Patent Publication Number: US-2022211010-A1

Title: Pet care system, pet care robot and method for controlling pet care robot

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a Bypass Continuation of International Application No. PCT/IB2021/061583, filed Dec. 10, 2021, which claims priority to Korean Patent Application No. 10-2020-0172378, filed Dec. 10, 2020, the disclosures of which are herein incorporated by reference in their entirety. 
    
    
     BACKGROUND 
     1. Field 
     The present disclosure relates to a pet care system, a pet care robot, and a method for controlling the pet care robot, capable of taking care of a pet even when an owner is absent. 
     2. Description of Related Art 
     Recently, an increasing number of households have pets at home. However, when an owner who takes care of the pet goes out, the pet left alone at home may feel anxious or lethargic and may not move. If the pet becomes psychologically unstable or the amount of physical activity decreases, the health issue of the pet may occur. Also, it can be uncomfortable for the owner to leave his or her pet alone. Therefore, there is a need for a technology that can secure the psychological stability and physical activity of the pet even when the owner is absent. 
     SUMMARY 
     The present disclosure is directed to providing a pet care system, a pet care robot, and a control method of the pet care robot, capable of keeping a pet&#39;s health by inducing a movement of the pet and providing a reward to the pet even when the owner is absent. 
     Further, the present disclosure is directed to providing a pet care system, a pet care robot, and a control method of the pet care robot, capable of changing a motion of the pet care robot according to a distance between a wearable device worn by a pet and the pet care robot configured to follow the pet. 
     One aspect of the present disclosure provides a pet care system including a mobile robot including a first communication circuit configured to transmit a search signal through a first communication method and a second communication circuit configured to transmit event occurrence information through a second communication method different from the first communication method, a wearable device including a sensor configured to transmit a response signal through the first communication method in response to the search signal, and a station including an operation dispenser configured to perform a predetermined operation based on the reception of the event occurrence information. The mobile robot further includes a processor configured to determine a moving direction of the mobile robot based on the response signal received from the wearable device. 
     The processor of the mobile robot may be configured to determine a direction, in which the mobile robot approaches the wearable device, as the moving direction. 
     The mobile robot may further include a speaker configured to output a sound, and the processor of the mobile robot may be configured to control the speaker to output the sound based on the response signal. 
     The first communication circuit may include a plurality of antennas, and the first communication method may follow an Ultra-wideband (UWB) communication protocol. 
     The mobile robot may further include a power source including a battery, and the station may further include a charging circuit configured to charge the battery of the mobile robot. The processor of the mobile robot may be configured to determine the moving direction based on a state of charge of the battery of the mobile robot. 
     The processor of the mobile robot may be configured to determine a separation distance between the mobile robot and the wearable device based on the response signal, and configured to determine the moving direction based on the separation distance. 
     The operation dispenser of the station may include a dispenser configured to store contents and discharge the contents, and the predetermined operation may include an operation of discharging the contents through the dispenser. 
     Another aspect of the present disclosure provides a pet care robot including a main body, a first communication circuit configured to transmit a search signal through a first communication method and configured to receive a response signal corresponding to the search signal from a first external device, a second communication circuit configured to transmit event occurrence information through a second communication method different from the first communication method, a mobility driver configured to move a position of the main body, and a processor configured to control an operation of the mobility driver. The processor is configured to control the mobility driver to move the main body along a moving direction determined based on the response signal, and configured to control the second communication circuit to transmit the event occurrence information to a second external device. 
     The first communication circuit may include a plurality of antennas, and the first communication method may follow an Ultra-wideband (UWB) communication protocol. 
     The processor may be configured to determine a separation distance between the pet care robot and the first external device based on the response signal, and configured to determine the moving direction based on the separation distance. 
     The processor may be configured to determine the moving direction to reduce the separation distance. 
     The pet care robot may further include a speaker configured to output a sound. The processor may be configured to control the speaker to output the sound based on the response signal. 
     Another aspect of the present disclosure provides a method for controlling a pet care robot configured to perform autonomous driving, including transmitting a search signal through a first communication method, receiving a response signal corresponding to the search signal from a first external device, detecting event occurrence, transmitting event occurrence information to a second external device through a second communication method different from the first communication method based on the detection of the event occurrence, determining a separation distance between the pet care robot and the first external device based on the response signal, and determining a moving direction based on the separation distance. 
     The determination of the moving direction may include determining the moving direction to reduce the separation distance. 
     The method for controlling the pet care robot may further include detecting a state of charge of a battery of the pet care robot, and the determination of the moving direction may include determining the moving direction based on the state of charge of the battery. 
     The first communication method may follow an Ultra-wideband (UWB) communication protocol. 
     It is possible to induce a movement of a pet and provide a reward to the pet even when an owner is absent. Therefore, the physical health and mental health of the pet may be improved. 
     Further, it is possible to change an operation of a pet care robot according to a distance between a wearable device worn by the pet and the pet care robot configured to follow the pet. Accordingly, the pet&#39;s interest in the pet care robot may be maintained, and the pet care may be performed more effectively. 
     Further, it is possible to perform the pet care even without a user&#39;s manipulation, and because a pet can directly touch the pet care robot, the pet&#39;s satisfaction with play may be improved. 
     Further, it is possible to easily perform the maintenance of the pet care robot because a station configured to store and charge the pet care robot is provided. 
