Patent Publication Number: US-11648161-B2

Title: Robot

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to and the benefit of Korean Patent Application No. 10-2019-0148108, filed on Nov. 18, 2019 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety. 
     FIELD OF THE DISCLOSURE 
     The present invention relates to a robot. 
     Robots are machines that automatically process given tasks or operate with their own capabilities. The application fields of robots are generally classified into industrial robots, medical robots, aerospace robots, and underwater robots. Recently, communication robots that can communicate with humans by voices or gestures have been increasing. 
     In recent years, there has been a trend of increasing in number of guidance robots, which provide a variety of guidance services at the airport, government offices, etc., a transport robot for transporting goods, or a boarding robot on which the user boards. 
     An example of the boarding robot includes a boarding robot and a boarding robot operation system including the same, which is disclosed in Korea Patent Publication No. 10-1273604 published on Jun. 11, 2013. In the boarding robot, a traveling body is disposed on a lower portion of a user seating portion, the user seating portion is coupled to the traveling body so as to be adjustable in height, a steering device for controlling a driving wheel is provided in front of the traveling body, and a controller for adjusting a traveling state is provided in front of the traveling body. 
     The boarding robot disclosed in Korean Patent Publication No. 10-1273604 is provided with a steering device in front of the traveling body. As a result, the user&#39;s boarding may be uncomfortable in that the user should be seated at a user seating portion while avoiding the steering device. 
     Another example of the boarding robot includes a boarding robot that employs an omnidirectional wheel disclosed in Korea Patent Publication No. 10-2015-0121753, published on Oct. 30, 2015). The boarding robot is provided with a steering device installed to be disposed in front of a seat so as to indicate a traveling direction of the boarding robot and a display device installed on an upper end of a main shaft. The steering device may be a joystick device that allows the user to input the travel direction by using a direction indicating bar. The joystick device includes a stick joystick and an armrest and is fixedly installed and supported on the main shaft by a coupling frame. 
     The steering device disclosed in Korean Patent Publication No. 10-2015-0121753 is exposed to the outside at all times. As a result, it is easy to be contaminated by foreign substances such as dust, and the steering device is easily damaged by external impact. 
     SUMMARY 
     Embodiments provide a robot that is capable of minimizing contamination and damage of a steering. 
     Embodiments also provide a robot that is capable of minimizing possibility of theft. 
     In an embodiment, a robot includes: a seating body provided with a seat and an armrest body; and a steering, wherein a steering housing having an opening in an upper portion thereof and an inner space therein is disposed on the armrest body, and the steering includes: a steering body; and an elevator configured to elevate the steering body. 
     The steering body may be provided with an upper portion on which a handle is provided and a lower portion passing through the opening, and the lower portion may be accommodated in the inner space. 
     The elevator may be accommodated in the inner space and be connected to the lower portion of the steering body to elevate the steering body. 
     An accommodation portion into which the steering housing is inserted and accommodated may be recessed from the armrest body. 
     The steering may further include an inner cover connected to the steering body to block the opening when the steering body ascends. 
     The elevator may be configured to allow the handle to ascend above the opening or descend to the opening. 
     When the handle descends to the opening, the opening may be configured to surround an outer circumference of the handle. 
     A vertical length of the inner space may be longer than a vertical length of the steering body. 
     The elevator may include: a motor accommodated in the steering housing; and a lever which is connected to a rotation shaft of the motor to rotate and to which a connection shaft disposed on a lower portion of the steering body is connected. 
     A guide hole configured to guide the connection shaft may be lengthily defined in the lever in a longitudinal direction of the lever. 
     The robot may further include a display rotatably connected to the steering housing. 
     The display may have a size greater than a size of the opening, and when the display rotates to cover a top surface of the steering housing, the display may be configured to cover the opening. 
     The display may be connected to a front end of the steering housing. The display may have a size greater than a size of a top surface of the steering housing. When the display rotates to cover the top surface of the steering housing, the display may be configured to cover a boundary between the steering housing and the armrest body. 
     In another embodiment, a robot includes: a seating body provided with a seat and a pair of armrest bodies, in which accommodation portions are defined, respectively; a steering housing which is disposed in one accommodation portion of the pair of armrest bodies; a steering disposed in the steering housing; and an accessory disposed in the other accommodation portion of the pair of armrest bodies. 
     An opening may be defined in an upper portion of the steering housing, and an inner space may be defined in the steering housing. 
