JP6672547B2 - Non-contact power transmission system and power receiving device - Google Patents

Description

  The present invention relates to a wireless power transmission system for wirelessly transmitting power and a power receiving device.

  For example, there is known an automatic guided vehicle (AGV) system that automatically moves an automated guided vehicle (AGV) along a preset circulation path in a factory or the like to carry a load. In the automatic guided vehicle system, if a charging device is arranged at a loading / unloading position of the luggage and charging is performed while the luggage is stopped for loading / unloading of the luggage, the decrease in the charged amount of the battery can be delayed.

  Also, a technique has been developed in which the power output from the power supply is transmitted to the load in a non-contact manner without directly connecting the load and the power supply. This technology is generally called wireless power transfer or wireless power transfer. The technology is also applicable to charging an automatic guided vehicle. If the technology of non-contact power transmission is applied, there is no need to connect or disconnect the charging device and the battery with a connection line, and work efficiency is improved. Patent Document 1 discloses an invention in which electric power is transmitted in a non-contact manner in an automatic guided vehicle system.

  In Patent Literature 1, a power transmission coil is arranged in the middle of the traveling path of the automatic guided vehicle, and it is detected that the automatic guided vehicle has come directly above the power transmission coil, and a power transmission start command is transmitted to the power transmission device. Then, power transmission is started.

JP 2014-33524 A

  When the charge amount of the power storage device of the automatic guided vehicle is insufficient, the automatic guided vehicle cannot travel automatically. In this case, it is necessary to manually move the automatic guided vehicle to the power supply position and supply power manually. For this reason, the power transmission device is provided with a power transmission start switch for starting power transmission. However, if the power transmission start switch is erroneously pressed when the automatic guided vehicle is not at the power supply position, an overcurrent may flow through the power transmission device and cause a failure.

  The present invention has been conceived under the circumstances described above, and has as its object to provide a non-contact power transmission system capable of starting power transmission without providing a power transmission start switch in a power transmission device. .

  In order to solve the above problems, the present invention takes the following technical measures.

  In the wireless power transmission system provided by the first aspect of the present invention, the power reception device outputs a power transmission start signal to the power transmission device at a predetermined power supply position, or the power transmission device transmits the power transmission start signal to the power reception device. A power transmission notification signal, the power transmission device is a non-contact power transmission system that transmits power to the power reception device in a non-contact manner, wherein the power reception device transmits the power transmission start signal based on an operation of an operator. An operating means for outputting is provided. According to this configuration, the power receiving device includes the operation unit, and the power transmission start signal is transmitted to the power receiving device based on the operation of the operation unit. Therefore, it is not necessary to provide a power transmission start switch in the power transmission device.

  In a preferred embodiment of the present invention, the power transmission device includes a high-frequency power supply device that outputs high-frequency power, a power transmission coil connected to the high-frequency power device, and a power transmission side communication circuit that performs communication, The device includes a power receiving coil magnetically coupled to the power transmitting coil, a power receiving side communication circuit that communicates with the power transmitting side communication circuit, and a control circuit of the operation unit, and the power transmitting device includes the power receiving side. When the power transmission start signal is input via a communication circuit and the power transmission side communication circuit, the high frequency power supply device is activated. According to this configuration, communication is performed via the power receiving side communication circuit and the power transmission side communication circuit, and power transmission can be started by activating the high frequency power supply device when a power transmission start signal is input.

  In a preferred embodiment of the present invention, the power-receiving-side communication circuit and the power-transmitting-side communication circuit communicate with each other using a highly directional communication method, and a position where the power transmission coil and the power reception coil are magnetically coupled. , It is arranged to be communicable. According to this configuration, communication cannot be performed when the power transmission coil and the power reception coil are not at a position where they are magnetically coupled. Therefore, even if the power transmission start switch is operated, the high-frequency power supply device can be prevented from starting.

  In a preferred embodiment of the present invention, the power receiving side communication circuit and the power transmitting side communication circuit communicate by infrared communication. According to this configuration, communication with high directivity can be performed.

  In a preferred embodiment of the present invention, the operation unit further outputs a power transmission stop signal based on an operation of an operator, and the power transmission device transmits the power transmission stop signal through the power reception side communication circuit and the power transmission side communication circuit. And stopping the high-frequency power supply device when the power transmission stop signal is input. According to this configuration, the high-frequency power supply is stopped by operating the operation unit. Thereby, power transmission from the power transmitting device to the power receiving device is stopped. That is, power transmission can be stopped on the power receiving device side.

  In a preferred embodiment of the present invention, the power receiving device detects that the power receiving coil is receiving power from the power transmission coil, and that the power receiving device is receiving power according to a detection result of the detection means. Notification means for notifying the user. According to this configuration, it is possible to recognize whether or not power is being received by notification by the notification unit.

  In a preferred embodiment of the present invention, the detection means includes a current sensor, and when the current sensor detects a current, determines that the power receiving coil is receiving power from the power transmitting coil. According to this configuration, it is possible to determine that the power receiving coil is receiving power from the power transmitting coil based on the current.

  In a preferred embodiment of the present invention, when the signal transmitted from the power receiving side communication circuit is not received by the power transmission side communication circuit, the notifying unit notifies the fact. According to this configuration, it is possible to recognize that communication has not been established by the notification by the notification unit.

  In a preferred embodiment of the present invention, a power transmission method from the power transmission device to the power reception device is a magnetic resonance method. According to this configuration, the distance between the power transmission coil and the power reception coil can be increased.

  In a preferred embodiment of the present invention, the power receiving device further includes a rectifying circuit for rectifying a current from the power receiving coil, and supplies the rectified current to the power storage device. According to this configuration, the power storage device can be charged from the power receiving device.

  In a preferred embodiment of the present invention, the power storage device is a capacitor, the frequency of the high-frequency power output from the high-frequency power supply device is 50 [kHz] or more, and the power receiving device has a capacitance of 50 [A]. The constant current charging is performed with the above current. According to this configuration, the power storage device can be charged at a high speed.

