U.S. patent application number 15/981293 was filed with the patent office on 2018-09-13 for electric power reception device for vehicle, electric power transmission device, and non-contact electric power transmission/reception system.
This patent application is currently assigned to TOYOTA JIDOSHA KABUSHIKI KAISHA. The applicant listed for this patent is TOYOTA JIDOSHA KABUSHIKI KAISHA. Invention is credited to Shinji ICHIKAWA.
Application Number | 20180257493 15/981293 |
Document ID | / |
Family ID | 48288676 |
Filed Date | 2018-09-13 |
United States Patent
Application |
20180257493 |
Kind Code |
A1 |
ICHIKAWA; Shinji |
September 13, 2018 |
ELECTRIC POWER RECEPTION DEVICE FOR VEHICLE, ELECTRIC POWER
TRANSMISSION DEVICE, AND NON-CONTACT ELECTRIC POWER
TRANSMISSION/RECEPTION SYSTEM
Abstract
An electric power reception device for a vehicle is equipped
with an electric power reception unit that is configured to be able
to receive electric power from an electric power transmission
device in a non-contact manner, a communication portion that
transmits information on a position or dimension of the electric
power reception unit to the electric power transmission device, and
a vehicle ECU that controls the communication portion. Preferably,
the vehicle ECU transmits pre-stored information to the electric
power transmission device with the aid of the communication
portion, before allowing a vehicle to be parked at an electric
power reception position of the electric power transmission device.
The information includes at least one of a size of the electric
power reception unit, a size of the vehicle in which the electric
power reception unit is mounted, and a mounting position of the
electric power reception unit in the vehicle.
Inventors: |
ICHIKAWA; Shinji;
(Toyota-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
TOYOTA JIDOSHA KABUSHIKI KAISHA |
Toyota-shi |
|
JP |
|
|
Assignee: |
TOYOTA JIDOSHA KABUSHIKI
KAISHA
Toyota-shi
JP
|
Family ID: |
48288676 |
Appl. No.: |
15/981293 |
Filed: |
May 16, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14353829 |
Apr 24, 2014 |
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PCT/JP2011/075673 |
Nov 8, 2011 |
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15981293 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H02J 7/025 20130101;
H02J 2300/28 20200101; Y04S 30/14 20130101; B60L 11/1809 20130101;
B60L 53/122 20190201; B60L 53/305 20190201; B60L 2210/40 20130101;
B60L 7/14 20130101; H02J 5/005 20130101; B60L 2240/527 20130101;
B60L 2250/12 20130101; B60L 2250/16 20130101; B60L 53/51 20190201;
Y02T 90/16 20130101; H02J 7/00034 20200101; H02J 7/35 20130101;
B60L 53/00 20190201; Y02T 90/14 20130101; H02J 50/80 20160201; Y02T
10/70 20130101; Y02T 90/169 20130101; B60L 53/52 20190201; Y02T
90/167 20130101; B60L 50/51 20190201; B60L 53/65 20190201; H02J
50/12 20160201; B60L 50/16 20190201; B60L 2220/14 20130101; Y02T
90/12 20130101; B60L 2210/10 20130101; B60L 53/36 20190201; B60L
2210/30 20130101; B60L 2240/549 20130101; B60L 53/66 20190201; H02J
2310/48 20200101; Y02T 10/72 20130101; H02J 7/34 20130101; B60L
2240/547 20130101; Y02T 10/7072 20130101 |
International
Class: |
B60L 11/18 20060101
B60L011/18; H02J 50/12 20160101 H02J050/12; B60L 7/14 20060101
B60L007/14; B60L 11/14 20060101 B60L011/14; H02J 50/80 20160101
H02J050/80; H02J 7/02 20160101 H02J007/02 |
Claims
1. An electric power reception device for a vehicle that can
receive electric power from an electric power transmission device
outside the vehicle in a non-contact manner, the electric power
reception device comprising: an electric power receiver configured
to receive electric power from the electric power transmission
device in a non-contact manner; a communicator configured to
receive information related to the electric power transmission
device; and a controller configured to determine whether or not
non-contact charging is possible based on the information received
by the communicator, wherein the communicator is configured to
transmit a result of the determination to the electric power
transmission device.
2. The electric power reception device according to claim 1,
wherein the controller is configured to notify a passenger of the
result.
3. An electric power transmission device for a vehicle that is
configured to transmit electric power to an electric power
reception device of the vehicle in a non-contact manner, the
electric power transmission device comprising: an electric power
transmitter configured to transmit electric power to the electric
power reception device in a non-contact manner; a communicator
configured to receive information related to the electric power
reception device; and a controller configured to determine whether
or not non-contact charging is possible based on information
received by the communicator, wherein the communicator is
configured to transmit a result of the determination to the
electric power reception device.
4. The electric power transmission device according to claim 3,
wherein the controller is configured to notify a passenger of the
result.
5. The electric power reception device according to claim 1,
wherein the information includes a shape of the electric power
transmission device.
6. The electric power reception device according to claim 1,
wherein the information includes at least one of: a size of the
electric power transmission device, a size of a parking space in
which the electric power transmission device is arranged, a
mounting position of the electric power transmission device in the
parking space, or a mounting angle of the electric power
transmission device in the parking space.
7. The electric power reception device according to claim 1,
wherein the electric power transmission device includes a plurality
of electric power transmitters, and the electric power transmission
device determines the electric power transmitter used to transmit
electric power among the plurality of the electric power
transmitters based on the result.
8. The electric power reception device according to claim 1,
wherein the electric power transmission device includes a movable
electric power transmitter, and the electric power transmission
device determines a position of the electric power transmitter
based on the information transmitted from the communication
portion.
9. The electric power transmission device according to claim 3,
wherein the received information includes a shape of the electric
power reception device.
10. The electric power transmission device according to claim 3,
wherein the electric power transmission device prepares for
electric power transmission according to the result.
11. The electric power transmission device according to claim 3,
wherein the received information includes at least one of: a size
of the electric power receiver, a size of the vehicle, a mounting
position of the electric power receiver in the vehicle, and a
mounting angle of the electric power receiver in the vehicle.
12. The electric power transmission device according to claim 3,
wherein the result includes a guidance direction of the
vehicle.
13. The electric power transmission device according to claim 3,
wherein the electric power transmission device includes a plurality
of electric power transmitters, and the electric power transmission
device determines the electric power transmitter used to transmit
electric power among the plurality of the electric power
transmitters based on the received information.
14. The electric power transmission device according to claim 3,
wherein the electric power transmission device includes a movable
electric power transmitter, and the electric power transmission
device determines a position of the electric power transmitter
based on the received information.
Description
TECHNICAL FIELD
[0001] This invention relates to an electric power reception device
for a vehicle, an electric power transmission device, and a
non-contact electric power transmission/reception system.
BACKGROUND ART
[0002] In recent years, electric vehicles and hybrid vehicles,
which run by using electric energy instead of fuel or in addition
to fuel with a view to reducing the amount of carbon dioxide
discharged from the vehicles for the purpose of preventing global
warming, have been attracting attention. Moreover, there have also
been plug-in hybrid vehicles that are configured such that their
batteries, which are also mounted in hybrid vehicles, can be
charged with electric energy from outside the vehicles.
[0003] Furthermore, with a view to achieving an improvement in
user-friendliness, technologies of feeding electric power in a
non-contact manner have been reviewed as a method of feeding
electric energy to a vehicle from outside the vehicle. In feeding
electric power in a non-contact manner, the alignment of an
electric power transmission unit with an electric power reception
unit poses a problem.
[0004] In the pamphlet of WO 2010/052785 (Patent Document 1), there
is disclosed a non-contact charging system that aligns an electric
power transmission coil and an electric power reception coil with
each other on the basis of a situation of electric power
reception.
RELATED ART DOCUMENTS
Patent Documents
[0005] Patent Document 1: Pamphlet of WO 2010/052785
[0006] Patent Document 2: Japanese Patent Application Publication
No. 2010-183812 (JP-2010-183812 A)
[0007] Patent Document 3: Japanese Patent Application Publication
No. 2010-183804 (JP-2010-183804 A)
SUMMARY OF THE INVENTION
Problems to be Solved by the Invention
[0008] In the non-contact charging system disclosed in the pamphlet
of WO 2010/052785 (Patent Document 1), it is impossible to
determine whether or not the positions of an electric power
transmission portion including the electric power transmission coil
and the like and an electric power reception portion including the
electric power reception coil and the like enable appropriate
electric power reception, unless an electric power reception
operation is actually performed. In certain vehicles, it is
possible to assume a case where the mounting position of the
electric power reception portion differs to various degrees. At a
certain mounting position of the electric power reception portion
on the vehicle side, there is also conceived a case where an
electric power transmission device side cannot cope with the
vehicle. Besides, there is assumed a case where the installation
position of the electric power transmission portion of the electric
power transmission device also differs to various degrees. There is
also conceived a case where the vehicle side cannot cope with the
electric power transmission device either.
[0009] In such cases, it is inconvenient that a determination on
the appropriateness of a positional relationship between the
electric power transmission portion and the electric power
reception portion cannot be made unless electric power is actually
transmitted/received. Besides, even if electric power is actually
transmitted/received to carry out a positional alignment, the
position at which received electric power is at its local maximum
may not be an optimal position.
[0010] It is an object of this invention to provide an electric
power reception device, an electric power transmission device, and
a non-contact electric power transmission/reception system for a
vehicle that make it possible to obtain information on positions of
an electric power transmission portion and an electric power
reception portion without recourse to the transmission/reception of
electric power.
Means for Solving the Problems
[0011] In summary, this invention is an electric power reception
device for a vehicle that can receive electric power from an
electric power transmission device outside the vehicle in a
non-contact manner. The electric power reception device is equipped
with an electric power reception unit that is configured to be able
to receive electric power from the electric power transmission
device in a non-contact manner, and a communication portion that
transmits to the electric power transmission device information on
a position or dimension of the electric power reception unit.
[0012] Preferably, the information includes at least of a size of
the electric power reception unit, a size of the vehicle in which
the electric power reception unit is mounted, a mounting position
of the electric power reception unit in the vehicle, and a mounting
angle of the electric power reception unit in the vehicle.
[0013] More preferably, the electric power reception device is
further equipped with a control device that controls the
communication portion. The control device receives from the
electric power transmission device a determination result about
whether or not non-contact charging is possible, on which a
determination has been made on a basis of the information, and
notifies a passenger of the determination result.
[0014] More preferably, the electric power reception device is
further equipped with a control device that controls the
communication portion. The control device receives from the
electric power transmission device a determination result about a
guidance direction of the vehicle on which a determination has been
made on a basis of the information, and notifies a passenger of the
determination result.
[0015] More preferably, the electric power transmission device
includes a plurality of electric power transmission units. The
electric power transmission device determines the electric power
transmission unit used to transmit electric power among the
plurality of the electric power transmission units, on a basis of
the information transmitted from the communication portion.
[0016] More preferably, the electric power transmission device
includes a movable electric power transmission unit. The electric
power transmission device determines a position of the electric
power transmission unit on a basis of the information transmitted
from the communication portion.
[0017] In another aspect, this invention is an electric power
transmission device that can transmit electric power in a
non-contact manner. The electric power transmission device is
equipped with an electric power transmission unit that is
configured to be able to transmit electric power to a vehicle from
outside the vehicle in a non-contact manner, and a communication
portion that transmits information on a position or dimension of
the electric power transmission unit to the vehicle.
