmitting unit 100. Further, in vehicle ECU 500, the correction unit may be embodied by an arithmetic device and a program executed by the arithmetic device.

  The embodiments disclosed this time are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description of the embodiments, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  DESCRIPTION OF SYMBOLS 1 Charging equipment, 2 vehicles, 10 power transmission systems, 100 power transmission units, 101 primary coils, 102 housings, 103 imaging devices, 103a cameras, 104a to 104d, 105a to 105c light emitters, 106a to 106d, 107a to 107d light emission Body group, 150 power transmission ECU, 160, 600 communication unit, 170, 410 input unit, 180, 420 notification unit, 200 power receiving unit, 201 secondary coil, 300 power storage device, 500 vehicle ECU, 700 AC power supply.

Claims (1)

A non-contact power transmission system including a power transmission unit including a primary coil and a power reception unit including a secondary coil, wherein power is transmitted from the primary coil to the secondary coil in a non-contact manner,
At least one of the power transmission unit and the power reception unit has an imaging device and at least one of a linear light emitter and two or more dot light emitters,
Using the imaging device, at least one of a line composed of the linear luminous body and a line connecting the two or more point-like luminous bodies is recognized, and a line recognized by the imaging device is used. A non-contact power transmission system, further comprising: a correction unit configured to correct a shift in a mounting angle of the imaging device.

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