     Before undertaking the detailed description below, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent document: the terms “include” and “comprise,” as well as derivatives thereof, mean inclusion without limitation; the term “or” is inclusive, meaning and/or; the phrases “associated with” and “associated therewith,” as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, or the like; and the term “controller” means any device, system or part thereof that controls at least one operation, such a device may be implemented in hardware, firmware or software, or some combination of at least two of the same. It should be noted that the functionality associated with any particular controller may be centralized or distributed, whether locally or remotely. 
     Moreover, various functions described below can be implemented or supported by one or more computer programs, each of which is formed from computer readable program code and embodied in a computer readable medium. The terms “application” and “program” refer to one or more computer programs, software components, sets of instructions, procedures, functions, objects, classes, instances, related data, or a portion thereof adapted for implementation in a suitable computer readable program code. The phrase “computer readable program code” includes any type of computer code, including source code, object code, and executable code. The phrase “computer readable medium” includes any type of medium capable of being accessed by a computer, such as read only memory (ROM), random access memory (RAM), a hard disk drive, a compact disc (CD), a digital video disc (DVD), or any other type of memory. A “non-transitory” computer readable medium excludes wired, wireless, optical, or other communication links that transport transitory electrical or other signals. A non-transitory computer readable medium includes media where data can be permanently stored and media where data can be stored and later overwritten, such as a rewritable optical disc or an erasable memory device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding of the present disclosure and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, in which like reference numerals represent like parts: 
         FIG. 1  illustrates a pet care system according to one embodiment of the present disclosure. 
         FIG. 2  illustrates a wearable device according to one embodiment of the present disclosure. 
         FIG. 3  illustrates an appearance of a pet care robot according to one embodiment of the present disclosure. 
         FIG. 4  illustrates an inside of the pet care robot according to one embodiment of the present disclosure. 
         FIG. 5  illustrates a control block diagram of the pet care robot according to one embodiment of the present disclosure. 
         FIG. 6  illustrates a station according to one embodiment of the present disclosure. 
         FIG. 7  illustrates a control block diagram of the station according to one embodiment of the present disclosure. 
         FIG. 8  illustrates an operation of the pet care system according to one embodiment of the present disclosure. 
         FIG. 9  illustrates an operation of the pet care robot according to a distance between a wearable device and the pet care robot. 
         FIG. 10  illustrates a method of controlling the station according to one embodiment of the present disclosure. 
         FIG. 11  illustrates a method of controlling the pet care robot according to one embodiment of the present disclosure. 
         FIGS. 12A through 12F  ( FIG. 12 ) illustrate the operation of the pet care system according to one embodiment of the present disclosure in more detail. 
     
    
    
     DETAILED DESCRIPTION 
       FIGS. 1 through 12 , discussed below, and the various embodiments used to describe the principles of the present disclosure in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the disclosure. Those skilled in the art will understand that the principles of the present disclosure may be implemented in any suitably arranged system or device 
     In the following description, like reference numerals refer to like elements throughout the specification. Well-known functions or constructions are not described in detail since they would obscure the one or more exemplar embodiments with unnecessary detail. Terms such as “unit”, “module”, “member”, and “block” may be embodied as hardware or software. According to embodiments, a plurality of “unit”, “module”, “member”, and “block” may be implemented as a single component or a single “unit”, “module”, “member”, and “block” may include a plurality of components. 
     It will be understood that when an element is referred to as being “connected” another element, it can be directly or indirectly connected to the other element, wherein the indirect connection includes “connection via a wireless communication network” and “electrical connection via an electric wire”. 
     Also, the terms used herein are used to describe the embodiments and are not intended to limit and/or restrict the disclosure. The singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. In this disclosure, the terms “including”, “having”, and the like are used to specify features, numbers, steps, operations, elements, components, or combinations thereof, but do not preclude the presence or addition of one or more of the features, elements, steps, operations, elements, components, or combinations thereof. 
     It will be understood that, although the terms first, second, third, etc., may be used herein to describe various elements, but elements are not limited by these terms. These terms are only used to distinguish one element from another element. For example, without departing from the scope of the disclosure, a first element may be termed as a second element, and a second element may be termed as a first element. The term of “and/or” includes a plurality of combinations of relevant items or any one item among a plurality of relevant items. 
       FIG. 1  illustrates a pet care system according to one embodiment of the present disclosure. 
     Referring to  FIG. 1 , a pet care system  1  may include a wearable device  10 , a mobile robot  20 , and a station  30 . The mobile robot  20  may be referred to as a pet care robot. The wearable device  10 , the mobile robot  20  and the station  30  may communicate with each other. Particularly, the wearable device  10  and the mobile robot  20  may communicate with each other, the wearable device  10  and the station  30  may communicate with each other, and the mobile robot  20  and the station  30  may communicate with each other. For example, the wearable device  10 , the mobile robot  20  and the station  30  may communicate with each other through an ultra-wideband (UWB) communication technology. At least one of the mobile robot  20  or the station  30  may determine a position of the wearable device  10  based on a communication signal received from the wearable device  10 . 
     The wearable device  10  may be worn on a pet and may be provided in various forms. For example, the wearable device  10  may be provided in the form of a necklace, clothes, shoes, or accessories. In  FIG. 1 , the wearable device  10  is exemplified in the form of a necklace worn on the neck of the pet. A configuration of the wearable device  10  will be described in more detail in  FIG. 2 . 