[0018] Preferably, the information includes at least one of a size
of the electric power transmission unit, a size of a parking space
in which the electric power transmission unit is arranged, a
mounting position of the electric power transmission unit in the
parking space, and a mounting angle of the electric power
transmission unit in the parking space.
[0019] More preferably, the electric power transmission device is
further equipped with a control device that controls the
communication portion. The control device receives from the vehicle
a determination result about whether or not non-contact charging is
possible, on which a determination has been made on a basis of the
information.
[0020] More preferably, the electric power transmission device is
further equipped with a control device that controls the
communication portion. The control device receives from the vehicle
a determination result about a guidance direction of the vehicle on
which a determination has been made on a basis of the
information.
[0021] More preferably, the electric power transmission device is
further equipped with a control device that controls the
communication portion. The vehicle includes a plurality of electric
power reception units. The control device transmits the information
to the vehicle through use of the communication portion, in order
to determine the electric power reception unit used to receive
electric power among the plurality of the electric power reception
units.
[0022] More preferably, the electric power transmission device is
further equipped with a control device that controls the
communication portion. The vehicle includes a movable electric
power reception unit. The control device transmits the information
to the vehicle through use of the communication portion, in order
to determine a position of the electric power reception unit.
[0023] In still another aspect, this invention is an electric power
transmission device that can transmit electric power to a vehicle
in a non-contact manner. The vehicle includes an electric power
reception unit that receives electric power from the electric power
transmission device, and transmits information on a position or
dimension of the electric power reception unit to the electric
power transmission device. The electric power transmission device
is equipped with a communication portion that receives the
information on the position or dimension of the electric power
reception unit from the vehicle, and an electric power transmission
unit that is configured to be able to transmit electric power to
the electric power reception unit in a non-contact manner.
[0024] In still another aspect, this invention is an electric power
reception device for a vehicle that can receive electric power from
an electric power transmission device in a non-contact manner. The
electric power transmission device includes an electric power
transmission unit that transmits electric power to the vehicle, and
transmits information on a position or dimension of the electric
power transmission unit to the electric power reception device for
the vehicle. The electric power reception device for the vehicle is
equipped with a communication portion that receives information on
the position or dimension of the electric power transmission unit
from the electric power transmission device, and an electric power
reception unit that is configured to be able to receive electric
power from the electric power transmission unit in a non-contact
manner.
[0025] In still another aspect, this invention is a non-contact
electric power transmission/reception system that is equipped with
an electric power reception device that is mounted in a vehicle,
and an electric power transmission device that is located outside
the vehicle. The electric power reception device includes an
electric power reception unit that is configured to be able to
receive electric power from the electric power transmission device
in a non-contact manner, and a communication portion that transmits
information on a position or dimension of the electric power
reception unit to the electric power transmission device.
[0026] In still another aspect, this invention is a non-contact
electric power transmission/reception system that is equipped with
an electric power reception device that is mounted in a vehicle,
and an electric power transmission device that is located outside
the vehicle. The electric power transmission device includes an
electric power transmission unit that is configured to be able to
transmit electric power to the vehicle from outside the vehicle in
a non-contact manner, and a communication portion that transmits
information on a position or dimension of the electric power
transmission unit to the vehicle.
Effect of the Invention
[0027] According to the invention, the information on the position
or dimension of the electric power transmission unit or the
electric power reception unit can be recognized even if charging is
actually not carried out, and an improvement in user-friendliness
is achieved.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIG. 1 is an overall configurational view of an electric
power transmission/reception system according to each embodiment of
this invention.
[0029] FIG. 2 is a view for illustrating a principle of electric
power transmission according to a resonance technique.
[0030] FIG. 3 is a view showing a relationship between a distance
from an electric current source (a magnetic current source) and an
intensity of an electromagnetic field.
[0031] FIG. 4 is a view showing a simulation model of an electric
power transfer system.
[0032] FIG. 5 is a view showing a relationship between a deviation
between natural frequencies of an electric power transmission unit
and an electric power reception unit, and an electric power
transfer efficiency.
[0033] FIG. 6 is a detailed configurational view of the electric
power transmission/reception system shown in FIG. 1.
[0034] FIG. 7 is a view for illustrating the arrangement of the
electric power reception unit in various vehicles.
[0035] FIG. 8 is a view for illustrating the arrangement of the
electric power transmission unit in various electric power
transmission devices.
[0036] FIG. 9 is a flowchart for illustrating the control performed
in the vehicle and the electric power transmission device in the
first embodiment of the invention.
[0037] FIG. 10 is a view for illustrating a first example in which
communication is established according to a processing of FIG.
9.
[0038] FIG. 11 is a lateral view for illustrating information
associated with the electric power reception unit of the
vehicle.
[0039] FIG. 12 is a top view for illustrating information
associated with the electric power reception unit of the
vehicle.
[0040] FIG. 13 is a view for illustrating a second example in which
communication is established according to the processing of FIG.
9.
[0041] FIG. 14 is a flowchart for illustrating the control
performed in a vehicle and an electric power transmission device in
the second embodiment of the invention.
[0042] FIG. 15 is a view for illustrating a first example in which
communication is established according to a processing of FIG.
14.
[0043] FIG. 16 is a view for illustrating a second example in which
communication is established according to the processing of FIG.
14.
[0044] FIG. 17 is a flowchart for illustrating the control
performed in a vehicle and an electric power transmission device in
the third embodiment of the invention.
[0045] FIG. 18 is a view for illustrating a first example in which
communication is established according to a processing of FIG.
17.
[0046] FIG. 19 is a top view for illustrating information
associated with an electric power transmission unit of the electric
power transmission device.
[0047] FIG. 20 is a lateral view for illustrating information
associated with the electric power transmission unit of the
electric power transmission device.
[0048] FIG. 21 is a view for illustrating a second example in which
communication is established according to the processing of FIG.
17.
[0049] FIG. 22 is a flowchart for illustrating the control
performed in a vehicle and an electric power transmission device in
the fourth embodiment of the invention.
[0050] FIG. 23 is a view for illustrating a first example in which
communication is established according to a processing of FIG.
22.
[0051] FIG. 24 is a view for illustrating a second example in which
communication is established according to the processing of FIG.
22.
MODES FOR CARRYING OUT THE INVENTION
[0052] The embodiments of the invention will be described
hereinafter in detail with reference to the drawings. Incidentally,
like or equivalent components in the drawings are denoted by like
reference symbols respectively, and the description thereof will
not be repeated.
[0053] [Description of Outline of Non-Contact Electric Power
Transmission/Reception]
[0054] FIG. 1 is an overall configurational view of an electric
power transmission/reception system according to each of the
embodiments of this invention.
[0055] Referring to FIG. 1, an electric power
transmission/reception system 10 includes a vehicle 100 and an
electric power transmission device 200. The vehicle 100 includes an
electric power reception unit 110 and a communication portion
160.
[0056] The electric power reception unit 110 is installed on a
bottom face of a vehicle body, and is configured to receive
electric power delivered from an electric power transmission unit
220 of the electric power transmission device 200, in a non-contact
manner. More specifically, the electric power reception unit 110
includes a later-described self-resonant coil (referred to also as
a resonant coil), and receives electric power from the electric
power transmission unit 220 in a non-contact manner by resonating
with the self-resonant coil included in the electric power
transmission unit 220 via an electromagnetic field. The
communication portion 160 is a communication interface for
establishing communication between the vehicle 100 and the electric
power transmission device 200.
[0057] The electric power transmission device 200 includes a
charging stand 210 and the electric power transmission unit 220.
The charging stand 210 includes a display portion 242, a fare
reception portion 246, and a communication portion 230. The
charging stand 210 converts, for example, a commercial
alternating-current electric power into a high-frequency electric
power, and outputs the high-frequency electric power to the
electric power transmission unit 220. Incidentally, the charging
stand 210 may be supplied with electric power from an electric
power supply device such as a solar photovoltaic device, a wind
generator device or the like.
[0058] The electric power transmission unit 220 is installed on,
for example, a floor face of a parking lot, and is configured to
deliver the high-frequency electric power supplied from the
charging stand 210 to the electric power reception unit 110 of the
vehicle 100 in a non-contact manner. More specifically, the
electric power transmission unit 220 includes a self-resonant coil,
and transmits electric power to the electric power reception unit
110 in a non-contact manner through resonance of this self-resonant
coil with the self-resonant coil included in the electric power
reception unit 110 via an electromagnetic field. The communication
portion 230 is a communication interface for establishing
communication between the electric power transmission device 200
and the vehicle 100.
[0059] It should be noted herein that in feeding electric power
from the electric power transmission device 200 to the vehicle 100,
there is a need to guide the vehicle 100 to the electric power
transmission device 200, and align the electric power reception
unit 110 of the vehicle 100 and the electric power transmission
unit 220 of the electric power transmission device 200 with each
other. That is, it is not easy to align the vehicle 100. A portable
instrument can be lifted by a hand of a user and placed with ease
at an appropriate position of an electric power feed unit such as a
charger or the like. However, the vehicle needs to be operated by
the user to be stopped at an appropriate position. The vehicle
cannot be lifted by a hand to be adjusted in position.
[0060] For this reason, the adoption of a method with a high
tolerance toward positional displacement is desirable in feeding
electric power from the electric power transmission device 200 to
the vehicle 100. An electromagnetic induction method is said to
have a short transmission distance and a low tolerance toward
positional displacement as well. If an attempt is made to adopt the
electromagnetic induction method in feeding electric power to the
vehicle, a highly accurate driving technique may be required of a
driver during parking, the mounting of a highly accurate vehicle
guidance device in the vehicle may become necessary, or a movable
portion that moves a coil position such that a rough parking
position can also be coped with may be required.
[0061] It is said that an electromagnetic field resonance method
allows a relatively large electric power to be transmitted even if
the transmission distance is several meters, and generally has a
higher tolerance toward positional displacement than the
electromagnetic induction method. Thus, in the electric power
transmission/reception system 10 according to this embodiment of
the invention, electric power is fed from the electric power
transmission device 200 to the vehicle 100 through the use of a
resonance technique.
[0062] Incidentally, in the electric power transmission/reception
system according to this embodiment of the invention, the natural
frequency of the electric power transmission unit and the natural
frequency of the electric power reception unit are set equal to
each other.
[0063] "The natural frequency of the electric power transmission
unit" means an oscillation frequency in the case where an electric
circuit including a capacitor and a coil of the electric power
transmission unit freely oscillates. Incidentally, "the resonant
frequency of the electric power transmission unit" means a natural
frequency at the time when the braking force or electric resistance
is set to zero in the electric circuit including the capacitor and
the coil of the electric power transmission unit.
[0064] By the same token, "the natural frequency of the electric
power reception unit" means an oscillation frequency in the case
where an electric circuit including a capacitor and a coil of the
electric power reception unit freely oscillates. Besides, "the
resonant frequency of the electric power reception unit" means a
natural frequency at the time when the braking force or electric
resistance is set to zero in the electric circuit including the
capacitor and the coil of the electric power reception unit.
[0065] In the present specification, "the same natural frequency"
includes not only a case where the natural frequencies are
completely equal to each other but also a case where the natural
frequencies are substantially equal to each other. The sentence
"the natural frequencies are substantially equal to each other"
means a case where the difference between the natural frequency of
the electric power transmission unit and the natural frequency of
the electric power reception unit falls within 10% of the natural
frequency of the electric power transmission unit or the natural
frequency of the electric power reception unit.
[0066] FIG. 2 is a view for illustrating a principle of electric
power transmission according to the resonance technique.
[0067] Referring to FIG. 2, in this resonance technique, two LC
resonant coils having the same natural frequency resonate with each
other in an electromagnetic field (a near field) as in the case
where two tuning forks resonate with each other, so that electric
power is transferred from one of the coils to the other coil via
the electromagnetic field.
