Patent Publication Number: US-2023135344-A1

Title: Urban air mobility power supply system and method according thereto

Description:
This application claims the benefit of Korean Patent Application No. 10-2021-0147866, filed on Nov. 1, 2021, which is hereby incorporated by reference as if fully set forth herein. 
     TECHNICAL FIELD 
     The present disclosure relates to a power supply system for urban air mobility (UAM) and a method according thereto which can supply power to a UAM device by being connected to the UAM device during takeoff and stably return the UAM device to the ground by separating a power cable from the UAM device after completion of takeoff. 
     BACKGROUND 
     Urban air mobility (UAM), a short-distance urban mobility system, is a flying means that vertically takes off from a city center, moves to a destination, and then vertically lands at the destination. 
     If a UAM device is powered by a battery without using a conventional fossil fuel, a large number of batteries needs to be loaded in the UAM device for taking off, landing, and operating for a long time, but battery capacity increase causes the weight of the UAM device to increase and thus more batteries need to be mounted for the heavy UAM device. 
     A UAM device, an electric airplane with vertical take-off and landing features that can accommodate multiple people, requires a method for increasing energy density while reducing a battery weight for efficient operation. 
     The UAM device consumes more energy during takeoff than during flight. When the UAM device includes a fuselage and a battery that supplies power to the UAM device, it has a considerable weight and requires tremendous energy to take off to an operational altitude (500 to 600 m). 
     Since the UAM device consumes a great amount of energy only to gain height in place, as described above, there is a problem that the overall flight distance is shortened. 
     In addition, the prior art (Korea Patent No. 10-2150856) proposes a method of supplying power to an aircraft from the ground by connecting an external cable to the aircraft. However, the technology of the prior art is not suitable for application to an aircraft that needs to be used for long-distance operation, such as a UAM device, because it relates to a device that continuously supplies power to an aircraft from the ground because the aircraft does not have its own energy source. 
     SUMMARY OF THE DISCLOSURE 
     An object of the present disclosure is to provide an external power supply system capable of supplying power by being connected to a UAM device during takeoff and stably returning the UAM device to the ground by removing a power cable from the UAM device after completion of takeoff, and a method according thereto. 
     The technical problems to be achieved in the present disclosure are not limited to the technical problems mentioned above, and other technical problems that are not mentioned will be clearly understood by those skilled in the art to which the present disclosure belongs from the description below. 
     To achieve these objects and other advantages and in accordance with the purpose of the disclosure, as embodied and broadly described herein, an urban air mobility (UAM) power supply system includes a UAM power supply mobility device physically connected to or disconnected from a UAM device, and a charging station including a power cable for supplying power to the UAM device. The UAM power supply mobility device is equipped with the power cable to supply the power from the charging station to the UAM device through the power cable while flying along with the UAM device until the UAM device separated from the charging station reaches an overhead position in a preset space from the charging station. 
     In another aspect of the present disclosure, a method for supplying power to an urban air mobility (UAM) device while the UAM device is separated from a charging station and takes off includes electrically connecting a UAM power supply mobility device to the UAM device, causing the UAM power supply mobility device to fly along with the UAM device flying away from the charging station, and supplying the power to the UAM device using a power cable mounted on the UAM power supply mobility device while the UAM power supply mobility device ascends along with the UAM device until the UAM device reaches an overhead position in a preset space. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the disclosure and together with the description serve to explain the principle of the disclosure. In the drawings: 
         FIG.  1    is a diagram illustrating a UAM power supply system according to an embodiment of the present disclosure; 
         FIG.  2    and  FIG.  3    are diagrams illustrating the operation of the UAM power supply system according to an embodiment of the present disclosure; 
         FIG.  4    is a diagram illustrating a configuration of a UAM power supply mobility device according to an embodiment of the present disclosure; 
         FIG.  5    is a plan view of the UAM power supply mobility device according to an embodiment of the present disclosure; 
         FIG.  6    is a cross-sectional view of the UAM power supply mobility device of  FIG.  5   ; 
         FIG.  7    is a plan view of a first UAM device according to an embodiment of the present disclosure; 
         FIG.  8    and  FIG.  9    are diagrams illustrating an operation in which the UAM power supply mobility device and the first UAM device UAM 1  are physically connected to each other according to an embodiment of the present disclosure; 
         FIG.  10    is a diagram illustrating an operation of the UAM power supply mobility device according to an embodiment of the present disclosure; and 
         FIG.  11    is a flowchart illustrating an operation of a power supply system for a UAM device according to an embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF THE DISCLOSURE 
     Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art can easily implement the same. However, the present disclosure may be implemented in various different forms and is not limited to the embodiments described herein. In order to clearly describe the present disclosure in the drawings, parts irrelevant to the description are omitted and similar reference numerals are attached to similar parts throughout the specification. 