     A handle may be disposed on an upper portion of the steering, and the steering may pass through the opening. A lower portion of the steering may be accommodated in an inner space. 
     The robot may include the elevator accommodated in the inner space to elevate the steering body. 
     The steering housing and the accessory may be selectively disposed on the pair of armrest bodies. 
     The robot may further include a display rotatably disposed to the steering housing. 
     A display connection portion to which the display is connected may be disposed in the steering housing. 
     The display connection portion may be horizontally spaced apart from the steering body when the steering body ascends. 
     The display may have a length that is longer than a distance between the display connection portion and the opening. 
     The steering may further include an inner cover connected to the steering body to block the opening when the steering body ascends. 
     When the steering body descends, and the display rotates to cover a top surface of the steering housing, the display may be disposed above the opening to cover the opening. 
     In further another embodiment, a robot includes: a seating body provided with a seat and an armrest, wherein an opening is defined in the armrest, and an inner space is defined in the armrest; a steering body provided with an upper portion on which a handle is provided and a lower portion passing through the opening, the lower portion being accommodated in the inner space; and an elevator accommodated in the inner space, the elevator being connected to the lower portion of the steering body to elevate the steering body. 
     The robot may further include an inner cover connected to the steering body to block the opening when the steering body ascends. 
     A vertical length of the inner space may be longer than a vertical length of the steering body. 
     The elevator may include: a motor accommodated in the inner space; and a lever which is connected to a rotation shaft of the motor to rotate and to which a connection shaft disposed on a lower portion of the steering body is connected. 
     The robot may further include a display rotatably connected to the steering housing. The display may be rotatably connected to the steering housing to cover the opening when the display rotates to cover a top surface of the steering housing. 
     The details of one or more implementations are set forth in the accompanying drawings and the description below. Other features will be apparent from the description and drawings, and from the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a view illustrating an AI device constituting a robot system according to an embodiment. 
         FIG.  2    is a view illustrating an AI server of a robot system according to an embodiment. 
         FIG.  3    is a view illustrating an AI system to which a robot system according to an embodiment is applied. 
         FIG.  4    is a perspective view of a robot according to an embodiment. 
         FIG.  5    is a plan view of the robot according to an embodiment. 
         FIG.  6    is a front view of the robot according to an embodiment. 
         FIG.  7    is a side view of the robot according to an embodiment. 
         FIG.  8    is a perspective view of a steering body and a display when the steering body of  FIG.  4    descends. 
         FIG.  9    is a perspective view illustrating a state in which the display of  FIG.  8    covers the steering body. 
         FIG.  10    is a cross-sectional view taken along line A-A of  FIG.  4   . 
         FIG.  11    is a cross-sectional view taken along line B-B of  FIG.  8   . 
         FIG.  12    is a cross-sectional view taken along line C-C of  FIG.  9   . 
         FIG.  13    is a perspective view illustrating a state in which a sub steering is disposed on an armrest according to an embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Hereinafter, detailed embodiments will be described in detail with reference to the accompanying drawings. 
     &lt;Robot&gt; 
     A robot may refer to a machine that automatically processes or operates a given task by its own ability. In particular, a robot having a function of recognizing an environment and performing a self-determination operation may be referred to as an intelligent robot. 
     Robots may be classified into industrial robots, medical robots, home robots, military robots, and the like according to the use purpose or field. 
     The robot includes a driving unit may include an actuator or a motor and may perform various physical operations such as moving a robot joint. In addition, a movable robot may include a wheel, a brake, a propeller, and the like in a driving unit, and may travel on the ground through the driving unit or fly in the air. 
     &lt;Artificial Intelligence (AI)&gt; 
     Artificial intelligence refers to the field of studying artificial intelligence or methodology for making artificial intelligence, and machine learning refers to the field of defining various issues dealt with in the field of artificial intelligence and studying methodology for solving the various issues. Machine learning is defined as an algorithm that enhances the performance of a certain task through a steady experience with the certain task. 
     An artificial neural network (ANN) is a model used in machine learning and may mean a whole model of problem-solving ability which is composed of artificial neurons (nodes) that form a network by synaptic connections. The artificial neural network can be defined by a connection pattern between neurons in different layers, a learning process for updating model parameters, and an activation function for generating an output value. 
