Patent Publication Number: US-2022236743-A1

Title: Power supply system and power supply device

Description:
TECHNICAL FIELD 
     The present disclosure relates to a power supply system and a power supply device. 
     BACKGROUND ART 
     In recent years, a work robot including a traveling device has been used in order to enable work in various places. For example, PTL 1 discloses a work robot including a moving mechanism and a work arm. The work robot of PTL 1 includes a power storage device, and performs work while consuming the power of the power storage device. When the amount of power remaining in the power storage device of the work robot becomes small, a power supply robot including a moving mechanism connects to the work robot to supply and charge the work robot with the power of a power storage device of the power supply robot. 
     CITATION LIST 
     Patent Literature 
     PTL 1: Japanese Laid-Open Patent Publication No. H06-133411 
     SUMMARY OF INVENTION 
     Technical Problem 
     The power supply robot of PTL 1 includes a larger power storage device than the power storage device of the work robot, but the storage capacity of the power storage device that can be mounted on the power supply robot has an upper limit. Therefore, when it is necessary to supply and charge work robots with power, the amount of power stored in the power storage device of the power supply robot may become insufficient. Furthermore, since it takes a long time to charge the power storage device of the power supply robot, the work robot cannot be supplied and charged with power during charging of the power supply robot in some cases. 
     Therefore, an object of the present disclosure is to provide a power supply system and a power supply device which enable stable power supply to a robot. 
     Solution to Problem 
     In order to achieve the above object, a power supply system according to an aspect of the present disclosure includes: a robot including a power storage device; a movable power supply device; and a controller, the power supply device includes a first electrical connector that is electrically connectable to a second electrical connector of the robot and that is electrically connected to a power supply source via a wire, and the controller performs control for electrically connecting the first electrical connector and the second electrical connector and supplying power to the robot, on the basis of information about an amount of power stored in the power storage device. 
     A power supply device according to an aspect of the present disclosure is a movable power supply device including: a first electrical connector that is electrically connectable to a second electrical connector of a robot including a power storage device and that is electrically connected to a power supply source via a wire; and a controller that performs control for supplying power to the robot via the first electrical connector, on the basis of information about an amount of power stored in the power storage device. 
     Advantageous Effects of Invention 
     According to the technology of the present disclosure, it is possible to stably supply power to a robot. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a plan view showing an example of the configuration of a power supply system according to an embodiment. 
         FIG. 2  is a side view showing an example of the configuration of a robot according to the embodiment. 
         FIG. 3  is a side view showing an example of the configuration of a power supply device according to the embodiment. 
         FIG. 4  is a block diagram showing an example of the configuration of the robot according to the embodiment. 
         FIG. 5  is a block diagram showing an example of the functional configuration of a robot controller according to the embodiment. 
         FIG. 6  is a block diagram showing an example of the configuration of the power supply device according to the embodiment. 
         FIG. 7  is a plan view showing an example of a connection state between the robot and the power supply device in  FIG. 1 . 
         FIG. 8  is a block diagram showing an example of the functional configuration of a power supply controller of the power supply device according to the embodiment. 
         FIG. 9  is a flowchart showing an example of a first operation of the power supply system according to the embodiment. 
         FIG. 10  is a plan view showing an example of arrangement of robots and one power supply device. 
         FIG. 11  is a flowchart showing an example of a second operation of the power supply system according to the embodiment. 
         FIG. 12  is a flowchart showing an example of a third operation of the power supply system according to the embodiment. 
         FIG. 13  is a plan view showing an example of arrangement of robots and power supply devices. 
         FIG. 14  is a flowchart showing an example of a fourth operation of the power supply system according to the embodiment. 
         FIG. 15  is a plan view showing an example of the configuration of a power supply system according to Modification 1. 
         FIG. 16  is a side view showing an example of a connection state between a robot and a power supply device according to Modification 1. 
         FIG. 17  is a plan view showing an example of the configuration of a power supply system according to Modification 2. 
         FIG. 18  is a side view showing an example of a connection state between a robot and a power supply device according to Modification 2. 
         FIG. 19  is a plan view showing an example of the configuration of a power supply system according to Modification 3. 
         FIG. 20  is a block diagram showing an example of the configuration of a power supply device according to Modification 3. 
         FIG. 21  is a block diagram showing an example of the functional configuration of a power supply controller of the power supply device according to Modification 3. 
         FIG. 22  is a block diagram showing an example of the configuration of a management apparatus and the functional configuration of a management controller according to Modification 3. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Embodiments 
     Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. The embodiments described below are all comprehensive or specific examples. In addition, among the components in the following embodiments, the components not described in the independent claims which represent broadest concepts are described as optional components. Moreover, each figure in the accompanying drawings is a schematic view and is not necessarily exactly illustrated. Furthermore, in each figure, substantially the same components are designated by the same reference signs, and the repetitive description thereof may be omitted or simplified. 
     &lt;Configuration of Power Supply System  1 &gt; 
       FIG. 1  is a plan view showing an example of the configuration of a power supply system  1  according to an embodiment.  FIG. 2  is a side view showing an example of the configuration of a robot  100  according to the embodiment.  FIG. 3  is a side view showing an example of the configuration of a power supply device  200  according to the embodiment. As shown in  FIG. 1  to  FIG. 3 , the power supply system  1  includes one or more robots  100 , one or more power supply devices  200 , and a power supply source  300 . 
     Each robot  100  includes a robot main body  101  and a traveling device  102 . The traveling device  102  travels on a floor surface or the like to move the robot  100  to a desired location. The traveling device  102  includes traveling means, such as wheels or crawlers (also referred to as “caterpillars (registered trademark)”). The robot main body  101  performs a desired operation, such as work, at a desired location. For example, the robot main body  101  includes one or more arms  101   a  and a manipulator  101   b  at the tip of each arm  101   a,  and performs work using the arm  101   a  and the manipulator  101   b.  The manipulator  101   b  can hold an object, for example, by grasping, sucking, or scooping up the object. In the present embodiment, the robot  100  is a work robot, but is not limited thereto and may be any robot. 
     The robot  100  also includes a power storage device  103 , a terminal  104 , and a robot controller  105 . The robot controller  105  controls the operation of the entire robot  100 , such as the robot main body  101  and the traveling device  102 . The power storage device  103  includes a storage battery, such as a secondary battery, and constitutes a power source of the robot  100 . The secondary battery is a battery capable of charging and discharging power. Examples of the secondary battery include lead storage batteries, lithium-ion secondary batteries, nickel-hydrogen storage batteries, and nickel-cadmium storage batteries. The terminal  104  is physically and electrically connectable to a terminal  201  of the power supply device  200 , and receives power supplied from the power supply device  200 . The power storage device  103  can store the power supplied via the terminal  104 . The terminal  104  is an example of a second electrical connector, and the terminal  201  is an example of a first electrical connector. 
     The power supply source  300  is a facility which is physically and electrically connected to each power supply device  200  by a power line  301  and which supplies DC power or AC power to the power supply device  200  via the power line  301 . For example, the power supply source  300  is arranged at a work place A, for example, in a factory or a warehouse where the robot  100  is arranged. The power supply source  300  receives power supplied from a power system, such as a commercial power supply, and sends the supplied power to the power supply device  200 . The power supply source  300  may include a power storage device which is not shown, and may supply power temporarily stored in this power storage device, to the power supply device  200 , or may directly supply the power from the power system to the power supply device  200 . 
     Each power supply device  200  includes the terminal  201 , a traveling device  202 , and a power supply controller  203 . The traveling device  202  travels on a floor surface or the like to move the power supply device  200  to a target robot  100 . The traveling device  202  includes traveling means, such as wheels or crawlers. The terminal  201  is electrically connected to the power line  301  and thereby electrically connected to the power supply source  300 . The terminal  201  is configured to be physically and electrically connected to the terminal  104  of the robot  100 . The power supply controller  203  controls the operation of the entire power supply device  200 , and controls, for example, traveling of the robot  100 , power supply to the robot  100  via the terminal  201 , etc. The power supply controller  203  is an example of a controller. 