     Throughout the specification, when a part “includes” a certain component, it means that other components may be further included, rather than excluding other components, unless otherwise stated. In addition, parts indicated by the same reference numerals throughout the specification mean the same components. 
     In addition, a unit or a control unit included in terms such as a mobility control unit (MCU) is only a term widely used in the naming of a controller that controls a specific function of an air mobility device and does not imply a generic functional unit. For example, each controller may include a communication device that communicates with other controllers or sensors to control the function of the controller, a memory that stores an operating system or logic commands, input/output information, and the like, and one or more processors that perform determination, operation, and decision necessary for controlling the function. 
       FIG.  1    is a diagram illustrating a UAM power supply system according to an embodiment of the present disclosure and  FIG.  2    and  FIG.  3    are diagrams illustrating an operation of the UAM power supply system according to an embodiment of the present disclosure. 
     Referring to  FIG.  1    to  FIG.  3   , the UAM power supply system according to an embodiment of the present disclosure may include a first urban air mobility (UAM) device  200 , a UAM power supply mobility device  300 , and a charging station  100 . 
     The first UAM device  200  may be an aircraft that can fly freely in the sky and can take off and land vertically even in a narrow space. The UAM device  200  is an urban air mobility device and can be defined as an aircraft in which an individual or a large number of passengers can freely fly in the sky in the city center. The UAM device  200  may be a concept including various manned/unmanned aerial vehicles that require vertical takeoff and landing, such as drones. The UAM device  200  may refer to a vertical takeoff and landing multicopter. 
     The first UAM device  200  may include one or more rotors because boarding/deboarding in the city center should be fast and comfortable. When one of the rotors provided in the first UAM device  200  malfunctions, flight balance can be controlled through the remaining rotors. That is, distributed electric propulsion (DEP) for independently driving multiple rotors may be applied to the first UAM device  200  for noise reduction and accident prevention. 
     DEP allows multiple rotors to be driven independently with power or electrical energy generated by a single battery. Even if an individual rotor has a problem, other rotors are continuously driven because DEP is applied to the first UAM device  200  and thus the UAM device  200  can safely fly. In addition, the first UAM device  200  uses smaller rotors than a helicopter and operates only necessary rotors depending on flight conditions such as takeoff, landing, and flying, and thus noise generation can be minimized. 
     In addition, distributed electric propulsion (DEP) applied to the first UAM device  200  may also be applied to the UAM power supply mobility device  300 . 
     The above-described first UAM device  200  may be provided with a connection terminal  270  (refer to  FIG.  7   ) on the bottom surface thereof. The first UAM device  200  may receive power or electrical energy through the connection terminal  270  (refer to  FIG.  7   ), store the power or electrical energy in a battery  230  (refer to  FIG.  8   ), individually provide the power or electrical energy stored in the battery  230  (refer to  FIG.  8   ) to each rotor, and provide the same to various components mounted in the first UAM device  200 . 
     The UAM power supply mobility device  300  includes at least one rotor  320  (refer to  FIG.  4   ) and can fly in the sky using the rotor. The UAM power supply mobility device  300  may supply power to the first UAM device  200  that is grounded or is flying using a supply terminal  370  (refer to  FIG.  5   ) electrically and physically connected to the power cable  110 . For example, the UAM power supply mobility device  300  may be disposed between the charging station  100  and the first UAM device  200  mounted or anchored in the charging station  100  and supply power to the first UAM device  200 . The UAM power supply mobility device  300  may be referred to as an auxiliary power drone (APD). 
     Referring to  FIG.  2   , the UAM power supply mobility device  300  may be mounted on the first UAM device  200  flying in a preset space and supply power to the first UAM device  200  while flying with the first UAM device  200 . That is, the UAM power supply mobility device  300  may be mounted on the first UAM device  200  and ascend to supply power to the first UAM device  200  until the first UAM device  200  removed from the charging station  100  reaches a position in a preset space a in the air. 
     Referring to  FIG.  3   , the UAM power supply mobility device  300  may be separated from the first UAM device  200  and descend to be mounted on the charging station  100  when the first UAM device  200  flies into a space b outside the preset space a. 