  In a preferred embodiment of the present invention, the power receiving device is mounted on an automatic guided vehicle, and the power receiving coil is disposed on a side surface of a vehicle body of the automatic guided vehicle such that a coil surface is substantially perpendicular to a floor surface. The power transmission coil is disposed in the power transmission device such that a coil surface is substantially perpendicular to a floor surface. According to this configuration, it can be used as a charging system for a power storage device of an automatic guided vehicle. In addition, the mechanism for detecting the circulation path and the stop position and the power transmission and reception of the power transmission coil and the power reception coil can be prevented from interfering with each other.

  The power receiving device provided by the second aspect of the present invention is such that the power receiving device outputs a power transmission start signal to the power transmitting device at a predetermined power supply position, or the power transmitting device outputs a power transmission start signal to the power receiving device. A power transmitting device is a power receiving device of a wireless power transmission system that wirelessly transmits power to the power receiving device, wherein the power receiving device includes an operation unit that outputs the power transmission start signal based on an operation of an operator. It is characterized by the following. According to this configuration, the power receiving device includes the operation unit, and the power transmission start signal is transmitted to the power receiving device based on the operation of the operation unit. Therefore, it is not necessary to provide a power transmission start switch in the power transmission device.

  According to the present invention, the power receiving device includes the operation unit, and the power transmission start signal is transmitted to the power receiving device based on the operation of the operation unit. Therefore, it is not necessary to provide a power transmission start switch in the power transmission device. That is, power transmission can be started without providing a power transmission start switch in the power transmission device.

  Other features and advantages of the present invention will become more apparent from the detailed description given below with reference to the accompanying drawings.

1 is a schematic diagram illustrating an entire configuration of a wireless power transmission system according to a first embodiment. This shows a state in which the power transmission coil of the power transmission device and the power reception coil of the power reception device face each other with a small distance. It is a flowchart for demonstrating a manual power supply control process. It is a figure showing the modification of the power receiving device concerning a 1st embodiment. It is the schematic which shows the whole structure of the non-contact electric power transmission system which concerns on 2nd Embodiment.

  Hereinafter, an embodiment of the present invention will be specifically described with reference to the drawings, taking as an example a case where a non-contact power transmission system according to the present invention is used as a charging system for an automatic guided vehicle. In addition, each dimension, shape, material, various values, and the like described below are examples for explanation, and are not limited to those described. It can be changed appropriately according to the specifications. In each drawing, the same or similar elements are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 1 is a schematic diagram illustrating the entire configuration of the wireless power transmission system according to the first embodiment.

  The non-contact power transmission system 1 </ b> A is a power supply system for charging a capacitor 41 provided on a body of the automatic guided vehicle 4.

  The automatic guided vehicle 4 automatically travels along a preset circulation path, and stops at a plurality of preset stop positions on the circulation path. At each stop position, loading and unloading of luggage is performed. The method by which the automatic guided vehicle detects the circulation path and the stop position is not limited. For example, a magnetic tape or a reflective tape may be attached to the floor along the circulation path, and the AGV may detect with a magnetic sensor or an optical sensor, or while the AGV detects its own position. You may make it run and stop.

  The power transmission device 2 is arranged at each stop position. The power receiving device 3 is mounted on the automatic guided vehicle 4. The power receiving coil Lr of the power receiving device 3 is, for example, a flat coil wound in a spiral shape, and is arranged on the side surface of the automatic guided vehicle 4 so that the coil surface is substantially perpendicular to the floor surface. . The power transmission coil Lt of the power transmission device 2 is, for example, a planar coil wound in a spiral shape, and is arranged such that the coil surface is substantially perpendicular to the floor surface. The power transmitting coil Lt and the power receiving coil Lr are arranged so as to be at the same height. When the automatic guided vehicle 4 stops at the stop position, the power transmission device 2 is positioned at a predetermined position of the stop position so that the power transmission coil Lt and the power reception coil Lr face each other with a small distance therebetween. It is arranged in the orientation. FIG. 2 illustrates a state in which the automatic guided vehicle 4 stops at the stop position, and the power transmission coil Lt of the power transmission device 2 and the power reception coil Lr of the power reception device 3 face each other with a small distance. While the automatic guided vehicle 4 is stopped at the stop position, the power transmission device 2 disposed at the stop position transmits power to the power receiving device 3 mounted on the automatic guided vehicle 4 in a non-contact manner. That is, the stop position is the power supply position. The power received by the power receiving device 3 is stored in the capacitor 41. The automatic guided vehicle 4 runs by driving the motor 43 using the electric power stored in the capacitor 41 and rotating the wheels.

  When the electric energy used by the automatic guided vehicle 4 for traveling or the like continues to be larger than the electric energy transmitted from the power transmission device 2 and stored, the charge amount of the capacitor 41 decreases and the motor 43 may be driven. become unable. Further, even when the automatic guided vehicle 4 is not used for a long time, the charged amount of the capacitor 41 is insufficient, and the motor 43 cannot be driven. In these cases, it is necessary to manually move the automatic guided vehicle 4 to the stop position (power supply position) and manually supply power from the power transmission device 2 to the power reception device 3. Processing for controlling power supply in this case (hereinafter, referred to as “manual power supply control processing”) will be described later.

  As shown in FIG. 1, the power transmission device 2 includes a high-frequency power supply device 21, a power transmission unit 22, a communication circuit 23, and a control circuit 24.

  The high-frequency power supply 21 supplies high-frequency power to the power transmission unit 22. The high frequency power supply 21 includes a DC power supply and an inverter circuit (not shown).

  The DC power supply generates and outputs DC power. The DC power supply includes a rectifier circuit, a smoothing capacitor, and a DC-DC converter circuit. The DC power supply device converts an AC voltage (for example, a commercial voltage of 200 [V]) input from a commercial power supply into a DC voltage by rectifying the AC voltage with a rectifier circuit and smoothing the rectified circuit with a smoothing capacitor. Then, the DC-DC converter circuit converts the DC voltage into a DC voltage of a predetermined level (target voltage) and outputs the DC voltage to the inverter circuit. Note that the configuration of the DC power supply device is not limited, and may be any device that outputs a DC voltage of a predetermined level.