     The mobile robot  20  may interact with the pet to play with the pet. For example, the mobile robot  20  may sense a pet&#39;s touch, and may output a sound that attracts the pet&#39;s interest in response to the pet&#39;s touch. In addition, the mobile robot  20  may be movable independently and follow the pet based on a communication signal transmitted from the wearable device  10  worn on the pet. The mobile robot  20  may effectively play with the pet by performing different motions according to a distance from the wearable device  10  worn on the pet. In addition, the mobile robot  20  may image the pet and transmit the image to a user terminal (not shown). A configuration of the mobile robot  20  will be described in more detail in  FIGS. 3, 4 and 5 . 
     The station  30  may accommodate and store the mobile robot  20 , perform charging of the mobile robot  20 , and provide snacks to pets. A door  311  configured to open or close an accommodation space of the mobile robot  20  may be provided on a front lower end of the station  30 . In addition, an outlet  321  through which snacks are discharged may be provided on an upper surface of the station  30 . A configuration of the station  30  will be described in more detail in  FIGS. 6 and 7 . 
       FIG. 2  illustrates a wearable device according to one embodiment of the present disclosure. 
     Referring to  FIG. 2 , the wearable device  10  may include a main body  110  and a wearing portion  120 . The wearing portion  120  may be connected to both ends of the main body  110  and may be provided as a band or a string. The wearing portion  120  serves to fix the main body  110  to a body of the pet. The wearing portion  120  may be formed of various materials. 
     The main body  110  may include a sensor  111  and a battery  112 . A circuit board on which the sensor  111  and the battery  112  are mounted may be provided inside the main body  110 . 
     The sensor  111  may transmit a response signal in response to a search signal received from the mobile robot  20  or the station  30 . The sensor  111  may include an ultra-wideband (UWB) module. UWB communication technology is a communication technology that uses a broadband frequency of 500 MHz or more and 2 nanoseconds (ns) of pulse width and that can transmit and receive signals with low power over a wide frequency band. By using UWB communication technology, high-precision position measurement is possible because a distance is theoretically measured with an accuracy of millimeters. Further, the sensor  111  may be implemented using various wireless communication technologies (for example, radio frequency (RF) communication, infrared communication, Wi-Fi™, Bluetooth™, or Zigbee™). 
     The sensor  111  may detect a movement of the pet and may transmit a movement signal. For example, the sensor  111  may further include an acceleration sensor, a magnetic sensor, a gravity sensor, and/or a gyroscope. The sensor  111  may include an inertial measurement unit (IMU). The IMU may be composed of an acceleration sensor, a magnetic sensor, and a gyroscope. The sensor  111  may measure a force, acceleration, and angular velocity generated by the movement of the pet, and may measure a magnetic field surrounding the pet. 
     The battery  112  may supply power to the sensor  111 . The battery  112  may be provided inside the main body  110 . The battery  112  may be provided integrally with the sensor  111  or provided to be separated from the sensor  111 . The battery  112  may be charged in a wired manner or a wireless manner. 
       FIG. 3  illustrates an appearance of a pet care robot according to one embodiment of the present disclosure.  FIG. 4  illustrates an inside of the pet care robot according to one embodiment of the present disclosure.  FIG. 5  is a control block diagram of the pet care robot according to one embodiment of the present disclosure. 
     Referring to  FIG. 3 , the pet care robot  20  may include a main body  200  and a wheel  202 . The wheel  202  may be provided on both left and right sides of the main body  200 . The pet care robot  20  may be moved by a rotation of the wheel  202 . The main body  200  may include a housing  201 , and components of the pet care robot  20  may be provided inside the housing  201 . The mobile robot  20  may be provided to have a spherical shape as a whole. The wheel  202  may be accommodated inside the housing  201 . The spherical pet care robot  20  is merely an example, and the pet care robot  20  may have various shapes. 
     Referring to  FIGS. 4 and 5 , the pet care robot  20  may include a mobility driver  210  circuit, a first communication circuit  220 , a second communication circuit  230 , a speaker  240 , a camera  250 , and an infrared senso (IR) sensor  260 , a power source  270 , and a controller  280 . In addition, although not shown, the pet care robot  20  may further include an obstacle sensor (not shown) configured to detect an obstacle in the vicinity. The pet care robot  20  may drive while avoiding obstacles. The controller  280  may be electrically connected to the components of the pet care robot  20  and may control an operation of each component. 
     In some embodiments, one or more of the configurations described in  FIGS. 4 and 5  may be omitted from the pet care robot  20 . In addition, the pet care robot  20  may include components other than those described in  FIGS. 4 and 5 . For example, the pet care robot  20  may further include a display (not shown) configured to output visual information. 
     The mobility driver  230  may rotate the wheel  202 . A position of the main body  200  may be changed according to the rotation of the wheel  202 . The mobility driver  230  may include a motor. The mobility driver  230  may be provided inside the main body  200 , and may be provided on both sides of the main body  200  corresponding to the position of the wheel  202 . The mobility driver  230  may be driven by receiving power from the power source  270  under the control of the controller  280 . 
     The first communication circuit  220  may be implemented using various wireless communication technologies. For example, the first communication circuit  220  may communicate with the wearable device  10  and the station  30  by using Ultra-wideband (UWB) communication, Radio Frequency (RF) communication, infrared communication, Wi-Fi™ communication, Bluetooth™ communication, and/or Zigbee™ communication. It is appropriate that the first communication circuit  220  is a UWB module. That is, the first communication circuit  220  of the pet care robot  20  may transmit and receive a signal using the UWB communication technology. 