[0068] More specifically, a primary coil 320 is connected to a
high-frequency electric power supply 310 to feed high-frequency
electric power to a primary self-resonant coil 330 that is
magnetically coupled to the primary coil 320 through
electromagnetic induction. The primary self-resonant coil 330 is an
LC resonator with a stray capacitance and an inductance of the coil
itself, and resonates with a secondary self-resonant coil 340,
which has the same resonant frequency as the primary self-resonant
coil 330, via the electromagnetic field (the near field). Then,
energy (electric power) moves from the primary self-resonant coil
330 to the secondary self-resonant coil 340 via the electromagnetic
field. The energy (electric power) that has moved to the secondary
self-resonant coil 340 is taken out by a secondary coil 350, which
is magnetically coupled to the secondary self-resonant coil 340
through electromagnetic induction, and is supplied to a load 360.
Incidentally, electric power transmission according to the
resonance technique is realized when a Q-value indicating a
resonance intensity of the primary self-resonant coil 330 and the
secondary self-resonant coil 340 is larger than, for example,
100.
[0069] Besides, in the electric power transmission/reception system
according to this embodiment of the invention, the electric power
transmission unit and the electric power reception unit are caused
to resonate (vibrate sympathetically) with each other through the
electromagnetic field, so that electric power is transmitted from
the electric power transmission unit to the electric power
reception unit. It is preferable that a coupling coefficient (K)
between the electric power transmission unit and the electric power
reception unit be equal to or smaller than 0.1. Incidentally, the
coupling coefficient (K) is not limited to this value, and can
assume various values that ensure good electric power transfer. In
general, in electric power transfer through the use of
electromagnetic induction, the coupling coefficient (K) between an
electric power transmission portion and an electric power reception
portion is close to 1.0.
[0070] Incidentally, as for a corresponding relationship with FIG.
1, the secondary self-resonant coil 340 and the secondary coil 350
correspond to the electric power reception unit 110 of FIG. 1, and
the primary coil 320 and the primary self-resonant coil 330
correspond to the electric power transmission unit 220 of FIG.
1.
[0071] FIG. 3 is a view showing a relationship between a distance
from an electric current source (a magnetic current source) and an
intensity of the electromagnetic field. Referring to FIG. 3, the
electromagnetic field includes three components. A curve k1
represents a component that is inversely proportional to the
distance from a wave source, and is referred to as "a radiation
electromagnetic field". A curve k2 represents a component that is
inversely proportional to the square of the distance from the wave
source, and is referred to as "an induction electromagnetic field".
Besides, a curve k3 represents a component that is inversely
proportional to the cube of the distance from the wave source, and
is referred to as "an electrostatic electromagnetic field".
[0072] Among these electromagnetic fields, there is a region in
which the intensity of electromagnetic waves suddenly decreases as
the distance from the wave source increases. In the resonance
technique, however, energy (electric power) is transferred through
the use of this near field (an evanescent field). That is, a pair
of resonators (e.g., a pair of LC resonant coils) having the same
natural frequency are caused to resonate with each other through
the use of the near field, so that energy (electric power) is
transferred from one of the resonators (the primary self-resonant
coil) to the other resonator (the secondary self-resonant coil).
This near field does not propagate energy (electric power) over a
long distance. Therefore, the resonance technique makes it possible
to transmit electric power with a smaller energy loss than
electromagnetic waves that transfer energy (electric power) through
"the radiation electromagnetic field" that propagates energy over a
long distance.
[0073] A simulation result of an analysis of a relationship between
the difference between the natural frequencies and the efficiency
of electric power transmission will be described using FIG. 4 and
FIG. 5. FIG. 4 is a view showing a simulation model of an electric
power transfer system. Besides, FIG. 5 is a view showing a
relationship between a deviation between the natural frequencies of
the electric power transmission unit and the electric power
reception unit and the efficiency of electric power transfer.
[0074] Referring to FIG. 4, an electric power transfer system 89
includes an electric power transmission unit 90 and an electric
power reception unit 91. The electric power transmission unit 90
includes a first coil 92 and a second coil 93. The second coil 93
includes a resonant coil 94 and a capacitor 95 that is connected to
the resonant coil 94. The electric power reception unit 91 includes
a third coil 96 and a fourth coil 97. The third coil 96 includes a
resonant coil 99, and a capacitor 98 that is connected to this
resonant coil 99.
[0075] It is assumed that the inductance of the resonant coil 94 is
an inductance Lt, and that the capacitance of the capacitor 95 is a
capacitance C1. Besides, it is assumed that the inductance of the
resonant coil 99 is an inductance Lr, and that the capacitance of
the capacitor 98 is a capacitance C2. If the respective parameters
are thus set, a natural frequency f1 of the second coil 93 is
indicated by an expression (1) shown below, and a natural frequency
f2 of the third coil 96 is indicated by an expression (2) shown
below.
f1=1/{2.pi.(Lt.times.C1).sup.1/2} (1)
f2=1/{2.pi.(Lr.times.C2).sup.1/2} (2)
[0076] It should be noted herein that FIG. 5 shows a relationship
between a deviation between the natural frequencies of the second
coil 93 and the third coil 96 and the efficiency of electric power
transfer in the case where only the inductance Lt is changed with
the inductance Lr and the capacitances C1 and C2 fixed.
Incidentally, in this simulation, the mutual positional
relationship between the resonant coil 94 and the resonant coil 99
is fixed, and furthermore, the frequency of the current supplied to
the second coil 93 is constant.
[0077] In the graph shown in FIG. 5, an axis of abscissa represents
a deviation between the natural frequencies (%), and an axis of
ordinate represents the efficiency (%) of electric power transfer.
The deviation (%) between the natural frequencies is indicated by
an expression (3) shown below.
(Deviation between Natural Frequencies)-{(f1-f2)/f2}.times.100(%)
(3)
[0078] As is also apparent from FIG. 5, the efficiency of electric
power transfer is close to 100% in the case where the deviation (%)
between the natural frequencies is 0%. The efficiency of electric
power transfer is about 40% in the case where the deviation (%)
between the natural frequencies is .+-.5%. The efficiency of
electric power transfer is about 10% in the case where the
deviation (%) between the natural frequencies is .+-.10%. The
efficiency of electric power transfer is about 5% in the case where
the deviation (%) between the natural frequencies is .+-.15%. That
is, it is apparent that the efficiency of electric power transfer
can be enhanced to a practical level by setting the natural
frequencies of the second coil 93 and the third coil 96 such that
the absolute value of the deviation (%) between the natural
frequencies (the difference between the natural frequencies) falls
within a range equal to or lower than 10% of the natural frequency
of the third coil 96. Furthermore, it is more preferable to set the
natural frequencies of the second coil 93 and the third coil 96
such that the absolute value of the deviation (%) between the
natural frequencies becomes equal to or lower than 5% of the
natural frequency of the third coil 96, because the efficiency of
electric power transfer can further be enhanced. Incidentally,
electromagnetic analysis software (JMAG (registered trademark):
manufactured by JSOL Inc.) is adopted as simulation software.
[0079] [Detailed Description of Configuration of Non-Contact
Electric Power Transmission/Reception]
[0080] FIG. 6 is a detailed configurational view of the electric
power transmission/reception system 10 shown in FIG. 1. Referring
to FIG. 6, the vehicle 100 includes a rectifier 180, a charging
relay (a CHR) 170, an electric storage device 190, a system main
relay (an SMR) 115, a power control unit (a PCU) 120, a
motor-generator 130, a motive power transmission gear 140, driving
wheels 150, a vehicle electronic control unit (a vehicle ECU) 300
as a control device, a current sensor 171, and a voltage sensor
172, in addition to the electric power reception unit 110 and the
communication portion 160. The electric power reception unit 110
includes a secondary self-resonant coil 111, a condenser 112, and a
secondary coil 113.
[0081] Incidentally, in this embodiment of the invention, an
electric vehicle will be described as an example of the vehicle
100. However, the configuration of the vehicle 100 is not limited
to this electric vehicle as long as the vehicle 100 can run through
the use of an electric power stored in an electric storage device.
Other examples of the vehicle 100 include a hybrid vehicle that is
mounted with an engine, a fuel cell vehicle that is mounted with a
fuel cell, and the like.
[0082] The secondary self-resonant coil 111 receives electric power
from the primary self-resonant coil 221 included in the electric
power transmission device 200, through electromagnetic resonance
with the aid of an electromagnetic field.
[0083] As for this secondary self-resonant coil 111, the number of
windings of the secondary self-resonant coil 111 and the distance
between the coils of the primary self-resonant resonant coil 221
and the secondary self-resonant coil 111 are appropriately set such
that the Q-value indicating the resonance intensity between the
primary self-resonant resonant coil 221 and the secondary
self-resonant coil 111 becomes large (e.g., Q>100) and that the
coupling coefficient (K) indicating the degree of coupling
therebetween or the like becomes small (e.g., equal to or smaller
than 0.1), on the basis of a distance from the primary
self-resonant coil 221 of the electric power transmission device
200, resonant frequencies of the primary self-resonant coil 221 and
the secondary self-resonant coil 111, and the like.
[0084] The condenser 112 is connected to both ends of the secondary
self-resonant coil 111, and forms an LC resonant circuit together
with the secondary self-resonant coil 111. The capacity of the
condenser 112 is appropriately set such that a predetermined
resonant frequency is obtained in accordance with an inductance of
the secondary self-resonant coil 111. Incidentally, the condenser
112 may be omitted if a desired resonant frequency is obtained with
a stray capacitance of the secondary self-resonant coil 111
itself.
[0085] The secondary coil 113 is provided coaxially with the
secondary self-resonant coil 111, and can be magnetically coupled
to the secondary self-resonant coil 111 through electromagnetic
induction. This secondary coil 113 takes out an electric power
received by the secondary self-resonant coil 111, through
electromagnetic induction, and outputs the electric power to the
rectifier 180.
[0086] The rectifier 180 rectifies an alternating-current electric
power received from the secondary coil 113, and outputs the
rectified direct-current electric power to the electric storage
device 190 via the CHR 170. The rectifier 180 can be configured to
include, for example, a diode bridge (not shown) and a smoothing
condenser (not shown). As the rectifier 180, it is also possible to
use a so-called switching regulator that carries out rectification
with the aid of switching control. However, there are also cases
where the rectifier 180 is included in the electric power reception
unit 110. A static rectifier such as a diode bridge is more
preferable in order to prevent a switching element from
malfunctioning etc. due to a generated electromagnetic field.
[0087] Incidentally, this embodiment of the invention adopts a
configuration in which the direct-current electric power rectified
by the rectifier 180 is directly output to the electric storage
device 190. However, in the case where a direct-current voltage
after rectification is different from a charging voltage
permissible by the electric storage device 190, a DC/DC converter
(not shown) for carrying out voltage conversion may be provided
between the rectifier 180 and the electric storage device 190.
[0088] A load resistor 173 and a relay 174, which are connected in
series to each other to detect a position, are connected to an
output region of the rectifier 180. Before full-scale charging is
started, feeble electric power is transmitted from the electric
power transmission device 200 to the vehicle as a test signal. At
this time, the relay 174 is controlled to be made conductive by a
control signal SE3 from the vehicle ECU 300.