  The inverter circuit converts DC power into high-frequency power, converts a DC voltage input from the DC power supply into a high-frequency voltage, and outputs the high-frequency voltage to the power transmission unit 22. The inverter circuit is, for example, a single-phase full-bridge type inverter circuit and includes four switching elements. As the switching element, a MOSFET (Metal Oxide Semiconductor Field Effect Transistor), a bipolar transistor, an IGBT (Insulated Gate Bipolar Transistor) or the like is used.

The inverter circuit receives a high-frequency control signal from a control circuit (not shown), and converts DC power into high-frequency power by switching each switching element between an ON state and an OFF state according to the high-frequency control signal. The high-frequency control signal is a pulse signal that repeats a high level and a low level at a predetermined frequency f ₀ (for example, 85 [kHz]) (a sine wave signal or the like may be used). Since the frequency f ₀ is a frequency at which the switching element is switched, hereinafter, it may be referred to as “switching frequency f ₀ ”. The switching element is turned off when the high-frequency control signal is at a low level, and turned on when the high-frequency control signal is at a high level.

  A voltage sensor (not shown) for detecting an output voltage is provided at an output terminal of the inverter circuit. The control circuit performs feedback control so that the output voltage detected by the voltage sensor matches a predetermined target voltage. Specifically, the control circuit generates a control pulse signal for reducing the deviation between the output voltage detected by the voltage sensor and the set target voltage to zero. Then, the control pulse signal is amplified by a drive circuit (not shown) and output to the inverter circuit as a high-frequency control signal. Thereby, the output voltage of the inverter circuit is controlled to the set target voltage. Note that the configurations of the inverter circuit and the control circuit are not limited to those described above, and any configuration may be used as long as the output voltage can be controlled to the set target voltage.

The configuration of the high-frequency power supply 21 is not limited to the above. In the present embodiment, since the switching frequency f ₀ of the high-frequency power supply device 21 is 85 [kHz], the frequency (output frequency) of the high-frequency power output from the power transmission unit 22 is also 85 [kHz]. Note that the output frequency (switching frequency f ₀ ) is not limited to 85 [kHz], but may be 50 [kHz] or more. Since the high-frequency power supply 21 outputs a large current, the high-frequency current output from the power transmission unit 22 is also a large current. Note that the output current of the high-frequency power supply device 21 is not limited, and the current for charging the capacitor 41 described later may be 50 [A] or more.

  The power transmission unit 22 includes a power transmission coil Lt and a resonance capacitor Ct. The power transmission coil Lt transmits high-frequency power supplied from the high-frequency power supply device 21 to the power receiving device 3. Note that the shape and the number of windings of the power transmission coil Lt are not limited. The resonance capacitor Ct is connected in series to the power transmission coil Lt to form a series resonance circuit.

The power transmission coil Lt and the resonance capacitor Ct are designed such that the resonance frequency matches the frequency f ₀ (switching frequency f ₀ ) of the high-frequency power supplied from the high-frequency power supply device 21. That is, the self-inductance L _t of transmission coil Lt, and the capacitance C _t of the resonance capacitor Ct is designed to be the following relation (1) below. When the switching frequency f ₀ is high, the floating capacitance between the windings of the power transmission coil Lt may be used as the resonance capacitor Ct.

  The communication circuit 23 performs bidirectional wireless communication with the communication circuit 33 of the power receiving device 3. The communication circuit 23 outputs a signal received from the communication circuit 33 to the control circuit 24. Further, the communication circuit 23 transmits the signal input from the control circuit 24 to the communication circuit 33. In the present embodiment, the communication circuit 23 performs infrared communication with the communication circuit 33.

  The control circuit 24 controls the power transmission device 2 and includes a microcomputer including a CPU (Central Processing Unit), a ROM (Read Only Memory) and a RAM (Random Access Memory), and an FPGA (Field-Programmable Gate Array). Is done. The control circuit 24 receives the signal received by the communication circuit 23 and outputs a predetermined signal to the communication circuit 23 for transmission. The signals received by the communication circuit 23 include a power transmission start signal for instructing a power transmission start, a power transmission stop signal for instructing a power transmission stop, and the like. The signal transmitted by the communication circuit 23 includes a response signal transmitted when a power transmission start signal and a power transmission stop signal are received, information such as transmission power and power transmission efficiency detected during power transmission, and occurrence of an error. There is an error signal to notify. Further, the control circuit 24 controls starting and stopping of the high-frequency power supply device 21. The control circuit 24 activates the high-frequency power supply device 21 when receiving the power transmission start signal from the communication circuit 33 of the power receiving device 3 via the communication circuit 23. Further, the control circuit 24 stops the high-frequency power supply device 21 when receiving the power transmission stop signal from the communication circuit 33 of the power receiving device 3 via the communication circuit 23. The control circuit 24 also stops the high-frequency power supply 21 when an abnormality occurs in the high-frequency power supply 21 or when a predetermined time has elapsed since the high-frequency power supply 21 was started.

  The power receiving device 3 is mounted on the automatic guided vehicle 4 and includes a power receiving unit 31, a rectifying and smoothing circuit 32, a communication circuit 33, an operation panel 34, and a control circuit 35. The power receiving device 3 is not supplied with power from the capacitor 41 but has a power source (not shown), and supplies power to the communication circuit 33 and the control circuit 35 from the power source. Therefore, even if the charge amount of the capacitor 41 is insufficient, it can be operated.

  The power receiving unit 31 includes a power receiving coil Lr and a resonance capacitor Cr. The power receiving coil Lr is magnetically coupled to the power transmitting coil Lt to receive power in a non-contact manner. The shape and the number of turns of the power receiving coil Lr are not limited. The resonance capacitor Cr is connected in series to the power receiving coil Lr to form a series resonance circuit.

