JP2013132121A - Power reception device and obstacle detection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power reception device which detects an obstacle between a power supply device and the power reception device before completing entrance, and to provide obstacle detection means.SOLUTION: A vehicle side control unit 154 reads the power supply efficiency variation pattern, in a state where there is no obstacle, stored in a power supply efficiency variation pattern storage unit 153, calculates the value, obtained by subtracting a sampled power supply efficiency kfrom the power supply efficiency kpof a power supply efficiency variation pattern thus read, as an error Δof power supply efficiency, every time when the power supply efficiency kis sampled, performs threshold determination of the total sum Δof the error Δthus calculated and a predetermined threshold Δprepared previously for each sampling number, and determines that an obstacle is detected at the timing when the total sum Δof error exceeds the threshold Δ.

Description

  The present invention relates to a power receiving device provided in a vehicle and an obstacle detection method in the power receiving device for receiving electric power fed from a power feeding device provided on the ground side using electromagnetic induction in a contactless manner.

  Conventionally, an energy supply technique for charging a storage battery mounted on a vehicle using a microwave is known. In this energy supply technology, electric power is supplied to a magnetron from a microwave power source of a power supply device installed on the ground such as a parking lot, and a microwave is generated by the magnetron. Microwaves generated from each magnetron are sent to a power receiving device disposed on the bottom surface of the vehicle via each power transmission antenna. Microwaves received by the power receiving device are converted into electric power, rectified, converted into DC power, and then supplied to the storage battery.

  On the other hand, in such an energy supply technology, when an obstacle is interposed between the microwave feeding side and the power receiving side, the microwave transmission efficiency is reduced due to the obstacle, and further, the obstacle is human or animal. In the case of creatures such as, there is a problem that creatures are affected by microwaves.

  As a method for solving such a problem, there is known a method for detecting the presence or absence of an obstacle between the power feeding side and the power receiving side, and starting microwave transmission after confirming that there is no obstacle. (For example, refer to Patent Document 1).

  Patent Document 1 describes a method for detecting an obstacle based on a power reception level of a reflected wave of a microwave transmitted from a power supply device as a method for detecting an obstacle between a power supply side and a power reception side. Yes.

JP 2007-267578 A

  However, in the obstacle detection method disclosed in Patent Document 1 described above, an obstacle is detected only after the vehicle is once stored in a parking lot or the like so that the power receiving device is located above the power supply device provided on the ground side. Therefore, there is a problem that it takes time to detect an obstacle. In addition, when an obstacle is detected, the vehicle must be moved in again after the vehicle is moved and the obstacle is removed, which is troublesome for the user.

  An object of the present invention is to provide a power receiving device and an obstacle detecting method for detecting an obstacle between a power feeding device and a power receiving device before completing warehousing.

A power receiving device according to the present invention is a power receiving device provided in a vehicle that receives power fed from an electric power feeding device provided outside a vehicle using electromagnetic induction in a non-contact manner. Storage means for storing a power supply efficiency pattern that varies according to a position of the power receiving device with respect to the power supply device in a state where there is no obstacle between the power receiving device and a power supply efficiency variation pattern for each approach path of the vehicle; An approach route detecting means for detecting an approach route of the vehicle with respect to the power feeding device, a position detecting means for detecting in which position of the detected approach route the power feeding device exists, and movement of the vehicle with calculates the power supply efficiency k _i, it reads patterns of feed efficiency corresponding to said detected approach path from the storage means, is detected among the patterns of the read power supply efficiency Said a value obtained by subtracting the power supply efficiency k _i from the feed efficiency kp _i corresponding to the position and the error delta _i of feed efficiency, and total delta _all of the error delta _i, predetermined threshold value set for each sampling number i And a control unit that performs threshold determination with _Δthi and determines detection of an obstacle based on a result of the threshold determination.

The obstacle detection method of the present invention is an obstacle detection method in a power receiving device provided in a vehicle, which receives electric power fed from a power feeding device provided outside the vehicle using electromagnetic induction in a contactless manner. Te detects the approach route of the vehicle with respect to the feeding device, wherein the detecting whether the power supply apparatus is present in any position of the detected the approach path, sampling the power supply efficiency k _i along with the movement of the vehicle A pattern of power supply efficiency that fluctuates depending on the position of the power receiving device with respect to the power feeding device in a state where there is no obstacle between the power feeding device and the power receiving device is determined in advance for each approach path of the vehicle, and is detected. of pattern of feed efficiency corresponding to the approach path, which is a value obtained by subtracting the power supply efficiency k _i from the feed efficiency kp _i corresponding to said detected position and error delta _i of power supply efficiency Calculated for each of the sampling Te, the sum delta _all of said calculated error delta _i, performs a threshold determination that the predetermined threshold delta _thi determined for each sampling number i, based on a result of the threshold determination Judgment of obstacle detection.

