Patent Publication Number: US-2021188041-A1

Title: Control device, vehicle, and control method

Description:
INCORPORATION BY REFERENCE 
     The disclosure of Japanese Patent Application No. 2019-229276 filed on Dec. 19, 2019 including the specification, drawings and abstract is incorporated herein by reference in its entirety. 
     BACKGROUND 
     1. Technical Field 
     The present disclosure relates to a control device, a vehicle, and a control method. 
     2. Description of Related Art 
     An autonomous driving vehicle including a traveling unit having no vehicle cabin and a structure detachably attached to the upper portion of the traveling unit is disclosed (for example, WO 2018/230720). 
     SUMMARY 
     One aspect of the disclosure is to provide a technique to accelerate heat dissipation from heat generated by a drive device in a vehicle in which a vehicle cabin unit and a traveling unit equipped with drive wheels and the drive device that drives the drive wheels are separable and connectable. 
     A first aspect of the present disclosure relates to a control device. The control device includes a controller that executes determining a connection between a first unit that has a boarding space which allows a user to board and is provided with a predetermined facility and that is provided with a first path through which a fluid used in the predetermined facility passes and a second unit that is configured to be separated from and connected to the first unit and that has a drive device of a vehicle that is formed by being connected to the first unit, and supplying the fluid in the first path to a second unit side to absorb heat generated from the drive device. 
     A second aspect of the present disclosure relates to a vehicle. The vehicle includes a first unit that has a boarding space which allows a user to board and is provided with a predetermined facility and that is provided with a first path through which a fluid used in the predetermined facility passes, a second unit that is configured to be separated from and connected to the first unit and that has a drive device of a vehicle that is formed by being connected to the first unit, a connection member that connects the first unit and the second unit, and a first controller that executes supplying the fluid in the first path to a second unit side to absorb heat generated from the drive device in a case where the first unit and the second unit are connected by the connection member. 
     A third aspect of the present disclosure relates to a control method. The control method includes a determination step of determining a connection between a first unit that has a boarding space which allows a user to board and is provided with a predetermined facility and that is provided with a first path through which a fluid used in the predetermined facility passes and a second unit that is configured to be separated from and connected to the first unit and that has a drive device of a vehicle that is formed by being connected to the first unit, and a supply step of supplying the fluid in the first path to a second unit side to absorb heat generated from the drive device. 
     According to the present disclosure, it is possible to provide the technique to accelerate the heat dissipation from the heat generated by the drive device in the vehicle in which the vehicle cabin unit and the traveling unit equipped with the drive wheels and the drive device that drives the drive wheels are separable and connectable. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Features, advantages, and technical and industrial significance of exemplary embodiments of the disclosure will be described below with reference to the accompanying drawings, in which like signs denote like elements, and wherein: 
         FIG. 1  shows an example of an outline of a vehicle according to a first embodiment; 
         FIG. 2  shows an example of an outline of a functional configuration of a control device; 
         FIG. 3  shows an example of a flowchart of processing executed by the control device; 
         FIG. 4  shows an example of an outline of a vehicle structure according to a second embodiment; and 
         FIG. 5  shows an example of a flowchart of processing executed by a control device according to the second embodiment. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     A predetermined facility according to a first aspect of the present disclosure includes a water heater and an air conditioner. A fluid according to the first aspect of the present disclosure includes clean water used in the air conditioner, a heating medium that exchanges heat with air supplied from the air conditioner, and wastewater generated in a first unit. A drive device included in a second unit includes a motor that drives drive wheels of a vehicle formed by connecting the second unit and the first unit. The drive device includes a secondary battery that supplies electric power to the motor. 
     With the control device as described above, the fluid in the first unit is used without providing a heat dissipation device in the second unit, and thus it is possible to accelerate heat dissipation of the drive device provided in the second unit. That is, such a control device can accelerate the heat dissipation of the second unit while suppressing an unnecessarily increase in size of the second unit that is separable and connectable with the first unit that allows a user to board. 