     The first communication circuit  220  may transmit a search signal through the first communication method. Further, the first communication circuit  220  may receive a response signal from the wearable device  10  responding to the search signal through the first communication method. The first communication method may be a UWB communication technology. Through the UWB communication, the controller  280  of the pet care robot  20  may easily and accurately calculate a distance from the pet care robot  20  to the wearable device  10  or the station  30 . Further, the controller  280  may determine a relative position of the wearable device  10  and a relative position of the station  30  based on the signal received by the first communication circuit  220 . 
     The first communication circuit  220  may include a plurality of antennas  221 . The pet care robot  20  may determine a moving direction based on a response signal received through the plurality of antennas  221 . In  FIG. 4 , two antennas  221  are exemplified. The plurality of antennas  221  may be horizontally mounted on the circuit board of the first communication circuit  220 . Particularly, the plurality of antennas  221  may be installed to be horizontal to the ground in a direction perpendicular to the front of the pet care robot  20 . The circuit board of the first communication circuit  220  including the plurality of antennas  221  may be installed in a direction perpendicular to the ground. The plurality of antennas  221  may be arranged to be symmetrical with respect to a straight line that passes through the center of the pet care robot  20  and connects the front and the rear. In addition, the pet care robot  20  may have a structure in which there are no metal parts obstructing the propagation of radio waves in the vicinity of the plurality of antennas  221  (front side, rear side, and lateral side of the antenna  221 ). 
     The second communication circuit  230  may detect occurrence of an event (an “event occurrence”) and transmit event occurrence information. The event occurrence may include the movement of the pet care robot  20  by an external force. For example, when the pet touches the pet care robot  20  with its foot or mouth, a force is applied to the pet care robot  20 , and thus an event of movement of the pet care robot  20  may occur. The second communication circuit  230  may transmit an event occurrence signal to the controller  280  of the pet care robot  20 , and the controller  280  may analyze the event occurrence signal to determine the event occurrence caused by an external force. 
     Further, the controller  280  of the pet care robot  20  may control the second communication circuit  230  to transmit event occurrence information to the station  30  through a second communication method. The second communication method may be different from the first communication method used in the first communication circuit  220 . For example, the second communication method may include radio frequency (RF) communication, infrared communication, Wi-Fi, Bluetooth, and/or Zigbee. As described above, the first communication method may follow an UWB communication protocol. 
     The second communication circuit  230  may include a motion sensor. For example, the second communication circuit  230  may include an acceleration sensor, a magnetic sensor, a gravity sensor, and/or a gyroscope. The second communication circuit  230  may include an inertial measurement unit (IMU). The second communication circuit  230  may be provided inside the housing  201  and may include a separate circuit board. In  FIG. 4 , the second communication circuit  230  is exemplified as being located at an upper end of the inside of the housing  201 . 
     The speaker  240  may output various sounds. For example, the speaker  240  may output a sound that attracts the pet&#39;s interest. The speaker  240  is illustrated as being provided at a lower end of the inside of the housing  201 , but may be provided at various positions. The controller  280  of the pet care robot  20  may control the speaker  280  to output a sound based on a response signal received from the wearable device  10 . Further, the controller  280  may control the speaker  280  to output a sound based on the event occurrence information. The pet care robot  20  may output a sound in response to the pet&#39;s touch to the mobile robot  20  with its mouth or foot. 
     The camera  250  may be provided in a front portion of the inside of the housing  201 . A position at which the camera  250  is provided is only an example, and thus the camera  250  may be provided at various positions. The camera  250  may obtain an image and transmit image data to the controller  280 . The controller  280  may control the communication circuits  220  and  230  to transmit the image data to the user&#39;s mobile device (not shown). Further, the controller  280  may identify the pet from the image data and determine the movement of the pet. The controller  280  may control the mobility driver  210  to follow the pet using the image data. 
     The IR sensor  260  may transmit and receive infrared signals, and may be provided in the front portion of the inside of the housing  201 . The IR sensor  260  may be used to return the pet care robot  20  to the station  30 . The pet care robot  20  may return to the station  30  in response to expiration of a predetermined play time or in response to requiring the charging of the battery  271  of the power source  270 . The controller  280  of the pet care robot  20  may determine a moving direction based on a state of charge (SoC) of the battery  271 . For example, in response the SoC of the battery  271  reaching a predetermined minimum threshold value as the SoC is reduced, the controller  280  of the pet care robot  20  may determine a direction toward the station  30  as the moving direction toward which to move. 
     The controller  280  of the pet care robot  20  may align a charging terminal of the mobile robot  20  with a charging terminal of a charging circuit  310  based on the transmitted and received infrared signal, and perform docking between the charging terminal of the mobile robot  20  and the charging terminal of the charging circuit  310 . Alternatively, when the charging circuit  310  of the station  30  includes a wireless charging pad, the controller  280  of the pet care robot  20  may align the battery  271  of the pet care robot  20  with the wireless charging pad based on the infrared signal, and may control the mobility driver  210  to move the pet care robot  20  to the wireless charging pad. 
     The return of the pet care robot  20  may also be performed by the UWB communication. The controller  280  of the pet care robot  20  may calculate a distance and an angle to the charging terminal or the wireless charging pad within the charging circuit  310  through the UWB communication with the station  30 , and the controller  280  may determine a position of the charging terminal or a position of the wireless charging pad within the charging circuit  310 . Further, the return of the pet care robot  20  may be performed by the UWB communication alone, and thus it is possible to omit the IR sensor  260 . 