  According to the present invention, an obstacle between the power feeding device and the power receiving device can be detected before the warehousing is completed.

The block diagram which shows the structure of the charging system which concerns on one embodiment of this invention Diagram for explaining power supply efficiency fluctuation pattern according to approach route The figure used for description of the power feeding efficiency according to the positional relationship between the power feeding coil of the power feeding unit and the power receiving coil of the power receiving unit Diagram for explaining the method of creating the power supply efficiency fluctuation pattern Diagram showing fluctuation pattern of power supply efficiency when there is an obstacle Diagram for explaining error Flow chart showing the procedure of the obstacle detection method in the vehicle side control unit

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(One embodiment)
FIG. 1 is a block diagram showing a configuration of a charging system 100 according to an embodiment of the present invention. The charging system 100 includes a power feeding device 120, a vehicle 130, a power receiving device 150, and a storage battery 170.

  The power feeding device 120 is installed on the ground or buried in the ground so that the power feeding unit 121 is exposed from the ground surface g. For example, the power supply device 120 is provided in a parking space or the like, and supplies power to the power receiving device 150 while the vehicle 130 is parked. Details of the power feeding device 120 will be described later.

  The vehicle 130 includes a power receiving device 150 and a storage battery 170, and travels using the storage battery 170 as a power source. The vehicle 130 is, for example, an automobile that travels with the electric power of the storage battery 170 such as HEV (Hybrid Electric Vehicle), PEV (Plug-in Electric Vehicle), or EV (Electric Vehicle).

  The power receiving device 150 supplies the power supplied from the power supply device 120 to the storage battery 170. Note that details of the power receiving device 150 will be described later.

  The storage battery 170 stores the power supplied by the power receiving device 150.

  The power feeding device 120 includes a power feeding unit 121, a power feeding side control unit 122, and a power feeding side communication unit 123.

  The power supply unit 121 has a power supply surface 121 a that faces the power reception unit 157 in a non-contact state when supplying power to the power reception unit 157 and serves as a part of the housing of the power supply unit 121. The power feeding surface 121a is formed of a member that is not heated by a magnetic field. The power feeding unit 121 feeds power to the power receiving unit 157 by electromagnetic induction using a circular power feeding coil (primary coil) facing the power receiving unit 157. This power supply is performed by, for example, an electromagnetic induction method or a magnetic resonance method.

  The power supply side control unit 122 controls the power supply unit 121 to start power supply in accordance with the power supply start signal input from the power supply side communication unit 123. At this time, the power feeding side control unit 122 outputs the power feeding power value to the power feeding side communication unit 123. The power supply side control unit 122 controls the power supply unit 121 to stop power supply in accordance with the power supply stop signal input from the power supply side communication unit 123.

  The power supply side communication unit 123 receives a power supply start signal or a power supply stop signal from the vehicle side communication unit 156. The power supply side communication unit 123 outputs the received power supply start signal or power supply stop signal to the power supply side control unit 122. In addition, the power supply side communication unit 123 transmits the power supply power value input from the power supply side control unit 122 to the vehicle side communication unit 156.

  The power receiving apparatus 150 includes an approach route detection unit 151, a position detection unit 152, a power supply efficiency variation pattern storage unit 153, a vehicle side control unit 154, a display unit 155, a vehicle side communication unit 156, and a power reception unit 157. .

  The approach route detection unit 151 detects a movement route for the vehicle power supply device, and outputs the detected movement route to the vehicle-side control unit 154. Specifically, the “entry route” represents a positional relationship between a straight line including the traveling direction of the vehicle and the center of the power feeding coil provided in the power feeding device.

  The position detection unit 152 detects which position of the approach route detected by the approach route detection unit 151 is the power feeding device, and outputs the detected position to the vehicle-side control unit 154. Specifically, the “position” indicates which position on the straight line including the traveling direction of the vehicle the power feeding device 120 is.

  Note that the approach route detection unit 151 and the position detection unit 152 can be realized by a camera that images the outside of the vehicle 130 reading and detecting a marker disposed in the vicinity of the power feeding device 120.