     &lt;Configuration of Robot  100 &gt; 
       FIG. 4  is a block diagram showing an example of the configuration of the robot  100  according to the embodiment. As shown in  FIG. 1 ,  FIG. 2 , and  FIG. 4 , the robot  100  includes the robot main body  101 , the traveling device  102 , the power storage device  103 , the terminal  104 , the robot controller  105 , a power control circuit  106 , a communication device  107 , and a position detector  108  as components. Not all of these components are essential. 
     The robot main body  101  includes a robot driver  101   c,  and the robot driver  101   c  includes drivers, which are, for example, electric motors, such as servomotors, arranged on joints of the arm  101   a  and the manipulator  101   b  or the like. The robot driver  101   c  operates the joints of the arm  101   a,  the manipulator  101   b,  etc., under the control of the robot controller  105 . In the present embodiment, the arm  101   a  is a vertical articulated arm having links and joints which sequentially connect the links, but is not limited thereto. 
     The traveling device  102  includes a travel driver  102   a,  and the travel driver  102   a  includes an electric motor which drives the traveling means of the traveling device  102 , an electric motor which changes the traveling direction of the traveling means, etc. The travel driver  102   a  causes the traveling device  102  to travel in a desired direction under the control of the robot controller  105 . 
     The components such as the power storage device  103 , the terminal  104 , the robot controller  105 , the power control circuit  106 , the communication device  107 , the position detector  108 , the robot driver  101   c,  and the travel driver  102   a  are electrically connected to each other. The connection relationship between each component is not limited to the relationship in  FIG. 4 . The connection between each component may be any wired or wireless connection. 
     The configuration of the power storage device  103  is as described above. 
     The terminal  104  is fixed to the robot main body  101 . In the present embodiment, the terminal  104  is fixed to a side surface of a rear portion, of the robot main body  101 , opposite to the arm  101   a,  although not limited thereto. 
     The power control circuit  106  supplies the power of the power storage device  103  to the other components of the robot  100  under the control of the robot controller  105 . In addition, the power control circuit  106  supplies the power supplied to the terminal  104 , to the power storage device  103  and the other components under the control of the robot controller  105 . The power control circuit  106  may include a charging circuit and/or a discharging circuit, and may further include an AC-DC conversion circuit and/or a DC-AC conversion circuit and perform power conversion. 
     The communication device  107  includes a wireless communication circuit and wirelessly communicates with the power supply device  200 , etc. The communication device  107  may communicate with an individual power supply device  200 , or may communicate with power supply devices  200  and transmit information thereto all at once. For example, the communication device  107  transmits information about the amount of power stored in the power storage device  103  and position information of the robot  100  to the power supply device  200  under the control of the robot controller  105 . 
     The information about the amount of power stored in the power storage device  103  may include information indicating the level of the amount of power stored in the power storage device  103 , such as the amount of power remaining in the storage battery, the SOC (State Of Charge), the DOD (Depth Of Discharge), and the voltage of the storage battery, and the like, may include information, such as the voltage value and the current value of the power storage device  103 , for detecting the level of the amount of power stored, and may include a command for requesting or instructing power supply to the power storage device  103 . The information about the amount of power stored in the power storage device  103  may include identification information, such as an ID, of the robot  100  on which the power storage device  103  is mounted. 
     Moreover, the communication device  107  may wirelessly communicate with a device other than the power supply device  200 . For example, the communication device  107  may communicate with a terminal device  400  which transmits a command to the robot  100 , acquire information such as the work place and work contents of the robot  100  from the terminal device  400 , and output the information to the robot controller  105 . 
     For the wireless communication used by the communication device  107 , a wireless LAN (Local Area Network), such as Wi-Fi (registered trademark) (Wireless Fidelity), may be applied, short-range wireless communication, such as Bluetooth (registered trademark) and ZigBee (registered trademark), may be applied, or any other wireless communication may be applied. 
     The position detector  108  is a device which detects the position of the robot  100 , and outputs information on the detected position of the robot  100  to the robot controller  105 . The position detector  108  includes a positioning device, such as a GPS (Global Positioning System) receiver and an IMU (Inertial Measurement Unit). 
     For example, the position detector  108  may acquire the three-dimensional coordinates of the robot  100  on Earth via the GPS receiver and output the three-dimensional coordinates to the robot controller  105 . The position detector  108  may acquire the measured values of a three-axis acceleration sensor and a three-axis angular velocity sensor included in the IMU and output the measured values to the robot controller  105 . The position detector  108  may acquire the three-dimensional coordinates of the robot  100  and the measured values of the IMU and output the three-dimensional coordinates and the measured values to the robot controller  105 . It is possible to calculate the moving direction, the moving distance, and the orientation of the robot  100  by using the measured values of the IMU. In the present embodiment, the robot controller  105  detects the position and the orientation of the robot  100  by using the information acquired from the position detector  108 , but the position detector  108  may detect the position and the orientation of the robot  100 . The position detector  108  may acquire the position of the robot  100  from an external device outside the robot  100 , which manages or measures the positions of the robot  100  and the like. 
     The configuration of the robot controller  105  will be described.  FIG. 5  is a block diagram showing an example of the functional configuration of the robot controller  105  according to the embodiment. As shown in  FIG. 5 , the robot controller  105  includes a stored power information acquisition unit  105   a,  a charge/discharge control unit  105   b,  a self-device position acquisition unit  105   c,  an information output unit  105   d,  a robot control unit  105   e,  a travel control unit  105   f,  and a storage unit  105   g  as functional components. Not all of these functional components are essential. 
     The functions of the components such as the stored power information acquisition unit  105   a,  the charge/discharge control unit  105   b,  the self-device position acquisition unit  105   c,  the information output unit  105   d,  the robot control unit  105   e,  and the travel control unit  105   f  may be realized by a computer system (not shown) which includes a processor, such as a CPU (Central Processing Unit), a volatile memory, such as a RAM (Random Access Memory), a non-volatile memory, such as a ROM (Read-Only Memory), etc. Some or all of the functions of the above components may be realized by the CPU using the RAM as a work area to execute a program recorded in the ROM. Some or all of the functions of the above components may be realized by the above computer system, may be realized by a dedicated hardware circuit, such as an electronic circuit or an integrated circuit, or may be realized by a combination of the above computer system and the above hardware circuit. 
     The storage unit  105   g  can store therein various kinds of information and allows the stored information to be read. The storage unit  105   g  is realized by a storage device, such as a semiconductor memory such as a volatile memory and a non-volatile memory, a hard disk, and an SSD (Solid State Drive). The storage unit  105   g  stores therein identification information of the robot  100 , stored power information of the power storage device  103 , position information of the robot  100 , etc. The storage unit  105   g  may store therein a program to be executed by each component of the robot controller  105 . 
     The stored power information of the power storage device  103  includes information about the amount of power stored in the power storage device  103 . The stored power information may include not only information about the present amount of power stored in the power storage device  103  but also information about the past amount of power stored in the power storage device  103 , together with the detection times thereof. Moreover, the stored power information may include a threshold for the level of the amount of power stored at which charging of the power storage device  103  becomes necessary. 
     The position information of the robot  100  includes information on the position and the orientation of the robot  100  and the like. The position information may include not only the present position information of the robot  100  but also the past position information of the robot  100  together with the detection times thereof. Moreover, the position information may include information on a map of the place where the robot  100  works, or information on the position and the orientation of the robot  100  and the like associated with the map. 
     The stored power information acquisition unit  105   a  acquires the level of the amount of power stored in the power storage device  103 . Specifically, the stored power information acquisition unit  105   a  acquires the voltage value, the current value, etc., of the power storage device  103  via the power control circuit  106 , detects the level of the amount of power stored, such as SOC, by using the voltage value, current value, etc., and stores the level in the storage unit  105   g.    
