Patent Publication Number: US-2023136665-A1

Title: Device and method of delivering item along circular route

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of International Application No. PCT/KR2022/011887 designating the United States, filed on Aug. 10, 2022, in the Korean Intellectual Property Receiving Office and claiming priority to Korean Patent Application No. 10-2021-0150687, filed on Nov. 4, 2021, in the Korean Intellectual Property Office, and to Korean Patent Application No. 10-2021-0165511, filed on Nov. 26, 2021, in the Korean Intellectual Property Office, the disclosures of all of which are incorporated by reference herein in their entireties. 
    
    
     BACKGROUND 
     1. Field 
     The disclosure relates to a device and method of delivering an item along a route. 
     2. Description of Related Art 
     Recently, driven by the advancement of electronics technology, various types of electronic devices have been developed and distributed. In stores, cafes, restaurants, and the like, electronic devices, such as kiosks and robots, that replace humans have been actively used. The electronic devices may perform operations, such as processing an order requested by a customer and delivering the order to a customer. 
     However, there has also been a constant demand for a method of efficiently delivering ordered food to satisfy many customers and providing a consistent service to many customers such that an electronic device, such as a robot, may perform labor rather perfectly, thus replacing humans. A needed method may efficiently deliver ordered food and a service item by a few robots while satisfying many customers. 
     SUMMARY 
     Embodiments of the disclosure may provide an electronic device configured to autonomously determine a destination to be circularly visited. 
     Embodiments of the disclosure may provide an electronic device that may determine a dynamic interaction to be performed at the circularly visited destination. 
     Embodiments of the disclosure may provide an electronic device that may determine to revisit the circularly visited destination, based on feedback therefrom. 
     According to example embodiments, an electronic device includes: a communication module comprising communication circuitry; a driver comprising a motor; a memory configured to store computer-executable instructions; and a processor configured to execute the computer-executable instructions by accessing the memory, wherein the processor, by executing the computer-executable instructions, is configured to: establish communication with an order server using the communication module and receive order information from the order server, generate a route including a point of departure and a first destination determined based on the order information, while the electronic device is moved along the route using the driver, in response to not receiving an order from the first destination identified based on seating information indicating at least one seated customer, perform an operation of outputting information indicating a serving tray accommodating a basic item based on the electronic device reaching the first destination, and based on a drive along the route being completed, in response to not delivering, to the first destination, at least one item indicated in an order received from the first destination, exclude the first destination from the route. 
     According to example embodiments, a method performed by an electronic device includes: receiving order information from an order server; generating a route including a point of departure and a first destination determined based on the order information; while the electronic device is moved along the route using a driver, in response to not receiving an order from the first destination identified based on seating information indicating at least one seated customer, performing an operation of outputting information indicating a serving tray accommodating a basic item based on the electronic device reaching the first destination; and based on a drive along the route being completed, in response to not delivering, to the first destination, at least one item indicated in an order received from the first destination, excluding the first destination from the route. 
     According to various example embodiments, an electronic device may reduce time and cost consumed for repetitive delivery of the same item by interoperating with a point-of-sales (POS) device and informing a customer of an item needed in a service state of each destination. 
     The electronic device according to various example embodiments may minimize and/or reduce a user&#39;s intervention by providing the repetitive delivery of the same item through a circular drive. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other aspects, features, and advantages of certain embodiments of the present disclosure will be more apparent from the following detailed description, taken in conjunction with the accompanying drawings, in which: 
         FIG.  1    is a block diagram illustrating an example electronic device in a network environment according to various example embodiments; 
         FIG.  2    is a diagram illustrating an example electronic device implemented as a serving robot according to various example embodiments; 
         FIG.  3    is a flowchart illustrating an example circular serving method of an electronic device according to various example embodiments; 
         FIG.  4    is a diagram illustrating an example determining a service state according to various example embodiments; 
         FIG.  5    is a flowchart illustrating an example method of determining a route according to various example embodiments; 
         FIG.  6    is a diagram illustrating an example operation of sensing inventory according to various example embodiments; 
         FIG.  7    is a diagram illustrating an example inventory sensor according to various example embodiments; 
         FIG.  8    is a flowchart illustrating an example operation of modifying a route for a revisit, according to various example embodiments; 
         FIG.  9    is a diagram illustrating an example operation of performing a circular drive on a plurality of destinations having the same serving state by an electronic device according to various example embodiments; 
         FIG.  10    is a diagram illustrating an example drive along a route including a destination to which a special order is received by an electronic device according to various example embodiments; 
         FIG.  11    is a diagram illustrating an example drive along a route including a plurality of destinations having different service states by an electronic device according to various example embodiments; 
         FIG.  12    is a diagram illustrating an example of skipping some destinations when inventory is insufficient during a circular drive by an electronic device according to various example embodiments; and 
         FIG.  13    is a diagram illustrating an example of reporting insufficient inventory to a manager by an electronic device according to various example embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, example embodiments will be described in greater detail with reference to the accompanying drawings. When describing the example embodiments with reference to the accompanying drawings, like reference numerals refer to like elements and a repeated description related thereto may not be provided. 
       FIG.  1    is a block diagram illustrating an example electronic device  101  in a network environment  100  according to various example embodiments. Referring to  FIG.  1   , the electronic device  101  in the network environment  100  may communicate with an electronic device  102  via a first network  198  (e.g., a short-range wireless communication network), or communicate with at least one of an electronic device  104  and a server  108  via a second network  199  (e.g., a long-range wireless communication network). According to an example embodiment, the electronic device  101  may communicate with the electronic device  104  via the server  108 . According to an example embodiment, the electronic device  101  may include a processor  120 , a memory  130 , an input module  150 , a sound output module  155 , a display module  160 , an audio module  170 , and a sensor module  176 , an interface  177 , a connecting terminal  178 , a haptic module  179 , a camera module  180 , a motor  187 , a power management module  188 , a battery  189 , a communication module  190 , a subscriber identification module (SIM)  196 , or an antenna module  197 . In various example embodiments, at least one of the components (e.g., the connecting terminal  178 ) may be omitted from the electronic device  101 , or one or more other components may be added to the electronic device  101 . In various example embodiments, some of the components (e.g., the sensor module  176 , the camera module  180 , or the antenna module  197 ) may be integrated as a single component (e.g., the display module  160 ). 