The power receiving coil Lr and the resonance capacitor Cr are designed such that the resonance frequency matches the frequency f ₀ (switching frequency f ₀ ) of the high-frequency power supplied from the high-frequency power supply device 21, similarly to the power transmission coil Lt and the resonance capacitor Ct. You. Incidentally, when the switching frequency f ₀ is high, the stray capacitance between the windings of the receiving coil Lr may be used as a resonant capacitor Cr.

  The power receiving device 3 receives the high-frequency power transmitted from the power transmitting device 2 by magnetically coupling the power receiving coil Lr with the power transmitting coil Lt. That is, when a high-frequency current flows through the power transmission coil Lt, the magnetic flux changes, and the high-frequency current flows through the power receiving coil Lr linked to the magnetic flux. Thus, power can be supplied from the power transmitting device 2 to the power receiving device 3 in a non-contact manner. FIG. 2 shows a state where the power receiving coil Lr is magnetically coupled to the power transmitting coil Lt.

  Each of the power transmission unit 22 and the power reception unit 31 is a resonance circuit, and is coupled in resonance. That is, power is transmitted from the power transmission unit 22 to the power reception unit 31 in a non-contact manner by the magnetic field resonance method. The power received by the power receiving unit 31 is output to the rectifying and smoothing circuit 32.

  The rectifying / smoothing circuit 32 rectifies a high-frequency current output from the power receiving unit 31 and converts it into a DC current. The rectifying and smoothing circuit 32 includes a full-wave rectifying circuit in which four diodes are bridge-connected. The rectifying and smoothing circuit 32 also includes a smoothing circuit for smoothing the rectified output. The configuration of the rectifying / smoothing circuit 32 is not limited, and may be any circuit that converts a high-frequency current to a DC current. The DC current output from the rectifying and smoothing circuit 32 is supplied to the capacitor 41.

  Each of the power transmission unit 22 and the power reception unit 31 is a series resonance circuit, and power is transmitted from the power transmission unit 22 to the power reception unit 31 in a non-contact manner by a magnetic field resonance method. In this case, the magnitude of the current output from the power receiving unit 31 is proportional to the magnitude of the voltage input to the power transmitting unit 22. Further, the high-frequency power supply device 21 controls the magnitude of the output voltage to be constant and outputs the output voltage to the power transmission unit 22. Therefore, the magnitude of the current output from the power receiving unit 31 is constant regardless of the impedance of the connected load. That is, the output of the power receiving unit 31 can be considered as a constant current source that outputs a current of a certain magnitude. Further, since the output current of the power receiving unit 31 has a constant magnitude, the current rectified and smoothed by the rectifying and smoothing circuit 32 becomes constant. Therefore, the current supplied to the capacitor 41 becomes constant regardless of the state of charge of the capacitor 41. That is, the capacitor 41 is charged at a constant current. Since the charging current is prevented from being excessively increased by the constant current charging, it is possible to prevent the destruction of the element and the increase in loss due to the overcurrent.

  The communication circuit 33 performs bidirectional wireless communication with the communication circuit 23 of the power transmission device 2. The communication circuit 33 outputs a signal received from the communication circuit 23 to the control circuit 35. Further, the communication circuit 33 transmits the signal input from the control circuit 35 to the communication circuit 23. In the present embodiment, the communication circuit 33 performs infrared communication with the communication circuit 23.

  As illustrated in FIG. 2, the communication circuit 23 emits infrared light to a surface of the power transmission device 2 on which the power transmission coil Lt is disposed, and receives infrared light (hereinafter, an “emission surface”). To be exposed). Similarly, the communication circuit 33 is disposed on the surface of the power receiving device 3 on which the power receiving coil Lr is disposed such that the emission / incident surface is exposed. Then, the automatic guided vehicle 4 stops at the stop position (power supply position), and the power transmission coil Lt of the power transmission device 2 and the power reception coil Lr of the power reception device 3 face each other (the power transmission coil Lt and the power reception coil Lr are magnetically driven). The communication circuit 23 and the communication circuit 33 are arranged such that the respective exit and incident surfaces face each other when the optical communication device is in a position where the optical circuits are in a state of being connected to each other. Therefore, when the automatic guided vehicle 4 stops at the stop position (power supply position), the communication circuits 23 and 33 can communicate with each other. When the automatic guided vehicle 4 is manually moved to the stop position (power supply position), the automatic guided vehicle 4 may not be accurately positioned at the stop position (power supply position), unlike the case of automatic traveling. Also in this case, the directivity of the communication circuit 23 and the communication circuit 33 is adjusted so that communication is possible if the power transmission coil Lt and the power reception coil Lr are shifted to the extent that non-contact power transmission is possible.

  The operation panel 34 includes an operation switch for operating the power transmission device 2, a lamp for notifying a power transmission state, and the like, and is disposed on a surface of a housing of the power reception device 3. The operation panel 34 outputs an operation signal to the control circuit 35 when each operation switch is operated. In addition, each lamp is turned on and off according to the notification signal input from the control circuit 35. The operation panel 34 includes a power transmission start switch 341, a power transmission stop switch 342, a power receiving lamp 343, and a communication abnormality lamp 344. Although other switches and lamps may be provided, they are omitted in FIG. The power transmission start switch 341 and the power transmission stop switch 342 are push-button automatic reset switches, and output operation signals when pressed. The configuration of each switch is not limited to this. Instead of the power transmission start switch 341 and the power transmission stop switch 342, a single changeover switch may be used to output different operation signals when switching to start and when to stop. Further, a keyboard may be provided on the operation panel 34 instead of each operation switch, and a corresponding operation signal may be output in response to a predetermined command input. Further, a display screen such as a monitor may be provided instead of each lamp, and a corresponding display may be performed according to an input notification signal. The notification may be made by a buzzer, sound, or the like. The operation panel 34 and the control circuit 35 correspond to “operation means” and “notification means” of the present invention.