     The charge/discharge control unit  105   b  controls the power control circuit  106  and controls power supply from the power storage device  103  to each component of the robot  100 . Furthermore, the charge/discharge control unit  105   b  controls the power control circuit  106  and controls power supply from the terminal  104  to the power storage device  103  and each component of the robot  100 . 
     The self-device position acquisition unit  105   c  detects the position and the orientation of the robot  100  by using the information acquired from the position detector  108 , and stores the position and the orientation of the robot  100  in the storage unit  105   g.    
     The information output unit  105   d  transmits the information about the amount of power stored in the power storage device  103 , to the power supply device  200  or the like via the communication device  107 . For example, the information output unit  105   d  may output the information about the amount of power stored in the power storage device  103  when the level of the present amount of power stored in the power storage device  103  becomes equal to or lower than the threshold, or may periodically output the information about the amount of power stored in the power storage device  103 . 
     The robot control unit  105   e  controls the operation of the robot main body  101 , specifically the operation of the arm  101   a  and the manipulator  101   b,  by controlling the robot driver  101   c.  The robot control unit  105   e  performs control according to a program corresponding to a preset command or a command acquired via the communication device  107 . 
     The travel control unit  105   f  controls the operation of the traveling device  102  by controlling the travel driver  102   a.  The travel control unit  105   f  moves the robot  100  to a preset work point or a work point acquired via the communication device  107 , by using the position information of the robot  100 . 
     &lt;Configuration of Power Supply Device  200 &gt; 
       FIG. 6  is a block diagram showing an example of the configuration of the power supply device  200  according to the embodiment. As shown in  FIG. 1 ,  FIG. 3 , and  FIG. 6 , the power supply device  200  includes the terminal  201 , the traveling device  202 , the power supply controller  203 , a power control circuit  204 , a communication device  205 , and a position detector  206  as components. Not all of these components are essential. 
     The traveling device  202  includes a driver  202   a,  and the driver  202   a  includes an electric motor which drives the traveling means of the traveling device  202 , an electric motor which changes the traveling direction of the traveling means, etc. The driver  202   a  causes the traveling device  202  to travel in a desired direction under the control of the power supply controller  203 . 
     The components such as the terminal  201 , the power supply controller  203 , the power control circuit  204 , the communication device  205 , the position detector  206 , and the driver  202   a  are electrically connected to each other. The connection relationship between each component is not limited to the relationship in  FIG. 6 . The connection between each component may be any wired or wireless connection. 
     The terminal  201  is fixed to the power supply device  200 . In the present embodiment, the terminal  201  is fixed to a side surface of a front portion in the forward direction of the power supply device  200 , although not limited thereto. Therefore, as shown in  FIG. 7 , the power supply device  200  can physically and electrically connect the terminal  201  at the front portion thereof to the terminal  104  at the rear portion of the robot  100  by moving forward toward the rear portion of the robot  100 .  FIG. 7  is a plan view showing an example of a connection state between the robot  100  and the power supply device  200  in  FIG. 1 .  FIG. 7  shows that the robot  100  and the power supply device  200  are connected to each other only via the terminals  104  and  201 , but the connection between the robot  100  and the power supply device  200  is not limited thereto. For example, the robot  100  and the power supply device  200  may be configured to engage or fit other parts with each other, or may include guides for guiding the connection. 
     The power control circuit  204  supplies the power supplied from the power supply source  300 , to each component of the power supply device  200  under the control of the power supply controller  203 . In addition, the power control circuit  204  supplies the power supplied from the power supply source  300 , to the terminal  104  of the robot  100  connected to the terminal  201 , under the control of the power supply controller  203 . The power control circuit  204  may include an AC-DC conversion circuit and/or a DC-AC conversion circuit or the like and perform power conversion. 
     The communication device  205  includes a wireless communication circuit and wirelessly communicates with the communication device  107  of the robot  100 , etc. The wireless communication used by the communication device  205  is the same as that by the communication device  107 . The communication device  205  may communicate with an individual robot  100 , or may communicate with robots  100 . The communication device  205  receives, from the robot  100 , the information about the amount of power stored in the power storage device  103  thereof, the position information of the robot  100 , etc. 
     Moreover, the communication device  205  may wirelessly communicate with a device other than the robot  100 . For example, the communication device  205  may communicate with the communication device  205  of another power supply device  200 . For example, when one robot  100  transmits, to power supply devices  200 , a command for requesting or instructing power supply, each power supply device  200  may transmit the position information of the power supply device  200  or the distance between the power supply device  200  and the robot  100  to the other power supply devices  200 . Then, each power supply device  200  may determine to supply power to the robot  100  when the distance from the power supply device  200  to the robot  100  is the shortest as compared to those of the other power supply devices  200 . Accordingly, efficient power supply to the robot  100  is enabled. 
     Alternatively, when one power supply device  200  receives a command for requesting or instructing power supply from robots  100 , the power supply device  200  may determine the robot  100  whose distance from the power supply device  200  is the shortest, as a power supply target. Then, the power supply device  200  may transmit the identification information of the robot  100  that is the power supply target, to the other power supply devices  200 . Accordingly, redundancy of power supply devices  200  that supply power to one robot  100  is suppressed. 
     The position detector  206  is a device which detects the position of the power supply device  200 , and outputs information on the detected position of the power supply device  200  to the power supply controller  203 . The position detector  206  includes a positioning device, such as a GPS receiver and an IMU. In the present embodiment, the power supply controller  203  detects the position and the orientation of the power supply device  200  by using the information acquired from the position detector  206 , but the position detector  206  may detect the position and the orientation of the power supply device  200 . The position detector  206  may acquire the position of the power supply device  200  from an external device outside the power supply device  200 , which manages or measures the positions of the power supply device  200  and the like. 
     The configuration of the power supply controller  203  will be described.  FIG. 8  is a block diagram showing an example of the functional configuration of the power supply controller  203  of the power supply device  200  according to the embodiment. As shown in  FIG. 8 , the power supply controller  203  includes a power supply control unit  203   a,  a stored power information acquisition unit  203   b,  an other-device position acquisition unit  203   c,  a self-device position acquisition unit  203   d,  a power supply target determination unit  203   e,  a route determination unit  203   f,  a travel control unit  203   g,  and a storage unit  203   h  as functional components. Not all of these functional components are essential. 
     The functions of the components such as the power supply control unit  203   a,  the stored power information acquisition unit  203   b,  the other-device position acquisition unit  203   c,  the self-device position acquisition unit  203   d,  the power supply target determination unit  203   e,  the route determination unit  203   f,  and the travel control unit  203   g  may be realized by a computer system which includes a processor, such as a CPU, a volatile memory, such as a RAM, a non-volatile memory, such as a ROM, etc. Some or all of the functions of the above components may be realized by the above computer system, may be realized by a dedicated hardware circuit, such as an electronic circuit or an integrated circuit, or may be realized by a combination of the above computer system and the above hardware circuit. 
     The storage unit  203   h  can store therein various kinds of information and allows the stored information to be read. The storage unit  203   h  is realized by a storage device, such as a semiconductor memory such as a volatile memory and a non-volatile memory, a hard disk, and an SSD. The storage unit  203   h  stores therein identification information of the power supply device  200 , position information of the power supply device  200 , map information, etc. The storage unit  203   h  may store therein a program to be executed by each component of the power supply controller  203 . 
     The position information of the power supply device  200  includes information on the position and the orientation of the power supply device  200  and the like. The position information may include not only the present position information of the power supply device  200  but also the past position information of the power supply device  200  together with the detection times thereof. 
     The map information includes information on a map of the place where the power supply device  200  is arranged. For example, the map may be a map of an area where one power supply device  200  can supply power, or may be a map including the entire area where power supply devices  200  including this power supply device  200  can supply power. 