     The processor  120  may execute, for example, software (e.g., a program  140 ) to control at least one other component (e.g., a hardware or software component) of the electronic device  101  connected to the processor  120  and may perform various data processing or computations. According to an example embodiment, as at least a part of data processing or computations, the processor  120  may store a command or data received from another component (e.g., the sensor module  176  or the communication module  190 ) in a volatile memory  132 , process the command or the data stored in the volatile memory  132 , and store resulting data in a non-volatile memory  134 . According to an example embodiment, the processor  120  may include a main processor  121  (e.g., a central processing unit (CPU) or an application processor (AP)), or an auxiliary processor  123  (e.g., a graphics processing unit (GPU), a neural processing unit (NPU), an image signal processor (ISP), a sensor hub processor, or a communication processor (CP)) that is operable independently from or in conjunction with the main processor  121 . For example, when the electronic device  101  includes the main processor  121  and the auxiliary processor  123 , the auxiliary processor  123  may be adapted to consume less power than the main processor  121  or to be specific to a specified function. The auxiliary processor  123  may be implemented separately from the main processor  121  or as a part of the main processor  121 . 
     The auxiliary processor  123  may control at least some of functions or states related to at least one (e.g., the display module  160 , the sensor module  176 , or the communication module  190 ) of the components of the electronic device  101 , instead of the main processor  121  while the main processor  121  is in an inactive (e.g., sleep) state or along with the main processor  121  while the main processor  121  is an active state (e.g., executing an application). According to an example embodiment, the auxiliary processor  123  (e.g., an ISP or a CP) may be implemented as a portion of another component (e.g., the camera module  180  or the communication module  190 ) that is functionally related to the auxiliary processor  123 . According to an example embodiment, the auxiliary processor  123  (e.g., an NPU) may include a hardware structure specifically for artificial intelligence model processing. An artificial intelligence model may be generated by machine learning. The machine learning may be performed by, for example, the electronic device  101 , in which artificial intelligence is performed, or performed via a separate server (e.g., the server  108 ). Learning algorithms may include, but are not limited to, for example, supervised learning, unsupervised learning, semi-supervised learning, or reinforcement learning. The artificial intelligence (AI) model may include a plurality of artificial neural network layers. An artificial neural network may include, for example, a deep neural network (DNN), a convolutional neural network (CNN), a recurrent neural network (RNN), a restricted Boltzmann machine (RBM), a deep belief network (DBN), and a bidirectional recurrent deep neural network (BRDNN), a deep Q-network, or a combination of two or more thereof, but is not limited thereto. The AI model may additionally or alternatively include a software structure other than the hardware structure. 
     The memory  130  may store various pieces of data used by at least one component (e.g., the processor  120  or the sensor module  176 ) of the electronic device  101 . The various pieces of data may include, for example, software (e.g., the program  140 ) and input data or output data for a command related thereto. The memory  130  may include the volatile memory  132  or the non-volatile memory  134 . 
     The program  140  may be stored as software in the memory  130  and may include, for example, an operating system (OS)  142 , middleware  144 , or an application  146 . 
     The input module  150  may receive, from outside (e.g., a user) the electronic device  101 , a command or data to be used by another component (e.g., the processor  120 ) of the electronic device  101 . The input module  150  may include, for example, a microphone, a mouse, a keyboard, a key (e.g., a button), or a digital pen (e.g., a stylus pen). 
     The sound output module  155  may output a sound signal to the outside of the electronic device  101 . The sound output module  155  may include, for example, a speaker or a receiver. The speaker may be used for general purposes, such as playing multimedia or playing a recording. The receiver may be used to receive an incoming call. According to an example embodiment, the receiver may be implemented separately from the speaker or as a part of the speaker. 
     The display module  160  may visually provide information to the outside (e.g., a user) of the electronic device  101 . The display module  160  may include, for example, a control circuit for controlling a display, a hologram device, or a projector and control circuitry to control its corresponding one of the display, the hologram device, and the projector. According to an example embodiment, the display module  160  may include a touch sensor adapted to detect a touch, or a pressure sensor adapted to measure the intensity of force of the touch. 
     The audio module  170  may convert sound into an electric signal or vice versa. According to an example embodiment, the audio module  170  may obtain the sound via the input module  150  or output the sound via the sound output module  155  or an external electronic device (e.g., the electronic device  102 , such as a speaker or headphones) directly or wirelessly connected to the electronic device  101 . 
     The sensor module  176  may detect an operational state (e.g., power or temperature) of the electronic device  101  or an environmental state (e.g., a state of a user) external to the electronic device  101  and generate an electric signal or data value corresponding to the detected state. According to an example embodiment, the sensor module  176  may include, for example, a gesture sensor, a gyro sensor, an atmospheric pressure sensor, a magnetic sensor, an acceleration sensor, a grip sensor, a proximity sensor, a color sensor, an infrared (IR) sensor, a biometric sensor, a temperature sensor, a humidity sensor, or an illuminance sensor. 
     The interface  177  may support one or more specified protocols to be used by the electronic device  101  to couple with the external electronic device (e.g., the electronic device  102 ) directly (e.g., by wire) or wirelessly. According to an example embodiment, the interface  177  may include, for example, a high-definition multimedia interface (HDMI), a universal serial bus (USB) interface, a secure digital (SD) card interface, or an audio interface. 
     The connecting terminal  178  may include a connector via which the electronic device  101  may physically connect to an external electronic device (e.g., the electronic device  102 ). According to an example embodiment, the connecting terminal  178  may include, for example, an HDMI connector, a USB connector, an SD card connector, or an audio connector (e.g., a headphones connector). 
     The haptic module  179  may convert an electric signal into a mechanical stimulus (e.g., a vibration or a movement) or an electrical stimulus, which may be recognized by a user via their tactile sensation or kinesthetic sensation. According to an example embodiment, the haptic module  179  may include, for example, a motor, a piezoelectric element, or an electric stimulator. 
     The camera module  180  may capture a still image and moving images. According to an example embodiment, the camera module  180  may include one or more lenses, image sensors, ISPs, and flashes. 
     A driving module may drive the electronic device  101 . The driving module may include the motor  187  and a wheel connected to the motor  187 . In  FIG.  2    to be described below, illustrated is an example of a pair of wheels spaced and disposed along an axis (e.g., a lateral axis) perpendicular to a driving direction (e.g., a longitudinal axis) at a bottom center of the electronic device  101 , but examples are not limited thereto. The disposition and number of wheels of the motor  187  of the driving module may vary depending on a design. 
     The power management module  188  may manage power supplied to the electronic device  101 . According to an example embodiment, the power management module  188  may be implemented as, for example, at least a part of a power management integrated circuit (PMIC). 
     The battery  189  may supply power to at least one component of the electronic device  101 . According to an example embodiment, the battery  189  may include, for example, a primary cell, which is not rechargeable, a secondary cell, which is rechargeable, or a fuel cell. 
     The communication module  190  may support establishing a direct (e.g., wired) communication channel or a wireless communication channel between the electronic device  101  and the external electronic device (e.g., the electronic device  102 , the electronic device  104 , or the server  108 ) and performing communication via the established communication channel. The communication module  190  may include one or more CPs that are operable independently from the processor  120  (e.g., an AP) and that support direct (e.g., wired) communication or wireless communication. According to an example embodiment, the communication module  190  may include a wireless communication module  192  (e.g., a cellular communication module, a short-range wireless communication module, or a global navigation satellite system (GNSS) communication module) or a wired communication module  194  (e.g., a local area network (LAN) communication module, or a power line communication (PLC) module). A corresponding one of these communication modules may communicate with the external electronic device, for example, the electronic device  104 , via the first network  198  (e.g., a short-range communication network, such as Bluetooth™, wireless-fidelity (Wi-Fi) direct, or infrared data association (IrDA)) or the second network  199  (e.g., a long-range communication network, such as a legacy cellular network, a 5G network, a next-generation communication network, the Internet, or a computer network (e.g., a LAN or a wide area network (WAN)). These various types of communication modules may be implemented as a single component (e.g., a single chip), or may be implemented as multiple components (e.g., multiple chips) separate from each other. The wireless communication module  192  may identify and authenticate the electronic device  101  in a communication network, such as the first network  198  or the second network  199 , using subscriber information (e.g., international mobile subscriber identity (IMSI)) stored in the SIM  196 . 