     The artificial neural network may include an input layer, an output layer, and optionally one or more hidden layers. Each layer includes one or more neurons, and the artificial neural network may include a synapse that links neurons to neurons. In the artificial neural network, each neuron may output the function value of the activation function for input signals, weights, and deflections input through the synapse. 
     Model parameters refer to parameters determined through learning and include a weight value of synaptic connection and deflection of neurons. A hyperparameter means a parameter to be set in the machine learning algorithm before learning, and includes a learning rate, a repetition number, a mini batch size, and an initialization function. 
     The purpose of the learning of the artificial neural network may be to determine the model parameters that minimize a loss function. The loss function may be used as an index to determine optimal model parameters in the learning process of the artificial neural network. 
     Machine learning may be classified into supervised learning, unsupervised learning, and reinforcement learning according to a learning method. 
     The supervised learning may refer to a method of learning an artificial neural network in a state in which a label for learning data is given, and the label may mean the correct answer (or result value) that the artificial neural network may infer when the learning data is input to the artificial neural network. The unsupervised learning may refer to a method of learning an artificial neural network in a state in which a label for learning data is not given. The reinforcement learning may refer to a learning method in which an agent defined in a certain environment learns to select a behavior or a behavior sequence that maximizes cumulative compensation in each state. 
     Machine learning, which is implemented as a deep neural network (DNN) including a plurality of hidden layers among artificial neural networks, is also referred to as deep learning, and the deep learning is part of machine learning. In the following, machine learning is used to mean deep learning. 
     &lt;Self-Driving&gt; 
     Self-driving refers to a technique of driving for oneself, and a self-driving vehicle refers to a vehicle that travels without an operation of a user or with a minimum operation of a user. 
     For example, the self-driving may include a technology for maintaining a lane while driving, a technology for automatically adjusting a speed, such as adaptive cruise control, a technique for automatically traveling along a predetermined route, and a technology for automatically setting and traveling a route when a destination is set. 
     The vehicle may include a vehicle having only an internal combustion engine, a hybrid vehicle having an internal combustion engine and an electric motor together, and an electric vehicle having only an electric motor, and may include not only an automobile but also a train, a motorcycle, and the like. 
     At this time, the self-driving vehicle may be regarded as a robot having a self-driving function. 
       FIG.  1    illustrates an AI device  100  including a robot according to an embodiment of the present invention. 
     The AI device  100  may be implemented by a stationary device or a mobile device, such as a TV, a projector, a mobile phone, a smartphone, a desktop computer, a notebook, a digital broadcasting terminal, a personal digital assistant (PDA), a portable multimedia player (PMP), a navigation device, a tablet PC, a wearable device, a set-top box (STB), a DMB receiver, a radio, a washing machine, a refrigerator, a desktop computer, a digital signage, a robot, a vehicle, and the like. 
     Referring to  FIG.  1   , the AI device  100  may include a communicator  110 , an input interface  120 , a learning processor  130 , a sensor  140 , an output interface  150 , a memory  170 , and a processor  180 . 
     The communicator  110  may transmit and receive data to and from external devices such as other AI devices  100   a  to  100   e  and the AI server  500  by using wire/wireless communication technology. For example, the communicator  110  may transmit and receive sensor information, a user input, a learning model, and a control signal to and from external devices. 
     The communication technology used by the communicator  110  includes GSM (Global System for Mobile communication), CDMA (Code Division Multi Access), LTE (Long Term Evolution), 5G, WLAN (Wireless LAN), Wi-Fi (Wireless-Fidelity), Bluetooth™, RFID (Radio Frequency Identification), Infrared Data Association (IrDA), ZigBee, NFC (Near Field Communication), and the like. 
     The input interface  120  may acquire various kinds of data. 
     At this time, the input interface  120  may include a camera for inputting a video signal, a microphone for receiving an audio signal, and a user input interface for receiving information from a user. The camera or the microphone may be treated as a sensor, and the signal acquired from the camera or the microphone may be referred to as sensing data or sensor information. 
     The input interface  120  may acquire a learning data for model learning and an input data to be used when an output is acquired by using learning model. The input interface  120  may acquire raw input data. In this case, the processor  180  or the learning processor  130  may extract an input feature by preprocessing the input data. 
     The learning processor  130  may learn a model composed of an artificial neural network by using learning data. The learned artificial neural network may be referred to as a learning model. The learning model may be used to an infer result value for new input data rather than learning data, and the inferred value may be used as a basis for determination to perform a certain operation. 