  The control circuit 35 controls the power receiving device 3 and includes a microcomputer or an FPGA having a CPU, a ROM, and a RAM. The control circuit 35 receives the signal received by the communication circuit 33 and outputs a predetermined signal to the communication circuit 33 for transmission. The signal received by the communication circuit 33 includes a response signal, information such as transmission power and transmission efficiency, and an error signal. The signal transmitted by the communication circuit 33 includes a power transmission start signal and a power transmission stop signal. The control circuit 35 receives an operation signal from the operation panel 34 and outputs a notification signal to the operation panel 34.

  When the automatic guided vehicle 4 is located at the predetermined power receiving position, the control circuit 35 receives a command from the control device of the automatic guided vehicle 4 and causes the communication circuit 33 to transmit a power transmission start signal. In addition, the method for detecting that the automatic guided vehicle 4 is located at the power receiving position is not limited. The control circuit 35 also causes the communication circuit 33 to transmit a power transmission start signal when an operation signal of the power transmission start switch 341 is input from the operation panel 34. Further, when the automatic guided vehicle 4 is not located at the predetermined power receiving position (moves from the power receiving position), the control circuit 35 receives a command from the control device of the automatic guided vehicle 4 and transmits a power transmission stop signal. The circuit 33 is transmitted. The control circuit 35 also causes the communication circuit 33 to transmit a power transmission stop signal when an operation signal of the power transmission stop switch is input from the operation panel 34. Furthermore, the power transmission stop signal is transmitted to the communication circuit 33 also when it is detected that the capacitor 41 of the automatic guided vehicle 4 is fully charged, or when an abnormality occurs in the capacitor 41 or the like. The power receiving device 3 includes a voltage sensor that detects a charging voltage of the capacitor 41. The control circuit 35 sets the capacitor 41 to a fully charged state when the charging voltage detected by the voltage sensor becomes equal to or higher than a predetermined threshold. Judge that it has become.

  In addition, the power receiving device 3 includes a current sensor 36 that detects a current flowing from the rectifying / smoothing circuit 32 to the capacitor 41, and the control circuit 35 performs power reception while the current sensor 36 detects the current. Judge that there is. In this case, the control circuit 35 outputs to the operation panel 34 a notification signal for turning on the lamp 343 during power reception. On the other hand, when the current sensor 36 stops detecting the current, the control circuit 35 determines that the power reception has stopped. In this case, the control circuit 35 outputs a notification signal to the operation panel 34 to turn off the power receiving lamp 343. The current sensor 36 and the control circuit 35 correspond to “detection means” of the present invention. Note that the current sensor 36 may detect a current flowing from the power receiving unit 31 to the rectifying / smoothing circuit 32. The method of detecting that the power receiving device 3 is receiving power is not limited to the detection of current by the current sensor 36. The fact that the power receiving device 3 is receiving power may be detected based on a change in the charging voltage of the capacitor 41 detected by the voltage sensor.

  Further, the control circuit 35 detects whether or not the communication by the communication circuit 33 is established. Specifically, the control circuit 35 transmits a signal such as a power transmission start signal or a power transmission constant signal to the communication circuit 33, but when the communication circuit 33 fails to receive a response signal within a predetermined time, It is determined that communication has not been established. In this case, the control circuit 35 outputs a notification signal for turning on the communication abnormality lamp 344 to the operation panel 34. Accordingly, the communication abnormality lamp 344 is turned on, so that the operator can recognize that the communication has not been established.

  Next, a manual power supply control process performed by the control circuit 35 will be described. The manual power supply control process is a process for controlling manual power supply.

  FIG. 3 is a flowchart for explaining the manual power supply control process performed by the control circuit 35. The manual power supply control process is started when the power receiving device 3 is activated, and is executed while the power receiving device 3 is operating.

  First, it is determined whether or not the power transmission start switch has been operated (S1). Specifically, it is determined whether or not an operation signal of power transmission start switch 341 has been input from operation panel 34. If it has not been operated (S1: NO), the determination in step S1 is repeated until it is operated. That is, no specific processing is performed until the power transmission start switch is operated. When the power transmission start switch is operated (S1: YES), a power transmission start signal is output to the communication circuit 33 (S2). The power transmission start signal is transmitted from the communication circuit 33 to the communication circuit 23.

  Next, it is determined whether a response signal to the power transmission start signal has been received (S3). Specifically, it is determined whether or not a response signal has been input from the communication circuit 33 within a predetermined time. If the response signal has not been received (S3: NO), it is determined that communication has not been established, the communication abnormality lamp 344 is turned on (S11), the process returns to step S1, and the determination of step S1 is repeated. Specifically, a notification signal for turning on the communication abnormality lamp 344 is output to the operation panel 34. The operation panel 34 receives the notification signal and turns on the communication abnormality lamp 344. Thereby, the operator can recognize that the communication has not been established. The operator operates the power transmission start switch again after moving the automatic guided vehicle 4 so that the communication circuit 33 can communicate with the communication circuit 23 or repairing an abnormality of the communication circuit 33 or the like. When the response signal is received by the second operation, the communication abnormality lamp 344 is turned off.

  On the other hand, when the response signal is received (S3: YES), it is determined whether the power receiving coil Lr is receiving power (S4). Specifically, it is determined whether or not the current sensor is detecting a current. When the current sensor detects the current, it is determined that the power receiving coil Lr is receiving power, and when it is not detecting the current, it is determined that the power receiving coil Lr is not receiving power. If power has not been received (S4: NO), the determination in step S4 is repeated until power is received. On the other hand, when the power is received (S4: YES), the power receiving lamp 343 is turned on (S5). Specifically, a notification signal for turning on the power receiving lamp 343 is output to the operation panel 34. The operation panel 34 receives the notification signal and turns on the power receiving lamp 343. Thus, the operator can recognize that power is being received.

  Next, it is determined whether or not the power transmission stop switch has been operated (S6). Specifically, it is determined whether or not an operation signal of power transmission stop switch 342 has been input from operation panel 34. If not operated (S6: NO), the determination in step S6 is repeated until the operation is performed. On the other hand, when operated (S6: YES), a power transmission stop signal is output to the communication circuit 33 (S7). The power transmission stop signal is transmitted from the communication circuit 33 to the communication circuit 23. If the capacitor 41 is fully charged while the determination in step S6 is repeated, the process proceeds to step S7 even if the power transmission stop switch is not operated, and a power transmission stop signal is output to the communication circuit 33. You.