Power supply efficiency variation pattern storage unit 153, the position of the power receiving coil of the vehicle 130 with respect to the feeding surface 121a of the power supply device 120, a variation pattern representing a correspondence relationship between the power supply efficiency kp _i in the absence of obstacles, each approach path I remember it.

  Here, the power supply efficiency fluctuation pattern according to the approach route will be described with reference to FIG. Referring to FIG. 2, if the lengths of the perpendiculars passing through the center of the power feeding coil included in power feeding device 120 with respect to the straight line including the traveling direction of vehicle 130 are the same, the power feeding efficiency variation patterns are the same. That is, the approach route A and the approach route B have the same power supply efficiency fluctuation pattern. The approach route C differs from the approach route A and the approach route B in the length of the perpendicular, so that the power feeding efficiency variation pattern of the approach route C is also different from the power feeding efficiency variation pattern of the approach route A and the approach route B. Therefore, the storage capacity can be reduced by storing the power supply efficiency variation pattern for each length of the perpendicular.

  Thus, the position of the power receiving coil of the vehicle 130 stored in the power feeding efficiency variation pattern storage unit 153 can be expressed as the distance from the intersection of the straight line and the perpendicular including the traveling direction of the vehicle 130 to the center of the power feeding coil.

The vehicle-side control unit 154 reads the power supply efficiency variation pattern corresponding to the approach route detected by the approach route detection unit 151 from the power supply efficiency variation pattern storage unit 153. Further, the vehicle-side control unit 154 calculates the power supply efficiency k _i from the received power value input from the power receiving unit 157 and the supplied power value input from the vehicle-side communication unit 156 as the vehicle 130 moves, and reads out the power supply efficiency k _i. The absolute value of the value obtained by subtracting the power supply efficiency k _i from the power supply efficiency kp _i corresponding to the position on the approach path detected by the position detection unit 152 in the power supply efficiency pattern is calculated as the error Δ _i of the power supply efficiency. In addition, the vehicle-side control unit 154 calculates a total sum Δ _all of errors every time _i of the error Δ _i increases, and performs a threshold determination between the calculated Δ _all and a predetermined threshold Δ _thi prepared in advance for each sampling number. Do. If Δ _all is equal to or greater than Δ _{thi as} a result of the threshold determination, the vehicle-side control unit 154 determines that an obstacle has been detected, and the vehicle-side communication unit 156 and the power receiving unit 157 perform various processes associated with stopping power reception. Control to start.

  In addition, when a power reception start instruction is input from the display unit 155, the vehicle side control unit 154 controls the vehicle side communication unit 156 and the power reception unit 157 to start various processes associated with power reception. The vehicle-side control unit 154 controls the vehicle-side communication unit 156 and the power reception unit 157 to start various processes associated with power reception stop when a power reception stop instruction is input from the display unit 155.

  Display unit 155 displays a menu screen that accepts an instruction from a user who starts or stops receiving power. When receiving a power reception start or power reception stop instruction from the user on the menu screen, the display unit 155 outputs a power reception start instruction or a power reception stop instruction to the vehicle-side control unit 154 according to the user instruction.

  The vehicle side communication unit 156 generates a power reception start signal or a power reception stop signal according to the control of the vehicle side control unit 154, and transmits the generated power reception start signal or power reception stop signal to the power supply side communication unit 123. Further, the vehicle side communication unit 156 notifies the vehicle side control unit 154 of the power supply power value input from the power supply side communication unit 123.

  The power reception unit 157 includes a circular power reception coil (secondary coil) provided on the bottom surface of the vehicle 130, and when the storage battery 170 is charged using electromagnetic induction, the power reception coil is connected to the power supply surface 121 a of the power supply unit 121. Opposes in a non-contact state. The power receiving unit 157 supplies the power supplied from the power supply unit 121 to the storage battery 170 and outputs the received power value to the vehicle side control unit 154 according to the control of the vehicle side control unit 154.

  Here, the power supply efficiency according to the positional relationship between the power supply coil of the power supply unit 121 and the power reception coil of the power reception unit 157 will be described with reference to FIG. 3. FIG. 3 defines an x-axis corresponding to the width direction of the vehicle 130 and a y-axis corresponding to the length direction of the vehicle 130 with the center of the power supply coil set to 0 when the power supply coil is viewed from directly above. At this time, three concentric circles with the origin 0 as the center are formed according to the power feeding efficiency, the circle with the radius a is 70% or more, the circle with the radius b (> a) is 65% or more, and the radius c (> b ) Indicates that the power supply efficiency is 60% or more. That is, the closer the distance between the center of the power feeding coil and the center of the power receiving coil is, the higher the power feeding efficiency is, and the longer the distance is, the lower the power feeding efficiency is.