     The wireless communication module  192  may support a 5G network after a 4G network, and next-generation communication technology, e.g., new radio (NR) access technology. The NR access technology may support enhanced mobile broadband (eMBB), massive machine type communications (mMTC), or ultra-reliable and low-latency communications (URLLC). The wireless communication module  192  may support a high-frequency band (e.g., a mmWave band) to achieve, e.g., a high data transmission rate. The wireless communication module  192  may support various technologies for securing performance on a high-frequency band, such as, e.g., beamforming, massive multiple-input and multiple-output (MIMO), full dimensional MIMO (FD-MIMO), an array antenna, analog beam-forming, or a large scale antenna. The wireless communication module  192  may support various requirements specified in the electronic device  101 , an external electronic device (e.g., the electronic device  104 ), or a network system (e.g., the second network  199 ). According to an example embodiment, the wireless communication module  192  may support a peak data rate (e.g., 20 Gbps or more) for implementing eMBB, loss coverage (e.g., 164 dB or less) for implementing mMTC, or U-plane latency (e.g., 0.5 ms or less for each of downlink (DL) and uplink (UL), or a round trip of 1 ms or less) for implementing URLLC. 
     The antenna module  197  may transmit or receive a signal or power to or from the outside (e.g., the external electronic device) of the electronic device  101 . According to an example embodiment, the antenna module  197  may include an antenna including a radiating element including a conductive material or a conductive pattern formed in or on a substrate (e.g., a printed circuit board (PCB)). According to an example embodiment, the antenna module  197  may include a plurality of antennas (e.g., an antenna array). In such a case, at least one antenna appropriate for a communication scheme used in a communication network, such as the first network  198  or the second network  199 , may be selected by, for example, the communication module  190  from the plurality of antennas. The signal or power may be transmitted or received between the communication module  190  and the external electronic device via the at least one selected antenna. According to an example embodiment, another component (e.g., a radio frequency integrated circuit (RFIC)) other than the radiating element may be additionally formed as a part of the antenna module  197 . 
     According to various example embodiments, the antenna module  197  may form a mmWave antenna module. According to an example embodiment, the mmWave antenna module may include a PCB, an RFIC on a first surface (e.g., the bottom surface) of the PCB, or adjacent to the first surface of the PCB and capable of supporting a designated high-frequency band (e.g., a mmWave band), and a plurality of antennas (e.g., array antennas) disposed on a second surface (e.g., the top or a side surface) of the PCB, or adjacent to the second surface of the PCB and capable of transmitting or receiving signals of the designated high-frequency band. 
     At least some of the above-described components may be coupled mutually and exchange signals (e.g., commands or data) therebetween via an inter-peripheral communication scheme (e.g., a bus, general purpose input and output (GPIO), serial peripheral interface (SPI), or mobile industry processor interface (MIPI)). 
     According to an example embodiment, commands or data may be transmitted or received between the electronic device  101  and the external electronic device (e.g., the electronic device  104 ) via the server  108  coupled with the second network  199 . Each of the external electronic devices (e.g., the electronic device  102  or  104 ) may be a device of the same type as or a different type from the electronic device  101 . According to an example embodiment, all or some of operations to be executed by the electronic device  101  may be executed by one or more external electronic devices (e.g., the electronic devices  102  and  104  and the server  108 ). For example, if the electronic device  101  needs to perform a function or a service automatically, or in response to a request from a user or another device, the electronic device  101 , instead of, or in addition to, executing the function or the service, may request the one or more external electronic devices to perform at least part of the function or service. The one or more external electronic devices receiving the request may perform the at least part of the function or service, or an additional function or an additional service related to the request and may transfer a result of the performance to the electronic device  101 . The electronic device  101  may provide the result, with or without further processing the result, as at least part of a response to the request. To that end, cloud computing, distributed computing, mobile edge computing (MEC), or client-server computing technology may be used, for example. The electronic device  101  may provide ultra low-latency services using, e.g., distributed computing or MEC. In an example embodiment, the external electronic device (e.g., the electronic device  104 ) may include an Internet-of-things (IoT) device. The server  108  may be an intelligent server using machine learning and/or a neural network. According to an example embodiment, the external electronic device (e.g., the electronic device  104 ) or the server  108  may be included in the second network  199 . The electronic device  101  may be applied to intelligent services (e.g., a smart home, a smart city, a smart car, or healthcare) based on 5G communication technology or IoT-related technology. 
     The electronic device according to various example embodiments may be one of various types of electronic devices. The electronic device may include, for example, a portable communication device (e.g., a smartphone), a computer device, a portable multimedia device, a portable medical device, a camera, a wearable device, a home appliance device, or the like. According to an example embodiment of the disclosure, the electronic device is not limited to those described above. 
     It should be understood that various example embodiments of the present disclosure and the terms used therein are not intended to limit the technological features set forth herein to particular embodiments and include various changes, equivalents, or replacements for a corresponding embodiment. In connection with the description of the drawings, like reference numerals may be used for similar or related components. It is to be understood that a singular form of a noun corresponding to an item may include one or more of the things unless the relevant context clearly indicates otherwise. As used herein, “A or B”, “at least one of A and B”, “at least one of A or B”, “A, B or C”, “at least one of A, B and C”, and “A, B, or C,” each of which may include any one of the items listed together in the corresponding one of the phrases, or all possible combinations thereof. Terms such as “first”, “second”, or “first” or “second” may simply be used to distinguish the component from other components in question, and do not limit the components in other aspects (e.g., importance or order). It is to be understood that if an element (e.g., a first element) is referred to, with or without the term “operatively” or “communicatively”, as “coupled with,” “coupled to,” “connected with,” or “connected to” another element (e.g., a second element), the element may be coupled with the other element directly (e.g., by wire), wirelessly, or via a third element. 
     As used in connection with various example embodiments of the disclosure, the term “module” may include a unit implemented in hardware, software, or firmware, or any combination thereof, and may interchangeably be used with other terms, for example, “logic,” “logic block,” “part,” or “circuitry”. A module may be a single integral component, or a minimum unit or part thereof, adapted to perform one or more functions. For example, according to an example embodiment, the module may be implemented in a form of an application-specific integrated circuit (ASIC). 
     Various example embodiments as set forth herein may be implemented as software (e.g., the program  140 ) including one or more instructions that are stored in a storage medium (e.g., the internal memory  136  or the external memory  138 ) that is readable by a machine (e.g., the electronic device  101 ). For example, a processor (e.g., the processor  120 ) of the machine (e.g., the electronic device  101 ) may invoke at least one of the one or more instructions stored in the storage medium and execute it. This allows the machine to be operated to perform at least one function according to the at least one instruction invoked. The one or more instructions may include code generated by a compiler or code executable by an interpreter. The machine-readable storage medium may be provided in the form of a non-transitory storage medium. Here, the “non-transitory” storage medium is a tangible device, and may not include a signal (e.g., an electromagnetic wave), but this term does not differentiate between where data is semi-permanently stored in the storage medium and where the data is temporarily stored in the storage medium. 