     First Embodiment 
     Configuration of Vehicle  1   
       FIG. 1  shows an example of an outline of a vehicle  1  according to a first embodiment. The vehicle  1  is, for example, an electric vehicle, and includes a vehicle cabin unit  10  that has a space allowing the user to board and a traveling unit  20  that is capable of autonomous traveling. The vehicle cabin unit  10  and the traveling unit  20  can be separated and connected vertically. The vehicle cabin unit  10  and the traveling unit  20  may be respectively provided with, for example, a mechanism that is separable and connectable to achieve the separation and the connection. The vehicle cabin unit  10  and the traveling unit  20  may be separated and connected by using the magnetic force of an electromagnet, for example. The vehicle cabin unit  10  is an example of the “first unit” of the present disclosure. The traveling unit  20  is an example of the “second unit” of the present disclosure. In the following embodiments, various sensors provided in the vehicle  1  include communication modules capable of wireless communication and wirelessly transmit measurement data to a control device  21  (described below) provided in the traveling unit  20 . Each pump provided in the vehicle  1  includes a communication module capable of wireless communication, wirelessly receives an operation control signal from the control device  21 , and operates according to the received operation control signal. Each valve provided in the vehicle  1  includes a communication module capable of wireless communication, wirelessly receives an opening-degree control signal from the control device  21 , and is opened and closed according to the received opening-degree control signal. 
     Configuration of Vehicle Cabin Unit  10   
     The vehicle cabin unit  10  has the space that allows the user to board, and a kitchen unit  101  is provided in the space. The kitchen unit  101  is provided with a water heater  102  and a clean water tank  103  that stores clean water. The kitchen unit  101  is provided with a pipe  104  that connects the clean water tank  103  and the water heater  102 . A pump  118  for pumping the clean water from the clean water tank  103  to the water heater  102  is provided in the middle of the pipe  104 . The pipe  104  is branched in the middle, and a branched pipe  105  is provided such that a tip opening of the branched pipe is connectable with a pipe provided in the traveling unit  20 . A valve  106  is provided in the middle of the pipe  105 . An opening degree of the valve  106  is controlled to adjust a flow rate of the clean water flowing from the pipe  104  to the pipe  105 . A pipe  104  near an outlet of the clean water tank  103  is provided with a temperature sensor  120  capable of measuring the temperature of the clean water passing through the pipe  104 . The pipe  104  is an example of a “first path” in the present disclosure. 
     The kitchen unit  101  includes a sink in which hot water generated in the water heater  102  is used, and a wastewater tank  107  below the sink. The hot water that is used for a predetermined purpose in the sink flows into the wastewater tank  107  as the wastewater and is stored. 
     The vehicle cabin unit  10  includes an air conditioner  108 , a circulation pipe that circulates between the wastewater tank  107  and the air conditioner  108 , and a pump  119  that pumps the wastewater from the wastewater tank  107  to the air conditioner  108 . When the wastewater stored in the wastewater tank  107  (an example of the heating medium of the present disclosure) passes through the circulation pipe and is supplied to the air conditioner  108 , the wastewater exchanges heat with the air passing through the outer surface of the circulation pipe and thus the air is heated in the air conditioner  108 . The air further exchanges the heat with a predetermined heating medium, is further heated, and is supplied to the inside of the vehicle cabin unit  10  as warm air. 
     The circulation pipe from the air conditioner  108  to the wastewater tank  107  is branched before the wastewater tank  107 , and water is discharged from the branched pipe to the outside of the system. A valve  111  is provided in the middle of the branched pipe. The opening degree of the valve  111  is controlled to adjust the flow rate of the water discharged to the system out of the water flowing through the circulation pipe connecting the wastewater tank  107  and the air conditioner  108 . The valve  111  may be opened, for example, while the vehicle  1  is stopped. 
     The vehicle cabin unit  10  includes a pipe  117 . The pipe  117  connects the pipe provided in the traveling unit  20  and the clean water tank  103 . 
     Configuration of Traveling Unit  20   
     The traveling unit  20  includes the control device  21 . The control device  21  is provided with an electronic control unit (ECU) having a central processing unit (CPU) and a memory. The control device  21  includes a communication module capable of wireless communication with an external device, an external storage device, and a Global Positioning System (GPS) module. 
     The traveling unit  20  includes a drive motor  202 . The drive motor  202  rotates each wheel provided in the traveling unit  20 . Note that the drive motor  202  may drive any one pair of two pairs of front and rear wheels. The traveling unit  20  includes a steering motor. The steering motor outputs power for changing a direction along a rotation shaft of at least a pair of wheels to steer the vehicle  1 . The traveling unit  20  includes an encoder that can detect a rotation angle and a steering angle of the wheels. The traveling unit  20  includes an environment sensor that can detect the environment around the vehicle  1 . The environment sensor, for example, emits an ultrasonic wave, an electromagnetic wave, or the like in a detection target direction, and detects presence, position, relative speed, and the like of an obstacle in the detection target direction by using a difference between the emitted wave and the received reflected wave. Examples of the obstacles include a pedestrian, a bicycle, a structure, and a building. The environment sensor may include, for example, a microphone, and may detect presence of a surrounding person by analyzing a frequency spectrum of a signal output from the microphone, by voice recognition, or the like. 