  Based on such a premise, a method for creating a power feeding efficiency fluctuation pattern to be stored in the power feeding efficiency fluctuation pattern storage unit 153 will be described with reference to FIG. Here, it is also assumed that there is no obstacle between the feeding coil and the receiving coil. FIG. 4A shows an approach path along which the vehicle 130 moves so that the center of the power feeding coil and the center of the power receiving coil coincide with each other. FIG. 4B shows an approach path along which the vehicle moves so that the center of the power feeding coil and the center of the power receiving coil are shifted.

  As the vehicle 130 moves, as the center of the power feeding coil and the center of the power receiving coil get closer, the power feeding efficiency takes a maximum value that varies from 0 for each approach route. This is shown in FIG. 4 (c). In FIG. 4C, the curve shown by the solid line shows the fluctuation pattern of the power supply efficiency in the approach route shown in FIG. 4A, and the curve shown by the dotted line shows the power supply in the approach route shown in FIG. 4B. The variation pattern of efficiency is shown. In FIG. 4C, the negative curve of the y-axis is not shown because it is assumed that the vehicle 130 stops due to a ring stop or the like.

  Next, the fluctuation pattern of the power supply efficiency when there is an obstacle will be described with reference to FIG. In FIG. 5, a curve indicated by a dotted line indicates a fluctuation pattern of the power supply efficiency in a state where there is no obstacle in a certain approach route A (a power supply efficiency fluctuation pattern stored in advance), and a curve indicated by a solid line indicates the approach route A. The fluctuation pattern of the power supply efficiency in the state where there is an obstacle is shown. As can be seen from this figure, in the state where there is an obstacle, the power supply efficiency is deteriorated compared to the state where there is no obstacle. This is because the power energy radiated from the power feeding coil is absorbed or reflected by the obstacle, and the energy reaching the power receiving coil is reduced. FIG. 6 shows how the degree of deterioration is calculated as an error.

In FIG. 6, the power feeding efficiency k _i is sampled (calculated) at a fixed timing as the vehicle 130 moves, and the sampling number i is set to 0-8. Each time the power supply efficiency k _i is sampled, an error Δ _i between the known power supply efficiency kp _i and the sampled power supply efficiency k _i is obtained, and the error Δ _i is cumulatively added. In the example of FIG. 6, it can be seen that no error occurs when i = 0-4, and an error occurs when i = 5-8.

  Next, the obstacle detection method in the vehicle side control unit 154 described above will be described with reference to FIG. In FIG. 7, when the center of the power receiving coil and the center of the power feeding coil are within a predetermined distance as the vehicle 130 moves (for example, reverse), the vehicle-side control unit 154 performs the following steps (hereinafter, “ The preliminary power supply process after 201 is started.

In ST201, a power feeding efficiency variation pattern corresponding to the approach route detected by the approach route detecting unit 151 is read from the power feeding efficiency variation pattern storage unit 153. In ST202, the vehicle side communication unit 156 and the power receiving unit 157 are accompanied by power reception. It was controlled to start various processes to calculate the power supply efficiency k _i from the received power value notified from the power receiving unit 157, and has been supplied power value input from the vehicle-side communication unit 156.

In ST 203, the absolute value of the read values the position detection unit 152 is obtained by subtracting the power supply efficiency k _i from the feed efficiency kp _i corresponding to the position on the approach path detected among the patterns of the power supply efficiency as an error delta _i of power supply efficiency In step ST204, m = 0 is set.

In ST205, she calculates the sum delta _all errors according the following equation (1).

In ST 206, performs threshold determination of the total delta _all with a predetermined threshold _{delta thi} error, if delta _all is less than the threshold _{delta thi,} the process proceeds to ST207, if the delta _all threshold _{delta thi} above, ST210 Transition.

  In ST207, it is determined whether m = M (M is the maximum value i can take). If m = M is not satisfied, m is incremented in ST208, and the process returns to ST205. On the other hand, if m = M, it is determined in ST209 that an obstacle has not been detected, and the process ends.

  In ST210, it is determined that an obstacle has been detected. In ST211, the vehicle-side communication unit 156 and the power reception unit 157 are controlled to start various processes associated with the stop of power reception.