     At this time, the learning processor  130  may perform AI processing together with the learning processor  540  of the AI server  500 . 
     At this time, the learning processor  130  may include a memory integrated or implemented in the AI device  100 . Alternatively, the learning processor  130  may be implemented by using the memory  170 , an external memory directly connected to the AI device  100 , or a memory held in an external device. 
     The sensor  140  may acquire at least one of internal information about the AI device  100 , ambient environment information about the AI device  100 , and user information by using various sensors. 
     Examples of the sensors included in the sensor  140  may include a proximity sensor, an illuminance sensor, an acceleration sensor, a magnetic sensor, a gyro sensor, an inertial sensor, an RGB sensor, an IR sensor, a fingerprint recognition sensor, an ultrasonic sensor, an optical sensor, a microphone, a lidar, and a radar. 
     The output interface  150  may generate an output related to a visual sense, an auditory sense, or a haptic sense. 
     At this time, the output interface  150  may include a display unit for outputting time information, a speaker for outputting auditory information, and a haptic module for outputting haptic information. 
     The memory  170  may store data that supports various functions of the AI device  100 . For example, the memory  170  may store input data acquired by the input interface  120 , learning data, a learning model, a learning history, and the like. 
     The processor  180  may determine at least one executable operation of the AI device  100  based on information determined or generated by using a data analysis algorithm or a machine learning algorithm. The processor  180  may control the components of the AI device  100  to execute the determined operation. 
     To this end, the processor  180  may request, search, receive, or utilize data of the learning processor  130  or the memory  170 . The processor  180  may control the components of the AI device  100  to execute the predicted operation or the operation determined to be desirable among the at least one executable operation. 
     When the connection of an external device is required to perform the determined operation, the processor  180  may generate a control signal for controlling the external device and may transmit the generated control signal to the external device. 
     The processor  180  may acquire intention information for the user input and may determine the user&#39;s requirements based on the acquired intention information. 
     The processor  180  may acquire the intention information corresponding to the user input by using at least one of a speech to text (STT) engine for converting speech input into a text string or a natural language processing (NLP) engine for acquiring intention information of a natural language. 
     At least one of the STT engine or the NLP engine may be configured as an artificial neural network, at least part of which is learned according to the machine learning algorithm. At least one of the STT engine or the NLP engine may be learned by the learning processor  130 , may be learned by the learning processor  540  of the AI server  500 , or may be learned by their distributed processing. 
     The processor  180  may collect history information including the operation contents of the AI apparatus  100  or the user&#39;s feedback on the operation and may store the collected history information in the memory  170  or the learning processor  130  or transmit the collected history information to the external device such as the AI server  500 . The collected history information may be used to update the learning model. 
     The processor  180  may control at least part of the components of AI device  100  so as to drive an application program stored in memory  170 . Furthermore, the processor  180  may operate two or more of the components included in the AI device  100  in combination so as to drive the application program. 
       FIG.  2    illustrates an AI server  500  connected to a robot according to an embodiment of the present invention. 
     Referring to  FIG.  2   , the AI server  500  may refer to a device that learns an artificial neural network by using a machine learning algorithm or uses a learned artificial neural network. The AI server  500  may include a plurality of servers to perform distributed processing, or may be defined as a 5G network. At this time, the AI server  500  may be included as a partial configuration of the AI device  100 , and may perform at least part of the AI processing together. 
     The AI server  500  may include a communicator  510 , a memory  530 , a learning processor  540 , a processor  520 , and the like. 
     The communicator  510  can transmit and receive data to and from an external device such as the AI device  100 . 
     The memory  530  may include a model storage unit  531 . The model storage unit  531  may store a learning or learned model (or an artificial neural network  531   a ) through the learning processor  540 . 
     The learning processor  540  may learn the artificial neural network  531   a  by using the learning data. The learning model may be used in a state of being mounted on the AI server  500  of the artificial neural network, or may be used in a state of being mounted on an external device such as the AI device  100 . 
     The learning model may be implemented in hardware, software, or a combination of hardware and software. If all or part of the learning models are implemented in software, one or more instructions that constitute the learning model may be stored in memory  530 . 
     The processor  520  may infer the result value for new input data by using the learning model and may generate a response or a control command based on the inferred result value. 
       FIG.  3    illustrates an AI system  1  according to an embodiment of the present invention. 