     The power supply control unit  203   a  detects the electrical connection between the terminal  201  and the terminal  104  via the power control circuit  204  and controls the power control circuit  204  to supply the power of the power supply source  300  to the robot  100 . The power supply control unit  203   a  may acquire the level of the amount of power stored in the power storage device  103  of the robot  100 , by acquiring the voltage value, the current value, etc., of the power storage device  103  via the terminal  201  and the power control circuit  204 , or may acquire the level of the amount of power stored in the power storage device  103 , from the stored power information acquisition unit  203   b.  The power supply control unit  203   a  controls power supply on the basis of the level of the amount of power stored in the power storage device  103 . 
     The stored power information acquisition unit  203   b  acquires the information about the amount of power stored in the power storage device  103  from the robot  100  or the like via the communication device  205 . 
     The other-device position acquisition unit  203   c  acquires the identification information and the position information of the robot  100  from the robot  100  or the like via the communication device  205 . The other-device position acquisition unit  203   c  may store the identification information and the position information of the robot  100  in the storage unit  203   h  in association with each other. 
     The other-device position acquisition unit  203   c  may acquire identification information and position information of another power supply device  200  from said another power supply device  200  or the like via the communication device  205 . Furthermore, the other-device position acquisition unit  203   c  may store the identification information and the position information of the other power supply device  200  in the storage unit  203   h  in association with each other. 
     The self-device position acquisition unit  203   d  detects the position and the orientation of the power supply device  200  by using the information acquired from the position detector  206 , and stores the position and the orientation of the power supply device  200  in the storage unit  203   h.    
     The power supply target determination unit  203   e  acquires the information about the amount of power stored in the power storage device  103  of the robot  100 , from the stored power information acquisition unit  203   b  or the like, and determines whether to perform power supply to the robot  100 . For example, the power supply target determination unit  203   e  may determine execution of power supply to the robot  100  whose level of the amount of power stored in the power storage device  103  is equal to or lower than a threshold. Alternatively, when the acquired information includes a command for requesting or instructing power supply, the power supply target determination unit  203   e  may determine power supply to the robot  100  that has transmitted this command. 
     Moreover, when the power supply target determination unit  203   e  acquires information about the amounts of power stored in robots  100  that may become a power supply target, the power supply target determination unit  203   e  may determine a robot  100  as a power supply target on the basis of the distance between each robot  100  and the power supply device  200 , the level of the amount of power stored in each robot  100 , and/or the distance between each robot  100  and another power supply device  200 , or the like. The information about the amount of power stored in a power supply target is information about an amount of power stored including the need to supply power to the power storage device  103  of the robot  100 , and may include information that the level of the amount of power stored in the power storage device  103  is equal to or lower than the threshold, and/or a command for requesting or instructing power supply to the power storage device  103 , or the like. 
     For example, the power supply target determination unit  203   e  extracts the robots  100  located in the area where the power supply device  200  can supply power, from the position of each robot  100 , and determines a robot  100  as a power supply target from among the extracted robots  100 . For example, the area where the power supply device  200  can supply power may be an area that is defined by the length of the power line  301  and in which the power supply device  200  is movable. The area where power can be supplied is stored in advance in the storage unit  203   h  in association with the map information. The power supply target determination unit  203   e  may determine a robot  100  as a power supply target from among all the robots  100  from which the information about the amount of power stored in a power supply target has been received, without extracting the robots  100  located in the area where the power supply device  200  can supply power. 
     In a first determination method, the power supply target determination unit  203   e  may calculate the distance between each robot  100  and the power supply device  200  from the position of each robot  100  and the position of the power supply device  200 , and determine the robot  100  having the shortest distance as a power supply target. 
     In a second determination method, the power supply target determination unit  203   e  may determine the robot  100  having the lowest level of the amount of power stored therein among the respective robots  100 , as a power supply target. 
     In a third determination method, the power supply target determination unit  203   e  may calculate the distance between each robot  100  and each power supply device  200  from the position of each robot  100  and the position of each of all the power supply devices  200 . Furthermore, the power supply target determination unit  203   e  may determine the robot  100  having the shortest distance from the power supply device  200  including this power supply target determination unit  203   e  as compared to the other power supply devices  200 , as a power supply target. 
     Alternatively, the power supply target determination unit  203   e  may determine a robot  100  as a power supply target from among the robots  100  determined by at least two determination methods out of the first to third determination methods. That is, the power supply target determination unit  203   e  may combine and use at least two of the first to third determination methods. For example, when the power supply target determination unit  203   e  determines two or more robots  100  as power supply targets by using one of the first to third determination methods, the power supply target determination unit  203   e  may narrow down the robots  100  as power supply targets by using another determination method. 
     The route determination unit  203   f  determines a route for moving the power supply device  200  to the robot  100  determined by the power supply target determination unit  203   e.  Specifically, the route determination unit  203   f  acquires the position and the orientation of the robot  100  determined by the power supply target determination unit  203   e,  the position and the orientation of the power supply device  200 , and the map information stored in the storage unit  203   h.  The route determination unit  203   f  identifies the relationship in position and orientation between the terminal  104  of the robot  100  and the terminal  201  of the power supply device  200  by using the acquired information. The route determination unit  203   f  determines a travel route of the power supply device  200  for connecting the terminal  201  to the terminal  104  on the basis of the above relationship and the map information. The travel route includes the position of the route and may further include the traveling direction of the power supply device  200  on the route. The route determination unit  203   f  outputs information on the determined travel route to the travel control unit  203   g.    
     The travel control unit  203   g  controls the operation of the traveling device  202  by controlling the driver  202   a.  The travel control unit  203   g  causes the power supply device  200  to travel to a target robot  100  according to the travel route acquired from the route determination unit  203   f,  to connect the terminal  201  to the terminal  104 . In addition, the travel control unit  203   g  may move the power supply device  200  to a predetermined location, such as a standby location, after charging of the power storage device  103  of the robot  100  is completed. The travel route to the predetermined location may be a travel route opposite to the above travel route, or may be determined by the route determination unit  203   f  on the basis of the position and the orientation of the power supply device  200  and the position of the predetermined location. Alternatively, when the travel control unit  203   g  acquires, from the route determination unit  203   f,  a travel route to the robot  100  to which power is to be supplied next, the travel control unit  203   g  may cause the power supply device  200  to travel according to this travel route. 
     &lt;First Operation of Power Supply System  1 &gt; 
     A first operation of the power supply system  1  according to the embodiment will be described. The first operation is an example of the operation of the power supply system  1  in case that one robot  100  and one power supply device  200  exist in the work place of the robot  100 .  FIG. 9  is a flowchart showing an example of the first operation of the power supply system  1  according to the embodiment. 
     As shown in  FIG. 1  and  FIG. 9 , the robot controller  105  of the robot  100  acquires the level of the amount of power stored, such as the SOC, of the power storage device  103  (step S 101 ). 
     Next, the robot controller  105  determines whether the level of the amount of power stored is equal to or lower than a threshold (step S 102 ). If the level of the amount of power stored is equal to or lower than the threshold (Yes in step S 102 ), the robot controller  105  proceeds to step S 103 , and if the level of the amount of power stored is higher than the threshold (No in step S 102 ), the robot controller  105  returns to step S 101 . In step S 103 , the robot controller  105  transmits information about the amount of power stored including a request for power supply to the robot  100 , and the position information of the robot  100  to the power supply device  200 . 
     Next, the power supply controller  203  of the power supply device  200  receives the above information (step S 104 ). Furthermore, the power supply controller  203  acquires the position information of the power supply device  200  and the map information of the work place A which is a place where the power supply device  200  and the robot  100  are arranged, from the storage unit  203   h  (step S 105 ). The power supply controller  203  may acquire the position information of the power supply device  200  from the position detector  206 . 
     Next, the power supply controller  203  determines a travel route from the power supply device  200  to the robot  100  by using the position information of the robot  100 , the position information of the power supply device  200 , and the map information (step S 106 ). The travel route is a travel route until the power supply device  200  travels to the robot  100  and connects the terminal  201  of the power supply device  200  to the terminal  104  of the robot  100 . 