In this way, each time the vehicle-side control unit 154 samples the power supply efficiency k _i , the power supply efficiency error sum Δ _all is calculated, and the threshold judgment between the calculated error sum Δ _all and the predetermined threshold value Δ _thi is performed. Since it can be determined that the obstacle has been detected at the timing when the sum of errors Δ _all exceeds the threshold value Δ _thi , the user can remove the obstacle before completing the warehousing of the vehicle. it can.

  Note that the vehicle-side control unit 154 may retry power supply every predetermined time after detecting an obstacle, determine whether the obstacle has been removed, and perform power supply if no obstacle is detected.

As described above, according to the present embodiment, the value obtained by subtracting the sampled power supply efficiency k _i from the power supply efficiency kp _i acquired in advance in the absence of an obstacle is used as the power supply efficiency error Δ _i and the power supply efficiency k calculating a _i each time the sampling, the total delta _all the calculated error delta _i, performs a threshold determination of the previously prepared predetermined threshold delta _thi every sampling number, total delta _all errors threshold delta _thi By determining that the obstacle has been detected at the timing exceeding, it is possible to detect the obstacle between the power feeding device and the power receiving device before completing the warehousing.

  In the present embodiment, the power supply efficiency fluctuation pattern is described as being stored in advance. However, the present invention is not limited to this, and the power supply efficiency sampled without an obstacle is stored as the power supply efficiency fluctuation pattern. You may do it.

  In the present embodiment, a warning may be issued when an obstacle is detected. Also, a warning may be issued when power supply is resumed. Examples of warnings include voice and sound waves.

  The power receiving device and the obstacle detection method according to the present invention can be applied to a vehicle charging system and the like.

DESCRIPTION OF SYMBOLS 100 Charging system 120 Power supply apparatus 121 Power supply part 121a Power supply surface 122 Power supply side control part 123 Power supply side communication part 130 Vehicle 150 Power receiving apparatus 151 Approach route detection part 152 Position detection part 153 Power supply efficiency fluctuation pattern storage part 154 Vehicle side control part 155 Display Unit 156 vehicle side communication unit 157 power receiving unit 170 storage battery

Claims (4)

A power receiving device provided in a vehicle that receives power fed from a power feeding device provided outside the vehicle using electromagnetic induction in a contactless manner,
A power feeding efficiency pattern that varies according to the position of the power receiving device with respect to the power feeding device in a state where there is no obstacle between the power feeding device and the power receiving device is previously set as a power feeding efficiency variation pattern for each approach path of the vehicle. Storage means for storing;
An approach route detecting means for detecting an approach route of the vehicle with respect to the power supply device;
Position detecting means for detecting at which position of the detected approach route the power feeding device is present;
Calculates a power supply efficiency k _i with the movement of the vehicle, reads the pattern of the power supply efficiency corresponding to the detected the approach path from the storage means, corresponding to said detected position of the pattern of the read power supply efficiency the value obtained by subtracting the feed efficiency k _i from power supply efficiency kp _i and error delta _i of the feed efficiency, the threshold determination of the error delta _i sum delta _all of, a predetermined threshold delta _thi determined for each sampling number i Control means for determining the detection of an obstacle based on the result of the threshold determination,
A power receiving apparatus comprising: 2. The power receiving device according to claim 1, wherein the control unit determines that an obstacle has been detected when the total sum Δ _{all of the} errors exceeds the threshold value Δ _thi . 2. The power receiving device according to claim 1, wherein when the sampling number i can take a maximum value, the control unit determines that an obstacle has not been detected when the total sum Δ _{all of the} errors is less than the threshold value Δ _thi . A method for detecting an obstacle in a power receiving device provided in a vehicle, wherein the power supplied from a power feeding device provided outside the vehicle using electromagnetic induction is received in a non-contact manner.
Detecting the approach path of the vehicle with respect to the power feeding device,
Detecting at which position of the detected approach route the power feeding device is present;
Sampling the power supply efficiency k _i with the movement of the vehicle,
A pattern of power supply efficiency that varies depending on the position of the power receiving device with respect to the power supply device in a state where there is no obstacle between the power supply device and the power receiving device is predetermined and detected for each approach path of the vehicle. The value obtained by subtracting the power supply efficiency k _i from the power supply efficiency kp _i corresponding to the detected position among the power supply efficiency patterns corresponding to the approach route is calculated for each sampling as the error Δ _i of the power supply efficiency. And
The sum delta _all of the calculated the error delta _i, a threshold decision with a predetermined threshold value delta _thi determined for each sampling number i is performed,
Determining the detection of an obstacle based on the result of the threshold determination;
Obstacle detection method.

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