     Referring to  FIG.  3   , in the AI system  1 , at least one of an AI server  500 , a robot  100   a , a self-driving vehicle  100   b , an XR device  100   c , a smartphone  100   d , or a home appliance  100   e  is connected to a cloud network  10 . The robot  100   a , the self-driving vehicle  100   b , the XR device  100   c , the smartphone  100   d , or the home appliance  100   e , to which the AI technology is applied, may be referred to as AI devices  100   a  to  100   e.    
     The cloud network  10  may refer to a network that forms part of a cloud computing infrastructure or exists in a cloud computing infrastructure. The cloud network  10  may be configured by using a 3G network, a 4G or LTE network, or a 5G network. 
     That is, the devices  100   a  to  100   e  and  500  configuring the AI system  1  may be connected to each other through the cloud network  10 . In particular, each of the devices  100   a  to  100   e  and  500  may communicate with each other through a base station, but may directly communicate with each other without using a base station. 
     The AI server  500  may include a server that performs AI processing and a server that performs operations on big data. 
     The AI server  500  may be connected to at least one of the AI devices constituting the AI system  1 , that is, the robot  100   a , the self-driving vehicle  100   b , the XR device  100   c , the smartphone  100   d , or the home appliance  100   e  through the cloud network  10 , and may assist at least part of AI processing of the connected AI devices  100   a  to  100   e.    
     At this time, the AI server  500  may learn the artificial neural network according to the machine learning algorithm instead of the AI devices  100   a  to  100   e , and may directly store the learning model or transmit the learning model to the AI devices  100   a  to  100   e.    
     At this time, the AI server  500  may receive input data from the AI devices  100   a  to  100   e , may infer the result value for the received input data by using the learning model, may generate a response or a control command based on the inferred result value, and may transmit the response or the control command to the AI devices  100   a  to  100   e.    
     Alternatively, the AI devices  100   a  to  100   e  may infer the result value for the input data by directly using the learning model, and may generate the response or the control command based on the inference result. 
     Hereinafter, various embodiments of the AI devices  100   a  to  100   e  to which the above-described technology is applied will be described. The AI devices  100   a  to  100   e  illustrated in  FIG.  3    may be regarded as a specific embodiment of the AI device  100  illustrated in  FIG.  1   . 
     &lt;AI+Robot&gt; 
     The robot  100   a , to which the AI technology is applied, may be implemented as a guide robot, a carrying robot, a cleaning robot, a wearable robot, an entertainment robot, a pet robot, an unmanned flying robot, or the like. 
     The robot  100   a  may include a robot control module for controlling the operation, and the robot control module may refer to a software module or a chip implementing the software module by hardware. 
     The robot  100   a  may acquire state information about the robot  100   a  by using sensor information acquired from various kinds of sensors, may detect (recognize) surrounding environment and objects, may generate map data, may determine the route and the travel plan, may determine the response to user interaction, or may determine the operation. 
     The robot  100   a  may use the sensor information acquired from at least one sensor among the lidar, the radar, and the camera so as to determine the travel route and the travel plan. 
     The robot  100   a  may perform the above-described operations by using the learning model composed of at least one artificial neural network. For example, the robot  100   a  may recognize the surrounding environment and the objects by using the learning model, and may determine the operation by using the recognized surrounding information or object information. The learning model may be learned directly from the robot  100   a  or may be learned from an external device such as the AI server  500 . 
     At this time, the robot  100   a  may perform the operation by generating the result by directly using the learning model, but the sensor information may be transmitted to the external device such as the AI server  500  and the generated result may be received to perform the operation. 
     The robot  100   a  may use at least one of the map data, the object information detected from the sensor information, or the object information acquired from the external apparatus to determine the travel route and the travel plan, and may control the driving unit such that the robot  100   a  travels along the determined travel route and travel plan. 
     The map data may include object identification information about various objects arranged in the space in which the robot  100   a  moves. For example, the map data may include object identification information about fixed objects such as walls and doors and movable objects such as pollen and desks. The object identification information may include a name, a type, a distance, and a position. 
     In addition, the robot  100   a  may perform the operation or travel by controlling the driving unit based on the control/interaction of the user. At this time, the robot  100   a  may acquire the intention information of the interaction due to the user&#39;s operation or speech utterance, and may determine the response based on the acquired intention information, and may perform the operation. 
     &lt;AI+Robot+Self-Driving&gt; 
     The robot  100   a , to which the AI technology and the self-driving technology are applied, may be implemented as a guide robot, a carrying robot, a cleaning robot, a wearable robot, an entertainment robot, a pet robot, an unmanned flying robot, or the like. 