[0089] The voltage sensor 172 is provided between a pair of
electric power lines that couple the rectifier 180 and the electric
storage device 190 to each other. The voltage sensor 172 detects a
direct-current voltage on the secondary side of the rectifier 180,
namely, a voltage received from the electric power transmission
device 200, and outputs a detected value VC thereof to the vehicle
ECU 300. The vehicle ECU 300 makes a determination on an efficiency
of electric power reception in accordance with the voltage VC, and
transmits information on the efficiency of electric power reception
to the electric power transmission device via the communication
portion 160.
[0090] The current sensor 171 is provided on an electric power line
that couples the rectifier 180 and the electric storage device 190
to each other. The current sensor 171 detects a charging current to
the electric storage device 190, and outputs a detected value IC
thereof to the vehicle ECU 300.
[0091] The CHR 170 is electrically connected to the rectifier 180
and the electric storage device 190. The CHR 170 is controlled by a
control signal SE2 from the vehicle ECU 300, and makes a changeover
between the supply of electric power from the rectifier 180 to the
electric storage device 190 and the shutoff of the supply of
electric power from the rectifier 180 to the electric storage
device 190.
[0092] The electric storage device 190 is an electric power storage
element that is configured to be chargeable/dischargeable. The
electric storage device 190 is configured to include, for example,
a secondary battery such as a lithium-ion battery, a nickel hydride
battery, a lead storage battery or the like, and an electric
storage element such as an electric double layer capacitor or the
like.
[0093] The electric storage device 190 is connected to the
rectifier 180 via the CHR 170. The electric storage device 190
stores an electric power that is received by the electric power
reception unit 110 and rectified by the rectifier 180. Besides, the
electric storage device 190 is connected to the PCU 120 as well via
the SMR 115. The electric storage device 190 supplies the PCU 120
with an electric power for generating a vehicle driving force.
Furthermore, the electric storage device 190 stores the electric
power generated by the motor-generator 130. The output of the
electric storage device 190 is, for example, about 200 V.
[0094] The electric storage device 190 is provided with a voltage
sensor (not shown) for detecting a voltage VB of the electric
storage device 190 and a current sensor (not shown) for detecting
an input/output current IB. These detected values are output to the
vehicle ECU 300. The vehicle ECU 300 calculates a state of charge
(referred to also as an SOC) of the electric storage device 190 on
the basis of this voltage VB and this current IB.
[0095] The SMR 115 is interposed on an electric power line that
couples the electric storage device 190 and the PCU 120 to each
other. Then, the SMR 115 is controlled by a control signal SE1 from
the vehicle ECU 300, and makes a changeover between the supply of
electric power and the shutoff of the supply of electric power
between the electric storage device 190 and the PCU 120.
[0096] The PCU 120 includes a converter (not shown) and an inverter
(not shown). The converter is controlled by a control signal PWC
from the vehicle ECU 300, and converts a voltage from the electric
storage device 190. The inverter is controlled by a control signal
PWI from the vehicle ECU 300, and drives the motor-generator 130
with the aid of the electric power converted by the converter.
[0097] The motor-generator 130 is an alternating-current rotating
electrical machine, and for example, is a permanent magnet-type
synchronous motor that is equipped with a rotor in which a
permanent magnet is embedded.
[0098] An output torque of the motor-generator 130 is transmitted
to the driving wheels 150 via the motive power transmission gear
140 to cause the vehicle 100 to run. During regenerative braking
operation of the vehicle 100, the motor-generator 130 can generate
an electric power through a rotating force of the driving wheels
150. Then, the generated electric power is converted into a
charging electric power of the electric storage device 190 by the
PCU 120.
[0099] Besides, in a hybrid vehicle that is mounted with an engine
(not shown) in addition to the motor-generator 130, this engine and
this motor-generator 130 are operated in a cooperative manner, so
that a required vehicle driving force is generated. In this case,
it is also possible to charge the electric storage device 190 with
the aid of the electric power generated through rotation of the
engine.
[0100] The communication portion 160 is a communication interface
for establishing radio communication between the vehicle 100 and
the electric power transmission device 200 as described above. The
communication portion 160 outputs battery information INFO, which
originates from the vehicle ECU 300 and includes the SOC of the
electric storage device 190, to the electric power transmission
device 200. Besides, the communication portion 160 outputs to the
electric power transmission device 200 signals STRT and STP
commanding the start and stop of electric power transmission from
the electric power transmission device 200 respectively.
[0101] Although not shown in FIG. 1, the vehicle ECU 300 includes a
central processing unit (a CPU), a storage device, and an
input/output buffer. Signals from respective sensors and the like
are input to the vehicle ECU 300, and the vehicle ECU 300 outputs
control signals to respective instruments to control the vehicle
100 and the respective instruments. Incidentally, the control of
these instruments is not absolutely required to be performed by
software, but can also be performed by dedicated hardware (an
electronic circuit).
[0102] Upon receiving a charging start signal TRG resulting from an
operation by a user or the like, the vehicle ECU 300 outputs the
signal STRT indicating the start of electric power transmission to
the electric power transmission device 200 via the communication
portion 160, on the basis of the fulfillment of a predetermined
condition. Besides, the vehicle ECU 300 outputs the signal STP
indicating the stop of electric power transmission to the electric
power transmission device 200 via the communication portion 160, on
the basis of a state where the electric storage device 190 is fully
charged or an operation by the user or the like.
[0103] The electric power transmission device 200 includes a
charging stand 210 and an electric power transmission unit 220. In
addition to the communication portion 230, the charging stand 210
further includes an electric power transmission ECU 240 as a
control device, an electric power supply portion 250, a display
portion 242, and a fare reception portion 246. Besides, the
electric power transmission unit 220 includes a primary
self-resonant coil 221, a condenser 222, and a primary coil
223.
[0104] The electric power supply portion 250 is controlled by a
control signal MOD from the electric power transmission ECU 240,
and converts an electric power received from an alternating-current
electric power supply such as a commercial electric power supply or
the like into a high-frequency electric power. Then, the electric
power supply portion 250 supplies the primary coil 223 with the
high-frequency electric power obtained as a result of
conversion.
[0105] Incidentally, a matching box that carries out impedance
conversion is not described in FIG. 6. However, it is also
appropriate to adopt a configuration in which a matching box is
provided between the electric power supply portion 250 and the
electric power transmission unit 220 or between the electric power
reception unit 110 and the rectifier 180.
[0106] The primary self-resonant coil 221 forwards electric power
to the secondary self-resonant coil 111 included in the electric
power reception unit 110 of the vehicle 100, through
electromagnetic resonance.
[0107] As for the primary self-resonant coil 221, the number of
windings of the primary self-resonant coil 221 and the distance
between the coils of the primary self-resonant coil 221 and the
secondary self-resonant coil 111 of the vehicle 100 are
appropriately set such that the Q-value indicating the resonance
intensity between the primary self-resonant coil 221 and the
secondary self-resonant coil 111 becomes large (e.g., Q>100) and
that the value K indicating the degree of coupling therebetween or
the like becomes small (e.g., equal to or smaller than 0.1), on the
basis of the distance from the secondary self-resonant coil 111 of
the vehicle 100, the resonant frequencies of the primary
self-resonant coil 221 and the secondary self-resonant coil 111,
and the like.
[0108] The condenser 222 is connected to both ends of the primary
self-resonant coil 221, and forms an LC resonant circuit together
with the primary self-resonant coil 221. The capacity of the
condenser 222 is appropriately set such that a predetermined
resonant frequency is obtained, in accordance with the inductance
of the primary self-resonant coil 221. Incidentally, if a desired
resonant frequency is obtained with a stray capacitance of the
primary self-resonant coil 221 itself, the condenser 222 may be
omitted.
[0109] The primary coil 223 is provided coaxially with the primary
self-resonant coil 221, and can be magnetically coupled to the
primary self-resonant coil 221 through electromagnetic induction.
The primary coil 223 transmits to the primary self-resonant coil
221 a high-frequency electric power supplied via a matching box
260, through electromagnetic induction.
[0110] As described above, the communication portion 230 is a
communication interface for establishing radio communication
between the electric power transmission device 200 and the vehicle
100. The communication portion 230 receives the battery information
INFO transmitted from the communication portion 160 on the vehicle
100 side, and the signals STRT and STP commanding the start and
stop of electric power transmission, and outputs these pieces of
information to the electric power transmission ECU 240.
[0111] Cash, a prepaid card, a credit card or the like is inserted
into the fare reception portion 246 prior to charging. The electric
power transmission ECU 240 causes the electric power supply portion
250 to transmit a test signal resulting from a feeble electric
power. It should be noted herein that "the feeble electric power"
may also include an electric power that is smaller than a charging
electric power with which the battery is charged after
authentication, or an electric power that is transmitted at the
time of alignment and is intermittently transmitted.
[0112] The vehicle ECU 300 turns the relay 174 on to receive a test
signal, and transmits control signals SE2 and SE3 to turn the CHR
170 off. The vehicle ECU 300 then calculates an efficiency of
electric power reception and a charging efficiency on the basis of
the voltage VC. The vehicle ECU 300 transmits the calculated
charging efficiency or the calculated efficiency of electric power
reception to the electric power transmission device 200 with the
aid of the communication portion 160.
[0113] The display portion 242 of the electric power transmission
device 200 displays to the user the charging efficiency and a
charging electric power unit price corresponding thereto. The
display portion 242 also has a function as an input portion, for
example, a touch panel, and can accept an input indicating whether
or not the user approves the charging electric power unit
price.
[0114] In the case where the charging electric power unit price is
approved, the electric power transmission ECU 240 causes the
electric power supply portion 250 to start full-scale charging. If
charging is completed, a fare adjustment is made in the fare
reception portion 246.
[0115] Although not shown in FIG. 1, the electric power
transmission ECU 240 includes a CPU, a storage device, and an
input/output buffer. Signals from the respective sensors and the
like are input to the electric power transmission ECU 240, and the
electric power transmission ECU 240 outputs control signals to the
respective instruments to control the respective instruments in the
charging stand 210. Incidentally, the control of these instruments
is not absolutely required to be performed by software, but can
also be performed by dedicated hardware (an electronic
circuit).
[0116] Incidentally, as for the transfer of electric power from the
electric power transmission device 200 to the vehicle 100, there is
established a relationship as to the electric power transmission
unit 90 and the electric power reception unit 91 as described with
reference to FIGS. 4 and 5. In the electric power transfer system
of FIG. 6, the difference between the natural frequency of the
electric power transmission unit 220 and the natural frequency of
the electric power reception unit 110 is equal to or smaller than
.+-.10% of the natural frequency of the electric power transmission
unit 220 or the natural frequency of the electric power reception
unit 110. The electric power transfer efficiency can be enhanced by
setting the natural frequencies of the electric power transmission
unit 220 and the electric power reception unit 110 within such a
range. On the other hand, if the aforementioned difference between
the natural frequencies becomes larger than .+-.10%, the efficiency
of electric power transfer becomes lower than 10%, and an
inconvenience such as an increase in the time of electric power
transfer or the like is caused.
[0117] Incidentally, the natural frequency of the electric power
transmission unit 220 (the electric power reception unit 110) means
an oscillation frequency in the case where an electric circuit (a
resonant circuit) that constitutes the electric power transmission
unit 220 (the electric power reception unit 110) freely oscillates.
Incidentally, in the electric circuit (the resonant circuit) that
constitutes the electric power transmission unit 220 (the electric
power reception unit 110), the natural frequency at the time when
the braking force or electric resistance is set to zero is also
referred to as the resonant frequency of the electric power
transmission unit 220 (the electric power reception unit 110).