     The control device  21  acquires information on a current point by the GPS module and generates a route to a target point. The drive motor  202  and the steering motor are controlled such that the vehicle  1  moves along the generated route. In a case where the drive motor  202  and the steering motor are controlled, the information on the wheel rotation angle and the steering angle detected by the encoder is used. The control device  21  acquires obstacle information by the environment sensor, and the initially generated route is modified to avoid the obstacle. Through such processing, the traveling unit  20  can autonomously travel from the current point to the target point. 
     The traveling unit  20  is provided with a jacket  203  that covers an outer surface of the drive motor  202 . The inside of the jacket  203  has a structure through which water can pass. The water passing through the inside of the jacket  203  absorbs heat generated from the drive motor  202  and cools the drive motor  202 . The traveling unit  20  is provided with a pipe  204  that is connected to an inlet of the jacket  203  and allows the water to flow into the jacket  203 . The pipe  204  is provided such that a tip opening of the pipe is connectable with the tip opening of the pipe  105  provided in the vehicle cabin unit  10 . The traveling unit  20  is provided with a pipe  206  that is connected to an outlet of the jacket  203  and through which the water passing through the jacket  203  passes. The pipe  206  is provided such that a tip opening of the pipe is connectable with a tip opening of the pipe  117  provided in the vehicle cabin unit  10 . The pipe  206  is provided with a pump  217  that pumps the water from the jacket  203  to the pipe  117  provided in the vehicle cabin unit  10 . The traveling unit  20  includes a temperature sensor  209  near the drive motor  202  that measures a temperature near the drive motor  202 . The traveling unit  20  includes a battery  208 . The battery  208  supplies the electric power to the drive motor  202 . 
     The traveling unit  20  includes a connection member  210 A that connects the tip opening of the pipe  204  and the tip opening of the pipe  105  on the vehicle cabin unit  10  side. The connection member  210 A is provided with a connection detection sensor  211 A capable of detecting a connection state between the tip opening of the pipe  204  and the tip opening of the pipe  105 . Similarly, the traveling unit  20  includes a connection member  210 B that connects the tip opening of the pipe  206  and the tip opening of the pipe  117  on the vehicle cabin unit  10  side. The connection member  210 B is provided with a connection detection sensor  211 B capable of detecting the connection state between the tip opening of the pipe  206  and the tip opening of the pipe  117 . The connection detection sensor  211 A and the connection detection sensor  211 B are exemplified to include a mechanical switch, an electric circuit for checking electrical conductivity, an optical waveguide for checking whether light arrives, and the like. 
     In the vehicle  1  as described above, when the valve  106  installed in the middle of the pipe  105  is closed, the supply of water from the clean water tank  103  to the traveling unit  20  side through the pipe  105  is suppressed. In such a case, the water is not supplied to the traveling unit  20  side. Therefore, it goes without saying that the water does not return to the vehicle cabin unit  10  side through the pipe  206  of the traveling unit  20 . That is, the water stored in the clean water tank  103  is used solely on the vehicle cabin unit  10  side. More specifically, the water stored in the clean water tank  103  is pumped to the water heater  102  by the pump  118  and then heated by the water heater  102  to become the hot water. The hot water is used in the sink for a predetermined purpose and then stored in the wastewater tank  107 . The warm water stored in the wastewater tank  107  is pumped to the air conditioner  108  by the pump  119  and used to generate the warm air. 
     Functional Configuration of Control Device  21   
       FIG. 2  shows an example of an outline of a functional configuration of the control device  21 . Each function described below is realized by the CPU of the ECU executing a computer program developed in the memory in an executable manner. The control device  21  includes a communication unit  221 . The communication unit  221  is formed including a communication module. The communication unit  221  wirelessly communicates, according to a predetermined communication standard, with control targets including various sensors (including the temperature sensor  120 , the temperature sensor  209 , the connection detection sensor  211 A, and the connection detection sensor  211 B), the valve  106 , and the pumps  118 ,  119 ,  217  which are disposed in the vehicle  1 . 