     Next, the power supply controller  203  controls the driver  202   a  to cause the power supply device  200  to travel according to the determined travel route and connect the terminal  201  to the terminal  104  of the robot  100  (step S 107 ). 
     Next, the power supply controller  203  determines whether the connection of the terminal  201  to the terminal  104  of the robot  100  has been completed to obtain an energized state therebetween (step S 108 ). If the connection has been completed (Yes in step S 108 ), the power supply controller  203  proceeds to step S 109 . If the connection has not been completed (No in step S 108 ), the power supply controller  203  returns to step S 107 . 
     In step S 109 , the power supply controller  203  executes power supply to the robot  100 . In step S 110 , the power supply controller  203  determines whether the charging of the power storage device  103  of the robot  100  has been completed. A state where the charging of the power storage device  103  has been completed may be a fully charged state, or may be a state where the level of the amount of power stored is equal to or higher than a threshold. The threshold may be higher than the threshold in step S 102 . In addition, while receiving power from the power supply device  200 , the robot  100  can continue operations, such as work, by using the power of the power storage device  103  or the power supplied from the power supply device  200 . 
     If the charging has been completed (Yes in step S 110 ), the power supply controller  203  proceeds to step S 111 . If the charging has not been completed (No in step S 110 ), the power supply controller  203  returns to step S 109 . In step S 111 , the power supply controller  203  performs control such that the power supply device  200  is moved to disconnect the terminal  201  and the terminal  104  and is caused to travel to the original location. The original location is the location before the start of travel for power supply to the robot  100 , and may be, for example, a determined standby location. 
     By executing the processes in steps S 101  to S 111 , the power supply system  1  can charge the power storage device  103  of the robot  100  when needed, while causing the robot  100  to continue working. In addition, since the robot  100  is connected to the power supply device  200  only while being charged, the influence of the power line  301  of the power supply device  200  on the work and movement of the robot  100  is suppressed. Moreover, since the power supply device  200  uses the power of the power supply source  300 , power can be stably supplied to the robot  100  without any restriction on the amount of power supplied. 
     &lt;Second Operation of Power Supply System  1 &gt; 
     A second operation of the power supply system  1  according to the embodiment will be described. The second operation is an example of the operation of the power supply system  1  in case that robots  100  and one power supply device  200  exist in the work place of the robot  100 . In the following, the second operation will be described for an example shown in  FIG. 10 .  FIG. 10  is a plan view showing an example of arrangement of robots  100  (hereinafter, also referred to as “robots  100 A to  100 D”) and one power supply device  200 .  FIG. 11  is a flowchart showing an example of the second operation of the power supply system  1  according to the embodiment. 
     As shown in  FIG. 10  and  FIG. 11 , the robot controller  105  of each of the robots  100 A to  100 D executes processes in steps S 201  to S 203  in the same manner as steps S 101  to S 103  of the first operation. In this example, in step S 203 , each of all of the robots  100 A to  100 D transmits information on the amount of power stored including a request for power supply to the robot, and the position information of the robot to the power supply device  200 . 
     Next, in step S 204 , the power supply controller  203  of the power supply device  200  receives the above information from each of the robots  100 A to  100 D. The power supply controller  203  may perform processes subsequent to step S 204 , on the information received within a predetermined period. The predetermined period may be any period, but may be, for example, a time taken for the power supply device  200  to cross or go around the area where the power supply device  200  can supply power. 
     Next, the power supply controller  203  acquires the position information of the power supply device  200  from the storage unit  203   h  or the position detector  206  (step S 205 ). Furthermore, the power supply controller  203  acquires distances LA to LD between the respective robots  100 A to  100 D and the power supply device  200  by using the position information of the respective robots  100 A to  100 D and the position information of the power supply device  200  (step S 206 ). In this example, the distances LA to LD are linear distances, but may each be a distance along a route which is indicated by the map information and on which the power supply device  200  can travel. Next, the power supply controller  203  extracts the robot  100 D having the shortest distance LD from among the distances LA to LD (step S 207 ) and determines the robot  100 D as a power supply target. 
     Next, the power supply controller  203  acquires the map information of the work place A where the power supply device  200  and the robots  100 A to  100 D are arranged, from the storage unit  203   h  (step S 208 ). Moreover, the power supply controller  203  determines a travel route from the power supply device  200  to the robot  100 D by using the position information of the robot  100 D, the position information of the power supply device  200 , and the map information (step S 209 ). 
     Furthermore, the power supply controller  203  executes processes in steps S 210  to S 214  in the same manner as steps S 107  to S 111  of the first operation. 
     By executing the processes in steps S 201  to S 214 , the power supply system  1  extracts the robot  100 D located closest to the power supply device  200  from among the robots  100 A to  100 D which request power supply, and charges the power storage device  103  of the robot  100 D. Therefore, the time taken for movement of the power supply device  200  is reduced, and efficient charging is enabled. 
     &lt;Third Operation of Power Supply System  1 &gt; 
     A third operation of the power supply system  1  according to the embodiment will be described. The third operation is another example of the operation of the power supply system  1  in case that robots  100  and one power supply device  200  exist in the work place of the robot  100 . In the following, the third operation will be described for the example shown in  FIG. 10 .  FIG. 12  is a flowchart showing an example of the third operation of the power supply system  1  according to the embodiment. 
     As shown in  FIG. 10  and  FIG. 12 , the robot controller  105  of each of the robots  100 A to  100 D executes processes in steps S 301  to S 303  in the same manner as steps S 201  to S 203  of the second operation. 
     Next, in step S 304 , the power supply controller  203  of the power supply device  200  receives, from each of the robots  100 A to  100 D, the information about the amount of power stored including a request for power supply to the robot, and the position information of the robot. Moreover, the power supply controller  203  extracts the robot having the lowest level of the amount of power stored in the power storage device  103  among the robots  100 A to  100 D (step S 305 ). In this example, the power supply controller  203  extracts the robot  100 C whose SOC is a minimum value Csoc, and determines the robot  100 C as a power supply target. The SOCs of the power storage devices  103  of the respective robots  100 A to  100 D are denoted by Asoc, Bsoc, Csoc, and Dsoc, and satisfy Asoc&gt;Bsoc&gt;Dsoc&gt;Csoc. 
     Next, the power supply controller  203  acquires the position information of the power supply device  200  and the map information of the work place A from the storage unit  203   h  and/or the position detector  206  (step S 306 ). Moreover, the power supply controller  203  determines a travel route from the power supply device  200  to the robot  100 C by using the position information of the robot  100 C, the position information of the power supply device  200 , and the map information (step S 307 ). 
     Furthermore, the power supply controller  203  executes processes in steps S 308  to S 312  in the same manner as steps S 107  to S 111  of the first operation. 
     By executing the processes in steps S 301  to S 312 , the power supply system  1  extracts the robot  100 C whose level of the amount of power stored in the power storage device  103  is the lowest, from among the robots  100 A to  100 D which request power supply, and charges the power storage device  103  of the robot  100 C. Therefore, a situation in which the amount of power stored in the power storage device  103  becomes insufficient to make it impossible for the robots  100 A to  100 D to operate is prevented. 
     &lt;Fourth Operation of Power Supply System  1 &gt; 
     A fourth operation of the power supply system  1  according to the embodiment will be described. The fourth operation is an example of the operation of the power supply system  1  in case that robots  100  and power supply devices  200  exist in the work place of the robot  100 . In the following, the fourth operation will be described for an example shown in  FIG. 13 .  FIG. 13  is a plan view showing an example of arrangement of robots  100 A to  100 C and power supply devices  200  (hereinafter, also referred to as “power supply devices  200 A to  200 C”).  FIG. 14  is a flowchart showing an example of the fourth operation of the power supply system  1  according to the embodiment. 
     As shown in  FIG. 13  and  FIG. 14 , the robot controller  105  of each of the robots  100 A to  100 C executes processes in steps S 401  to S 403  in the same manner as steps S 201  to S 203  of the second operation. In step S 403 , each of the robots  100 A to  100 C transmits information on the amount of power stored including a request for power supply to the robot, and the position information of the robot to all the power supply devices  200 A to  200 C existing in the work place A, all at once. The following processes subsequent to step S 404  are processes of one power supply device, and will be described with the power supply device  200 A as an example. 