     The robot  100   a , to which the AI technology and the self-driving technology are applied, may refer to the robot itself having the self-driving function or the robot  100   a  interacting with the self-driving vehicle  100   b.    
     The robot  100   a  having the self-driving function may collectively refer to a device that moves for itself along the given movement line without the user&#39;s control or moves for itself by determining the movement line by itself. 
     The robot  100   a  and the self-driving vehicle  100   b  having the self-driving function may use a common sensing method so as to determine at least one of the travel route or the travel plan. For example, the robot  100   a  and the self-driving vehicle  100   b  having the self-driving function may determine at least one of the travel route or the travel plan by using the information sensed through the lidar, the radar, and the camera. 
     The robot  100   a  that interacts with the self-driving vehicle  100   b  exists separately from the self-driving vehicle  100   b  and may perform operations interworking with the self-driving function of the self-driving vehicle  100   b  or interworking with the user who rides on the self-driving vehicle  100   b.    
     At this time, the robot  100   a  interacting with the self-driving vehicle  100   b  may control or assist the self-driving function of the self-driving vehicle  100   b  by acquiring sensor information on behalf of the self-driving vehicle  100   b  and providing the sensor information to the self-driving vehicle  100   b , or by acquiring sensor information, generating environment information or object information, and providing the information to the self-driving vehicle  100   b.    
     Alternatively, the robot  100   a  interacting with the self-driving vehicle  100   b  may monitor the user boarding the self-driving vehicle  100   b , or may control the function of the self-driving vehicle  100   b  through the interaction with the user. For example, when it is determined that the driver is in a drowsy state, the robot  100   a  may activate the self-driving function of the self-driving vehicle  100   b  or assist the control of the driving unit of the self-driving vehicle  100   b . The function of the self-driving vehicle  100   b  controlled by the robot  100   a  may include not only the self-driving function but also the function provided by the navigation system or the audio system provided in the self-driving vehicle  100   b.    
     Alternatively, the robot  100   a  that interacts with the self-driving vehicle  100   b  may provide information or assist the function to the self-driving vehicle  100   b  outside the self-driving vehicle  100   b . For example, the robot  100   a  may provide traffic information including signal information and the like, such as a smart signal, to the self-driving vehicle  100   b , and automatically connect an electric charger to a charging port by interacting with the self-driving vehicle  100   b  like an automatic electric charger of an electric vehicle. 
     Hereinafter, the robot  100   a  will be described as an example of the boarding robot on which the user is capable of boarding. 
       FIG.  4    is a perspective view of a robot according to an embodiment,  FIG.  5    is a plan view of the robot according to an embodiment,  FIG.  6    is a front view of the robot according to an embodiment, and  FIG.  7    is a side view of the robot according to an embodiment. 
     The robot  100   a  may include a main body  200 . 
     The main body  200  may include at least one traveling wheel and may be a traveling module or a mobile robot that is capable of traveling according to a user&#39;s input or autonomously traveling. 
     The main body  200  may be an assembly of a plurality of parts, and the main body  200  may further include a driving mechanism (or traveling mechanism) that is connected to the traveling wheel to allow the traveling wheel to rotate forward and backward. 
     The traveling wheel may be provided in a pair on the main body  200 . The pair of traveling wheels  202  and  204  may be provided on the main body  200  so as to be spaced apart from each other in a left-right direction (i.e., horizontal direction) Y. 
     The driving mechanism may include a traveling motor generating driving force for allowing the traveling wheels  202  and  204  to rotate. In an example of the driving mechanism, the traveling motor may be directly connected to the traveling wheels  202  and  204  so that the traveling wheels  202  and  204  directly rotate forward and backward by the traveling motor. In another example of the driving mechanism, the traveling motor may be connected to the traveling wheels  202  and  204  through various power transmission members such as a rotation shaft and gears to allow the traveling wheels  202  and  204  to rotate forward and backward through the power transmission member. 
     The main body  200  may include a separate steering wheel disposed to be spaced apart from the traveling wheels  202  and  204  so as to switch a traveling direction of the robot  100   a . The direction of the steering wheel and the traveling direction of the main body  200  may be determined by a steering  600  that will be described below. 