[0118] The electric power transmission unit 220 and the electric
power reception unit 110 give and receive electric power in a
non-contact manner through at least one of a magnetic field that is
formed between the electric power transmission unit 220 and the
electric power reception unit 110 and oscillates at a specific
frequency and an electric field that is formed between the electric
power transmission unit 220 and the electric power reception unit
110 and oscillates at a specific frequency. The coupling
coefficient K between the electric power transmission unit 220 and
the electric power reception unit 110 is equal to or smaller than
0.1. Electric power is transferred from the electric power
transmission unit 220 to the electric power reception unit 110 by
causing the electric power transmission unit 220 and the electric
power reception unit 110 to resonate (vibrate sympathetically) with
each other through an electromagnetic field.
[0119] [Review of Arrangement of Electric Power
Transmission/Reception Units]
[0120] FIG. 7 is a view for illustrating the arrangement of the
electric power reception unit in various vehicles. FIG. 7 shows
examples of four vehicles.
[0121] A vehicle 100A is a vehicle that is the largest in size
among the four vehicles. The vehicle 100A has a total length of
5000 mm and a total width of 1900 mm, and an electric power
reception unit 110A is installed on a lower portion of a central
floor face of the vehicle. A lower face of the electric power
reception unit 110A has a height of 150 mm above the ground.
[0122] A vehicle 100B is the second largest in size among the four
vehicles. The vehicle 100B has a total length of 4500 mm and a
total width of 1800 mm. The vehicle 100B is mounted with three
electric power reception units 110B to 110B3. The electric power
reception unit 110B is installed on a lower portion of a front
floor face of the vehicle. The electric power reception unit 110B2
is installed on a lower portion of a central floor face of the
vehicle. The electric power reception unit 110B3 is installed on a
lower portion of a rear floor face of the vehicle. Lower faces of
the electric power reception units 110B1 to 110B3 have a height of
150 mm above the ground. Incidentally, the vehicle 100B may be
mounted with one of the electric power reception units 110B1 to
110B3.
[0123] A vehicle 100C is the third largest in size among the four
vehicles. The vehicle 100C has a total length of 4000 mm and a
total width of 1700 mm, and an electric power reception unit 110C
is installed on a lower portion of a central floor face of the
vehicle. A lower face of the electric power reception unit 110C has
a height of 120 mm above the ground.
[0124] A vehicle 100D is the smallest in size among the four
vehicles. The vehicle 100D has a total length of 3000 mm and a
total width of 1600 mm, and an electric power reception unit 110D
is installed on a lower portion of a central floor face of the
vehicle. A lower face of the electric power reception unit 110D has
a height of 130 mm above the ground.
[0125] In this manner, there is assumed a case where the
arrangement of each of the electric power reception units in each
of the vehicles also differs depending on each of the vehicles.
[0126] In order to define the position of each of the electric
power reception units in each of the vehicles, for example, the
following data 1) to 6) are required:
[0127] 1) a distance (mm) from a rear axle to the center of gravity
(or the center) of each of the electric power reception units;
[0128] 2) a distance (mm) from a front axle to the center of
gravity (or the center) of each of the electric power reception
units;
[0129] 3) distances (mm) of deviations from the center of gravity
(or the center) of each of the electric power reception units and
the center of the vehicle;
[0130] 4) (longitudinal and lateral) sizes (mm) of each of the
electric power reception units;
[0131] 5) (longitudinal and lateral) sizes (mm) of each of the
vehicles; and
[0132] 6) a height (mm) of the lower face of each of the electric
power reception units above the ground.
[0133] Incidentally, the center of gravity of each of the electric
power reception units means the center of gravity of the contour of
a unit that is projected onto a plane. Besides, in the present
specification, the center of a unit means the center of a circle if
the unit is circular in shape, and means the center of an inscribed
circle or a circumscribed circle of a polygon if the unit is
polygonal in shape. Besides, in addition to the center of gravity
or the center, any piece of information that allows the position of
the unit to be specified, for example, the position of an end of
the unit or the like can be used instead.
[0134] FIG. 8 is a view for illustrating the arrangement of each of
the electric power transmission units in various electric power
transmission devices. FIG. 8 shows examples of four electric power
transmission devices.
[0135] In an electric power transmission device 200A, an electric
power transmission unit 220A is arranged in the vicinity of car
stops (wheel stoppers). In an electric power transmission device
200B, the electric power transmission unit 220B is arranged at a
position spaced apart from car stops (wheel stoppers) toward the
center of a parking space.
[0136] In an electric power transmission device 200C, electric
power transmission units 220C1 to 220C4 are arranged offset in
position from one another sequentially from the vicinity of car
stops (wheel stoppers). In an electric power transmission device
200D, an electric power transmission unit 220D that can be moved
along a moving direction of a vehicle is arranged.
[0137] In this manner, there is assumed a case where the
arrangement of each of the electric power transmission units in
each of the electric power transmission devices also differs
depending on each of the electric power transmission devices.
[0138] In order to define the position of each of the electric
power transmission units in each of the electric power transmission
devices, for example, the following data 11) to 16) are
required:
[0139] 11) a distance (mm) from front ends of the wheel stoppers to
the center of gravity (or the center) of each of the electric power
transmission units;
[0140] 12) distances (mm) of deviations from the center of gravity
(or the center) of each of the electric power transmission units
and the center of the parking space;
[0141] 13) (longitudinal and lateral) sizes (mm) of each of the
electric power transmission units;
[0142] 14) (longitudinal and lateral) sizes (mm) of the parking
space;
[0143] 15) a distance (mm) from the center of gravity (or the
center) of the parking space to the front ends of the wheel
stoppers; and
[0144] 16) a height (mm) of an upper face of each of the electric
power transmission units above the ground.
[0145] Incidentally, the center of gravity of each of the electric
power transmission units means the center of gravity of the contour
of a unit that is projected onto a plane. Besides, in the present
specification, the center of a unit means the center of a circle if
the unit is circular in shape, and means the center of an inscribed
circle or a circumscribed circle of a polygon if the unit is
polygonal in shape. Besides, in addition to the center of gravity
or the center, any piece of information that allows the position of
the unit to be specified, for example, the position of an end of
the unit or the like can be used instead.
First Embodiment
[0146] FIG. 9 is a flowchart for illustrating the control performed
in the vehicle and the electric power transmission device in the
first embodiment of the invention.
[0147] Referring to FIG. 6 and FIG. 9, in the vehicle 100, in step
S10, the vehicle ECU 300 monitors whether or not there is a request
for charging. If it is determined that the charging start signal
TRG has been input through an operation by a user or the like, the
vehicle ECU 300 transmits to the electric power transmission device
200 a message indicating that there is a request for charging, via
the communication portion 160. Then, the processing proceeds from
step S10 to step S20.
[0148] On the other hand, in the electric power transmission device
200, in step S110, the electric power transmission ECU 240 monitors
whether or not there is a request for charging. If a message
indicating that a request for charging has been made is transmitted
from the communication portion 160 of the vehicle 100 and the
electric power transmission ECU 240 detects the request for
charging via the communication portion 230, the processing proceeds
from step S110 to step S120.
[0149] In the vehicle 100, in step S20, information on the electric
power reception unit 110 is transmitted toward the electric power
transmission device 200 by the communication portion 160. In the
electric power transmission device 200, in step S120, information
on the electric power reception unit 110 is received by the
communication portion 230.
[0150] In step S130, in the electric power transmission device 200,
the electric power transmission ECU 240 makes determinations on
whether or not electric power transmission is possible, and a
guidance direction of the vehicle. Then, in step S140, the electric
power transmission ECU 240 transmits determination results toward
the vehicle 100 via the communication portion 230.
[0151] In the vehicle 100, the determination results are received
by the communication portion 160 in step S30, and the vehicle ECU
300 causes a display portion such as a liquid crystal display (not
shown) or the like to display the determination results.
Incidentally, a driver may be acoustically notified of the
determination results, instead of causing the display portion to
display the determination results.
[0152] If the aforementioned processing ends, the processing
returns to a main routine of the vehicle and the electric power
transmission device in step S50 and step S150.
[0153] FIG. 10 is a view for illustrating a first example in which
communication is established in accordance with the processing of
FIG. 9. Referring to FIG. 9 and FIG. 10, in step S20 and step S120,
a message M1 from the vehicle to the electric power transmission
device is transmitted. The message M1 includes information
associated with the electric power reception unit 110 of the
vehicle.
[0154] FIG. 11 is a lateral view for illustrating information
associated with the electric power reception unit of the vehicle.
FIG. 12 is a top view for illustrating information associated with
the electric power reception unit of the vehicle.
[0155] The information associated with the position or dimension of
the electric power reception unit of the vehicle, which is included
in the message M1, includes the following data 1) to 6).
Incidentally, the following is an exemplification. Any piece of
information indicating the position or dimension of the electric
power reception unit of the vehicle or any piece of information
utilized to indirectly obtain these values may be adopted.
[0156] 1) a distance L1 (mm) from the rear axle to the center of
gravity (or the center) of the electric power reception unit;
[0157] 2) a distance L2 (mm) from the front axle to the center of
gravity (or the center) of the electric power reception unit;
[0158] 3) distances L3 and D3 (mm) of deviations from the center of
gravity (or the center) of the electric power reception unit and
the center of the vehicle;
[0159] 4) (longitudinal and lateral) sizes L4 and W4 (mm) of the
electric power reception unit;
[0160] 5) (longitudinal and lateral) sizes L5 and W5 (mm) of the
vehicle; and
[0161] 6) a height H6 (mm) of the lower face of the electric power
reception unit above the ground.
[0162] Incidentally, the center of gravity of the electric power
reception unit means the center of gravity of the contour of a unit
that is projected onto a plane. Besides, in the present
specification, the center of a unit means the center of a circle if
the unit is circular in shape, and means the center of an inscribed
circle or a circumscribed circle of a polygon if the unit is
polygonal in shape. Besides, in addition to the center of gravity
or the center, any piece of information that allows the position of
the unit to be specified, for example, the position of an end of
the unit or the like can be used instead. Besides, in the case
where the unit has directivity or the like, a mounting angle may be
included in the aforementioned information. It should be noted
herein that the mounting angle means, for example, a rotational
angle of the unit with respect to a longitudinal direction of the
vehicle.
[0163] "The information on the position or dimension of the unit"
can also include a size of the vehicle and the like. For example,
if an agreement is made "to provide the unit at the center of the
vehicle", the position of the unit can be specified by the size of
the vehicle in some cases.
[0164] In addition to information on the position as described
above, information on an electric power transmission/reception
method (a resonance method, an electromagnetic induction method, a
microwave method or the like) may be transmitted together.
[0165] Referring again to FIG. 9 and FIG. 10, the electric power
transmission device 200 determines whether or not the electric
power reception unit of the vehicle 100 can be aligned with the
electric power transmission unit 220, on the basis of the
arrangement of the electric power transmission unit 220 in the
parking space and received information associated with the electric
power reception units 110A to 110D of the vehicle. The electric
power transmission device 200 then returns to the vehicle a message
M2 including information on whether or not electric power
transmission is possible. The message M2 indicates that electric
power can be transmitted if the electric power reception unit of
the vehicle 100 can be aligned with the electric power transmission
unit 220, and indicates that electric power cannot be transmitted
if the electric power reception unit of the vehicle 100 cannot be
aligned with the electric power transmission unit 220.
[0166] Incidentally, before determining whether or not the
alignment can be made as to positional information, a determination
on whether or not electric power transmission is possible may first
be made on the basis of information on the electric power
transmission/reception method.
[0167] This result is displayed by the display portion of the
vehicle or acoustically conveyed, so that the driver determines
whether to park the vehicle in the parking space of this electric
power transmission device 200 or not, and determines whether to
receive electric power from the electric power transmission device
200 or not.