     Next, in step S 404 , the power supply controller  203  of the power supply device  200 A receives the above information from each of the robots  100 A to  100 C. Moreover, the power supply controller  203  acquires the position information of the power supply device  200 A from the storage unit  203   h  or the position detector  206  (step S 405 ). Furthermore, the power supply controller  203  requests and acquires the position information of the other power supply devices  200 B and  200 C from the power supply devices  200 B and  200 C (step S 406 ). 
     Next, the power supply controller  203  extracts one robot from among the robots  100 A to  100 C from which the information has been received in step S 404  (step S 407 ). For example, the robot  100 A is extracted. Next, the power supply controller  203  acquires a distance LAA between the robot  100 A and the power supply device  200 A by using the position information of the robot  100 A and the position information of the power supply device  200 A (step S 408 ). Moreover, the power supply controller  203  acquires distances LAB and LAC between the robot  100 A and the other power supply devices  200 B and  200 C by using the position information of the robot  100 A and the position information of the power supply devices  200 B and  200 C (step S 409 ). 
     Next, the power supply controller  203  determines whether the distance LAA between the robot  100 A and the power supply device  200 A is the shortest among the distances LAA to LAC between the robot  100 A and all the power supply devices  200 A to  200 C (step S 410 ). If the distance LAA is the shortest (Yes in step S 410 ), the power supply controller  203  proceeds to step S 411 . If the distance LAA is not the shortest (No in step S 410 ), the power supply controller  203  returns to step S 407 . In step S 407 , the power supply controller  203  extracts one robot from the robots  100 B and  100 C which have not been extracted, and repeats the processes in steps S 407  to S 410 . 
     In step S 411 , the power supply controller  203  determines the robot  100 A extracted in step S 407 , as a power supply target. In this example, the distance LAA is the shortest among the distances LAA to LAC. As a result of repeating the processes in steps S 407  to S 410 , if no robot having the shortest distance from the power supply device  200 A is extracted, the power supply controller  203  may determine not to execute power supply to all the robots  100 A to  100 C from which the information has been received in step S 404 . 
     Next, the power supply controller  203  acquires the map information of the work place A where the power supply devices  200 A to  200 C and the robots  100 A to  100 C are arranged, from the storage unit  203   h  (step S 412 ). Next, the power supply controller  203  determines a travel route from the power supply device  200 A to the robot  100 A by using the position information of the robot  100 A, the position information of the power supply device  200 A, and the map information (step S 413 ). 
     Furthermore, the power supply controller  203  executes processes in steps S 414  to S 418  in the same manner as steps S 107  to S 111  of the first operation. 
     By executing the processes in steps S 401  to S 418 , in the power supply system  1 , the power supply device  200 A charges the robot  100 A having the shortest distance between the power supply device and the robot as compared to the other power supply devices  200 B and  200 C. Therefore, among all the power supply devices  200 A to  200 C, the power supply device located closest to the robot that requests power supply charges this robot, so that the moving distance of the power supply device is reduced and efficient charging is enabled. 
     &lt;Effects, etc.&gt; 
     The power supply system  1  according to the embodiment includes the robot  100  including the power storage device  103 , the movable power supply device  200 , and the power supply controller  203  as a controller. The power supply device  200  includes the terminal  201 , as the first electrical connector, which is electrically connectable to the terminal  104  as the second electrical connector of the robot  100  and which is electrically connected to the power supply source  300  via a wire. The power supply controller  203  performs control for electrically connecting the terminal  201  and the terminal  104  and supplying power to the robot  100 , on the basis of the information about the amount of power stored in the power storage device  103 . 
     According to the above configuration, the power supply controller  203  can cause the power supply device  200  to supply power to the robot  100  via the terminal  201  in accordance with the information about the amount of power stored in the robot  100 . Since the terminal  201  is electrically connected to the power supply source  300  via a wire, the power supply device  200  can stably supply sufficient power to the robot  100  without causing a shortage of power to be supplied. For example, the power supply device  200  can continuously supply power to robots  100 . In addition, the robot  100  does not need to be connected to the power supply device  200  except when power is supplied thereto, and does not require a wired connection. Therefore, the restriction on the movement of the robot  100  is suppressed. 
     In the power supply system  1  according to the embodiment, the power supply device  200  may include the traveling device  202  which causes the power supply device  200  to travel, and may travel to the robot  100  by using the traveling device  202  in response to the control of the power supply controller  203 . According to the above configuration, the power supply device  200  can autonomously travel to the robot  100  and supply power thereto. Therefore, automatic power supply to the robot  100  is enabled. 
     In the power supply system  1  according to the embodiment, the power supply device  200  may electrically connect the terminal  201  to the terminal  104  of the robot  100  in response to the control of the power supply controller  203 . According to the above configuration, the power supply device  200  can autonomously connect the terminal  201  to the terminal  104  of the robot  100  and supply power thereto. Therefore, automatic power supply to the robot  100  is enabled. 
     In the power supply system  1  according to the embodiment, the power supply controller  203  may receive the information about the amount of power stored, from the robot  100  via wireless communication. According to the above configuration, no wired connection is needed for communication between the power supply controller  203  and the robot  100 . 
     The power supply system  1  according to the embodiment may include at least one robot  100  and at least one power supply device  200 . Moreover, the power supply controller  203  may determine at least either one of a robot  100  that is a power supply target or a power supply device  200  that is to perform power supply, on the basis of the information about the amount of power stored in at least one robot  100 , the information on the position of at least one robot  100 , and the information on the position of at least one power supply device  200 . According to the above configuration, the power supply controller  203  determines a robot  100  that is a power supply target and a power supply device  200  that is to perform power supply, in consideration of the positional relationship between each robot  100  and each power supply device  200 . Therefore, efficient and reliable power supply of the power supply device  200  is enabled. 
     The power supply system  1  according to the embodiment may include robots  100 . Moreover, the power supply controller  203  may determine the robot  100  closest to the power supply device  200  among the robots  100  that need power supply, as a robot  100  that is a power supply target, on the basis of the information about the amounts of power stored in the robots  100 , the information on the positions of the robots  100 , and the information on the position of the power supply device  200 . According to the above configuration, the moving distance of the power supply device  200  to the robot  100  that is the power supply target can be reduced. Therefore, efficient power supply of the power supply device  200  is enabled. 
     The power supply system  1  according to the embodiment may include power supply devices  200 . Moreover, the power supply controller  203  may determine the power supply device  200  closest to the robot  100  that needs power supply, as a power supply device  200  that is to supply power to the robot  100 , on the basis of the information about the amount of power stored in the robot  100 , the information on the position of the robot  100 , and the information on the positions of the power supply devices  200 . According to the above configuration, the power supply device  200  located closest to the robot  100  supplies power to the robot  100 . Therefore, efficient power supply of the power supply device  200  is enabled. 
     The power supply system  1  according to the embodiment may include robots  100 . Moreover, the power supply controller  203  may determine the robot  100  having the lowest level of the amount of power stored therein among the robots  100  that need power supply, as a robot  100  that is a power supply target, on the basis of the information about the amounts of power stored in the robots  100 . According to the above configuration, the power supply device  200  can supply power to the robot  100  that needs power supply most. Therefore, it is possible to prevent a situation in which the power of the power storage device  103  becomes insufficient, making it impossible for the robot  100  to operate. 
     In the power supply system  1  according to the embodiment, the power supply device  200  may include the power supply controller  203 . According to the above configuration, the power supply device  200  can determine a robot  100  as a power supply target by itself and execute power supply to this robot  100 . Therefore, execution of automatic power supply by the power supply device  200  alone is enabled. 