     The UAM power supply mobility device  300  may include the supply terminal  370  (refer to  FIG.  5   ) electrically connected to or separated from the connection terminal  270  (refer to  FIG.  7   ) of the first UAM device  200 . The supply terminal  370  (refer to  FIG.  5   ) may be electrically connected to the power cable  110 . The UAM power supply mobility device  300  may include a fixing part (not shown) that can firmly fix the power cable  110  in order to prevent the power cable  110  from being arbitrarily detached or separated from the UAM power supply mobility device  300 . 
     The charging station  100  is disposed on the ground and may include the power cable  110  having a predetermined length. The power cable  110  may be used to supply power to the first UAM device  200  through the supply terminal  370  (refer to  FIG.  5   ) of the UAM power supply mobility device  300  electrically connected thereto under the control of the charging station  100 . 
     Although not shown, the charging station  100  may include a communication module and a charging processor. The communication module may transmit information to a communication module of the UAM power supply mobility device  300  under the control of the charging processor. For example, the charging station  100  may unwind or wind a power cable  110  on the basis of position information of the UAM power supply mobility device  300  received from the UAM power supply mobility device  300 . 
     As shown in  FIG.  2   , the charging station  100  may control the power cable  110  such that the power cable  110  continues to be unwound on the basis of position information and flight information of the UAM power supply mobility device  300  received from the UAM power supply mobility device  300  until the first UAM device  200  is removed from the charging station  100  and reaches a position in the preset space a in the air. Accordingly, the UAM power supply mobility device  300  may stably supply power to the first UAM device  200 . 
     In addition, the charging station  100  may receive position information and flight information of the UAM power supply mobility device  300  in real time from the UAM power supply mobility device  300  that has been separated from the first UAM device  200  flying in the space b out of the preset space a and control the power cable  110  such that it is gradually wound on the basis of the position information and the flight information, as shown in  FIG.  3   . Accordingly, the UAM power supply mobility device  300  can prevent the power cable  110  from deviating from the preset space a during descending under the control of the charging station  100 . 
       FIG.  4    is a block diagram illustrating the configuration of the UAM power supply mobility device according to an embodiment of the present disclosure. 
     Referring to  FIG.  4   , the UAM power supply mobility device  300  according to an embodiment of the present disclosure may include a processor  310 , a body  390 , a propulsion unit  320 , a camera  340 , a communication module  350 , and a sensing unit  360 . The present disclosure is not limited thereto, and components may be omitted or added as necessary. 
     The body  390  has a predetermined internal space and may be formed to a predetermined thickness. For example, the body  401  may be formed so as to have an upper surface, a lower surface, and four sides (or lateral surfaces). The present disclosure is not limited thereto and the body  401  may have any shape as long as it can firmly fasten or mount a plurality of propulsion units  320 , which will be described later. 
     The body  390  may have the supply terminal  370  (refer to  FIG.  5   ) disposed at a part of the upper surface. Further, the body  390  may have guide pins  380   a  to  380   d  (refer to  FIG.  5   ) and the camera  340  (refer to  FIG.  5   ) disposed to be spaced apart from the supply terminal  370  (refer to  FIG.  5   ) on the upper surface. Details will be described later with reference to  FIG.  5   . 
     The propulsion unit  320  is disposed on the circumferential surface of the body  390  and may operate to cause the UAM power supply mobility device  300  to fly. The propulsion unit  320  may be referred to as a rotor. The propulsion unit  320  may operate by receiving electric energy. 
     A plurality of propulsion units  320  may be provided. For example, the propulsion unit  320  includes a first rotor  320   a  (refer to  FIG.  5   ), a second rotor  320   b  (refer to  FIG.  5   ), a third rotor  320   c  (refer to  FIG.  5   ), and a fourth rotor  320   d  (refer to  FIG.  5   ). The first rotor  320   a  (refer to  FIG.  5   ) to the fourth rotor  320   d  (refer to  FIG.  5   ) may fly the UAM power supply mobility device  300  in the ascending or descending direction or in the forward, backward, left, and right directions under the control of the processor  310 . Details will be described later with reference to  FIG.  5    and  FIG.  6   . 
     The processor  310  may be disposed in the internal space of the body  390  to be electrically connected to a plurality of components mounted on the UAM power supply mobility device  300 . That is, the processor  310  may control a plurality of hardware or software components electrically connected to the processor  310  by executing an operating system or an application program and perform processing/operations of various types of data including data related to the propulsion unit  320 . The processor  310  may be referred to as a mobility controller (MCU) or a controller. 
     The processor  310  may be configured as a single integrated circuit (IC). For example, the processor  410  may include a system on chip (SoC), a graphics processing unit (GPU), or the like. 