  Next, it is determined whether a response signal to the power transmission stop signal has been received (S8). Specifically, it is determined whether or not a response signal has been input from the communication circuit 33 within a predetermined time. When the response signal is received (S8: YES), it is determined whether or not the power receiving coil Lr is receiving power (S9). Specifically, it is determined whether or not the current sensor is detecting a current. If power has been received (S9: YES), the determination in step S9 is repeated until power reception is stopped. On the other hand, when the power reception is stopped (S9: NO), the power receiving lamp 343 is turned off (S10). Specifically, a notification signal for turning off the power receiving lamp 343 is output to the operation panel 34. The operation panel 34 receives the notification signal and turns off the power receiving lamp 343. Thus, the operator can recognize that the power reception has ended. Then, the manual power supply control process returns to step S1, and the determination in step S1 is repeated until the next power transmission starts.

  If no response signal is received in step S8 (S8: NO), it is determined that communication has not been established, the communication abnormality lamp 344 is turned on (S12), and the process proceeds to step S9. Even when the power transmission stop signal cannot be transmitted due to a communication error after the start of power transmission, the control circuit 24 of the power transmission device 2 determines whether a predetermined time has elapsed since the activation of the high frequency power device 21 When it is determined that the power transmission has occurred, the high-frequency power supply 21 is stopped, so that the power transmission state does not continue unduly. Even when the power transmission is stopped under the control of the power transmission device 2, the power receiving coil Lr cannot receive power. Therefore, it is determined that the power reception has stopped in step S9 (S9: NO), and the power receiving lamp 343 is turned off (S10). . The operator sees that the communication abnormality lamp 344 is lit, recognizes that communication has not been established, and moves the automatic guided vehicle 4 so that the communication circuit 33 can communicate with the communication circuit 23. Repair the abnormality of the communication circuit 33 and the like.

  The processing procedure of the manual power supply control processing is not limited to this. For example, in the case of a communication error (S3: NO, S8: NO), the manual power supply control process may be terminated after the communication error lamp 344 is turned on (S11, S12). Further, the manual power supply control process may be started when the state of charge of the capacitor 41 becomes insufficient.

  Returning to FIG. 1, the capacitor 41 stores electricity, and is a capacitor in which, for example, a capacitor such as an electric double layer capacitor or a lithium ion capacitor is connected in series / parallel so as to obtain a required charging capacity. . In addition, you may comprise with one capacitor of large capacity. Capacitors are characterized by less deterioration due to charging and discharging, longer product life, and the ability to rapidly charge with a large current compared to other power storage devices, making them suitable for charging systems that repeatedly charge and discharge. I have. As described above, the power transmission unit 22 outputs a large high-frequency current having a high frequency (85 [kHz]). The high-frequency current received by the power receiving unit 31 is rectified by the rectifying / smoothing circuit 32 and output to the capacitor 41. Therefore, the capacitor 41 is charged at a constant current with a large DC current. In the present embodiment, the capacitor 41 is charged at 50 [A]. Therefore, capacitor 41 can store large electric energy in a short time. Note that the current for charging the capacitor 41 is not limited, and may be 50 [A] or more. The capacitor 41 supplies power to the motor 43 via the DC-DC converter circuit 42.

  The DC-DC converter circuit 42 converts the voltage output from the capacitor 41 into a drive voltage (for example, 24 [V] or 48 [V]) for driving the motor 43 and applies the drive voltage to the motor 43. Since the voltage of the capacitor 41 changes according to the amount of charge, the DC-DC converter circuit 42 is provided to make the voltage applied to the motor 43 a predetermined drive voltage. Note that the configuration of the DC-DC converter circuit 42 is not limited.

  The motor 43 rotates the wheels of the automatic guided vehicle 4. The automatic guided vehicle 4 includes a control device (not shown) for controlling the DC-DC converter circuit 42 and the motor 43. The control device stops the motor 43 when the automatic guided vehicle 4 reaches the stop position, and drives the motor 43 when the automatic guided vehicle 4 travels. Electric power for driving the motor 43 is supplied from the capacitor 41. In addition, power is also supplied from the capacitor 41 to the control device. Therefore, when the electric energy stored in the capacitor 41 is insufficient, not only the motor 43 cannot be driven but also the control of the automatic guided vehicle 4 cannot be performed.

  Next, the operation and effect of the wireless power transmission system 1A according to the first embodiment will be described.

  According to the present embodiment, the power receiving device 3 includes the power transmission start switch 341 on the operation panel 34. By operating the power transmission start switch 341, the operator can input a power transmission start signal to the control circuit 24 of the power transmission device 2 via the communication circuit 23 and the communication circuit 33. When the power transmission start signal is input, the control circuit 24 activates the high-frequency power supply device 21. Thereby, power transmission from the power transmission device 2 to the power reception device 3 is started. Therefore, there is no need to provide the power transmission device 2 with a power transmission start switch.

  Further, according to the present embodiment, the power receiving device 3 includes the power transmission stop switch 342 on the operation panel 34. By operating the power transmission stop switch 342, the operator can input a power transmission stop signal to the control circuit 24 of the power transmission device 2 via the communication circuit 23 and the communication circuit 33. When receiving the power transmission stop signal, the control circuit 24 stops the high-frequency power supply device 21. Thereby, the power transmission from the power transmitting device 2 to the power receiving device 3 is stopped. That is, power transmission can be stopped on the power receiving device 3 side.

  According to the present embodiment, the power receiving device 3 includes the power receiving lamp 343 on the operation panel 34. The control circuit 35 turns on and off the receiving lamp 343 according to the detection result of the current sensor 36. Therefore, the operator can recognize whether or not power is being received. In addition, the power receiving device 3 includes a communication abnormality lamp 344 on the operation panel 34. When the control circuit 35 determines that the communication is not established, the control circuit 35 turns on the communication abnormality lamp 344. Therefore, the operator can recognize that the communication has not been established.