     The main body  200  may not include the separate steering wheel for switching the traveling direction of the main body  200 , and the traveling direction of the main body  200  may be determined using a pair of traveling wheels  202  and  204 . The traveling direction of the main body  200  may be determined using the rotation direction of each of the pair of traveling wheels  202  and  204  or a difference in rotation speed of the pair of traveling wheels  202  and  204 . 
     The main body  200  may be configured to allow the pair of traveling wheels  202  and  204  to rotate independently with respect to each other and include a pair of traveling motors  206  and  208  for allowing the pair of traveling wheels  202  and  204  to rotate. The pair of traveling motors  206  and  208  may include a right traveling motor  206  for allowing the right traveling wheel  202  of the pair of traveling wheels  202  and  204  to rotate and a left traveling motor  208  for allowing the left traveling wheel  204  of the pair of traveling wheels  202  and  204  to rotate. 
     The main body  200  may further include a battery  210  for supplying power to each component of the robot  100   a . The battery  210  may be disposed in the main body  200  in consideration of a center of gravity of the entire robot  100   a.    
     The main body  200  may include a housing  220  defining an outer appearance. The housing  220  may be provided as an assembly of a plurality of members. The housing  220  may include a top surface  221 , a bottom surface  222 , and a circumferential surface  223 . 
     Each of the top surface  221  and the bottom surface  222  of the housing  220  may have a planar shape, and the circumferential surface  223  of the housing  220  may have a curved shape. 
     The circumferential surface  223  may include a left surface  224 , a right surface  225 , a rear surface  226 , and a front surface  227 . 
     The left surface  224  may be convex toward a left side, and the right surface  225  may be convex toward a right side. And, the rear surface  226  may be convex toward a rear side between an upper end and a lower end. The front surface  227  may be convex forward between the upper and lower ends. 
     The upper end of the front surface  227  of the circumferential surface  223  may extend closer to a rear end among a front end of the top surface  221  and the rear end of the top surface  221  of the housing  220 . 
     The circumferential surface  223  may further include a plane  228  extending from one side of the convex front surface  227  to the front end of the top surface  221 . The plane  228  may be an inclined surface that is inclined to face in a front lower direction. 
     The housing  220  may further include an upper rear surface  229  extending upward from an upper portion of the convex rear surface  226 . 
     The housing  220  includes a lower housing  220   a  including the top surface  221 , the bottom surface  222 , and the circumferential surface  223  and an upper housing  220   b  extending from one side of the lower housing  220   a  to protrude upward and including the upper rear surface  229 . 
     The lower housing  220   a  may be provided in a spherical shape of which each of top and bottom surfaces  221  and  222  are flat as a whole. 
     The upper housing  220   b  may extend from a rear upper portion of the lower housing  220   a  to a rear side of a backrest  320  to be described later. 
     The traveling wheels  202  and  204  may be rotatably disposed in the housing  220 , and a lower portion of each of the traveling wheels  202  and  204  may be disposed in the housing  220  to pass through a wheel through-hole defined in a lower portion of the housing  220 . 
     A space may be defined in the housing  220 , and the battery  210  may be accommodated in the space defined in the housing  220 . 
     The robot  100   a  may further include a seating body  300  disposed above the main body  200  and a foot supporter  400  disposed in front of the main body  200 . 
     The seating body  300  may be configured to allow the user to be seated. The seating body  300  may be provided with a seat for allowing the user to be seated thereon. Also, the seating body  300  may be provided with an armrest for allowing a user&#39;s arm to be placed. A height of the armrest may be higher than a height of the seat. 
     The seating body  300  may further include a seat body  310  on which the user sits and a backrest  320  on which the user leans back. 
     The seat body  310  may include a lower cushion  311  and a lower seat body  312  on which the lower cushion  311  is mounted. 
     The lower cushion  311  may be disposed on a top surface of the lower seat body  312 . The lower cushion  311  may be provided to be more elastic than the lower seat body  312 . 
     The lower seat body  312  may be disposed on an upper portion of the housing  220 , in particular, the lower housing  220   a . The lower seat body  312  may cover a space defined in the housing  220 . 
     The seat body  310  may not include the lower cushion  311 , but may include the lower seat body  312 . 
     The backrest  320  may include a rear cushion  321  and a rear seat body  322  supporting the rear cushion  321 . The rear seat body  322  may be supported by a rear supporter  324 , and the backrest  320  may further include the rear supporter  324 . 
     The rear cushion  321  may be disposed on a front surface of the rear seat body  322 . The rear cushion  321  may be provided to be more elastic than the rear seat body  322 . 