     The processor  310  controls the communication module  350  to execute functions of managing data links and converting communication protocols in communication between the UAM power supply mobility device  300  and the first UAM device  200 , a second UAM device UAM 2  (refer to  FIG.  11   ), the charging station  100 , or another UAM power supply mobility device  300  connected through a network. The processor  310  may control data transmission/reception of the communication module  350 . 
     The processor  310  may load a command or data received from at least one of a non-volatile memory or other components connected thereto into a volatile memory and process the same. In addition, the processor  310  may store data received from or generated by at least one of the other components in the nonvolatile memory. 
     The processor  310  having the above-described functions may control the propulsion unit  320  such that the UAM power supply mobility device  300  is mounted on the first UAM device  200  or the charging station  100  or separated therefrom. The processor  310  may operate by receiving power from the power cable  110  and control a plurality of components. 
     The camera  340  may be disposed on the upper surface of the body  390  and may capture an image of a marker  240  (refer to  FIG.  7   ) while mounted on the first UAM device  200  under the control of the processor  310 . The camera  340  may capture an image of the UAM power supply mobility device  300  and the first UAM device  200  or a second UAM device UAM 2  (refer to  FIG.  11   ) while the UAM power supply mobility device  300  is mounted on or docked with the first UAM device  200  or the second UAM device UAM 2  and provide the captured image to the processor  310 . The processor  310  may calculate a distance between the UAM power supply mobility device  300  and the first UAM device  200  on the basis of the captured image. 
     The communication module  350  may transmit flight information and position information of the UAM power supply mobility device  300  to the first UAM device  200  or the charging station  100  under the control of the processor  310 . The communication module  350  may receive flight information and position information of the first UAM device  200  from the first UAM device  200  or receive position information of the charging station  100  from the charging station  100 . The communication module  350  may include a wireless communication module  350  or an RF module. 
     The wireless communication module  350  may include Wi-Fi, BT, GPS or NFC. For example, the wireless communication module  350  may provide a wireless communication function using a radio frequency. Additionally or alternatively, the wireless communication module  350  may include a network interface, a modem, or the like for connecting the UAM power supply mobility device  300  to a network (e.g., the Internet, a LAN, a WAN, a telecommunication network, a cellular network, a satellite network, POTS, 5G network, or the like). 
     The RF module may serve to transmit/receive data, for example, transmit/receive RF signals or called electronic signals. For example, the RF module may include a transceiver, a power amplifier module (PAM), a frequency filter, a low noise amplifier (LNA), or the like. 
     The sensing unit  360  may be disposed on the body  390  to sense a position state of the UAM power supply mobility device  300 . The sensing unit  360  may include at least one sensor. For example, the sensing unit  360  may include at least one of a gyro sensor, an air pressure sensor, a magnetic sensor, an acceleration sensor, a proximity sensor, a temperature/humidity sensor, and an illuminance sensor. The sensing unit  360  may sense a position or operating state of the UAM power supply mobility device  300  under the control of the processor  310  and convert measured or sensed information into an electrical signal. The sensing unit  360  may be referred to as a sensor module or a sensing module. 
     Although not shown in  FIG.  4   , the UAM power supply mobility device  300  may include a memory. The memory may include a built-in memory or an external memory. The built-in memory may include at least one of a volatile memory (e.g., dynamic RAM (DRAM), static RAM (SRAM), synchronous dynamic RAM (SDRAM), etc.) and a non-volatile memory (e.g., one-time programmable ROM (OTPROM), programmable ROM (PROM), erasable and programmable ROM (EPROM), electrically erasable and programmable ROM (EEPROM), mask ROM, flash ROM, NAND flash memory, NOR flash memory, etc.). 
     According to an embodiment, the built-in memory may take the form of a solid state drive (SSD). The external memory may include a flash drive, for example, compact flash (CF), secure digital (SD), micro secure digital (micro-SD), mini secure digital (mini-SD), extreme digital (xD), a memory stick, etc. 
       FIG.  5    is a plan view of the UAM power supply mobility device according to an embodiment of the present disclosure and  FIG.  6    is a cross-sectional view of the UAM power supply mobility device of  FIG.  5   . 
     Referring to  FIG.  5    and  FIG.  6   , the UAM power supply mobility device  300  may include the propulsion unit  320 , the supply terminal  370 , guide pins  380   a  to  380   d , the camera  340 , and a terminal protector  375 . 
     A plurality of propulsion units  320  may be disposed on the circumferential surface or the sides of the body  390 . Although  FIG.  5    illustrates that the propulsion units  320  are disposed at corners between neighboring sides, the present disclosure is not limited thereto. The propulsion unit  320  may be referred to as a propulsion device or a rotor. 