  Further, according to the present embodiment, the communication circuit 23 and the communication circuit 33 perform infrared communication, and can perform communication when the power transmission coil Lt and the power reception coil Lr are at positions where they are magnetically coupled. Are located. Therefore, when the automatic guided vehicle 4 is located at the stop position (power supply position), the communication circuit 23 and the communication circuit 33 can communicate with each other, so that the operation of starting and stopping the power transmission is performed on the power receiving device 3 side. be able to. On the other hand, when the automatic guided vehicle 4 is not located at the stop position (power supply position), the communication circuit 23 and the communication circuit 33 cannot communicate with each other. Cannot start. Thus, even when the power transmission start switch 341 is erroneously operated, it is possible to prevent the power transmission from starting.

  In the present embodiment, the case has been described where the communication circuits 23 and 33 perform infrared communication, but the present invention is not limited to this. The communication method of the communication circuit 23 and the communication circuit 33 and the type of the electromagnetic wave used are not limited. When a communication method with low directivity is adopted, the communication range is widened, so that it is easy to allow positional deviation when the automatic guided vehicle 4 is manually moved to the stop position (power supply position). In addition, the degree of freedom in the location of the communication circuit 23 and the communication circuit 33 is increased. However, if the directivity is too low, communication may be possible even in an arrangement in which the power transmitting coil Lt and the power receiving coil Lr cannot perform non-contact power transmission. On the other hand, if the directivity is too high, it is difficult to tolerate a positional deviation of the automatic guided vehicle 4 at the stop position (power supply position). That is, communication becomes impossible even with a slight deviation, and manual power supply becomes difficult. Therefore, as in the present embodiment, it is desirable to adopt infrared communication with high directivity and adjust the directivity appropriately.

  In the present embodiment, the case where the communication circuit 23 and the communication circuit 33 perform bidirectional communication has been described, but the present invention is not limited to this. For example, the communication circuit 33 may perform only transmission and the communication circuit 23 may perform only reception. In this case, although a response signal or the like cannot be transmitted from the communication circuit 23 to the communication circuit 33, a power transmission start signal and a transmission stop signal can be transmitted from the communication circuit 33 to the communication circuit 23. It is possible to operate the start and stop of power transmission.

  In the present embodiment, a case has been described in which power transmission can be stopped by operating the power transmission stop switch 342, but the present invention is not limited to this. The power transmission may be stopped only when the battery is fully charged without providing the power transmission stop switch 342. Further, a switch for stopping power transmission may be provided in power transmission device 2.

  In the present embodiment, the case where each operation switch of the operation panel 34 provided on the housing of the power receiving device 3 is operated has been described, but the present invention is not limited to this. For example, instead of the operation panel 34, an operation remote controller 34 'having the same function as the operation panel 34 is provided, and the power receiving device 3 is provided with a second communication circuit 37 for communicating with the operation remote controller 34'. The operation signal and the notification signal may be transmitted and received by wireless communication between the control signal and the second communication circuit 37 (see FIG. 4). Alternatively, the operation remote controller 34 'and the second communication circuit 37 may be connected by a communication cable to perform wired communication. Instead of the operation remote controller 34 ', a computer in which software is installed in a general-purpose computer or portable device may be used.

  In the present embodiment, the case has been described where the automatic guided vehicle 4 detects that it is located at the power receiving position, sends a command to the power receiving device 3, and the power receiving device 3 transmits a power transmission start signal to the power transmitting device 2. However, it is not limited to this. The power transmission device 2 may detect the automatic guided vehicle 4, transmit a power transmission notification signal to the power reception device 2, and activate the high-frequency power supply device 21.

  In the present embodiment, both the power transmission unit 22 and the power reception unit 31 are series resonance circuits, but both may be parallel resonance circuits. Further, in the present embodiment, the case has been described in which the high-frequency power supply device 21 is a constant voltage source that outputs a high-frequency voltage having a constant magnitude, but the present invention is not limited to this. The high-frequency power supply 21 may be a constant current source that outputs a high-frequency current of a certain magnitude. In this case, by using one of the power transmission unit 22 and the power reception unit 31 as a series resonance circuit and the other as a parallel resonance circuit, the output of the power reception unit 31 can be used as a constant current source to charge the capacitor 41 with a constant current.

  In the present embodiment, the case where the power transmission method from the power transmission device 2 to the power reception device 3 is the magnetic field resonance method has been described, but is not limited thereto. For example, an electromagnetic induction method or an electric field resonance method may be used.

  In the present embodiment, the case where the capacitor 41 is used as the power storage device has been described, but the present invention is not limited to this. Instead of the capacitor 41, another power storage device such as a lead storage battery or a lithium ion battery may be used.

  In the present embodiment, when power is supplied manually, the automatic guided vehicle 4 is moved to a stop position on the circulation path to supply power, but the invention is not limited to this. The power transmission device 2 may be arranged at a predetermined position outside the circulation path, and power may be supplied from the power transmission device 2.

  In the present embodiment, the automatic guided vehicle 4 incorporating the power receiving device 3 in advance has been described, but the present invention is not limited to this. A power receiving device 3 may be mounted on a conventional automatic guided vehicle as a charging system later and connected to a power storage device. Alternatively, the power storage device may be removed from the conventional automatic guided vehicle, and the power receiving device 3 and the capacitor 41 may be mounted later as a power supply system. In these cases, an unmanned guided vehicle that has been conventionally used can be used, so that costs can be reduced as compared with a case where an unmanned guided vehicle 4 on which the power receiving device 3 is mounted is newly purchased.