     In addition, as an example, in response to the pet care robot  20  being located in the vicinity of the station  30  (e.g., within 2 m), the pet care robot  20  may be moved to the inside of the charging circuit  310  of the station  30  by communicating with the station  30  through the infrared communication. In response to the pet care robot  20  being located at a distance (e.g., more than 2 m) from the station  30 , the pet care robot  20  may be moved to the inside of the charging circuit  310  of the station  30  by communicating with the station  30  through the UWB communication. The power source  270  may supply power to components of the pet care robot  20 . The power source  270  may be implemented as a power circuit and may include the battery  271 . The power circuit and the battery  271  may be provided integrally or provided separately. The power source  270  may be provided inside the main body  200 . The battery  271  may be charged in a wired manner or a wireless manner. 
     The controller  280  may be provided inside the housing  201  and may control the overall operation of the pet care robot  20 . The controller  280  may include a processor  281  and a memory  282 . The memory  282  may store programs, instructions, and data for controlling the operation of the pet care robot  20 . The processor  281  may generate a control signal for controlling the operation of the pet care robot  20  based on the program, instructions, and data memorized and/or stored in the memory  282 . The controller  280  may be implemented as a control circuit in which the processor  281  and the memory  282  are mounted. Further, the controller  280  may include a plurality of processors and a plurality of memories. 
     The processor  281  is hardware and may include a logic circuit and an arithmetic circuit. The processor  281  may process data according to a program and/or instructions provided from the memory  282 , and generate a control signal according to the processing result. The memory  282  may include a volatile memory, such as a static random access memory (SRAM) or a dynamic random access memory (DRAM), for temporarily storing data, and a nonvolatile memory, such as a read only memory (ROM), an erasable programmable read only memory (EPROM) or an electrically erasable programmable read only memory (EEPROM) for storing data for a long period of time. 
       FIG. 6  illustrates a station according to one embodiment of the present disclosure.  FIG. 7  is a control block diagram of the station according to one embodiment of the present disclosure. 
     Referring to  FIGS. 6 and 7 , the station  30  may include the charging circuit  310 , an operation dispenser  320 , a communication circuit  330 , a speaker  340 , and a controller  350 . The controller  350  may be electrically connected to components of the station  30  and may control an operation of each component. 
     The station  30  may include configurations other than those described with reference to  FIGS. 6 and 7 . For example, the station  30  may further include a display (not shown) configured to output visual information. 
     The charging circuit  310  may be provided in the lower portion of the station  30 . The charging circuit  310  may include an accommodation space through which the pet care robot  20  enters and exits, and may include a door  311  configured to open or close the accommodation space. The door  311  may be opened in response to the pet care robot  20  moving from the inside of the station  30  to the outside or in response to the pet care robot  20  returning to the inside of the station  30  from the outside. The door  311  may be closed in response to the pet care robot  20  being operated on the outside of the station  30  or in response to the pet care robot  20  waiting inside the station  30 . 
     A charging terminal and/or a charging pad for charging the battery  271  of the pet care robot  20  may be provided in the accommodation space of the charging circuit  310 . For example, the charging circuit  310  may include a wired charging terminal and/or a wireless charging pad. The pet care robot  20  may return to the inside of the charging circuit  310  in response to the expiration of the predetermined play time or in response to requiring the charging of the battery  271  of the power source  270 . 
     The operation dispenser  320  may be provided in an upper portion of the station  30 . The operation dispenser  320  may include a dispenser configured to store contents and discharge the contents. The contents may be snacks for pets. The operation dispenser  320  may include the outlet  321  through which snacks are discharged. The outlet  321  may be provided on the upper surface of the station  30 . The position of the outlet  321  is only an example, the outlet  321  may be provided at various positions of the station  30 . 
     The operation dispenser  320  may include a storage box and a launch pad. In response to the discharge of the snacks being required, the operation dispenser  320  may move the snacks in the storage box to the launch pad and drive the launch pad to launch the snacks through the outlet  321 . The launch pad may include a structure configured to launch snacks by an elastic force of a spring. For example, the launch pad may be provided in the form of a catapult. 
     On the other hand, in response to the pet care robot  20  being located in the charging circuit  310 , the controller  350  of the station  30  may determine the position of the wearable device  10  based on a communication signal received from the wearable device  10 , and determine whether to start the operation of the pet care robot  20  based on the position of the wearable device  10 . In response to the wearable device  10  being located within a predetermined snack dispensing range, the station  30  may transmit an operation start signal to the pet care robot  20  and open the door  311 . 
     The communication circuit  330  may be implemented using various wireless communication technologies. The communication circuit  330  may communicate with the wearable device  10  and the pet care robot  20  by using Ultra-wideband (UWB) communication, Radio Frequency (RF) communication, infrared communication, Wi-Fi™ communication, Bluetooth™ communication, and/or Zigbee™ communication. It is appropriate that the communication circuit  330  is an UWB module. That is, the communication circuit  330  of the station  30  may transmit and receive an ultra-wideband communication signal. For example, the communication circuit  330  of the station  30  may be operated as a ‘UWB anchor’ configured to receive the UWB signal transmitted from the sensor  111  of the wearable device  10  or the first communication circuit  220  of the pet care robot  20 . Further, the communication circuit  330  of the station  30  may be operated as a ‘UWB tag’ configured to transmit an UWB signal to the pet care robot  20 . The speaker  340  may output various sounds. The speaker  340  may be provided at various positions of the station  30 . The controller  350  of the station  30  may control the speaker  340  to output a sound. For example, in response to the motion signal, which is received from the wearable device  10 , not being changed for a predetermined period of time, the controller  350  of the station  30  may control the speaker  340  to output a sound that attracts the pet&#39;s interest. In other words, in response to the pet not moving for a predetermined period of time, the station  30  may output a sound to attract the pet&#39;s interest, and induce the pet to move near the station  30 . 