     The control device  21  includes a temperature determination unit  222 . The temperature determination unit  222  determines whether or not the temperature measured by the temperature sensor  209  installed near the drive motor  202  exceeds a determination reference. The determination reference is set to a value that does not affect the driving of the drive motor  202  due to the heat, for example, a value such that internal windings inside the drive motor  202  are not burned. The temperature determination unit  222  also determines whether or not the temperature measured by the temperature sensor  120  installed in the pipe  104  of the vehicle cabin unit  10  is lower than the above determination reference. 
     The control device  21  includes a connection determination unit  223 . The connection determination unit  223  determines whether or not the vehicle cabin unit  10  and the traveling unit  20  are connected. More specifically, in a case where both signals of a signal, generated by the connection detection sensor  211 A, indicating the connection state between the tip opening of the pipe  105  and the tip opening of the pipe  204  and a signal, generated by the connection detection sensor  211 B, indicating the connection state between the tip opening of the pipe  117  and the tip opening of the pipe  206  indicate that the tip openings are connected, the connection determination unit  223  determines that the vehicle cabin unit  10  and the traveling unit  20  are connected. 
     The control device  21  includes a controller  224 . The controller  224  generates the opening-degree control signal to control the opening degree of the valve  106  provided in the vehicle  1 . The controller  224  also generates the opening-degree control signal to control the opening degree of the valves other than the valve  106  provided in the vehicle  1 . The controller  224  generates an operation control signal to operate the pumps  118 ,  119 ,  217  provided in the vehicle  1 . The controller  224  is an example of the “controller” in the present disclosure. 
     Processing Flow of Control Device  21   
     Next, a processing flow executed by the control device  21  will be described.  FIG. 3  shows an example of a flowchart of processing executed by the control device  21 . It is assumed that the pump  118  operates and that the clean water is supplied from the clean water tank  103  to the water heater  102 . It is assumed that the pump  119  operates and the wastewater circulates between the wastewater tank  107  and the air conditioner  108 . It is assumed that the connection detection sensor  211 A and the connection detection sensor  211 B periodically transmit signals indicating the connection state to the communication unit  221 . 
     S 1001   
     In step S 1001 , the connection determination unit  223  determines whether or not the vehicle cabin unit  10  and the traveling unit  20  are connected, using the signal, transmitted by the connection detection sensor  211 A, indicating the connection state between the tip opening of the pipe  204  and the tip opening of the pipe  105  and the signal, transmitted by the connection detection sensor  211 B, indicating the connection state between the tip opening of the pipe  206  and the tip opening of the pipe  117  (an example of a “determination step” in the present disclosure). 
     S 1002   
     In step S 1002 , in a case where both signals of the signal indicating the connection state between the tip opening of the pipe  105  and the tip opening of the pipe  204  and the signal indicating the connection state between the tip opening of the pipe  117  and the tip opening of the pipe  206  indicate that the tip openings are connected and the vehicle cabin unit  10  and the traveling unit  20  are determined to be connected in step S 1001 , the communication unit  221  receives the temperature information near the drive motor  202  from the temperature sensor  209 . The communication unit  221  receives the temperature information of the clean water passing through the pipe  104  from the temperature sensor  120 . 
     S 1003   
     In step S 1003 , the temperature determination unit  222  determines whether or not the temperature near the drive motor  202  received in step S 1002  exceeds the determination reference. In a case where the temperature near the drive motor  202  is determined to exceed the determination reference, the temperature determination unit  222  further determines whether or not the temperature of the clean water passing through the pipe  104  measured by the temperature sensor  120  is lower than the determination reference. The determination reference to determine the temperature of the clean water passing through the pipe  104  may be the same as the determination reference to determine the temperature near the drive motor  202  or may be a numerical value lower than the determination reference. 
     S 1004   
     In step S 1004 , in a case where the temperature near the drive motor  202  is determined to be higher than the determination reference and further the temperature of the clean water passing through the pipe  104  is lower than the determination reference in step S 1003 , the controller  224  generates an opening-degree control signal to issue an instruction to open the valve  106 . The controller  224  generates the operation control signal to operate the pump  217 . The communication unit  221  transmits the opening-degree control signal for the valve  106  and the operation control signal of the pump  217  generated by the controller  224  to the respective devices (an example of a “supply step” in the present disclosure). 
     Description of Water Flow 
     Next, a water flow in the vehicle  1  will be described. It is assumed that the vehicle  1  is in traveling and the vehicle cabin unit  10  and the traveling unit  20  are determined to be connected in step S 1001 . In step S 1003 , it is assumed that the temperature determination unit  222  determines that the temperature near the drive motor  202  received in step S 1002  is higher than the determination reference and further the temperature of the clean water passing through the pipe  104  measured by the temperature sensor  120  is lower than the determination reference. 