     The power supply device  200  according to the embodiment is a movable power supply device, and includes the terminal  201  which is electrically connectable to the terminal  104  of the robot  100  including the power storage device  103  and which is electrically connected to the power supply source  300  via a wire, and the power supply controller  203  which performs control for supplying power to the robot  100  via the terminal  201  on the basis of the information about the amount of power stored in the power storage device  103 . According to the above configuration, the same effects as those of the power supply system  1  according to the embodiment are obtained. 
     &lt;Modification 1&gt; 
     A power supply system according to Modification 1 of the embodiment will be described. In a power supply system  11  according to Modification 1, the configuration of terminals  1041  and  2011  of a robot  1001  and a power supply device  2001  are different from those of the embodiment. Hereinafter, the present modification will be described focusing on the differences from the embodiment, and the same points as the embodiment are omitted. 
       FIG. 15  is a plan view showing an example of the configuration of the power supply system  11  according to Modification 1.  FIG. 16  is a side view showing an example of a connection state between the robot  1001  and the power supply device  2001  according to Modification 1. As shown in  FIG. 15  and  FIG. 16 , the power supply device  2001  includes the terminal  2011  which is movable relative to the power supply device  2001 . For example, the terminal  2011  is connected to a power line  2011   a  extending from the power supply device  2001 , and is electrically connected to a power line  301  of a power supply source  300  via the power line  2011   a.  The terminal  2011  is movable within an area defined by the length of the power line  2011   a.  The robot  1001  includes the terminal  1041  within the reach of an arm  101   a  thereof. 
     Therefore, when the power supply device  2001  travels to the vicinity of the robot  1001  by itself, the robot controller  105  of the robot  1001  causes the arm  101   a  and a manipulator  101   b  to grasp and move the terminal  2011  of the power supply device  2001  to connect the terminal  2011  to the terminal  1041  of the robot  1001 . The robot controller  105  may acquire the position of the terminal  2011  on the basis of the position information of the power supply device  2001 . Accordingly, even when the power supply device  2001  is at various positions with respect to the robot  1001 , it is possible to supply power from the power supply device  2001  to the robot  1001 . 
     With the power supply system  11  according to Modification 1 as described above, the same effects as those of the embodiment are obtained. Moreover, in the power supply system  11 , the robot  1001  may include the arm  101   a  which holds and moves the terminal  2011 , and may electrically connect the terminal  2011  and the terminal  1041  by using the arm  101   a.  According to the above configuration, if the power supply device  2001  is located within the reach of the arm  101   a,  it is possible to connect the terminal  2011  and the terminal  1041 . Therefore, the restrictions on the position and the orientation of the power supply device  2001  at the time of power supply are reduced, so that precise position control of the power supply device  2001  becomes unnecessary. 
     &lt;Modification 2&gt; 
     A power supply system according to Modification 2 of the embodiment will be described. In a power supply system  12  according to Modification 2, the configuration of a terminal  1042  of a robot  1002  is different from that of the embodiment. Hereinafter, the present modification will be described focusing on the differences from the embodiment and Modification 1, and the same points as the embodiment and Modification 1 are omitted. 
       FIG. 17  is a plan view showing an example of the configuration of the power supply system  12  according to Modification 2.  FIG. 18  is a side view showing an example of a connection state between the robot  1002  and a power supply device  200  according to Modification 2. As shown in  FIG. 17  and  FIG. 18 , the robot  1002  includes a terminal  1042  which is movable relative to the robot  1002 . The robot  1002  includes the terminal  1042  within the reach of an arm  101   a  thereof. For example, the terminal  1042  is connected to a power line  1042   a  extending from the robot  1002 , and is electrically connected to a power storage device  103  or the like via the power line  1042   a.  The terminal  1042  is movable within an area defined by the length of the power line  1042   a.    
     Therefore, when the power supply device  200  travels to the vicinity of the robot  1002  by itself, the robot controller  105  of the robot  1002  causes the arm  101   a  and a manipulator  101   b  to grasp and move the terminal  1042  to connect the terminal  1042  to the terminal  201  of the power supply device  200 . The robot controller  105  may acquire the position of the terminal  201  on the basis of the position information of the power supply device  200 . Accordingly, even when the power supply device  200  is at various positions with respect to the robot  1002 , it is possible to supply power from the power supply device  200  to the robot  1002 . With the power supply system  12  according to Modification 2 as described above, the same effects as those of Modification 1 are obtained. In the present modification, similar to Modification 1, the terminal  201  of the power supply device  200  may be movable relative to the power supply device  200 . 
     &lt;Modification 3&gt; 
     A power supply system according to Modification 3 of the embodiment will be described. A power supply system  13  according to Modification 3 is different from that of the embodiment in including a management apparatus  500  which manages a robot  100  and a power supply device  2003 . Hereinafter, the present modification will be described focusing on the differences from the embodiment and Modifications 1 and 2, and the same points as the embodiment and Modifications 1 and 2 are omitted. 
       FIG. 19  is a plan view showing an example of the configuration of the power supply system  13  according to Modification 3.  FIG. 20  is a block diagram showing an example of the configuration of the power supply device  2003  according to Modification 3.  FIG. 21  is a block diagram showing an example of the functional configuration of a power supply controller  2033  of the power supply device  2003  according to Modification 3. As shown in  FIG. 19 , the power supply system  13  according to the present modification includes the robot  100 , the power supply device  2003 , and the management apparatus  500  which wirelessly communicate with each other. The management apparatus  500  manages one or more robots  100  and one or more power supply devices  2003 . An example of the management apparatus  500  is a computer device. 
     As shown in  FIG. 20 , the power supply device  2003  includes the power supply controller  2033  instead of the power supply controller  203  according to the embodiment. As shown in  FIG. 21 , the power supply controller  2033  includes a power supply control unit  203   a,  a self-device position acquisition unit  203   d,  a power supply target determination unit  2033   e,  a route determination unit  2033   f,  a travel control unit  203   g,  and a storage unit  203   h.  The functions of the power supply control unit  203   a,  the self-device position acquisition unit  203   d,  the travel control unit  203   g,  and the storage unit  203   h  are the same as those of the embodiment. 
     The communication device  205  of the power supply device  2003  wirelessly communicates with the management apparatus  500 , but may also wirelessly communicate with the robot  100  and another power supply device  2003 . In addition, the self-device position acquisition unit  203   d  of the power supply controller  2033  transmits the position information of the power supply device  2003  to the management apparatus  500  via the communication device  205 . However, as described below, the management apparatus  500  may detect the position of the power supply device  2003 . 
     The power supply target determination unit  2033   e  receives information on the robot  100  determined as a power supply target by the management apparatus  500 , from the management apparatus  500  via the communication device  205 , and determines this robot  100  as a power supply target. 
     The route determination unit  2033   f  receives a travel route, from the power supply device  2003  to the robot  100  that is the power supply target, determined by the management apparatus  500 , from the management apparatus  500  via the communication device  205 , and determines this travel route as a travel route of the power supply device  2003 . 
       FIG. 22  is a block diagram showing an example of the configuration of the management apparatus  500  and the functional configuration of a management controller  502  according to Modification 3. As shown in  FIG. 22 , the management apparatus  500  includes a communication device  501  and the management controller  502 . The communication device  501  includes a wireless communication circuit and communicates with the robot  100  and the power supply device  2003 . For example, the communication device  501  receives information about the amount of power stored in the power storage device  103 , and position information of the robot  100  from the robot  100 , and receives position information of the power supply device  2003  from the power supply device  2003 . In addition, the communication device  501  transmits a command for power supply to the robot  100  that is the power supply target and a travel route to the robot  100  that is the power supply target, to the power supply device  2003 . 
     The management controller  502  includes a stored power information acquisition unit  502   a,  a robot position acquisition unit  502   b,  a power supply device position acquisition unit  502   c,  a power supply target determination unit  502   d,  a route determination unit  502   e,  and a storage unit  502   f  as functional components. Not all of these functional components are essential. 