     The propulsion unit  320  may include the first rotor  320   a , the second rotor  320   b , the third rotor  320   c , and the fourth rotor  320   d.    
     The first rotor  320   a  may be disposed on the left front side of the upper surface of the body  390 . The second rotor  320   b  may be disposed on the right front side of the upper surface of the body  390 . The third rotor  320   c  may be disposed on the right rear side of the upper surface of the body  390 . The fourth rotor  320   d  may be disposed on the left rear side of the upper surface of the body  390 . 
     The first rotor  320   a  to the fourth rotor  320   d  may operate individually or together under the control of the processor  310  to allow the UAM power supply mobility device  300  to fly in the ascending or descending direction or in the forward, backward, left, and right directions. For example, the first to fourth rotors  320   a  to  320   d  can push the air downward to create lift or propulsion and use the lift or propulsion to allow the UAM power supply mobility device  300  to fly. 
     The supply terminal  370  may be disposed at the center of the upper surface of the body  390  and may be electrically connected to or separated from the connection terminal  270  (refer to  FIG.  7   ) which will be described later. The supply terminal  370  may be electrically connected to the power cable  110  connected to the charging station  100 . 
     The supply terminal  370  may be formed in a bar shape having a predetermined thickness and length. The supply terminal  370  may be formed of a metal material to supply power or electrical energy to the connection terminal  270  (refer to  FIG.  7   ). 
     The terminal protector  375  may be embedded in the body  390  and may be disposed on the upper surface of the body  390  such that a part thereof surrounds the supply terminal  370 . The terminal protector  375  may serve to protect the supply terminal  370  from the outside. The terminal protector  375  may be formed to cover the supply terminal  370  disposed on the upper surface of the body  390 . That is, the terminal protector  375  may be formed to be flexible. 
     The terminal protector  375  may perform an opening operation to expose the supply terminal  370  to the outside or a closing operation to protect the supply terminal  370  from the outside under the control of the processor  310 . The terminal protector  375  may be referred to as a supply terminal door. A detailed description thereof will be provided later. 
     The guide pins  380   a  to  380   d  may be disposed on the upper surface of the body  390  and may protrude in a direction in which the UAM power supply mobility device  300  is mounted on the first UAM device  200  such that the guide pins  380   a  to  380   d  are inserted into guide pin insertion portions  280   a  to  280   d  (refer to  FIG.  7   ) which will be described later. The guide pins  380   a  to  380   d  may be formed to protrude upward. 
     The guide pins  380   a  to  380   d  may be disposed on the upper surface of the body  390  such that they are not superposed on the supply terminal  370  or the terminal protector  375 . 
     The guide pins  380   a  to  380   d  may include the first guide pin  380   a  to the fourth guide pin  380   d.    
     The first guide pin  380   a  may be disposed on the left front side of the upper surface of the body  390 . The second guide pin  380   b  may be disposed on the right front side of the upper surface of the body  390 . The third guide pin  380   c  may be disposed on the right rear side of the upper surface of the body  390 . The fourth guide pin  380   d  may be disposed on the left rear side of the upper surface of the body  390 . 
     As described above, in the present disclosure, the first guide pin  380   a  to the fourth guide pin  380   d  are disposed on the upper surface of the body  390 , and thus the UAM power supply mobility device  300  can be aligned with the first UAM device  200  or the second UAM device UAM 2  (refer to  FIG.  11   ) at a more correct position. 
     Although  FIG.  5    illustrates four guide pins  380   a  to  380   d , the number of guide pins  380   a  to  380   d  is not limited thereto. 
     The camera  340  may be disposed on the upper surface of the body  390  between the first guide pin  380   a  and the second guide pin  380   b . The processor  310  may induce the UAM power supply mobility device  300  to be aligned with the first UAM device  200  or the second UAM device UAM 2  (refer to  FIG.  11   ) at a correct position by receiving a captured image from the camera  340 . 
       FIG.  7    is a plan view of the first UAM device according to an embodiment of the present disclosure. 
     Referring to  FIG.  7   , the first UAM device  200  according to an embodiment of the present disclosure may include the connection terminal  270 , the guide pin insertion portions  280   a  to  280   d , and the marker  240  on the lower surface thereof facing the upper surface of the UAM power supply mobility device  300 . 
     The connection terminal  270  may be disposed at the center of the lower surface at a position corresponding to the supply terminal  370  and electrically connected to or separated from the supply terminal  370  of the UAM power supply mobility device  300 . The connection terminal  270  may be connected to the supply terminal  370  in such a manner that the supply terminal  370  is inserted thereinto. 