     In the above case, the valve  106  is opened by the control device  21  executing the processing of step S 1004 . Therefore, at least a part of the clean water flowing from the clean water tank  103  toward the water heater  102  passes through the pipe  105  and flows into the pipe  204  provided in the traveling unit  20 . The clean water that passes through the pipe  204  flows into the jacket  203 . The water flowing into the jacket  203  absorbs the heat generated from the drive motor  202 . The warm water that absorbs the heat flows out to the pipe  206 . The pump  217  provided in the middle of the pipe  206  is operated by the operation control signal received from the control device  21 . Therefore, the warm water flowing out from the jacket  203  to the pipe  206  flows into the pipe  117  provided in the vehicle cabin unit  10 . The warm water that passes through the pipe  117  flows into the clean water tank  103 . 
     That is, the clean water supplied from the clean water tank  103  to the water heater  102  is mixed with the warm water that has absorbed the heat generated from the drive motor  202 . The mixed water is heated by the water heater  102  to generate the hot water. 
     The generated hot water is used in the sink for a predetermined purpose and stored in the wastewater tank  107 . The warm water stored in the wastewater tank  107  is pumped to the air conditioner  108  by the pump  119  and used to generate the warm air. That is, the warm water used to generate the warm air in the air conditioner  108  is also mixed with the warm water that has absorbed the heat generated from the drive motor  202 . The pump  118  and the valve  106  are examples of a “first controller” in the present disclosure. The pump  217  is an example of a “second controller” in the present disclosure. 
     Effect of First Embodiment 
     In a case of the electric vehicle, the heat generated from the drive motor  202  while the vehicle travels is a problem. A cooling function corresponding to the heat generation may be generated. However, in a vehicle in which the traveling unit  20  and the vehicle cabin unit  10  are separable and connectable, provision of a sufficient heat dissipation mechanism for the traveling unit  20  may be difficult due to a dimensional limitation of the traveling unit  20 . However, in the vehicle  1  as described above, a part of the water stored in the clean water tank  103  in the vehicle cabin unit  10  and flowing toward the water heater  102  is supplied to the jacket  203  that covers the drive motor  202  installed in the traveling unit  20 . Therefore, with the vehicle  1  as described above, the traveling unit  20  is provided with a simple heat dissipation structure (jacket  203 ) and the water stored in the vehicle cabin unit  10  is used, and thus it is possible to accelerate the heat dissipation of the drive motor  202 . The heat dissipation of the drive motor  202  is accelerated in this manner, but the traveling unit  20  is not provided with a device for heat dissipation. Therefore, the traveling unit  20  suppresses the increase in size. 
     With the vehicle  1  as described above, the warm water that passes through the jacket  203  and has absorbed the heat generated from the drive motor  202  flows into the clean water tank  103  and is mixed with the clean water originally stored in the clean water tank  103 . The mixed water is heated by the water heater  102 . That is, the heat generation of the drive motor  202  is used to save the energy for heating the water in the water heater  102 . 
     The warm water heated in the water heater  102  is used for a predetermined purpose in the sink installed in the kitchen unit  101 . The warm water is stored in the wastewater tank  107  and then circulates between the tank and the air conditioner  108 . That is, the heat generation of the drive motor  202  is used to save the energy for generating the warm air in the air conditioner  108 . 
     With the vehicle  1  as described above, heat storage is realized in the wastewater tank  107 . Therefore, even when the drive motor  202  does not generate the heat, the warm water stored in the wastewater tank  107  is sent to the air conditioner  108  to save the energy for generating the warm air in the air conditioner  108 . 
     Modification Example 
     In the above first embodiment, the opening degree of the valve  106  may be adjusted according to the values of the temperature of the drive motor  202  and the temperature of the clean water passing through the pipe  104 . With such a control device  21 , it is possible to adjust the flow rate of the clean water flowing into the jacket  203  of the traveling unit  20  from the vehicle cabin unit  10  side according to the values of the temperature of the drive motor  202  and the temperature of the clean water passing through the pipe  104 . The water flowing from the vehicle cabin unit  10  side to the traveling unit  20  side may be executed regardless of the value of the temperature measured by the temperature sensor  209  installed in the drive motor  202 . 