[0168] FIG. 13 is a view for illustrating a second example in which
communication is established in accordance with the processing of
FIG. 9. Referring to FIG. 9 and FIG. 13, the message M1 from the
vehicle to the electric power transmission device is transmitted in
step S20 and step S120. The message M includes information
associated with the electric power reception unit 110 of the
vehicle. Since the message M1 has been described with reference to
FIG. 12, the description thereof will not be repeated.
[0169] Then, the electric power transmission device 200 determines,
on the basis of the arrangement of the electric power transmission
unit 220 in the parking space and received information associated
with the electric power reception units 11A to 11D of the vehicle,
whether the electric power reception unit of the vehicle 100 can be
aligned with the electric power transmission unit 220 when the
vehicle is parked forward or when the vehicle is parked backward.
Incidentally, in the present specification, "forward parking" means
the direction of parking in which the vehicle moves forward toward
the wheel stoppers to be parked, and "backward parking" means the
direction of parking in which the vehicle moves backward toward the
wheel stoppers to be parked. There may be no wheel stopper in some
cases. Therefore, the forward direction and the backward direction
may be construed as a direction coincident with a predetermined
direction and a direction reverse thereto, respectively.
[0170] The electric power transmission device 200 then returns to
the vehicle a message M3 including the guidance direction of the
vehicle, namely, the forward direction or the backward direction.
This result is displayed by the display portion of the vehicle, or
is acoustically conveyed, so that the driver can find out whether
to park the vehicle forward or backward in parking the vehicle in
the parking space of this electric power transmission device 200.
Incidentally, in order for the driver to understand with ease, a
sign such as "Move Forward and Park", "Move Backward and Park" or
the like may be displayed.
[0171] Incidentally, the positional guidance in the longitudinal
direction has been described above. However, guidance may be
carried out in the lateral direction. For example, a sign such as
"Park Close to the Left Side (or Close to the Right Side) of a
Parking Frame" or the like may be displayed.
[0172] As described above, according to the first embodiment of the
invention, information on the secondary-side unit is conveyed in
advance to the primary-side unit. Thus, even if charging operation
is actually not performed between the primary-side unit and the
secondary-side unit, the primary-side unit can be brought into a
state suited for charging.
[0173] Besides, since information on the secondary-side unit is
conveyed in advance, an appropriate guidance direction of the
vehicle as well as whether or not non-contact charging is possible
can be determined beforehand. Therefore, an improvement in
user-friendliness is achieved.
Second Embodiment
[0174] In the second embodiment of the invention, an example in the
case where an electric power transmission device is provided with a
plurality of electric power transmission units or a movable
electric power transmission unit will be described. In the second
embodiment of the invention, a processing of selecting or moving an
electric power transmission coil is performed as indicated by steps
S132 and S134, in addition to the processing described with
reference to FIG. 9 of the first embodiment of the invention.
[0175] FIG. 14 is a flowchart for illustrating the control
performed in the vehicle and the electric power transmission device
in the second embodiment of the invention.
[0176] Referring to FIG. 6 and FIG. 14, in the vehicle 100, in step
S10, the vehicle ECU 300 monitors whether or not there is a request
for charging. If it is detected that the charging start signal TRG
has been input due to an operation by the user or the like, the
vehicle ECU 300 transmits to the electric power transmission device
200 a message indicating that there is a request for charging, via
the communication portion 160. Then, the processing proceeds from
step S10 to step S20.
[0177] On the other hand, in the electric power transmission device
200, in step S110, the electric power transmission ECU 240 monitors
whether or not there is a request for charging. If a message
indicating that a request for charging has been made is transmitted
from the communication portion 160 of the vehicle 100 and the
electric power transmission ECU 240 detects the request for
charging via the communication portion 230, the processing proceeds
from step S110 to step S120.
[0178] In the vehicle 100, in step S20, information on the electric
power reception unit 110 is transmitted toward the electric power
transmission device 200 by the communication portion 160. In the
electric power transmission device 200, in step S120, information
on the electric power reception unit 110 is received by the
communication portion 230.
[0179] In step S130, in the electric power transmission device 200,
the electric power transmission ECU 240 makes determinations on
whether or not electric power transmission is possible, and a
guidance direction of the vehicle. Then, in step S132, the electric
power transmission ECU 240 calculates a position of an electric
power transmission unit (an electric power transmission coil) that
can transmit electric power, in such a manner as to correspond to
the position of the electric power reception unit 110 of the
vehicle.
[0180] Furthermore, in step S134, the electric power transmission
ECU 240 selects an electric power transmission unit in the case
where the electric power transmission device has a plurality of
electric power transmission units. In the case where the electric
power transmission device has a movable electric power transmission
unit, the electric power transmission ECU 240 moves the electric
power transmission unit to a position that enables electric power
transmission. The selection or movement of the electric power
transmission unit is carried out such that the electric power
transmission unit and the electric power reception unit establish a
positional relationship that guarantees the best efficiency of
electric power reception.
[0181] Furthermore, in step S140, the electric power transmission
ECU 240 transmits to the vehicle 100, via the communication portion
230, results of determinations on whether or not electric power
transmission is possible and the guidance direction of the
vehicle.
[0182] In the vehicle 100, in step S30, the determination results
are received by the communication portion 160, and the vehicle ECU
300 causes a display portion such as a liquid crystal display (not
shown) or the like to display the determination results.
Incidentally, instead of causing the display portion to display the
determination results, the driver may be acoustically notified of
the determination results.
[0183] If the aforementioned processing ends, the processing
returns to a main routine of the vehicle and the electric power
transmission device in step 550 and step S150.
[0184] FIG. 15 is a view for illustrating a first example in which
communication is established according to the processing of FIG.
14. FIG. 15 shows an electric power transmission device 200C that
has a plurality of electric power transmission units 220C1 to
220C4.
[0185] Referring to FIG. 14 and FIG. 15, in step S20 and step S120,
a message M4 from the vehicle to the electric power transmission
device is transmitted. The message M4 includes information
associated with the electric power reception unit 110 of the
vehicle. The information associated with the electric power
reception unit of the vehicle, which is included in the message M4,
is similar to the message M1 described with reference to FIGS. 10
to 12. Therefore, the description of the information will not be
repeated.
[0186] The electric power transmission device 200 selects the
electric power transmission unit used for electric power
transmission, on the basis of the information on the electric power
reception unit of the vehicle. Besides, the electric power
transmission device 200 determines whether the guidance direction
of the vehicle is appropriate as a forward parking direction or as
a backward parking direction, on the basis of a mounting position
of the electric power reception unit in the vehicle and a position
of installation of the electric power transmission unit.
[0187] For example, in the case where the electric power reception
unit is provided in a substantially central region of the vehicle
as is the case with the vehicle 100A, the electric power
transmission device 200C selects electric power transmission unit
220C2 or 220C3. For example, in the case where the electric power
reception unit is provided in the vicinity of the rear wheels of
the vehicle as is the case with the vehicle 110B, the electric
power transmission device 200C guides the vehicle such that the
vehicle is parked backward, and selects the electric power
transmission unit 220C1. Incidentally, the electric power
transmission device 200C may guide the vehicle such that the
vehicle is parked forward, and select the electric power
transmission unit 220C3 or 220C4.
[0188] FIG. 16 is a view for illustrating a second example in which
communication is established according to the processing of FIG.
14. FIG. 16 shows the electric power transmission device 200D that
has a movable electric power transmission unit 220D.
[0189] Referring to FIG. 14 and FIG. 16, in step S20 and step S120,
a message M5 from the vehicle to the electric power transmission
device is transmitted. The message M5 includes information
associated with the electric power reception unit 110 of the
vehicle. The information associated with the electric power
reception unit of the vehicle, which is included in the message M5,
is similar to the message M1 described with reference to FIGS. 10
to 12. Therefore, the description of the information will not be
repeated.
[0190] Incidentally, in FIG. 15 and FIG. 16, there are shown
examples in which a plurality of electric power transmission units
are provided offset from one another in the longitudinal direction
of the vehicle and an electric power transmission unit is movable
in the longitudinal direction of the vehicle. However, a plurality
of electric power transmission units may be provided in the lateral
direction of the vehicle, or an electric power transmission unit
may be movable in the lateral direction of the vehicle.
[0191] Besides, positional guidance in the longitudinal direction
has been described above. However, guidance in the lateral
direction may be carried out. For example, a sign such as "Park
Close to the Left Side (or Close to the Right Side) of the Parking
Frame" may be displayed.
[0192] The electric power transmission device 200 determines a
position to which the electric power transmission unit used for
electric power transmission is moved, on the basis of the
information on the electric power reception unit of the vehicle.
This position is a position of the electric power transmission unit
at which the vehicle can be charged in a shortest charging time
(most efficiently). This position can be made to be a position at
which, for example, the deviation between the central axes of the
electric power reception unit and the electric power transmission
unit in the horizontal direction is minimized.
[0193] As described above, according to the second embodiment of
the invention, information on the secondary-side unit is conveyed
in advance to the primary-side unit. Thus, even if charging
operation is actually not performed between the primary-side unit
and the secondary-side unit, the primary-side unit can be brought
into a state suited for charging.
[0194] Besides, since information on the secondary-side unit is
conveyed in advance, an appropriate guidance direction of the
vehicle as well as whether or not non-contact charging is possible
can be determined beforehand. Therefore, an improvement in
user-friendliness is achieved.
[0195] Furthermore, the primary unit can be appropriately selected
or moved beforehand. Therefore, the time to the start of charging
can be shortened.
Third Embodiment
[0196] FIG. 17 is a flowchart for illustrating the control
performed in the vehicle and the electric power transmission device
in the third embodiment of the invention.
[0197] Referring to FIG. 6 and FIG. 17, in the vehicle 100, in step
S210, the vehicle ECU 300 monitors whether or not there is a
request for charging. If it is detected that the charging start
signal TRG has been input through an operation by the user or the
like, the vehicle ECU 300 transmits to the electric power
transmission device 200 a message indicating that there is a
request for charging, via the communication portion 160. Then, the
processing proceeds from step S210 to step S220.
[0198] On the other hand, in the electric power transmission device
200, in step S310, the electric power transmission ECU 240 monitors
whether or not there is a request for charging. If the message
indicating that a request for charging has been made is transmitted
from the communication portion 160 of the vehicle 100 and the
electric power transmission ECU 240 detects the request for
charging via the communication portion 230, the processing proceeds
from step S310 to step S320.
[0199] In the electric power transmission device 200, in step S320,
information on the electric power transmission unit 220 is
transmitted toward the electric power transmission device 200 by
the communication portion 230. In the vehicle 100, in step S220,
information on the electric power transmission unit 220 is received
by the communication portion 160.
[0200] In step S230, in the vehicle 100, the vehicle ECU 300 makes
determinations on whether or not electric power transmission is
possible, and a parking direction of the vehicle. Then, in step
S240, the vehicle ECU 300 transmits the determination results
toward the electric power transmission device 200 via the
communication portion 160.
[0201] In the electric power transmission device 200, the
determination results are received by the communication portion 230
in step S330. In the electric power transmission device 200, a
preparation for electric power transmission is made in accordance
with the received results.
[0202] On the other hand, in the vehicle 100, in step S250, the
vehicle ECU 300 causes the display portion such as a liquid crystal
display (not shown) or the like to display the determination
results. Incidentally, instead of causing the display portion to
display the determination results, the driver may be acoustically
notified of the determination results.
[0203] If the aforementioned processing ends, the processing
returns to the main routine of the vehicle and the electric power
transmission device in step S260 and step S240.