     According to an example embodiment, a method according to various example embodiments of the disclosure may be included and provided in a computer program product. The computer program product may be traded as a product between a seller and a buyer. The computer program product may be distributed in the form of a machine-readable storage medium (e.g., a compact disc read-only memory (CD-ROM)), or be distributed (e.g., downloaded or uploaded) online via an application store (e.g., PlayStore™), or between two user devices (e.g., smartphones) directly. If distributed online, at least part of the computer program product may be temporarily generated or at least temporarily stored in the machine-readable storage medium, such as a memory of the manufacturer&#39;s server, a server of the application store, or a relay server. 
     According to various example embodiments, each component (e.g., a module or a program) of the above-described components may include a single entity or multiple entities, and some of the multiple entities may be separately disposed in different components. According to various example embodiments, one or more of the above-described components may be omitted, or one or more other components may be added. Alternatively or additionally, a plurality of components (e.g., modules or programs) may be integrated into a single component. In such a case, according to various example embodiments, the integrated component may still perform one or more functions of each of the plurality of components in the same or similar manner as they are performed by a corresponding one of the plurality of components before the integration. According to various example embodiments, operations performed by the module, the program, or another component may be carried out sequentially, in parallel, repeatedly, or heuristically, or one or more of the operations may be executed in a different order or omitted, or one or more other operations may be added. 
       FIG.  2    is a diagram illustrating an example electronic device implemented as a serving robot according to various example embodiments. 
     An electronic device  210  (e.g., the electronic device  101  of  FIG.  1   ) may be implemented as a serving robot as illustrated in  FIG.  2   . For example, the electronic device  210  may be a public mobile robot, which is a serving robot configured to autonomously drive and visit a plurality of destinations (e.g., a table). The electronic device  210  may establish communication with an order server  220  (e.g., the server  108  of  FIG.  1   ) and receive, from the order server  220 , information related to orders of customers among the plurality of destinations. 
     The order server  220  may manage order information of each destination. For example, the order server  220  may collect order information (e.g., point-of-sale (POS) data) on a customer of each destination from the electronic device  210  and/or an external device (e.g., a mobile terminal of a customer, a tablet terminal of an employee, and a kiosk terminal). The order information may include at least one of seated information of each destination, order receiving information, ordered menu item information, or serving information. The seated (e.g., seating) information of each destination may include identification information (e.g., a table number and a table location) of the destination, whether a customer sits in the destination, and the number of seated customers. The order receiving information of each destination may include whether a customer seated in the destination places an order and the time of the order. The ordered menu item information of each destination may include a type of item ordered by a seated customer at the destination and the number of ordered items. The serving information of each destination may include whether each item ordered from each destination has been served. In addition, the order information may include a side item (e.g., a side menu item) accompanying an ordered main item (e.g., a main dish), a special order (e.g., whether additional tableware is needed), additional food, whether a customer is a customer with a reservation, the number of visits of the customer, and whether the customer is a very-important-person (VIP) customer. 
     The electronic device  210  may include a display module (e.g., including a display)  211  (e.g., the display module  160  of  FIG.  1   ), a camera module (e.g., including a camera)  212  (e.g., the camera module  180  of  FIG.  1   ), a lighting module (including light emitting circuitry)  213 , a serving tray  214 , a sensor module (e.g., including a sensor)  215  (e.g., the sensor module  176  of  FIG.  1   ), a sound output module (e.g., including sound output circuitry)  216  (e.g., the sound output module  155  of  FIG.  1   ), a communication module (e.g., including communication circuitry  218  (e.g., the communication module  190  of  FIG.  1   ), and a driver (e.g., including a motor)  219  (e.g., the motor  187  of  FIG.  1   ). Although in  FIG.  2   , the sensor module  215 , the sound output module  216 , the communication module  218 , and the driver  219  are illustrated as being included in a base driving platform  217 , examples are not limited thereto. The base driving platform  217  may further include a battery (e.g., the battery  189  of  FIG.  1   ) and a power management module (e.g., the power management module  188  of  FIG.  1   ). 
     The display module  211  may include a display and visually output information related to item delivery to at least one of a user and a customer. For example, the display module  211  may output visual information (e.g., text and an image) that guides the user and the customer to an item to be delivered to a destination where the electronic device  210  reaches. 
     In addition, the electronic device  210  may further include an input module (e.g., the input module  150  of  FIG.  1   ) including various input circuitry integrated with the display module  211 . The electronic device  210 , through the input module, may receive at least one of a touch input and a voice input from at least one of a user and a customer. 
     The camera module  212  may include a camera and face each serving tray. For example, in  FIG.  2   , the camera module  212  may face a serving tray from the ceiling facing the serving tray. In other words, the camera module  212  may have a view angle for capturing the serving tray. The camera module  212  may capture an image including an item (e.g., food) on the serving tray. A processor (e.g., the processor  120  of  FIG.  1   ) of the electronic device  210 , based on an image captured by the camera module  212 , may recognize a type (e.g., a food type) of item on each serving tray and the number of items (e.g., the number of food items). 
     The lighting module  213  may be a module and include various circuitry for projecting light onto a serving tray. The lighting module  213 , when the electronic device  210  reaches a first destination to which a target item on a serving tray needs to be delivered, may light up the serving tray and the target item on the serving tray. 
     Each serving tray (e.g., the serving tray  214 ) may be a tray for accommodating an item. Although in  FIG.  2    three serving trays are illustrated as being spaced and in a direction perpendicular to the ground, the number and structure of the serving tray  214  may not be limited thereto and may vary depending on a design. At least one serving tray among a plurality of serving trays may be on the same surface as another serving tray. The electronic device  210  may include one or more serving trays (e.g., the serving tray  214 ). For example, a first serving tray among the plurality of serving trays may accommodate a basic item (e.g., a menu, water, tableware, and a plate). The basic item may be an item that needs to be basically provided before a main item (e.g., a main dish) being provided to a seated customer at a destination. For reference, the main item may be served to the seated customer by another serving robot or an employee. A second serving tray may accommodate an auxiliary item (e.g., a side dish). The auxiliary item may be an item accompanying an item (e.g., the main item) ordered by a customer and may be provided with the ordered item as a set. A third serving tray may accommodate an additional item (e.g., kids tableware, shared tableware, and special tableware). However, the foregoing example is merely an example for helping understanding, and an item accommodated in each serving tray may not be limited thereto. 
     The sensor module  215  may include a sensor for driving the electronic device  210 . For example, the sensor module  215  may include at least one of a light detection and ranging (LiDAR) sensor, a depth sensor (e.g., a time-of-flight (ToF) sensor), and an ultrasonic sensor. The electronic device  210 , through the sensor module  215 , may set a driving route by detecting an object and the background around the electronic device  210  and perform a maneuver for avoiding an obstacle. 
     The sound output module  216  may include various sound output circuitry and output, to a customer, a sound signal (e.g., voice guidance) for indicating information (e.g., the name and number of currently delivered items) related to item delivery. The sound output module  216  may record a sound signal (e.g., guidance to a customer) to be delivered from a user to the customer and a sound signal (e.g., a request from the customer) to be delivered from the customer to the user. In  FIG.  2   , for example, a speaker of the sound output module  216  is illustrated as being at the lower part of the electronic device  210 , and a microphone of the sound output module  216  may be integrated with the display module  211 . 