     The vehicle cabin unit  10  may have a structure in which at least a part of the warm air generated in the air conditioner  108  is supplied to the inside of the wastewater tank  107 . With such a vehicle cabin unit  10 , at least a part of the wastewater stored in the wastewater tank  107  is evaporated by the warm air. Therefore, an amount of the wastewater discharged from the valve  111  is reduced and the wastewater is easily handled. 
     The vehicle cabin unit  10  may have a structure in which the warm water that passes through the jacket  203  is not returned to the vehicle cabin unit  10  side. The vehicle cabin unit  10  may have a structure in which a refrigerant used in the air conditioner  108  provided in the vehicle cabin unit  10  flows into the jacket  203  of the traveling unit  20 . 
     Second Embodiment 
     Configuration of Vehicle Cabin Unit  10 A 
       FIG. 4  shows an example of an outline of a structure of a vehicle  1 A according to a second embodiment. A vehicle cabin unit  10 A of the vehicle  1 A according to the second embodiment includes a kitchen unit  101 A. The kitchen unit  101 A is provided with the clean water tank  103  as in the first embodiment. The clean water stored in the clean water tank  103  is used for a predetermined purpose and becomes the wastewater. The kitchen unit  101 A is provided with a wastewater tank  107 A that stores the wastewater. A pipe  115  for discharging the wastewater is connected to the wastewater tank  107 A. The pipe  115  is provided such that a tip opening of the pipe is connectable with a pipe provided in a traveling unit  20 A. A pump  112  is provided in the middle of the pipe  115 . The operation of the pump  112  is controlled to adjust the flow rate of the wastewater discharged from the wastewater tank  107 A. The pipe  115  is an example of the “first path” in the present disclosure. 
     Configuration of Traveling Unit  20 A 
     The traveling unit  20 A has the same component as the traveling unit  20  according to the first embodiment. In addition, the traveling unit  20 A includes a temperature sensor  209 A, near a battery  208 A, that measures the temperature near the battery  208 A. The traveling unit  20 A is provided with a cooling plate  215  so as to be in contact with a surface of the battery  208 A. A flow pipe that allows the water to pass through is laid so as to meander along a plate plane inside the cooling plate  215 . That is, the water flowing through the flow pipe can exchange heat with the surface of the battery  208 A through the cooling plate  215 . 
     The traveling unit  20 A includes a pipe  204 A that is connected to a flow pipe inlet of the cooling plate  215  and causes the water to flow into the flow pipe. The pipe  204 A is provided such that a tip opening of the pipe is connectable with the tip opening of the pipe  115  provided in the vehicle cabin unit  10 A. The traveling unit  20 A is provided with a wastewater tank  225  that stores the wastewater that passes through the flow pipe of the cooling plate  215  and a pump  227  that pumps the wastewater from the flow pipe of the cooling plate  215  to the wastewater tank  225 . 
     In the wastewater tank  225 , decomposition treatment using a microorganism is performed on a contaminant contained in the wastewater. A temperature sensor  226  capable of measuring the temperature of the stored wastewater is installed inside the wastewater tank  225 . The traveling unit  20  is provided with a pipe that connects the flow pipe of the cooling plate  215  and the wastewater tank  225 , and a branch pipe that branches from the pipe and joins the pipe  204 A. A valve  216  is provided in the branch pipe. The opening degree of the valve  216  is controlled to adjust the flow rate of the wastewater that joins the pipe  204 A and flows into the flow pipe inlet of the cooling plate  215  again out of the wastewater flowing from a flow pipe outlet of the cooling plate  215  toward the wastewater tank  225 . 
     The traveling unit  20 A includes a discharge pipe that is connected to the wastewater tank  225  and that allows the wastewater to discharge from the wastewater tank  225  to the outside of the system. A valve  207  is provided in the middle of the discharge pipe. The opening degree of the valve  207  is controlled to adjust the flow rate of the wastewater discharged from the wastewater tank  225  to the outside of the system is adjusted. 
     The traveling unit  20 A includes a connection member  210 C that connects the tip opening of the pipe  204 A and the tip opening of the pipe  115  on the vehicle cabin unit  10 A side. The connection member  210 C includes a connection detection sensor  211 C capable of detecting the connection state between the tip opening of the pipe  204 A and the tip opening of the pipe  115  on the vehicle cabin unit  10 A side. 
     Processing Flow of Control Device  21 A 
     Next, a processing flow executed by the control device  21 A will be described.  FIG. 5  shows an example of a flowchart of processing executed by the control device  21 A. It is assumed that the pumps  112 ,  227  are initially not operated and valve  216  is initially closed. Details of the processing executed in each step will be exemplified below. 