  In the present embodiment, the case where the power transmitting coil Lt and the power receiving coil Lr are arranged such that the coil surfaces are substantially perpendicular to the floor surface has been described, but the present invention is not limited to this. For example, the power receiving coil Lr is disposed on the vehicle body bottom surface of the automatic guided vehicle 4 so that the coil surface is substantially parallel to the floor surface, and the power transmission coil Lt is arranged such that the coil surface is substantially parallel to the floor surface. It may be arranged on the floor. In this case, since the distance between the floor surface and the vehicle body bottom surface of the automatic guided vehicle 4 is constant, the coil surfaces of the power receiving coil Lr and the power transmitting coil Lt when the automatic guided vehicle 4 stops at the stop position (power supply position). Can be made a fixed distance. Further, the power transmission device 2 can be arranged so as not to hinder work or traffic. In this case, it is necessary to prevent the detection mechanism of the circulation path and the stop position of the automatic guided vehicle 4 from interfering with the power transmission and reception of the power transmission coil Lt and the power reception coil Lr.

  In the first embodiment, the case where the non-contact power transmission system according to the present invention is used for charging the capacitor 41 incorporated in the automatic guided vehicle 4 is described as an example, but the present invention is not limited to this. For example, it can be used for charging a battery of an electric vehicle and the like. That is, the power receiving device 3 may be mounted on an electric vehicle. In addition, the present invention can be applied to a case where a power storage device of an electric product such as a portable device, a notebook computer, or a power tool is charged.

  FIG. 5 is a schematic diagram showing the entire configuration of a wireless power transmission system 1B according to the second embodiment, showing a case where the wireless power transmission system according to the present invention is used as a charging system for a portable device 4 ′. I have. The wireless power transmission system 1B according to the first embodiment is different from the wireless power transmission system 1A according to the first embodiment in that the power receiving device 3 is mounted on a portable device 4 ′ and supplies power to a power storage device 41 ′ (see FIG. 1). And different. The power transmission device 2 includes, for example, a box-shaped housing arranged on a desk, and the power transmission coil Lt is arranged on the upper surface side of the housing such that the coil surface is horizontal. The power receiving device 3 is mounted on a portable device 4 ', and the power receiving coil Lr is arranged inside one surface of the portable device 4' so as to be parallel to the surface. When the portable device 4 ′ is placed on the upper surface of the housing of the power transmission device 2 with the surface on which the power reception coil Lr is disposed facing downward, the power transmission coil Lt and the power reception coil Lr can be magnetically coupled. Power transmission becomes possible. The internal configurations of the power transmitting device 2 and the power receiving device 3 are the same as those of the non-contact power transmission system 1A according to the first embodiment. Also in the second embodiment, the same effects as in the first embodiment can be obtained.

  The wireless power transmission system and the power receiving device according to the present invention are not limited to the above embodiments. The specific configuration of each part of the wireless power transmission system and the power receiving device according to the present invention can be variously changed in design.

1A, 1B Non-contact power transmission system 2 Power transmission device 21 High frequency power supply device 22 Power transmission unit Lt Power transmission coil Ct Resonant capacitor 23 Communication circuit (power transmission side communication circuit)
24 Control circuit 3 Power receiving device 31 Power receiving unit Lr Power receiving coil Cr Resonant capacitor 32 Rectifying smoothing circuit (rectifying circuit)
33 Communication circuit (power receiving side communication circuit)
34 Operation panel (operation means, notification means)
341 Power transmission start switch 342 Power transmission stop switch 343 Power receiving lamp 344 Communication error lamp 34 'Remote controller (operation means, notification means)
35 control circuit (detection means, operation means, notification means)
36 Current sensor (detection means)
37 Second communication circuit 4 Automatic guided vehicle (vehicle)
4 'Portable equipment 41 Capacitor (power storage device)
41 'Power storage device 42 DC-DC converter circuit 43 Motor

Claims (9)

Electricity transmission device transmits power in a non-contact power receiving apparatus mounted on an automated guided vehicle, a non-contact power transmission system AGV,
The power receiving device includes an operation means for outputting an electricity transmission start signal based on the operation of the operator,
The power transmission device starts transmitting power when the power transmission start signal is input,
A non-contact power transmission system for an automatic guided vehicle, characterized in that : The power transmission device,
A high-frequency power supply that outputs high-frequency power,
A power transmission coil connected to the high-frequency power supply,
A power transmission side communication circuit for performing communication,
With
The power receiving device,
A power receiving coil magnetically coupled to the power transmitting coil;
A power receiving communication circuit that communicates with the power transmitting communication circuit,
A control circuit of the operating means,
With
The power transmission device, via the power receiving communication circuit and the power transmission communication circuit, when the power transmission start signal is input, to start the high-frequency power supply device,
The wireless power transmission system according to claim 1. The power receiving side communication circuit and the power transmission side communication circuit,
Communicate using a highly directional communication method,
When the power transmitting coil and the power receiving coil are at a position where they are magnetically coupled, they are arranged to be communicable.
The wireless power transmission system according to claim 2. The power receiving side communication circuit and the power transmission side communication circuit perform communication by infrared communication ,
The wireless power transmission system according to claim 3. The operating means further outputs a power transmission stop signal based on an operation of the operator,
The power transmission device, via the power receiving communication circuit and the power transmission communication circuit, when the power transmission stop signal is input, to stop the high-frequency power supply device,
The wireless power transmission system according to claim 2. The power receiving device,
Detecting means for detecting that the power receiving coil is receiving power from the power transmitting coil,
Notifying means for notifying that power is being received, according to a detection result of the detecting means,
Further comprising
The wireless power transmission system according to claim 2. The detecting means includes a current sensor, and when the current sensor detects a current, determines that the power receiving coil is receiving power from the power transmitting coil.
The wireless power transmission system according to claim 6. The notifying unit further notifies, when the signal transmitted from the power receiving communication circuit is not received by the power transmitting communication circuit,
The wireless power transmission system according to claim 6. A power receiving apparatus of the non-contact power transmission system that transmits power electricity transmission device in a non-contact power receiving apparatus mounted on an automated guided vehicle,
An operation means for outputting an electricity transmission start signal on the basis of the operation of the steering author,
The power transmission device starts transmitting power when the power transmission start signal is input,
A power receiving device for an automatic guided vehicle, characterized in that :

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