[0204] FIG. 18 is a view for illustrating a first example in which
communication is established according to the processing of FIG.
17. Referring to FIG. 17 and FIG. 18, in step S220 and step S320, a
message M6 from the electric power transmission device 200A or 200B
to the vehicle 100B is transmitted. The message M6 includes
information associated with the electric power transmission unit
220A or 220B of the electric power transmission device.
[0205] FIG. 19 is a top view for illustrating information
associated with the electric power transmission unit of the
electric power transmission device. FIG. 20 is a lateral view for
illustrating information associated with the electric power
transmission unit of the electric power transmission device.
[0206] The information associated with the electric power
transmission unit of the electric power transmission device, which
is included in the message M6, includes the following data 11) to
16):
[0207] 11) a distance K1 (mm) from the front ends of the wheel
stoppers to the center of gravity (or the center) of the electric
power transmission unit;
[0208] 12) distances K2L and K2W (mm) of deviations from the center
of gravity (or the center) of the electric power transmission unit
and the center of a parking space;
[0209] 13) (longitudinal and lateral) sizes KL3 and KW3 (mm) of the
electric power transmission unit;
[0210] 14) (longitudinal and lateral) sizes KL4 and KW4 (mm) of the
parking space;
[0211] 15) a distance K5 (mm) from the center of gravity (or the
center) of the parking space to the front ends of the wheel
stoppers; and
[0212] 16) a height KH6 (mm) of an upper face of the electric power
transmission unit above the ground.
[0213] Incidentally, the center of gravity of the electric power
transmission unit means the center of gravity of the contour of a
unit that is projected onto a plane. Besides, in the present
specification, the center of a unit means the center of a circle if
the unit is circular in shape, and means the center of an inscribed
circle or a circumscribed circle of a polygon if the unit is
polygonal in shape. Besides, in addition to the center of gravity
or the center, any piece of information that allows the position of
the unit to be specified, for example, the position of an end of
the unit or the like can be used instead. Besides, in the case
where the unit has directivity or the like, a mounting angle may be
included in the aforementioned information. It should be noted
herein that the mounting angle means a rotational angle with
respect to a longitudinal direction (or a length direction) of the
parking space.
[0214] "The information on the position or dimension of the unit"
can also include a size of the vehicle and the like. For example,
if an agreement is made "to provide the unit at the center of the
vehicle", the position of the unit can be specified by the size of
the vehicle in some cases.
[0215] In addition to information on the position as described
above, information on an electric power transmission/reception
method (a resonance method, an electromagnetic induction method, a
microwave method or the like) may be transmitted together.
[0216] Referring again to FIG. 17 and FIG. 18, the vehicle 100B
determines whether or not the electric power reception unit of the
vehicle 100B can be aligned with the electric power transmission
unit 220A or 220B, on the basis of received information associated
with the electric power transmission unit 220A or 220B (information
indicating the arrangement or the like in the parking space) and
information on the mounting position of the electric power
reception unit 110B of the vehicle. Then, the vehicle 100 returns a
message M7 including information on whether or not electric power
transmission to the vehicle is possible. The message M7 indicates
that electric power can be transmitted if the electric power
reception unit of the vehicle 100B can be aligned with the electric
power transmission unit 220A or 220B, and that electric power
cannot be transmitted if the electric power reception unit of the
vehicle 100B cannot be aligned with the electric power transmission
unit 220A or 220B.
[0217] Incidentally, before determining whether or not the
alignment can be made as to positional information, a determination
on whether or not electric power transmission is possible may first
be made on the basis of information on the electric power
transmission/reception method.
[0218] This result is displayed by the display portion of the
vehicle or acoustically conveyed, so that the driver determines
whether to park the vehicle in the parking space of one of these
electric power transmission devices 200A and 200B or not, and
determines whether to receive electric power from the electric
power transmission device 200A or 200B.
[0219] FIG. 21 is a view for illustrating a second example in which
communication is established in accordance with the processing of
FIG. 17. Referring to FIG. 17 and FIG. 21, the message M6 is
transmitted from the electric power transmission device to the
vehicle in step S220 and step S320. The message M6 includes
information associated with the electric power transmission unit
220A or 220B of the electric power transmission device. The message
M6 includes the information described with reference to FIGS. 18 to
20, and the description of the information will not be repeated
herein.
[0220] Then, the vehicle 100B determines, on the basis of received
information associated with the electric power transmission unit
220A or 220B (the arrangement of the electric power transmission
unit 220 in the parking space or the like) and information on the
mounting position of the electric power reception unit 110B in the
vehicle, whether the electric power reception unit of the vehicle
100B can be aligned with the electric power transmission unit 220A
or 220B when the vehicle is parked forward or when the vehicle is
parked backward. Then, the vehicle 100B returns to the vehicle a
message M8 including the parking direction of the vehicle, namely,
the forward direction or the backward direction.
[0221] This result is transmitted to the electric power
transmission device, and is displayed by the display portion of the
vehicle or acoustically conveyed in step S250, so that the driver
can find out whether to park the vehicle forward or backward in
parking the vehicle in the parking space of this electric power
transmission device 200A or 200B.
[0222] As described above, according to the third embodiment of the
invention, information on the primary-side unit is conveyed in
advance to the secondary-side unit. Thus, even if charging
operation is actually not performed between the primary-side unit
and the secondary-side unit, the secondary-side unit can be brought
into a state suited for charging.
[0223] Besides, since information on the primary-side unit is
conveyed in advance, an appropriate parking direction of the
vehicle as well as whether or not non-contact charging is possible
can be determined beforehand. Therefore, an improvement in
user-friendliness is achieved.
Fourth Embodiment
[0224] In the fourth embodiment of the invention, an example in the
case where a vehicle is provided with a plurality of electric power
reception units or a movable electric power reception unit will be
described. In the fourth embodiment of the invention, a processing
of selecting or moving an electric power reception coil is
performed as indicated by steps S232 and S234, in addition to the
processing described with reference to FIG. 17 of the third
embodiment of the invention.
[0225] FIG. 22 is a flowchart for illustrating the control
performed in the vehicle and the electric power transmission device
in the fourth embodiment of the invention.
[0226] Referring to FIG. 6 and FIG. 22, in the vehicle 100, in step
S210, the vehicle ECU 300 monitors whether or not there is a
request for charging. If it is detected that the charging start
signal TRG has been input due to an operation by the user or the
like, the vehicle ECU 300 transmits a message indicating that there
is a request for charging, to the electric power transmission
device 200 via the communication portion 160. Then, the processing
proceeds from step S210 to step S220.
[0227] On the other hand, in the electric power transmission device
200, in step S310, the electric power transmission ECU 240 monitors
whether or not there is a request for charging. If a message
indicating that a request for charging has been made is transmitted
from the communication portion 160 of the vehicle 100 and the
electric power transmission ECU 240 detects the request for
charging via the communication portion 230, the processing proceeds
from step S310 to step S320.
[0228] In the electric power transmission device 200, in step S320,
information on the electric power transmission unit 220 is
transmitted toward the electric power transmission device 200 by
the communication portion 230. In the vehicle 100, in step S220,
information on the electric power transmission unit 220 is received
by the communication portion 160.
[0229] In step S230, in the vehicle 100, the vehicle ECU 300 makes
determinations on whether or not electric power transmission is
possible, and a parking direction of the vehicle. Then, in step
S232, the vehicle ECU 300 calculates a position of an electric
power reception unit (an electric power reception coil) that can
receive electric power, in such a manner as to correspond to the
position of the electric power transmission unit 220.
[0230] Furthermore, in step S234, the vehicle ECU 300 selects an
electric power reception unit in the case where the vehicle has a
plurality of electric power reception units. In the case where the
vehicle has a movable electric power reception unit, the vehicle
ECU 300 moves the electric power reception unit to a position that
enables electric power reception. The selection or movement of the
electric power reception unit is carried out such that the electric
power transmission unit and the electric power reception unit
establish a positional relationship that guarantees the best
electric power reception efficiency. This positional relationship
can ensure, for example, a minimum deviation between the central
axes of the electric power reception unit and the electric power
transmission unit in the horizontal direction.
[0231] Furthermore, in step S240, the vehicle ECU 300 transmits
determination results toward the electric power transmission device
200 via the communication portion 160.
[0232] In the electric power transmission device 200, in step S330,
the determination results are received by the communication portion
230. In the electric power transmission device 200, a preparation
for electric power transmission is made in accordance with the
received results.
[0233] On the other hand, in the vehicle 100, in step S250, the
vehicle ECU 300 causes the display portion such as a liquid crystal
display (not shown) or the like to display the determination
results. Incidentally, instead of causing the display portion to
display the determination results, the driver may be acoustically
notified of the determination results.
[0234] If the aforementioned processing ends, the processing
returns to the main routine of the vehicle and the electric power
transmission device in step S260 and step S240.
[0235] FIG. 23 is a view for illustrating a first example in which
communication is established according to the processing of FIG.
22. FIG. 23 shows the vehicle 100B that has a plurality of electric
power reception units 110B1 to 110B3.
[0236] Referring to FIG. 22 and FIG. 23, in step S220 and step
S320, a message M9 is transmitted from the electric power
transmission device to the vehicle. The message M9 includes
information associated with the electric power transmission unit
220A or 220B of the electric power transmission device. The
information associated with the electric power transmission unit of
the electric power transmission device, which is included in the
message M9, is similar to the message M6 described with reference
to FIGS. 18 to 20. Therefore, the description of the information
will not be repeated.
[0237] The vehicle 100B selects the electric power reception unit
used for electric power reception among the electric power
reception units 110B1 to 110B3, on the basis of the information on
the electric power transmission unit of the electric power
transmission device. Besides, the vehicle 110B determines whether
the parking direction of the vehicle is appropriate as a forward
parking direction or as a backward parking direction, on the basis
of a mounting position of the electric power reception unit in the
vehicle and a position of installation of the electric power
transmission unit.
[0238] For example, in the case where the electric power
transmission unit 220A is provided in the vicinity of the wheel
stoppers as is the case with the electric power transmission device
200A, the vehicle 100B selects either a combination of forward
parking and the electric power reception unit 110B1 or a
combination of backward parking and the electric power reception
unit 110B3. For example, in the case where the electric power
transmission unit 220B is provided at a position spaced apart from
the wheel stoppers as is the case with the electric power
transmission device 200B, the vehicle 100B selects a combination of
backward parking and the electric power reception unit 110B2.
Incidentally, a combination of forward parking and the electric
power reception unit 110B2 may be selected. The selection is made
such that the positional relationship between the electric power
transmission unit and the electric power reception unit guarantees
the best electric power reception efficiency.
[0239] FIG. 24 is a view for illustrating a second example in which
communication is established according to the processing of FIG.
22. FIG. 24 shows a vehicle 100BX that has a movable electric power
reception unit 110BX.
[0240] Referring to FIG. 22 and FIG. 24, in step S220 and step
S320, the message M5 is transmitted from the vehicle to the
electric power transmission device. The message M5 includes
information associated with the electric power reception unit 110
of the vehicle. The information associated with the electric power
reception unit of the vehicle, which is included in the message M5,
is similar to the message M1 described with reference to FIGS. 10
to 12. Therefore, the description of the information will not be
repeated.
[0241] The vehicle 100BX determines a position to which the
electric power reception unit used for electric power reception is
moved, on the basis of the information on the electric power
transmission unit of the electric power transmission device. This
position is a position of the coil at which the vehicle can be
charged in a shortest charging time (most efficiently).