     The controller  350  may be provided inside the station  30  and may control the overall operation of the station  30 . The controller  280  may include a processor  351  and a memory  352 . The memory  352  may store programs, instructions, and data for controlling the operation of the station  30 . The processor  351  may generate a control signal for controlling the operation of the station  30  based on the program, instructions, and data stored and/or stored in the memory  352 . The controller  350  may be implemented as a control circuit in which the processor  351  and the memory  352  are mounted. Further, the controller  350  may include a plurality of processors and a plurality of memories. 
     In certain embodiments, the controller  280  of the pet care robot  20  may be referred to as a ‘first controller’, and the controller  350  of the station  30  may be referred to as a ‘second controller’. 
     Hereinafter the operation of the pet care system according to one embodiment will be described in detail. 
       FIG. 8  is a flowchart illustrating an operation of the pet care system according to one embodiment of the present disclosure. 
     Referring to  FIG. 8 , at block  401 , the pet care robot  20  may transmit a search signal through the first communication method. The first communication method may be an UWB communication technology, and the search signal may be an UWB signal according to an UWB communication protocol. At block  402 , the wearable device  10  may transmit a response signal in response to the search signal through the first communication method. At block  402 , the pet care robot  20  may receive a response signal from the wearable device  10 . 
     At block  403 , the pet care robot  20  may determine a moving direction based on the response signal received from the wearable device  10 . The processor  281  of the pet care robot  20  may allow the mobility driver  210  to move to the main body along the moving direction. The pet care robot  20  may determine a direction closer to the wearable device  10  as a moving direction. The pet care robot  20  may determine a separation distance between the pet care robot  20  and the wearable device  10  based on a response signal received from the wearable device  10 . The pet care robot  20  may be moved to the position of the wearable device  10 . In response to the movement of the pet wearing the wearable device  10 , the pet care robot  20  may drive while following the wearable device  10 . In response to the communication among the wearable device  10 , the pet care robot  20 , and the station  30  through the UWB communication, the pet care robot  20  may determine the position of the wearable device  10  and the station  30  with high accuracy, and the station  30  may determine the position of the wearable device  10  and the pet care robot  20  with high accuracy. 
     Particularly, the pet care robot  20  may transmit a search signal (UWB signal) to the wearable device  10  and receive a response signal (UWB response signal) from the wearable device  10 . The controller  280  of the pet care robot  20  may obtain delay time information based on a time, at which the response signal is received from the wearable device  10 , and a time, at which the search signal is transmitted. The controller  280  of the pet care robot  20  may calculate the distance to the wearable device  10  using a Time of Flight (ToF) technology. 
     Alternatively, the controller  280  of the pet care robot  20  may calculate the distance to the wearable device  10  using two-way ranging. Two-way ranging is a method of measuring a distance in a way in which the transmitter and receiver share their own time information while exchanging signals several times, thereby removing a time error. 
     The first communication circuit  220  of the pet care robot  20  may include the plurality of antennas  221 , and the controller  280  may determine the relative position of the wearable device  10  by using a time difference between signals received through the plurality of antennas  221 . That is, the controller  280  of the pet care robot  20  may determine the relative position of the wearable device  10  and the pet care robot  20  by using an Angle of Arrival (AoA) positioning technology. Time Delay on Arrival (TDoA) or Phase Delay on Arrival (PDoA) positioning technology may be used. The controller  280  may calculate the angle between the wearable device  10  and the antenna  221  by using a time difference between signals received by each of the antennas  221  (TDoA technology). The controller  280  may detect a pulse period of signals received by each of the antennas  221  and calculate the angle between the wearable device  10  and the antenna  221  by using the phase difference between the pulse periods (PDoA technology). A detailed description of the positioning technology using UWB communication omitted so as to not unnecessarily obscure the embodiments herein. 
     In the same way, the pet care robot  20  may calculate the distance and angle to the station  30  and determine a driving route to the station  30 . 
     At block  404 , the pet care robot  20  may detect the event occurrence and transmit event occurrence information to the station  30  through the second communication method. The event occurrence may include the movement of the pet care robot  20  caused by an external force. In other words, in response to detecting the movement of the pet care robot  20  caused by the external force, the pet care robot  20  may transmit event occurrence information to the station  30 . In addition, the pet care robot  20  may output a sound in response to the event occurrence caused by the external force. 
     At block  405 , the station  30  may control the operation dispenser  320  to perform a predetermined operation based on the reception of the event occurrence information. The operation dispenser  320  may include a dispenser configured to discharge contents, and the predetermined operation may include discharging the contents through the dispenser. Further, the predetermined operation may include outputting sound through the speaker  340 . The station  30  may launch a snack to the position of the pet care robot  20  in response to the reception of the event occurrence information. 
       FIG. 9  illustrates an operation of the pet care robot according to a distance between the wearable device and the pet care robot. 