     S 1001 A 
     In step S 1001 A, a connection determination unit  223 A determines whether or not the vehicle cabin unit  10 A and the traveling unit  20 A are connected, using a signal, transmitted by the connection detection sensor  211 C, indicating the connection state between the tip opening of the pipe  115  and the tip opening of the pipe  204 A (an example of the “determination step” in the present disclosure). 
     S 1002 A 
     In step S 1002 A, in a case where the signal indicating the connection state between the tip opening of the pipe  115  and the tip opening of the pipe  204 A indicates that the tip openings are connected and the vehicle cabin unit  10 A and the traveling unit  20 A are determined to be connected in step S 1001 A, a communication unit  221 A receives the temperature information near the battery  208 A from the temperature sensor  209 A. 
     S 1003 A 
     In step S 1003 A, determination is made whether or not the temperature near the battery  208 A received in step S 1002 A is higher than a determination reference. The determination reference is a value that does not affect the battery  208 A due to the heat. For example, in a case where a threshold value of temperature at which a failure rate of the battery  208 A rapidly increases is known, the temperature is set as the determination reference. 
     S 1004 A 
     In step S 1004 A, in a case where the temperature near the battery  208 A is determined to be higher than the determination reference in step S 1003 A, a controller  224 A generates an operation control signal to issue an instruction to operate the pump  112 . The communication unit  221 A transmits the generated operation control signal to the pump  112 . The controller  224 A generates an operation control signal to issue an instruction to operate the pump  227 . The generated operation control signal is transmitted to the pump  227  by the communication unit  221 A. The pump  112  is an example of the “first controller” in the present disclosure. Step S 1004 A is an example of the “supply step” in the present disclosure. 
     S 1005 A 
     In step S 1005 A, the communication unit  221 A receives the temperature information of the wastewater stored in the wastewater tank  225  from the temperature sensor  226 . In a case where the temperature in the wastewater tank  225  received from the temperature sensor  226  is lower than the temperature near the battery  208 A received from the temperature sensor  209 A in step S 1002 A, the controller  224 A generates an opening-degree control signal to issue an instruction to open the valve  216 . The generated opening-degree control signal is transmitted to the valve  216  by the communication unit  221 A. The opening-degree control signal to open the valve  216  may be generated in a case where the temperature of the wastewater stored in the wastewater tank  225  received from the temperature sensor  226  is lower than the temperature near the battery  208 A by a predetermined value or more. The opening-degree control signal to open the valve  216  may be generated in a case where the temperature of the wastewater stored in the wastewater tank  225  is lower than the temperature near the battery  208 A and lower than a temperature at which a decomposition reaction using the microorganism rapidly proceeds. 
     Description of Wastewater Flow 
     Next, a flow of the wastewater will be described. It is assumed that the vehicle  1 A is stopped, the battery  208 A is supplied with the electric power from an external power supply device, and the battery  208 A is being charged. In step S 1003 A, it is assumed that a temperature determination unit  222 A determines that the temperature near the battery  208 A received in step S 1002 A is higher than the determination reference. 
     In such a case, the control device  21 A executes the processing of step S 1004 A to operate the pump  112 . Therefore, the wastewater stored in the wastewater tank  107 A passes through the pipe  115  and is pumped to the pipe  204 A provided in the traveling unit  20 A. The wastewater that passes through the pipe  204 A flows into the flow pipe of the cooling plate  215 . The wastewater flowing into the flow pipe of the cooling plate  215  absorbs the heat generated from the battery  208 A disposed so as to be in contact with the cooling plate  215  through the cooling plate  215 . The wastewater that has absorbed the heat is pumped to the wastewater tank  225  by the pump  227 . 
     In the wastewater tank  225 , the decomposition treatment using the microorganism is performed on the contaminant contained in the wastewater. The wastewater stored in the wastewater tank  225  absorbs the heat generated from the battery  208 A being charged. Therefore, the decomposition treatment may be accelerated. In a case where the temperature in the wastewater tank  225  is lower than the temperature near the battery  208 A, the valve  216  is opened and a part of the wastewater that has absorbed the heat generated from the battery  208 A flows into the flow pipe of the cooling plate  215  of the battery  208 A again. Therefore, the temperature of the wastewater flowing out from the flow pipe of the cooling plate  215  rises. Therefore, the temperature of the wastewater flowing into the wastewater tank  225  rises. Therefore, the decomposition treatment in the wastewater tank  225  may be accelerated. Since the wastewater stored in the wastewater tank  225  absorbs the heat generated from the battery  208 A being charged, a part thereof may be dried. Such wastewater stored in the wastewater tank  225  is discharged to the outside of the system in a case where the valve  207  is open. 