     The connection terminal  270  may be electrically connected to the battery  230  (refer to  FIG.  8   ) built into the first UAM device  200 . The connection terminal  270  may provide electric energy or power provided from the supply terminal  370  to the battery  230  (refer to  FIG.  8   ) of the first UAM device  200 . The connection terminal  270  may contain a metal material to smoothly provide electrical energy or power. 
     The guide pin insertion portions  280   a  to  280   d  may be disposed on the lower surface in an area other than the central region. That is, the guide pin insertion portions  280   a  to  280   d  may be disposed to be spaced apart from the connection terminal by a predetermined distance. 
     The guide pin insertion portions  280   a  to  280   d  may be positioned to correspond to the guide pins of the UAM power supply mobility device  300 . The guide pin insertion portions  280   a  to  280   d  may include the first guide pin insertion portion  280   a  to the fourth guide pin insertion portion  280   d . For example, the first guide pin insertion portion  280   a  to the fourth guide pin insertion portion  280   d  may be positioned to correspond to the first guide pin  380   a  to the fourth guide pin  380   d.    
     The first guide pin insertion portion  280   a  may be disposed on the left front side of the lower surfaces of the first UAM device  200 . The second guide pin insertion portion  280   b  may be disposed on the right front side of the lower surface of the first UAM device  200 . The third guide pin insertion portion  280   c  may be disposed on the right rear side of the lower surface of the first UAM device  200 . The fourth guide pin insertion portion  280   d  may be disposed on the left rear side of the lower surface of the first UAM device  200 . 
     The marker  240  may be provided in an area other than the central region and disposed to be spaced apart from the guide pin insertion portions  208   a  to  280   d . The marker  240  may be positioned to correspond to the camera  340  of the UAM power supply mobility device  300 . 
     The marker  240  may be provided to be biased toward one side from the central region. Accordingly, when the marker  240  is controlled to be positioned at the center of an image captured by the camera  340  of the UAM power supply mobility device  300 , the UAM power supply mobility device  300  can be caused to accurately approach the first UAM device  200 . 
     In addition, the connection terminal protector  275  may be built into the first UAM device  200  such that a part thereof is disposed on the lower surface of the first UAM device  200  to surround the connection terminal. The connection terminal protector  275  may serve to protect the connection terminal from the outside. The connection terminal protector  275  may be formed to cover the connection terminal disposed on the lower surface of the first UAM device  200 . The connection terminal protector  275  may perform an opening operation to expose the connection terminal to the outside or a closing operation to protect the supply terminal  370  from the outside under the control of the processor  310  of the first UAM device  200 . A detailed description thereof will be provided later. 
       FIG.  8    and  FIG.  9    are diagrams illustrating an operation in which the UAM power supply mobility device and the first UAM device are physically connected to each other according to an embodiment of the present disclosure. 
     Referring to  FIG.  8   , the UAM power supply mobility device  300  and the first UAM device  200  may approach each other to be physically connected to each other according to an embodiment of the present disclosure. That is, the UAM power supply mobility device  300  may gradually approach the first UAM device  200  to be mounted thereon. Alternatively, the first UAM device  200  may gradually approach the UAM power supply mobility device  300  to be mounted thereon. 
     The UAM power supply mobility device  300  and the first UAM device  200  may gradually approach each other while the communication module  350  of the UAM power supply mobility device  300  and the communication module of the first UAM device  200  transmit and receive position information and flight information of the UAM power supply mobility device  300  and the first UAM device  200 . 
     The UAM power supply mobility device  300  may capture an image of the marker  240  of the first UAM device  200  using the camera  340 . The UAM power supply mobility device  300  may approach the first UAM device  200  by controlling the propulsion unit  320  while controlling the processor  310  such that the marker  240  is disposed at the center of the captured image. 
     While the UAM power supply mobility device  300  and the first UAM device  200  approach each other, the terminal protector  375  of the UAM power supply mobility device  300  is gradually opened under the control of the processor  310  to expose the supply terminal  370  to the outside. In this case, the terminal protector  375  may be embedded in the UAM power supply mobility device  300  in a rollable state. 
     In addition, the connection terminal protector  275  of the first UAM device  200  may be gradually opened under the control of the processor  310  to expose the connection terminal to the outside. 
     Referring to  FIG.  9   , the UAM power supply mobility device  300  and the first UAM device  200  may be physically connected to each other according to an embodiment of the present disclosure. Accordingly, the guide pins  380   a  to  380   d  of the UAM power supply mobility device  300  may be inserted into the guide pin insertion portions  280   a  to  280   d  of the first UAM device  200  and the supply terminal  370  of the UAM power supply mobility device  300  may be inserted into the connection terminal  270  of the first UAM device  200 . 