     Referring to  FIG. 9 , the pet care robot  20  may perform different operations according to a distance from the wearable device  10 . For example, the pet care robot  20  may stop in response to the distance to the wearable device  10  being within a first distance, and in response to the distance to the wearable device  10  being within a second distance greater than the first distance, the pet care robot  20  may change a direction based on the position of the wearable device  10 . Further, in response to the distance to the wearable device  10  being greater than the second distance, the pet care robot  20  may move while following the wearable device  10 . 
     An area in which the distance between the pet care robot  20  and the wearable device  10  is within the first distance may be defined as a first area  510 . For example, the first distance may be 50 cm. Based on the distance between the pet care robot  20  and the wearable device  10  being within the first distance, the pet care robot  20  may be considered to be close to the pet. In this case, the pet may touch the pet care robot  20  with its mouth or feet, and thus the pet care robot  20  may take a stop motion. 
     The pet care robot  20  may determine the moving direction based on the distance from the wearable device  10 . An area in which the distance between the pet care robot  20  and the wearable device  10  is greater than the first distance and within the second distance may be defined as a second area  520 . For example, the second distance may be 100 cm. When the pet care robot  20  and the pet are located in the second area  520 , the pet care robot  20  and the wearable device  10  may be a distance apart, but the pet may quickly approach the pet care robot  20  again. Accordingly, the pet care robot  20  may continue to attract the pet&#39;s interest by taking an action to change the direction toward the position where the pet is placed. 
     An area in which the distance between the pet care robot  20  and the wearable device  10  is greater than the second distance may be defined as a third area  530 . Further, the third area  530  may be defined as a snack dispensing range of the station  30 . That is, in certain embodiments, the distance from the station  30  to the point of the third region  530  furthest away from the station  30  may be the maximum distance at which the station  30  may launch snacks  540 . The snack dispensing range of the station  30  may vary depending on the design. In response to the distance between the pet care robot  20  and the wearable device  10  being greater than the second distance, it can be seen that the pet temporarily loses interest in the pet care robot  20  and leaves the pet care robot  20 . The pet care robot  20  may drive while following the pet, thereby attracting the pet&#39;s interest again. 
       FIG. 10  is a flowchart illustrating a method of controlling the station according to one embodiment of the present disclosure. 
     In  FIG. 10 , the pet care robot  20  is located inside the charging circuit  310  of the station  30 . At block  601 , the communication circuit  330  of the station  30  may receive a motion signal from the wearable device  10  worn on the pet. 
     At block  602 , the controller  350  of the station  30  may determine whether the motion signal of the wearable device  10  is changed or not. At block  603 , in response to the motion signal received from the wearable device  10  not being changed for a predetermined period of time, the controller  350  of the station  30  may control the speaker  340  to output a sound that attracts the pet&#39;s interest. 
     Further, at block  604 , the controller  350  of the station  30  may determine the position of the wearable device  10  based on a response signal received from the wearable device  104 . As described above, the wearable device  10  and the station  30  may perform the UWB communication, and the controller  350  of the station  30  may determine the position of the wearable device  10  using the positioning technology by UWB communication. 
     At block  606 , in response to the wearable device  10  being located within the predetermined snack dispensing range, the controller  350  of the station  30  may transmit an operation start signal to the pet care robot  20  and open the door  311 . In response to the door  311  being opened, the pet care robot  20  may come out of the station  30  and move to a place where the wearable device  10  is located. 
     At block  607 , the station  30  may receive the event occurrence information from the pet care robot  20 . In response to the movement of the pet care robot  20  caused by the external force, the pet care robot  20  may transmit the event occurrence information to the station  30 . At block  608 , the controller  350  of the station  30  may control the operation dispenser  320  to perform a predetermined operation based on the event occurrence information. 
     At block  609 , the station  30  may receive a return signal from the pet care robot  20 . The pet care robot  20  may transmit the return signal to the station  30  in response to the expiration of the predetermined play time or in response to requiring the charging of the battery  271 . At block  610 , the controller  350  of the station  30  may open the door  311  in response to the return signal of the mobile robot  20 . 
       FIG. 11  is a flowchart illustrating a method of controlling the pet care robot according to one embodiment of the present disclosure. 
     Referring to  FIG. 11 , at block  701 , the processor  281  of the pet care robot  20  may control the first communication circuit  220  to transmit the search signal through the first communication method. The first communication method may be an UWB communication technology, and the search signal may be an UWB signal according to an UWB communication protocol. At block  702 , the first communication circuit  220  of the pet care robot  20  may receive a response signal in response to the search signal from a first external device. Further, the processor  281  may control the speaker  240  to output a sound based on the response signal. The first external device may be the wearable device  10 . 
     The processor  281  of the pet care robot  20  may determine a moving direction based on the response signal, and may control the mobility driver  210  to move the main body along the moving direction. Particularly, at block  703 , the processor  281  of the pet care robot  20  may determine the separation distance between the pet care robot  20  and the first external device based on the response signal received from the first external device. Further, at block  704 , the processor  281  may determine the moving direction based on the separation distance. The processor  281  may determine the moving direction to reduce the separation distance. 
     The processor  281  of the pet care robot  20  may monitor whether the distance to the first external device is increased. As described above, the pet care robot  20  may perform different operations according to the distance from the first external device. 
     At block  705 , the second communication circuit  230  of the pet care robot  20  may detect event occurrence. At block  706 , the processor  281  may control the second communication circuit  230  to transmit event occurrence information to the second external device through the second communication method. The second communication method may be different from the first communication method used in the first communication circuit  220 . The second external device may be the station  30 . In addition, the processor  281  may control the speaker  240  to output a sound in response to detection of the event occurrence. 