     As in the first embodiment, a pipe may be installed that allows the wastewater heated by absorbing the heat in the flow pipe of the cooling plate  215  to return to the wastewater tank  107 A on the vehicle cabin unit  10 A side. A valve may be provided in the middle of the pipe, and the opening degree of the valve may be controlled to adjust the flow rate of the wastewater returning to the vehicle cabin unit  10 A side. 
     Effect of Second Embodiment 
     In a case of the electric vehicle, the battery  208 A may generate heat when the battery  208 A mounted therein is rapidly charged. A cooling function corresponding to the heat generation may be provided. However, in the vehicle  1 A in which the traveling unit  20 A and the vehicle cabin unit  10 A are separable and connectable, provision of a sufficient heat dissipation mechanism for the traveling unit  20 A may be difficult due to a dimensional limitation of the traveling unit  20 A. However, in the vehicle  1 A as described above, the water stored in the wastewater tank  107 A in the vehicle cabin unit  10 A is supplied to the flow pipe of the cooling plate  215  provided so as to be in contact with the battery  208 A installed in the traveling unit  20 A. Therefore, with the vehicle  1 A as described above, the traveling unit  20 A is provided with a simple heat dissipation structure (cooling plate  215 ) and the water stored in the wastewater tank  107 A of the vehicle cabin unit  10 A is used, and thus it is possible to accelerate the heat dissipation of the battery  208 A during charging. The heat dissipation of the battery  208 A during charging is accelerated, but the traveling unit  20 A is not provided with a device for heat dissipation. Therefore, the traveling unit  20 A suppresses the increase in size. 
     In the vehicle  1 A as described above, the contaminant contained in the wastewater is decomposed by the microorganism. Therefore, the wastewater is easily handled in a case where the wastewater is discharged from the vehicle  1 A or the like. The wastewater stored in the wastewater tank  225  absorbs the heat generated from the battery  208 A, and the contaminant is decomposed in a state where the temperature of the water is higher than that in the case where the water is stored in the wastewater tank  107 A. Therefore, the decomposition reaction may be accelerated. As shown in step S 1005 A, in a case where the temperature in the wastewater tank  225  is lower than the temperature near the battery  208 A, the valve  216  is opened and the wastewater that has absorbed the heat generated from the battery  208 A flows into the flow pipe of the cooling plate  215  again to absorb the heat generated from the battery  208 A. Therefore, the temperature of the wastewater flowing into the wastewater tank  225  rises, and the decomposition reaction of the contaminant contained in the wastewater is accelerated. 
     Since the wastewater stored in the wastewater tank  225  absorbs the heat generated from the battery  208 A, at least a part of the wastewater may be dried. Therefore, an amount of the wastewater stored in the wastewater tank  107 A may be reduced and discharged. From this point of view, the vehicle  1 A may be a vehicle in which the wastewater is easily handled. 
     The heat generated by the driving of the drive motor  202  while the vehicle travels may be absorbed by the wastewater stored in the wastewater tank  107 A. With such a structure, it is possible to accelerate the heat dissipation of the drive motor  202 . 
     The above embodiments are merely examples, and the present disclosure may be modified and implemented as appropriate within a scope not departing from the gist thereof. 
     The configurations and processing described in the present disclosure can be freely combined and implemented as long as no technical contradiction occurs. 
     The processing described as being performed by one device may be shared and executed by a plurality of devices. Alternatively, the processing described as being performed by different devices may be executed by one device. In a computer system, it is possible to flexibly change the hardware configuration (server configuration) for realizing each function. 
     The present disclosure can also be realized by supplying a computer with a computer program that implements the functions described in the above embodiments, and one or more processors included in the computer read and execute the program. Such a computer program may be provided to the computer by a non-transitory computer readable storage medium connectable to a system bus of the computer, or may be provided to the computer through a network. Examples of the non-transitory computer-readable storage medium include any type of disc such as a magnetic disc (floppy (registered trademark) disc, hard disk drive (HDD), or the like) and an optical disc (CD-ROM, DVD disc, Blu-ray disc, or the like), a read solely memory (ROM), a random access memory (RAM), an EPROM, an EEPROM, a magnetic card, a flash memory, an optical card, and any type of medium suitable for storing an electronic command.