     The storage unit  502   f  is realized by a storage device, such as a semiconductor memory such as a volatile memory and a non-volatile memory, a hard disk, and an SSD. Similar to the storage unit  203   h,  the storage unit  502   f  stores therein identification information of the robot  100 , stored power information of the power storage device  103 , position information of the robot  100 , identification information of the power supply device  2003 , position information of the power supply device  2003 , map information, etc. 
     The functions of the components such as the stored power information acquisition unit  502   a,  the robot position acquisition unit  502   b,  the power supply device position acquisition unit  502   c,  the power supply target determination unit  502   d,  and the route determination unit  502   e  may be realized by a computer system which includes a processor, such as a CPU, a volatile memory, such as a RAM, a non-volatile memory, such as a ROM, etc. Some or all of the functions of the above components may be realized by the above computer system, may be realized by a dedicated hardware circuit, such as an electronic circuit or an integrated circuit, or may be realized by a combination of the above computer system and the above hardware circuit. 
     The stored power information acquisition unit  502   a  acquires the information about the amount of power stored in the power storage device  103 , from the robot  100  via the communication device  501 . 
     The robot position acquisition unit  502   b  acquires the identification information and the position information of the robot  100  from the robot  100  via the communication device  501 . The robot position acquisition unit  502   b  may store the identification information and the position information of the robot  100  in the storage unit  502   f  in association with each other. The robot position acquisition unit  502   b  may detect the position of the robot  100 . For example, the robot position acquisition unit  502   b  sends a signal to the robot  100 , and when the robot controller  105  of the robot  100  receives the signal, the robot controller  105  returns the signal to the management apparatus  500 . The robot position acquisition unit  502   b  can detect the position of the robot  100  with respect to the management apparatus  500  on the basis of the time for which the signal is sent back and forth between the management apparatus  500  and the robot  100 , the direction in which the signal is received, and the like. 
     The power supply device position acquisition unit  502   c  acquires the identification information and the position information of the power supply device  2003  from the power supply device  2003  via the communication device  205 . The power supply device position acquisition unit  502   c  may store the identification information and the position information of the power supply device  2003  in the storage unit  502   f  in association with each other. Similar to the robot position acquisition unit  502   b,  the power supply device position acquisition unit  502   c  may detect the position of the power supply device  2003 . 
     Similar to the power supply target determination unit  203   e  according to the embodiment, the power supply target determination unit  502   d  determines whether power supply to the robot  100  is needed, on the basis of the information about the amount of power stored in the power storage device  103  of the robot  100 . Moreover, the power supply target determination unit  502   d  determines a robot  100  that is a power supply target and a power supply device  2003  that is to supply power to the robot  100  that is the power supply target, on the basis of the information about the amount of power stored in the power storage device  103  of the robot  100  that needs power supply, the position information of the robot  100 , the position information of the power supply device  2003 , etc. The power supply target determination unit  502   d  transmits a command for power supply to the robot  100  determined as the power supply target, to the determined power supply device  2003 . 
     Similar to the route determination unit  203   f  according to the embodiment, the route determination unit  502   e  determines a travel route for moving the power supply device  2003  determined by the power supply target determination unit  502   d,  to the robot  100  determined as the power supply target by the power supply target determination unit  502   d.  The route determination unit  502   e  transmits information on the determined travel route to the power supply device  2003 . 
     As described above, the management apparatus  500  manages the level of the amount of power stored in the power storage device  103  of at least one robot  100 , and the position of the robot  100 , and manages the position of at least one power supply device  2003 . Moreover, the management apparatus  500  determines a robot  100  that is a power supply target and a power supply device  2003  that is to supply power to the robot  100  that is the power supply target, and causes the power supply device  2003  to execute power supply. Such a management apparatus  500  has some of the functions of the power supply controller  203  according to the embodiment. 
     With the power supply system  13  according to Modification 3 as described above, the same effects as those of the embodiment are obtained. Moreover, in the power supply system  13 , the management controller  502  as a controller may be arranged separately from the robot  100  and the power supply device  2003 . According to the above configuration, the throughput of the robot controller  105  of the robot  100  and the power supply controller  2033  of the power supply device  2003  can be reduced. Therefore, it is possible to reduce the cost of the robot  100  and the power supply device  2003 . 
     In the present modification, the management apparatus  500  causes the power supply device  2003  to execute power supply by transmitting a command and information to the power supply device  2003 , but is not limited thereto. The management apparatus  500  may remotely control some or all of the functions of the power supply device  2003  via the communication device  501 . The terminal device  400  may also serve as the management apparatus  500 . 
     &lt;Other Embodiments&gt; 
     Although the examples of the embodiment of the present disclosure have been described above, the present disclosure is not limited to the above embodiment and modifications. That is, various modifications and improvements may be made within the scope of the present disclosure. For example, modes in which various modifications are applied to the embodiment and the modifications and modes constructed by combining the components in different embodiments and modifications are also included within the scope of the present disclosure. 
     For example, in the embodiment and the modifications, the power supply device, the robot, and the management apparatus are configured to wirelessly communicate with each other, but are not limited thereto. For example, the power supply device, the robot, and the management apparatus may be configured to output light, sound, or a combination thereof and receive them. Light, sound, and a combination thereof can indicate information about the amount of power stored in the power storage device, the position information of each device, etc. 
     In the embodiment and the modifications, the power supply device is configured to travel to the robot by itself, but is not limited thereto. For example, the power supply device or the terminal thereof may be moved to the robot by a person and the terminal may be connected to the terminal of the robot. In this case, the power supply device may include a display device, and the display device may indicate the robot that is a power supply target. Alternatively, the robot may output light, sound, or a combination thereof, and a person may identify the robot that is a power supply target, by perceiving these. 
     In the modifications, the robot main body  101  is configured to connect the terminal by using the arm  101   a  and the manipulator  101   b,  but is not limited thereto. For example, the power supply device may include a device which can connect the terminal such as the robot main body  101 , and may connect the terminal by using this device. Alternatively, the above device of the power supply device and the robot main body  101  may cooperate to connect the terminal. 
     In the embodiment and the modifications, the power supply device and the robot are configured to connect the terminals thereof to each other, but are not limited thereto. For example, the power supply device and the robot may simply bring the terminals thereof into contact with each other. Alternatively, the power supply device and the robot may be configured to be electrically connected to each other, for example, by contacting, engaging, or fitting conductive members thereof with each other. Still alternatively, the power supply device and the robot may include wireless power transfer devices, and may be configured such that the power supply device supplies power to the robot in a non-contact manner when the power supply device and the robot come close to each other. 
     In the embodiment and the modifications, the power supply device and the robot are configured to acquire their own positions by using the GPS and/or IMU, but are not limited thereto. For example, the power supply device and the robot may acquire the positions of the power supply device and the robot by detecting the magnetic field of a magnet embedded in a floor surface. Alternatively, the positions of the power supply device and the robot may be detected by analyzing images of the power supply device and the robot captured by a camera. Still alternatively, distance measuring sensors, such as a laser sensor, a laser lidar, and an ultrasonic sensor, may be provided, and the positions of the power supply device and the robot may be detected using the measured values thereof. 
     In the embodiment and the modifications, the robot main body  101  is configured as a vertical articulated robot, but is not limited thereto. For example, the robot main body  101  may be configured as a horizontal articulated robot, a polar coordinate robot, a cylindrical coordinate robot, a Cartesian coordinate robot, a vertical articulated robot, or another robot. The robot main body  101  includes one arm  101   a,  but may include two or more arms  101   a.    
     REFERENCE SIGNS LIST 
       1 ,  11 ,  12 ,  13  power supply system 
       100 ,  100 A to  100 D,  1001 ,  1002  robot 
       103  power storage device 
       104 ,  1041 ,  1042  terminal (second electrical connector) 
       200 ,  200 A to  200 C,  2001 ,  2003  power supply device 
       201 ,  2011  terminal (first electrical connector) 
       202  traveling device 
       203 ,  2033  power supply controller (controller) 
       300  power supply source 
       500  management apparatus 
       502  management controller (controller)