     At block  707 , the processor  281  of the pet care robot  20  may detect a state of charge (SoC) of the battery  271 . At block  708 , the processor  281  may determine the moving direction based on the SoC of the battery  271 . For example, in response the SoC of the battery  271  reaching a predetermined minimum threshold value due to the decrease in the SoC, the controller  280  of the pet care robot  20  may determine a direction toward the second external device as the moving direction. 
       FIG. 12  (including  FIGS. 12A-12F ) illustrates the operation of the pet care system according to one embodiment of the present disclosure in more detail. 
     When the owner goes out, the pet can sit quietly in front of an entrance and wait for the owner. That is, the pet may not move in front of the entrance for a certain period of time. In an operation  801  as shown in  FIG. 12A , the pet wearing the wearable device  10  may be located in front of the entrance, and the station  30  accommodating the pet care robot  20  may be located in a corner of a living room. The station  30  may receive a motion signal from the wearable device  10  to determine a change in the motion signal. 
     In an operation  802  as shown in  FIG. 12B , in response to determining the motion signal received from the wearable device  10  has not changed for the predetermined period of time, the station  30  may output a sound  1202  that attracts the pet&#39;s interest. Operation  802  may be similar to or include operation  603  of  FIG. 10 . The pet may move towards the station  30  in response to the sound  1202 . In an operation  803  as shown in  FIG. 12C , in response to the pet being located within the snack dispensing range  1204  (e.g., third area  503 ), the station  30  may transmit the operation start signal to the pet care robot  20  and open the door  311 . In response to the door  311  being opened, the pet care robot  20  may come out of the station  30  and move to the place  1206  where the wearable device  10  is located. Operation  803  may be similar to or include operations  606  of  FIG. 10 and 704  of  FIG. 11 . 
     In an operation  804  as shown in  FIG. 12D , the pet care robot  20  may output a sound  1208  in response to the event occurrence caused by an external force. The pet care robot  20  may transmit event occurrence information to the station  30 . The station  30  may launch a snack  1210  (e.g., snacks  540 ) to the location of the pet care robot  20  based on the reception of the event occurrence information. Operation  804  may be similar to or include operations  608  of  FIG. 10 and 706  of  FIG. 11 . 
     In an operation  805  as shown in  FIG. 12E , the pet may temporarily lose interest in the pet care robot  20  and leave the pet care robot  20 . The pet care robot  20  may determine a moving direction  1212  based on the distance  1214  to the wearable device  10 . For example, as described in  FIG. 9 , in response to the distance  1214  between the pet care robot  20  and the wearable device  10  being greater than the second distance, the pet care robot  20  may drive while following the pet. Operation  805  may be similar to or include operation  704  of  FIG. 11 . In an operation  806  as shown in  FIG. 12F , the pet care robot  20  may return to the station  30  in response to the expiration of the predetermined play time or in response to requiring the charging of the battery  271  of the power source  270 . The pet care robot  20  may determine the moving direction based on the SoC of the battery  271 . Operation  806  may be similar to or include operation  708  of  FIG. 11 . 
     As described above, it is possible to induce the movement of the pet and provide a reward to the pet even when the owner is absent. Therefore, it is possible to improve the physical health and mental health of the pet. 
     Further, it is possible to change the motion of the mobile robot according to the distance between the wearable device worn by the pet and the mobile robot configured to follow the pet. Accordingly, it is possible to maintain the pet&#39;s interest in the mobile robot, and it is possible to more effectively perform the pet care. 
     Further, it is possible to perform the pet care without a user&#39;s manipulation, and it is possible to improve the pet&#39;s satisfaction with play because the pet can directly touch the mobile robot. 
     Further, it is possible to easily perform the maintenance of the mobile robot because the station, in which the mobile robot is store and charged, is provided. 
     In certain embodiments, the disclosed embodiments may be embodied in the form of a recording medium storing instructions executable by a computer. The instructions may be stored in the form of program code and, when executed by a processor, may generate a program module to perform the operations of the disclosed embodiments. The recording medium may be embodied as a computer-readable recording medium. 
     Storage medium readable by machine, may be provided in the form of a non-transitory storage medium. “Non-transitory” means that the storage medium is a tangible device and does not contain a signal (e.g., electromagnetic wave), and this term includes a case in which data is semi-permanently stored in a storage medium and a case in which data is temporarily stored in a storage medium. For example, “non-transitory storage medium” may include a buffer in which data is temporarily stored. 
     The method according to the various disclosed embodiments may be provided by being included in a computer program product. Computer program products may be traded between sellers and buyers as commodities. Computer program products are distributed in the form of a device-readable storage medium (e.g., compact disc read only memory (CD-ROM)), or are distributed directly or online (e.g., downloaded or uploaded) between two user devices (e.g., smartphones) through an application store (e.g., Play Store™). In the case of online distribution, at least a portion of the computer program product (e.g., downloadable app) may be temporarily stored or created temporarily in a device-readable storage medium such as the manufacturer&#39;s server, the application store&#39;s server, or the relay server&#39;s memory. 
     While the present disclosure has been particularly described with reference to exemplary embodiments, it should be understood by those of skilled in the art that various changes in form and details may be made without departing from the spirit and scope of the present disclosure. 
     Although the present disclosure has been described with various embodiments, various changes and modifications may be suggested to one skilled in the art. It is intended that the present disclosure encompass such changes and modifications as fall within the scope of the appended claims.