     Upon determining that the connection terminal  270  is physically connected to the supply terminal  370  of the UAM power supply mobility device  300 , the first UAM device  200  may turn on a switch  231  to be provided with electric energy or power and to charge the battery  330  of the first UAM device  200 . 
     Although not shown in  FIG.  8    and  FIG.  9   , the UAM power supply mobility device  300  may control the supply terminal  370  to be exposed to the outside such that a part or all of the supply terminal  370  is exposed from the upper surface while the terminal protector  375  is opened. That is, the supply terminal  370  is positioned to protrude from the upper surface like the guide pins and thus can be stably inserted into the connection terminal of the first UAM device  200 . Accordingly, power and electrical energy can be smoothly supplied. 
       FIG.  10    is a diagram illustrating the operation of the UAM power supply mobility device according to an embodiment of the present disclosure. 
     Referring to  FIG.  10   , the UAM power supply mobility device  300  according to an embodiment of the present disclosure may ascend or descend while controlling the propulsion unit  320  such that the power cable  110  does not deviate from a preset space on the basis of a position state of the UAM power supply mobility device  300  provided by the sensing unit  360 . The preset space may be a ground area where the charging station  100  is installed and an area above the charging station  100 . 
     The processor  310  of the UAM power supply mobility device  300  may collect information about a position or operating state of the UAM power supply mobility device  300  provided by the sensing unit  360  in real time and calculate or predict a wind direction in the preset space on the basis of the collected information. 
     When there is no wind over the charging station  100  or the platform, the power cable  110  may be positioned vertically with respect to the charging station  100  and the UAM power supply mobility device  300 . Accordingly, when the wind hardly blows, the propulsion unit  320  may generate the propulsion in the upward direction such that the UAM power supply mobility device  300  flies down under the control of the processor  310 . 
     On the other hand, when the wind blows over the charging station  100  or the platform, the power cable  110  and the UAM power supply mobility device  300  are moved in the opposite direction to the wind. In this case, they may collide with other facilities and may interfere with a route of another UAM in a nearby charging station  100 . Accordingly, when the wind blows in a first direction, the propulsion unit  320  may generate the propulsion in the upward direction and at the same time in a second direction opposite to the first direction such that the UAM power supply mobility device  300  can descend. 
     As described above, when the wind blows, the UAM power supply mobility device  300  may control the propulsion unit  320  such that the propulsion acts in the opposite direction to the wind to prevent the power cable  110  from deviating by a predetermined range or more. 
     Accordingly, the UAM power supply mobility device  300  disconnected from the first UAM device  200  can slowly descend to the charging station  100  with the power cable  110  remaining in a preset space even if the wind blows. 
       FIG.  11    is a flowchart illustrating the operation of the UAM power supply system according to an embodiment of the present disclosure. 
     Referring to  FIG.  11   , the UAM power supply system according to an embodiment of the present disclosure may operate as follows. 
     First, the UAM power supply mobility device  300  may be electrically connected to the first UAM device  200  in the charging station  100  (S 101 ) and may provide power or electrical energy necessary for the first UAM device  200  on the ground while charging the battery  330  built into the first UAM device  200  (S 102 ). 
     Then, when the first UAM device  200  starts to take off (YES in S 103 ), the UAM power supply mobility device  300  may operate the propulsion unit  320  to take off along with the first UAM  200  (S 104 ). That is, the UAM power supply mobility device  300  may ascend while being mounted on the first UAM device  200  to provide power to the first UAM  200  until the first UAM device  200  separated from the charging station  100  reaches an overhead position in a preset space. 
     Upon completion of takeoff of the first UAM device  200  (YES in S 105 ), the UAM power supply mobility device  300  may release docking with the first UAM device  200  (S 106 ). 
     Thereafter, the disconnected UAM powered mobility device  300  may slowly land on the charging station  100  from the undocked position by its own propulsion. The charging station  100  may be referred to as a helipad. 
     That is, when the first UAM device  200  flies out of a preset space, the UAM power supply mobility device  300  may be separated from the first UAM device  200  and descend to be mounted on the charging station  100 . 
     If there is the second UAM device UAM 2  that intends to land on the same charging station  100  when the UAM power supply mobility device  300  is about to land thereon (YES in S 107 ), the UAM power supply mobility device  300  may attempt to dock with the second UAM device UAM 2  (S 109 ). 