     The communication module  218  may include various communication circuitry and establish wired or wireless communication with the order server  220 . The processor of the electronic device  210  may include various processing circuitry and establish communication with the order server  220  using the communication module  218  and may receive order information from the order server  220 . The order information may include at least one of seated information of each destination, order receiving information, ordered menu item information, and serving information. The order information may be generated based on POS data. For example, the communication module  218  may receive POS data from the order server  220 . The POS data may include one or more pieces of order data that indicate an item ordered by each customer. The item, for example, may include food items and things. The communication module  218 , when delivery of a target item is completed by the electronic device  210 , may report the completed delivery of the target item (e.g., served food) to the order server  220 . In addition, the communication module  218  may establish communication with an external device (e.g., another terminal of a user and a wearable device) other than the order server  220 . The communication module  218  may transfer an anomaly detected by the electronic device  210  to the other terminal of the user. 
     The driver  219  may move the electronic device  210 . The driver  219  may include a motor and wheels. The driver  219  may move the electronic device  210  forward and backward and rotate the electronic device  210  on the ground by driving the motor. For example, the processor of the electronic device  210  may move the electronic device  210  along a route including a point of departure and one or more destinations (e.g., a first destination) using the driver  219 . The point of departure may be a reference point at which a route starts and may be a position where the electronic device  210  waits before initiating a circular drive. For example, the route may be a circular route. 
     The electronic device  210  may serve simultaneously prepared items (e.g., simultaneously cooked food items) in a service space (e.g., a restaurant) to multiple destinations (e.g., multiple tables) in one drive. For reference, an example of the electronic device  210  accommodating an item visiting the first destination is mainly described herein, but examples are not limited thereto. When the electronic device  210  visits a plurality of destinations (e.g., first and second destinations), the electronic device  210  may visit the destinations in a serving sequence by identifying an item on each serving tray. 
       FIG.  3    is a flowchart illustrating an example circular serving method of an electronic device according to various example embodiments. 
     In operation  310 , an electronic device (e.g., the electronic device  101  of  FIG.  1   ) may collect order information of each destination. As described above, the electronic device may collect, as order information, seated information (e.g., sitting completion, the number of customers, destination identification information, and seated time), order receiving information (e.g., order received time), order menu item information (e.g., a name of a menu item ordered by a customer, a quantity, and whether an order is a general order or a special order), and serving information (e.g., whether serving is completed). In addition, the electronic device may collect additional information (e.g., whether a child is accompanied, a customer type, such as gender, and whether a reservation has been made). The general order may be an order for a menu item providing only a main item (e.g., food), and a special order may be an order for a menu item requesting an additional item (e.g., kids tableware, tableware for sharing food, and other special tableware). The tableware for sharing food may be an item (e.g., a knife) for dividing a sharable food item (e.g., pizza and steak). 
     In operation  320 , the electronic device may determine a destination to be visited, based on order information. The electronic device may generate a route including a point of departure and a first destination determined based on the order information. For example, the electronic device may identify a service state of an individual destination, based on the order information described above. The service state may be a state of service being provided for an order received at each destination. An example of the service state may be described below with reference to  FIG.  3   . The electronic device may determine whether to visit a destination, based on a service state determined for each destination. The electronic device may generate a route, based on one or more destinations (e.g., a first destination) determined to be visited. The electronic device may be a serving robot for accommodating an item universally needed at each destination and circularly driving itself, and the route may be a route set for a circular drive of the serving robot. 
     In operation  330 , the electronic device may sense the inventory of items on a plurality of serving trays. The electronic device may monitor a type and quantity of items on each serving tray, based on data collected using a sensor installed on each of the plurality of serving trays. For example, the electronic device may sense the items on each serving tray through vision recognition using a camera module. The electronic device may compare a prepared item with an item needed for each destination. For example, the electronic device may identify whether an item is recognized and a type (e.g., a type of side dish, a place, and tableware) and quantity of a recognized item. The electronic device may replenish an insufficient item when the number of prepared items on each serving tray is less than the number of items needed for each of a plurality of serving destinations included in a determined route. For example, the electronic device may request a user (e.g., a manager and an employee) to replenish inventory or may move to a region where inventory replenishment may be performed. 
     In operation  340 , the electronic device may perform interaction determined based on order information when reaching a destination (e.g., a first destination) to be visited. For example, the electronic device may perform an operation of indicating a serving tray accommodating an item needed for a visited destination through interaction. The electronic device may indicate the above-described serving tray through at least one of a display module, a sound output module, and a lighting module. The electronic device may output speech guiding to an item through the sound output module. The electronic device may illuminate light on a serving tray. The electronic device may slide a serving tray accommodating an item toward a customer by mechanically actuating the serving tray. The electronic device may provide guiding information customized for a service state of each destination or provide an item corresponding to an ordered menu item and a customer&#39;s characteristics at a destination. 
     In operation  350 , the electronic device may revisit each destination by repeating a circular drive. For example, the electronic device may identify a destination to be revisited, based on order information based on POS data updated in real time. The electronic device may distinguish a destination requesting a revisit from a destination refusing a revisit, based on a service refusal history of each destination. The electronic device may identify a user&#39;s intent to request or refuse a revisit service through questions and answers, gesture recognition, and a variety of feedback. In addition, the electronic device, other than the service refusal history, may determine whether a customer sits in a destination and finishes their meal through vision recognition. Furthermore, the electronic device may determine when to initiate a drive along a current route, based on the amount of time elapsing from a drive along a previous route. Operations  340  and  350  described above may be performed repeatedly after initiating a first circular drive. 
     However, operations  310  to  350  described above may not be limited to being performed sequentially, and each operation may be performed sequentially with or in parallel to another operation. For example, sensing inventory in operation  330  may be illustrated as being performed before operation  340 , but examples are not limited thereto. The electronic device may perform inventory sensing while performing operation  340 , between performing operations  340  and  350 , or while performing operation  350 . 
     The electronic device may be implemented as a serving robot and may operate in a public environment (e.g., a family restaurant and a franchise restaurant) involving a circular drive. 
       FIG.  4    is a diagram illustrating an example operation of determining a service state according to various example embodiments. 
     An electronic device (e.g., the electronic device  101  of  FIG.  1   ) may classify each destination into one of a plurality of service states, based on order information. For example, a service state may be classified into order waiting  410 , order complete  420 , service incomplete  430 , and serving complete  440 . However, the service state may not be limited to the foregoing example and may further include payment complete and destination empty. 
     