[0242] Incidentally, in FIG. 23 and FIG. 24, there are shown
examples in which a plurality of electric power reception units are
provided offset from one another in the longitudinal direction of
the vehicle and an electric power reception unit is movable in the
longitudinal direction of the vehicle. However, a plurality of
electric power reception units may be provided in the lateral
direction of the vehicle, or an electric power reception unit may
be movable in the lateral direction of the vehicle.
[0243] Besides, positional guidance in the longitudinal direction
has been described above. However, guidance in the lateral
direction may be carried out. For example, a sign such as "Park
Close to the Left Side (or Close to the Right Side) of the Parking
Frame" may be displayed.
[0244] As described above, according to the fourth embodiment of
the invention, information on the primary-side unit is conveyed in
advance to the secondary-side unit. Thus, even if charging
operation is actually not performed between the primary-side unit
and the secondary-side unit, the secondary-side unit can be brought
into a state suited for charging.
[0245] Besides, since information on the primary-side unit is
conveyed in advance, an appropriate parking direction of the
vehicle as well as whether or not non-contact charging is possible
can be determined beforehand. Therefore, an improvement in
user-friendliness is achieved.
[0246] Furthermore, since the secondary unit can be appropriately
selected or moved beforehand, the time to the start of charging can
be shortened.
[0247] Finally, the first to fourth embodiments of the invention
will be summarized referring again to the drawings.
[0248] As shown in FIG. 6 and FIGS. 9 to 16, the invention
according to each of the first and second embodiments thereof
relates to the electric power reception device for the vehicle that
can receive electric power from the electric power transmission
device 200 outside the vehicle in a non-contact manner. The
electric power reception device for the vehicle 100 is equipped
with the electric power reception unit 110 that is configured to be
able to receive electric power from the electric power transmission
device 200 in a non-contact manner, and the communication portion
160 that transmits information on the electric power reception unit
110 (information on the position or dimension or the like thereof)
to the electric power transmission device 200.
[0249] Preferably, the electric power reception device is equipped
with the control device (the vehicle ECU 300) that controls the
communication portion 160.
[0250] Preferably, before allowing the vehicle 100 to be parked at
the electric power reception position of the electric power
transmission device 200, the control device (the vehicle ECU 300)
transmits pre-stored information on the electric power reception
unit 110 to the electric power transmission device 200, with the
aid of the communication portion 160.
[0251] Preferably, as described with reference to FIG. 11 and FIG.
12, the information on the electric power reception unit 110
includes information indicating at least one of the size of the
electric power reception unit 110, the size of the vehicle 100 that
is mounted with the electric power reception unit 110, the mounting
position of the electric power reception unit 110 in the vehicle
100, and the mounting angle of the electric power reception unit
110 in the vehicle 100. Thus, the electric power transmission
device side can make a determination on whether or not charging is
possible before the start of charging, for a plurality of vehicles
that are different in the mounting position of the electric power
reception unit and the size of the electric power reception unit
from one another to various degrees. Besides, it is possible to
confirm where the vehicle position essentially suited for charging
is, regardless of whether or not charging has been started.
[0252] More preferably, the control device (the vehicle ECU 300)
receives from the electric power transmission device 200 the
determination result about whether or not non-contact charging is
possible on which the determination has been made on the basis of
information on the electric power reception unit 110, and notifies
a passenger of the determination result. Whether or not non-contact
charging is possible is known beforehand even if the vehicle is
actually not parked to make an attempt to receive electric power.
Therefore, an improvement in user-friendliness is achieved.
[0253] More preferably, the control device (the vehicle ECU 300)
receives from the electric power transmission device 200 the
determination result about the guidance direction of the vehicle on
which the determination has been made on the basis of information
on the electric power reception unit 110, and notifies the
passenger of the determination result. The direction in which the
vehicle should be parked is known beforehand even if the vehicle is
actually not parked to make an attempt to receive electric power.
Therefore, an improvement in user-friendliness is achieved.
[0254] More preferably, as shown in FIG. 15, the electric power
transmission device 200C includes the plurality of the electric
power transmission units 220C1 to 220C4. The control device (the
vehicle ECU 300) transmits information to the electric power
transmission device 200C with the aid of the communication portion
230, in order to determine the electric power transmission unit
used for electric power transmission among the plurality of the
electric power transmission units 220C1 to 220C4.
[0255] More preferably, as shown in FIG. 16, the electric power
transmission device 200D includes the movable electric power
transmission unit 220D. The control device (the vehicle ECU 300)
transmits information to the electric power transmission device
200D with the aid of the communication portion 230, in order to
determine the position of the electric power transmission unit
200D. In this manner, the electric power transmission unit can be
appropriately adjusted in position beforehand. Therefore, the
charging time can be shortened.
[0256] Preferably, the electric power transmission device 200
includes the electric power transmission unit 220. The electric
power reception unit 110 is configured such that the difference
between the natural frequencies of the electric power reception
unit 110 and the electric power transmission unit 220 falls within
.+-.10%.
[0257] More specifically, the coupling coefficient between the
electric power reception unit 110 and the electric power
transmission unit 220 is equal to or smaller than 0.1.
[0258] More specifically, the electric power reception unit 110
receives electric power from the electric power transmission unit
220 through at least one of a magnetic field that is formed between
the electric power reception unit 110 and the electric power
transmission unit 220 and oscillates at a specific frequency, and
an electric field that is formed between the electric power
reception unit 110 and the electric power transmission unit 220 and
oscillates at a specific frequency.
[0259] As shown in FIG. 6 and FIGS. 7 to 24, the invention
according to each of the third and fourth embodiments of the
invention relates to the electric power transmission device 200
that can transmit electric power in a non-contact manner. The
electric power transmission device 200 is equipped with the
electric power transmission unit 220 that is configured to be able
to transmit electric power to the vehicle 100 from outside the
vehicle in a non-contact manner, and the communication portion 230
that transmits information on the electric power transmission unit
220 (information on the position or dimension thereof) to the
vehicle 100.
[0260] Preferably, the electric power transmission device 200 is
further equipped with the control device (the electric power
transmission ECU 240) that controls the communication portion
230.
[0261] Preferably, the control device (the electric power
transmission ECU 240) transmits pre-stored information on the
electric power transmission unit 220 to the vehicle with the aid of
the communication portion 230, before the vehicle 100 is parked at
the electric power reception position of the electric power
transmission device 200.
[0262] Preferably, as described with reference to FIG. 19 and FIG.
20, the information on the electric power transmission unit 220
includes information indicating at least one of the size of the
electric power transmission unit 220, the size of the parking space
in which the electric power transmission unit 220 is arranged, the
mounting position of the electric power transmission unit 220 in
the parking space, and the mounting angle of the electric power
transmission unit 220 in the parking space. Thus, the vehicle side
can make a determination on whether or not charging is possible
before the start of charging, for a plurality of electric power
transmission devices that are different in the mounting position of
the electric power transmission unit and the size of the electric
power transmission unit from one another to various degrees.
Besides, it is possible to confirm where the vehicle position
essentially suited for charging is, regardless of whether or not
charging has been started.
[0263] More preferably, the control device (the electric power
transmission ECU 240) receives from the vehicle the determination
result about whether or not non-contact charging is possible on
which the determination has been made on the basis of information
on the electric power transmission unit 220. Whether or not
non-contact charging is possible is known beforehand even if the
vehicle is actually not parked to make an attempt to receive
electric power. Therefore, an improvement in user-friendliness is
achieved.
[0264] More preferably, the control device (the electric power
transmission ECU 240) receives from the vehicle 100 the
determination result about the guidance direction of the vehicle
100 on which the determination has been made on the basis of
information on the electric power transmission unit 220. The
direction in which the vehicle should be parked is known beforehand
even if the vehicle is actually not parked to make an attempt to
receive electric power. Therefore, an improvement in
user-friendliness is achieved.
[0265] More preferably, as shown in FIG. 23, the vehicle 100B
includes the plurality of the electric power reception units 100B1
to 100B3. The control device (the electric power transmission ECU
240) transmits information to the vehicle with the aid of the
communication portion 230, in order to determine the electric power
reception unit used for electric power reception among the
plurality of the electric power reception units 100B1 to 100B3.
[0266] More preferably, as shown in FIG. 24, the vehicle 100BX
includes the movable electric power reception unit 110BX. The
control device (the electric power transmission ECU 240) transmits
information on the electric power transmission unit 220 to the
vehicle with the aid of the communication portion 230, in order to
determine the position of the electric power reception unit 110BX.
In this manner, the electric power reception unit can be
appropriately adjusted in position beforehand. Therefore, the
charging time can be shortened.
[0267] Incidentally, in each of these embodiments of the invention,
the electric power transmission unit and the electric power
reception unit, which include the electromagnetic induction coils
respectively, have been exemplified. However, the invention is also
applicable to a resonance-type non-contact electric power
transmission/reception device that does not include an
electromagnetic induction coil (a resonance-type non-contact
electric power transmission/reception device that employs only
self-resonant coils). Besides, the invention is not limited to the
resonance-type electric power transmission/reception device, but is
also applicable to non-contact electric power
transmission/reception devices that transmit/receive electric power
according to other methods (electromagnetic induction, microwaves,
light and the like).
[0268] The embodiments of the invention disclosed this time should
be considered to be exemplary in all respects and non-limitative.
The scope of the invention is indicated not by the aforementioned
description but by the claims. The invention is intended to
encompass all modifications that are equivalent in significance and
range to the claims.
DESCRIPTION OF REFERENCE SYMBOLS
[0269] 10 ELECTRIC POWER TRANSMISSION/RECEPTION SYSTEM [0270] 89
ELECTRIC POWER TRANSFER SYSTEM [0271] 90, 200A, 220, 220A, 220B,
220C2, 220C1, 220C3, 220C1 to 220C4, 220D ELECTRIC POWER
TRANSMISSION UNIT [0272] 91, 110, 110A to 110D, 110B1 to 110B3,
110BX ELECTRIC POWER RECEPTION UNIT [0273] 92 FIRST COIL [0274] 93
SECOND COIL [0275] 94, 99 RESONANT COIL [0276] 95, 98 CAPACITOR
[0277] 96 THIRD COIL [0278] 97 FOURTH COIL [0279] 100, 100A to
100D, 100BX VEHICLE [0280] 111, 340 SECONDARY SELF-RESONANT COIL
[0281] 112, 222 CONDENSER [0282] 113, 350 SECONDARY COIL [0283] 130
MOTOR-GENERATOR [0284] 140 MOTIVE POWER TRANSMISSION GEAR [0285]
150 DRIVING WHEELS [0286] 160, 230 COMMUNICATION PORTION [0287] 171
CURRENT SENSOR [0288] 172 VOLTAGE SENSOR [0289] 173 LOAD RESISTOR
[0290] 174 RELAY [0291] 180 RECTIFIER [0292] 190 ELECTRIC STORAGE
DEVICE [0293] 200, 200A to 200D ELECTRIC POWER TRANSMISSION DEVICE
[0294] 210 CHARGING STAND [0295] 221, 330 PRIMARY SELF-RESONANT
COIL [0296] 223, 320 PRIMARY COIL [0297] 240 ELECTRIC POWER
TRANSMISSION ECU [0298] 242 DISPLAY PORTION [0299] 246 FARE
RECEPTION PORTION [0300] 250 ELECTRIC POWER SUPPLY PORTION [0301]
260 MATCHING BOX [0302] 300 VEHICLE ECU [0303] 310 HIGH-FREQUENCY
ELECTRIC POWER SUPPLY [0304] 360 LOAD [0305] PCU POWER CONTROL
UNIT
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