     If there is no second UAM device UAM 2  that intends to land on the same charging station  100  when the UAM power supply mobility device  300  is about to land thereon (NO in S 107 ), the UAM power supply mobility device  300  may land alone while controlling the vertical propulsion and the horizontal propulsion such that the power cable connected to the ground does not deviate beyond a predetermined range during landing (S 108 ). 
     Upon completion of docking with the second UAM device UAM 2  (YES in S 110 ), the UAM power supply mobility device  300  may land along with the second UAM device UAM 2  on the charging station  100  (S 112 ) while supplying power or electrical energy to the second UAM device UAM 2  (S 111 ). 
     That is, when the second UAM device UAM 2  enters a preset space to be mounted on the charging station  100  after the UAM power supply mobility device  300  is separated from the first UAM device  200 , the UAM power supply mobility device  300  may receive flight information and position information of the second UAM device UAM 2  from the second UAM device UAM 2  and fly to dock with the second UAM device UAM 2  on the basis of the information. Here, the second UAM device UAM 2  may receive flight information and position information of the UAM power supply mobility device  300  and fly to dock with the UAM power supply mobility device  300  on the basis of the information. 
     At this time, the camera  340  mounted on the UAM power supply mobility device  300  is provided to be biased to one side from the center of the UAM power supply mobility device  300  and the marker  240  disposed on the second UAM device UAM 2  is also provided to be biased to one side like the camera  340 , and thus the UAM power supply mobility device  300  and the second UAM device UAM 2  can approach each other at a correct position while controlling the marker  240  to be positioned at the center of a camera image. 
     Upon docking with the second UAM device UAM 2 , the UAM power supply mobility device  300  may land along with the second UAM device UAM 2  on the charging station  100  while supplying power to the second UAM device UAM 2 . 
     Although the first UAM device  200  and the second UAM device UAM 2  have been separately described in order to clarify the description of the present disclosure in  FIG.  11   , the present disclosure is not limited thereto and the first UAM device  200  and the second UAM device UAM 2  may be the same UAM device. 
     As described above, when a UAM device is anchored at the charging station  100  or the platform, the UAM power supply system according to an embodiment of the present disclosure can control the battery  300  of the anchored UAM device to be charged using the UAM power supply mobility device  300  electrically and physically connected to the UAM device. 
     In addition, in the UAM power supply system, the UAM power supply mobility device  300  takes off along with the UAM device to supply power to the UAM device when the UAM device takes off such that energy necessary for takeoff of the UAM device can be supplied from the outside. 
     The UAM device is provided with power from the outside through the UAM power supply mobility device  300  instead of using the power stored in the battery  330  during takeoff, and thus the capacity of the battery  330  mounted on the UAM device can be reduced. 
     Since the weight of UAM device can also decrease as the capacity of the battery  330  is reduced, the range of the UAM device can be relatively increased. 
     The present disclosure described above can be implemented as computer-readable code on a medium in which a program is recorded. A computer-readable medium includes all kinds of recording devices in which data readable by a computer system is stored. Examples of the computer-readable medium include a hard disk drive (HDD), a solid state drive (SSD), a silicon disk drive (SDD), a ROM, a RAM, a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, etc. When a corresponding processor (or processors) executes the program, the corresponding processor (or processors) may be configured to perform the above-described operations. 
     Therefore, the above detailed description should not be construed as restrictive in all respects but as exemplary. The scope of the present disclosure should be determined by reasonable interpretation of the appended claims, and all modifications within the equivalent scope of the present disclosure are included in the scope of the present disclosure. 
     The UAM power supply system according to at least one embodiment of the present disclosure configured as described above can receive energy necessary for takeoff of a UAM device from the outside, and thus the capacity of a battery mounted on the UAM device can be reduced and the weight of the UAM device can also be reduced, thereby maximizing the range of the UAM device. 
     In addition, the UAM power supply system according to at least one embodiment of the present disclosure can achieve stable system operation by preventing a power cable separated from a UAM device after completion of takeoff of the UAM device from freely falling to the ground using the UAM power supply mobility device equipped with the propulsion unit. 
     Furthermore, when the second UAM device attempts to land on the same charging station or platform after completion of takeoff of the first UAM device, the UAM power supply system according to at least one embodiment of the present disclosure can perform power supply and battery charging while the UAM power supply mobility device in the air docks with the second UAM device that intends to land and lands along with the second UAM device, and thus a time taken for the second UAM device to wait to charge the battery on the ground can be shortened. 
     Effects which may be obtained by the present disclosure are not limited to the above-described effects, and various other effects may be evidently understood by those skilled in the art to which the present disclosure pertains from the following description.