       
         
           
               
               
               
               
             
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                 Service state 
                 Required visit counts 
                 Required item 
               
               
                   
                   
               
             
            
               
                   
                 order waiting 
                 1 visit 
                 menu, water, 
               
               
                   
                   
                   
                 tableware, plate 
               
               
                   
                 order complete 
                 no visit required 
                 none 
               
               
                   
                 serving incomplete 
                 1 visit 
                 side dish 
               
               
                   
                 serving complete 
                 1 or more visits 
                 side dish 
               
               
                   
                   
               
            
           
         
       
     
     The order waiting  410  may be a state in which a customer sits in a destination and is yet to place an order. Delivery of a basic item (e.g., a menu, water, tableware, and a plate) may be needed for a destination of which a state is determined to be the order waiting  410 . The electronic device may guide a customer to a serving tray accommodating the basic item and provide the basic item to the customer by visiting the destination determined to be the order waiting  410  once. The order complete  420  may be a state in which a customer sitting in a destination orders an item and the ordered item is yet to be served. For example, the order complete  420  may refer to a state after receiving an order from at least one customer at a destination (e.g., a first destination) and before delivering at least one item indicated in the order from the destination. A destination determined to be the order complete  420  may not need a visit because there is no required item. The serving incomplete  430  may be a state in which some items are delivered among ordered items and a state in which a customer places an order, receives some ordered food items but not all ordered food items. The serving complete  440  may be a state in which all ordered items are delivered and a state in which all ordered food items are completely served. A destination determined to be the serving incomplete  430  or the serving complete  440  may need delivery of an auxiliary item related to an ordered item. The electronic device may guide a customer to a serving tray accommodating the auxiliary item and provide the auxiliary item to the customer by visiting the destination determined to be the serving incomplete  430  or the serving complete  440  one or more times. In addition, the electronic device, according to an order, may further guide the customer to a serving tray accommodating an additional item. 
     In  FIG.  4   , an example is illustrated as table D being the order waiting  410 , table A being the order complete  420 , table B being the serving incomplete  430 , and table C being the serving complete  440 . 
     Payment complete may be a state in which all items are completely served and payment for the served items is also completed. Destination empty may be a destination in which a seated customer has left or a customer is yet to be seated. 
       FIG.  5    is a flowchart illustrating an example operation of determining a route according to various example embodiments. 
     In operation  511 , the electronic device, as described above with reference to  FIG.  4   , may classify a service state of each destination. In operation  512 , the electronic device may determine, among a plurality of destinations, whether a first destination is in an order waiting state. In operation  513 , the electronic device, when the first destination is in an order waiting state, may determine whether the first destination has a previously visited history. For example, the electronic device may determine whether to visit the first destination in an order waiting state at least once. In operation  515 , the electronic device may exclude the first destination from a route when visiting the first destination in an order waiting state at least once. In operation  514 , the electronic device, when the first destination is not in an order waiting state, may determine whether a state of the first destination is serving incomplete or serving complete. In operation  515 , the electronic device may exclude the first destination from the route when the first destination is not in a serving incomplete or serving complete state, in other words, is in an order complete state. In operation  516 , the electronic device may determine whether a visit is needed for the first destination in a serving incomplete or serving complete state. 
     In operation  516  described above, the electronic device may determine whether the visit is needed according to a priority of each destination. The electronic device may determine a visiting order based on order information including at least one of seated information of each destination, order receiving information, order menu information, serving information, and whether an additional item has been requested. For example, the electronic device may form a route in a visiting order determined based on at least one of a seated time (e.g., a time elapsing from when a customer is seated) of each destination, order receiving information (e.g., receiving an order), or whether an additional item has been requested. The electronic device may determine a destination of which a seated time is the longest among the plurality of destinations to be a destination to be preferentially visited. Then, the electronic device may determine a destination identified to be in an order waiting state to be a destination to be visited. The destination in an order waiting state may need to be provided with a basic item for having a meal. In addition, the electronic device may determine a destination with a special order to be a destination to be visited with the next priority. As described above, the special order may require an additional item, and the additional item may include, for example, special tableware, tableware for sharing food, or additional tableware. On the other hand, a general order may be an order for a menu item only providing a main item. 
     In operation  517 , the electronic device may determine a route including the first destination being in an order waiting state and having no previously visited history and to which a visit is determined to be needed. For example, the electronic device may drive itself along a route (e.g., a default route) including a plurality of default destinations using a driver. The electronic device, when a drive along the route has been completed, in operation  516  described above, may modify the route by excluding, among the plurality of default destinations included in the default route, a destination to which a visit is determined to be skipped. The electronic device may drive itself along the modified route using the driver. 
     For reference, when determining a route, the electronic device may exclude, from the route, a destination where intent of refusal is expressed. The electronic device may exclude the destination from the route until a customer expressing the intent of refusal leaves. However, after the customer expressing the intent of refusal leaves, the electronic device may reset a service refusal history related to the intent of refusal expressed at the destination. 
     The electronic device may perform operations  512  to  517  described above after completing an individual circular drive and before initiating a next circular drive. However, examples are not limited thereto. 
       FIG.  6    is a diagram illustrating an example operation of sensing inventory according to various example embodiments. 
     An electronic device  600  (e.g., the electronic device  101  of  FIG.  1   ) may further include a sensor module that may sense an inventory item on each serving tray. The electronic device  600  may sense, through the sensor module, an inventory quantity of the inventory item on each serving tray accommodating each inventory item. Although in  FIG.  6   , for example, a camera module is illustrated as the sensor module, examples are not limited thereto. Various examples of the sensor module may be described below with reference to  FIG.  7   . 
     In operation  631 , the electronic device  600  may sense an inventory item and a quantity of the inventory item on each serving tray. For example, the electronic device  600  may capture an image including an inventory item on a serving tray through a camera sensor and may identify the type and quantity of the inventory item by analyzing the captured image. 
     In operation  632 , the electronic device  600  may compare an item needed for each destination with the sensed inventory item. For example, the electronic device  600  may match the type and quantity of the needed item, based on order information of each destination, with the types and quantities of inventory items on serving trays. In the example illustrated in  FIG.  6   , side dishes on a first serving tray may be needed for tables A and B. Cutlery and plates on a second serving tray may be needed for tables A, B, and E. Water and glasses on a third serving tray may be needed for tables A, B, and E. 
     In operation  633 , the electronic device  600 , in response to insufficient inventory as a result of comparing the item needed for each destination with the sensed inventory item, may transmit a message for requesting inventory replenishment to an external device. For example, the electronic device  600  may transmit a signal for requesting the supply of inventory items to a terminal (e.g., a wearable device) of a user (e.g., an employee). However, examples are not limited to the foregoing example. The electronic device  600  may move to a region (e.g., a storage where inventory is stocked or a region adjacent to the storage) for replenishing inventory when inventory is insufficient. 
     The electronic device  600  may perform a circular drive according to operation  340  when inventory is determined to be sufficient. 
       FIG.  7    is a diagram illustrating an example inventory sensor according to various example embodiments. 
     Electronic devices  700   a  and  700   b  may further include a sensor module including at least one of a camera sensor for capturing an inventory item on each serving tray, a weight sensor  710   a  for measuring the weight of the inventory item on each serving tray, and a distance sensor for measuring the distance from the distance sensor to the inventory item on each serving tray. 
     The electronic device  700   a  illustrates an example of an inventory sensor including the weight sensor  710   a . The weight sensor  710   a  may be included in each serving tray and may measure the weight of an object on a serving tray. The electronic device  700   a  may determine whether the object&#39;s weight detected by the weight sensor  710   a  in each serving tray is greater than or equal to a threshold weight. The electronic device  700   a , when the object&#39;s weight is less than the threshold weight, may determine that an inventory item on a serving tray is insufficient. The electronic device  700   b , when the object&#39;s weight is greater than the threshold weight, may determine that an inventory item on a serving tray is sufficient. 
     The electronic device  700   b  illustrates an example of an inventory sensor including a depth sensor  710   b . The depth sensor  710   b  may include, for example, a time-of-flight (ToF) sensor. The depth sensor  710   b  may measure a distance to an inventory item. In other words, the electronic device  700   b , through the distance to the inventory item measured by the depth sensor  710   b , may estimate a height, from the bottom of each serving tray, of stacked inventory items on a serving tray. The electronic device  700   b  may determine a quantity of inventory items, based on the estimated height of the stacked inventory items and a volume defined for each type of inventory item. 
     In the foregoing examples, a type of inventory items accommodated in each serving tray may be predetermined. For example, a first serving tray that is highest may accommodate side dishes, a second serving tray in the middle may accommodate tableware, and a third serving tray that is lowest may accommodate tableware related to an alcoholic beverage. The electronic devices  700   a  and  700   b  may determine the height and weight corresponding to a required quantity, based on item types designated for each serving tray. Accordingly, the electronic devices  700   a  and  700   b  may verify whether an inventory item is on a serving tray even though there is no vision recognition based on a camera or the vision recognition is unavailable. 
       FIG.  8    is a diagram illustrating an example operation of modifying a route for a revisit, according to various example embodiments. 
     An electronic device (e.g., the electronic device  101  of  FIG.  1   ) may determine a subsequent route (e.g., a current route) to a route (e.g., a previous route) based on a service refusal history received from a customer at a destination included in the route, when completing a drive along the route. For example, the electronic device, after performing a circular drive along the previous route in operation  340 , may determine the current route in operation  350 . For reference, the electronic device may determine the route, based on whether each destination has completed payment except for the service refusal history. For example, the electronic device, by excluding a destination having completed payment among destinations included in the previous route, may generate the current route. 
     For example, the electronic device, before initiating a drive along the subsequent route (e.g., the current route), may determine the subsequent route, based on seated information of each destination in the subsequent route and a detection result of a predefined action at each destination. In operation  811 , the electronic device may determine whether at least one customer sits in each of destinations potentially to be visited in the current route. For example, the electronic device, by analyzing an image capturing a destination through a camera module, may detect a customer within a region corresponding to the destination. In operation  815 , the electronic device may exclude a destination in which no one sits from destinations in the current route. In other words, the electronic device may exclude a destination with no customers from the current route. 
     In operation  812 , the electronic device may determine whether a predefined action is detected in a destination in which at least one customer sits among the destinations in the current route. For example, the electronic device may detect, as a predefined action, whether a customer is eating. The electronic device may identify a customer&#39;s action by analyzing an image capturing a destination. The electronic device may determine whether the customer performs an action of holding tableware and bringing their hands from a plate to the mouth one or more times within a threshold time. In operation  814 , the electronic device may determine whether a threshold time elapses from when all serving has been completed for a destination where a predefined action is not detected. In operation  815 , the electronic device may exclude, from the destinations of the current route, a destination where a predefined action is not detected and a threshold time elapses after all serving has been completed. In other words, the electronic device may exclude a destination where a customer has finished eating and the threshold time has elapsed from the current route. 
     According to operations  811 ,  812 ,  814 , and  815  described above, the electronic device may modify the current route by maintaining or excluding destinations potentially included in the current route. 
     In operation  813 , the electronic device, after determining the current route, may determine whether a waiting time for driving again elapses after a drive along the previous route. The waiting time for driving again may be a threshold time interval set between previous and current circular drives and may be set for cyclical, circular serving that is temporally spaced apart from another serving. For example, the electronic device may determine from when to initiate a drive along the subsequent route (e.g., the current route), based on a waiting time elapsing after completing the drive along the route (e.g., the previous route). In operation  820 , the electronic device may sequentially visit destinations along the current route when the waiting time for driving again has elapsed after a previous drive. In other words, the electronic device may perform serving along the current route when the waiting time for driving again elapses after completing serving along the previous route. 
     In operation  831 , the electronic device may determine whether a person (e.g., a customer) at a first destination expresses intent of refusal. The intent of refusal may be intent to refuse a service provided by a serving robot. The electronic device may determine the intent of refusal, based on at least one of a voice input received from a customer, a gesture input based on vision recognition, and other inputs. For example, the electronic device may receive a voice input through a microphone, identify speech from the voice input through a speech recognition engine (e.g., a machine-learning model), and determine whether the identified speech includes intent of refusal. The electronic device may identify a customer&#39;s gesture from an image capturing the customer and determine whether the identified gesture (e.g., shaking their head) includes intent of refusal. As another example, the electronic device may also verify the intent of refusal through a direct input (e.g., a touch input) to an input module from a customer. When the intent of refusal is verified at the first destination, the electronic device may record the intent of refusal in a service refusal history received from the customer at the first destination. 
     In operation  832 , the electronic device, in response to the intent of refusal expressed by the customer at the first destination, may determine whether an additional service is needed. The additional service may be a service involving the intervention of a user (e.g., an employee). In operation  833 , the electronic device, in response to determining that the additional service is needed, may receive a feedback input (e.g., a voice input, a gesture input, and a direct input) from a customer and may inform a manager (e.g., the user) of the received feedback input. For example, the electronic device may transmit the feedback input received from the customer to a terminal (e.g., a wearable device) of the user. After completing the current circular drive, in operation  834 , the electronic device may exclude, from a next route, the first destination where there is the customer that expressed the intent of refusal. The next route may be a route where the electronic device circulates after completing a circular drive along a current route. 
     In operation  835 , unlike operation  834  described above, the electronic device may perform a dynamic interaction at the first destination. An example of a dynamic interaction is described below with reference to  FIGS.  9  to  13   . In operation  836 , the electronic device may include the first destination in the next route since the customer at the first destination did not express an intent of refusal. 
     The electronic device, by sequentially visiting the destinations in the current route and performing operations  831  to  836  described above, may maintain each destination in the next route or exclude each destination from the next route. 
     In operation  837 , the electronic device may detect a service state change from at least one destination. For example, the electronic device may repeatedly revisit along a route, as illustrated in  FIG.  8   , before a service state change occurs. As another example, the electronic device, in response to the service state change from at least one destination, may return to operation  320 , generate a new route, and perform serving along the new route. 
       FIG.  9    is a diagram illustrating an example operation of performing a circular drive on a plurality of destinations having the same serving state by an electronic device according to various example embodiments. 
     As described above, an electronic device  900  (e.g., the electronic device  101  of  FIG.  1   ) may determine whether to visit each destination, based on a service state of each destination, and may drive itself along a route including a destination determined to be visited. The electronic device  900  reaching each destination may perform an interaction corresponding to a service state of each destination. 
     In the example illustrated in  FIG.  9   , destinations  910 ,  920 ,  930 , and  940  included in the route may be in an order waiting state. The electronic device  900 , while moving along the route using a driver, in response to not receiving an order from a first destination on which identified is seated information indicating at least one seated customer, may perform an operation of outputting information indicating a serving tray accommodating a basic item when reaching the first destination. For example, the outputting information indicating a serving tray accommodating a basic item may include at least one of outputting, on a display module, visual information indicating the serving tray accommodating the basic item, outputting, from a sound output module, auditory information indicating the serving tray accommodating the basic item, and emitting light indicating the serving tray accommodating the basic item through a lighting module. For example, a second serving tray  902  among a plurality of serving trays may accommodate the basic item (e.g., a menu, water and tableware). The electronic device  900  may output speech sound indicating the second serving tray and emit light on the second serving tray. 
       FIG.  10    is a diagram illustrating an example drive along a route including a destination to which a special order is received by an electronic device according to various example embodiments. 
     An electronic device  1000  may store items for each type on each of the plurality of serving trays and may travel along a circulation route. For example, a first serving tray  1001  of the electronic device  1000  may accommodate an auxiliary item (e.g., a side dish including pickles and sauce). A second serving tray  1002  may accommodate a basic item. A third serving tray  1003  may accommodate an additional item (e.g., kids tableware and a pizza cutter). The electronic device  1000  may perform an interaction based on a service state of a destination at each destination to be visited while driving itself along a route. 
     In the example illustrated in  FIG.  10   , the electronic device  1000  may sequentially visit a first destination  1021  (e.g., table B), a second destination  1041  (e.g., table D), a third destination  1031  (e.g., table C), and a fourth destination  1011  (e.g., table A). Some of ordered items may have been delivered to the first, second, third, and fourth destinations  1021 ,  1041 ,  1031 , and  1011 . 
     The electronic device  1000 , in response to recognizing delivery of at least one item indicated in an order received from a destination, may perform an operation of indicating a serving tray accommodating an auxiliary item relevant to the at least one item. For example, the electronic device  1000  may perform at least one of outputting, on a display module, an image indicating the serving tray accommodating the auxiliary item, outputting, from a sound output module, speech sound indicating the serving tray accommodating the auxiliary item, and emitting, from a lighting module, light indicating the serving tray accommodating the auxiliary item. The lighting module may emit light toward an item on a serving tray or light from one side of the serving tray. In the example illustrated in  FIG.  10   , the electronic device  1000 , at the third destination  1031 , may output a guide  1032  (e.g., speech sound and text) to the first serving tray  1001  accommodating an auxiliary item (e.g., sauce) accompanied by one (e.g., steak) of the delivered items. The electronic device  1000 , at the fourth destination  1011 , may output a guide  1012  to the first serving tray  1001  accommodating an auxiliary item (e.g., pickles) accompanied by a delivered item (e.g., a salad). 
     In addition, the electronic device  1000 , based on a type of order received independently from a service state, may determine a serving tray to be guided at each destination. For example, an order (e.g., a pizza order) involving an additional item (e.g., kids tableware and tableware for sharing food) may be received from the first destination  1021 . The electronic device  1000 , in response to receiving an order for which an additional item is needed from a customer at the first destination  1021 , may perform an operation of indicating a serving tray accommodating the additional item at the first destination  1021 . For example, the electronic device  1000  may perform at least one of outputting, on a display module  1009 , an image indicating the serving tray accommodating the auxiliary item, outputting, from a sound output module, speech sound indicating the serving tray accommodating the auxiliary item, and emitting, from a lighting module, light indicating the serving tray accommodating the auxiliary item. In the example illustrated in  FIG.  10   , the electronic device  1000  may output a guide  1022  to the third serving tray  1003  accommodating tableware for sharing food (e.g., a pizza cutter) as an additional item needed for an item (e.g., pizza) delivered to the first destination  1021 . In addition, the electronic device  1000  may output the guide  1022  to the third serving tray  1003  accommodating an additional item (e.g., kids tableware) for a child customer among customers at the first destination  1021 . 
     The electronic device  1000  may guide a customer to a serving tray (e.g., the second serving tray  1002 ) accommodating a basic item at a destination where all auxiliary and additional items needed to be provided in a service state of the destination have been provided. For example, at the second destination  1041 , an auxiliary item (e.g., ketchup) accompanied by an item (e.g., French fries) delivered in a serving incomplete state may have been delivered already. The electronic device  1000  may output a guide  1042  to a basic item at the second destination  1041 . 
       FIG.  11    is a diagram illustrating an example drive along a route including a plurality of destinations having different service states by an electronic device according to various example embodiments. 
     An electronic device  1100 , when a drive along a route is completed, in response to not delivering, to a first destination, at least one item indicated in an order received from the first destination, may exclude the first destination from the route. For example, the electronic device  1100  may exclude, from the route, a destination having completed payment or a destination where an order has been received and at least one item indicated in the order is yet to be delivered. For example, in the example illustrated in  FIG.  11   , a fourth destination  1111  may be in a payment complete state and may not need to be visited. A third destination  1131  may be in an order complete state where an order has been received but none of the ordered items have been delivered at all. The electronic device  1100  may determine not to visit the third and fourth destinations  1131  and  1111  respectively in operations  1132  and  1112  and exclude the third and fourth destinations  1131  and  1111  from a route  1190 . Accordingly, the electronic device  1100 , unlike the description provided with reference to  FIGS.  9  and  10   , may drive itself along the route  1190  modified from a default route. 
     However, examples are not limited to a destination in an order complete state, such as the third destination  1131 , being always excluded from a route. The electronic device  1100  may include the destination in an order complete state in the route when the destination does not have a visited history. The electronic device  1100  may output information guiding a customer to a serving tray (e.g., a second serving tray  1102 ) accommodating a basic item at a destination having no visited history using at least one of a display module  1109 , a sound output module, and a lighting module. When there is no visited history, basic tableware needed for having a meal may not be set. As another example, the electronic device  1100  may visit a destination in an order complete state in response to a customer&#39;s request. The electronic device  1100 , in response to receiving a request for an additional item (e.g., water and glasses) from a customer, may guide the customer to a serving tray (e.g., a third serving tray  1103 ) accommodating the additional item by visiting a destination where the customer is located. 
     In  FIG.  11   , a first destination  1121  may be in a serving incomplete state and auxiliary and additional items related to an ordered item (e.g., pizza) may have been delivered already. The electronic device  1100 , in response to a plurality of visits to the first destination  1121  in a serving incomplete state, when reaching the first destination  1121 , may provide a guide  1122  to a serving tray (e.g., the second serving tray  1102 ) accommodating a basic item. A second destination  1141  may be in a serving complete state, and the electronic device  1100  may provide a guide  1142  to a serving tray (e.g., a first serving tray  1101 ) accommodating an auxiliary item. 
       FIG.  12    is a diagram illustrating an example of skipping some destinations when inventory is insufficient during a circular drive by an electronic device according to various example embodiments. 
     An electronic device  1200 , in response to insufficient inventory while driving a route, may continue a drive to the remaining first destination of the first destination and a second destination of the route while skipping the second destination for which an inventory item is insufficient for a needed item. 
     The same example of order information of each destination as the example provided in  FIG.  11    is illustrated in  FIG.  12   . The electronic device  1200  may not visit third and fourth destinations  1231  and  1211  respectively in operations  1232  and  1212 . The electronic device  1200  may provide a guide  1222  to a second serving tray accommodating a basic item, similar to the description provided with reference to  FIG.  11   . In the example illustrated in  FIG.  12   , the electronic device  1200  may sequentially visit first and second destinations  1221  and  1241 . The electronic device  1200  may detect, from a first serving tray  1201 , insufficient inventory of an auxiliary item (e.g., pickles) needed for the second destination  1241  on the way to the second destination  1241 . The electronic device  1200 , while driving itself along a route  1290 , may skip a visit to the second destination  1241  and visit the remaining destination. 
     As another example, the electronic device  1200 , while driving itself along the route  1290 , when a customer at one destination takes a greater quantity of an item than a quantity estimated to be needed, may have inventory of which the quantity is less than a quantity needed for a destination to be visited next. The electronic device  1200  may skip a visit to the destination scheduled to be visited next. In other words, the electronic device  1200  may monitor inventory in real time during a circular drive and may dynamically determine whether to visit each destination when the monitored inventory is insufficient. The electronic device  1200 , when determining to skip a visit to a destination during the circular drive, may skip the destination while maintaining a route or modify the route by excluding the destination. 
       FIG.  13    is a diagram illustrating an example operation of reporting insufficient inventory to a manager by an electronic device according to various example embodiments. 
     An electronic device  1300  may monitor inventory of each serving tray during a drive along a route  1391 . When detecting insufficient inventory during the drive, the electronic device  1300  may skip a visit to a destination needing an item of which inventory is insufficient. The electronic device  1300  may form a new route  1392  by excluding some destinations from the route  1391 . For example, in the example illustrated in  FIG.  13   , the electronic device  1300 , which drove along the route  1391 , in the middle of the route  1391 , may detect that an auxiliary item (e.g., a side dish) and an additional item (e.g., water and glasses) are insufficient. In other words, the electronic device  1300  may detect insufficient inventory from first and third serving trays  1301  and  1303 . As described above, the electronic device  1300 , through a camera sensor  1310 , may monitor inventory of the first serving tray  1301 , a second serving tray  1302 , and the third serving tray  1303 . 
     For example, the electronic device  1300 , in response to detecting insufficient inventory, may update an insufficient inventory situation in a database having recorded a customer&#39;s request. As another example, the electronic device  1300  may notify a user  1380  (e.g., an employee) of insufficient inventory. The electronic device  1300  may transmit a message including information  1350  (e.g., a type of insufficient item on the first and third serving trays  1301  and  1303 ) notifying the user  1380  of the insufficient inventory on a terminal (e.g., a wearable device and a device for executing an application for a manager) of the user  1380 . Yet another example, the electronic device  1300  may move to a location near the user  1380  and directly request the user  1380  to replenish inventory by outputting, to the user  1380 , the information  1350  notifying the user  1380  of the insufficient inventory through speech sound or on a display module. 
     In addition, other than notifying of the insufficient inventory, the electronic device  1300 , when completing serving items by visiting each destination, may report serving completion to a POS device and a terminal (e.g., a wearable device) of the user  1380 . 
     The electronic device  1300  may automatically determine a destination to be visited, based on each destination&#39;s service state determined based on order information, while autonomously, circular driving in a service space (e.g., a restaurant). The electronic device  1300  may guide a customer to a serving tray accommodating an item needed for each destination in each service state while driving itself along a route including the automatically determined destination. 
     While the disclosure has been illustrated and described with reference to various example embodiments, it will be understood that the various example embodiments are intended to be illustrative, not limiting. It will be further understood by those skilled in the art that various changes in form and detail may be made without departing from the true spirit and full scope of the disclosure, including the appended claims and their equivalents. It will also be understood that any of the embodiment(s) described herein may be used in conjunction with any other embodiment(s) described herein.