     The rear seat body  322  may entirely or partially overlap the upper housing  220   b  in a front-rear direction (i.e., longitudinal direction), and the rear supporter  324  may overlap the upper housing  220   b  in the front-rear direction. The rear seat body  322  and the rear supporter  324  may be protected by the upper housing  220   b.    
     A lower portion of the rear supporter  324  may be connected to the lower seat body  312 . The rear supporter  324  may be configured so that an upper part thereof is bent with respect to the lower part thereof. The lower portion of the rear supporter  324  may be rotatably connected to the lower seat body  312  by a hinge shaft, and the backrest  320  may be disposed to rotate about the lower portion. 
     The backrest  320  may not include the rear cushion  321 , but may include the rear seat body  322  and the rear supporter  324 . 
     The armrest may be disposed in the seat body  310  so as to move forward and backward. The armrest may be provided in a pair on the seating body  300 . 
     The pair of armrests  330  and  340  may include a right armrest  330  and a left armrest  340  and the right armrest  330  and the left armrest  340  may be spaced apart from each other in the left-right direction Y and may be arranged symmetrical to each other in the left-right direction Y. 
     The pair of armrests  330  and  340  may be disposed on the seat body  310 , in particular, the lower seat body  312  so as to move forward and backward, and a lower portion of each of the pair of armrests  330  and  340  may be inserted into the lower seat body  312 . The lower portion of each of the pair of armrests  330  and  340  may be guided to move forward and backward in a front-rear direction X along a guide provided in the seat body  310 . 
     The foot supporter  400  may be disposed on the main body  200 . The foot supporter  400  may be disposed on the main body  200  to protrude in the front-rear direction (i.e., longitudinal direction). The foot supporter  400  may be disposed at a front lower portion of the main body  200 . The foot supporter  400  may be disposed on the main body  200  to move forward and backward in the front-rear direction X. 
     An auxiliary wheel supporting the foot supporter  400  may be disposed on the foot supporter  400 . A pair of auxiliary wheels may be provided on the foot supporter  400 , and the pair of auxiliary wheels  402  and  404  may be disposed the foot supporter  400  so as to be spaced apart from each other in a horizontal direction. 
     The robot  100   a  may include a steering  600  operated by the user. The steering  600  may be an adjusting device such as a jog &amp; shuttle or a joystick. 
     The steering  600  may include a handle  612  held by the user. The steering  600  may be an input interface that is held and manipulated by the user&#39;s hand to input a traveling direction or traveling speed of the robot  100   a.    
     The steering  600  may be disposed on at least one armrest. The steering  600  may be provided on each of the pair of armrests  330  and  340  and may be disposed on one of the pair of armrests  330  and  340 . 
     The steering  600  may include a steering body  610  that is held by the user&#39;s hand. The steering body  610  may be a body which is held by the user&#39;s hand so as to be manipulated in various directions such as front, rear, left, and right directions. A handle  612  that is held by the user&#39;s hand may be disposed on an upper portion of the steering body  610 . The steering body  610  may include a steering shaft  614  extending from a lower portion of the handle  612 . 
     The user may hold the handle  612  while sitting on the seat body  310  to push the steering body  610  forward, pull the steering body  610  backward, or push the steering body to a left or right side. 
     For example, in the steering body  610 , the handle  612  is inclined to one side such as the front, rear, left, or right side with respect to the steering shaft  614 . The robot  100   a  may include a sensor sensing an inclination angle and an inclination direction of the steering body  610 . The robot  100   a  may sense a steering direction or speed by the inclination angle (or inclination angle), the inclination direction, etc. of the steering body  610 , which are sensed by the sensor. 
     For another example, in the steering body  610 , the steering shaft  614  and the handle  612  may be disposed to move to the front, rear, left, or right side. The robot  100   a  may include a sensor sensing a position of the steering body  610 . The robot  100   a  may sense the steering direction or speed according to the position of the steering body  610 , which is sensed by the sensor. 
     For another example, in the steering body  610 , the steering shaft  614  and the handle  612  may be disposed to rotate in a clockwise or counterclockwise direction. The robot  100   a  may include a sensor sensing a rotation angle of the steering body  610 . The robot  100   a  may sense the steering direction or speed according to the rotation angle of the steering body  610 , which is sensed by the sensor. 
     The sensor may transmit a signal of the sensed steering direction or speed to a processor  180 , and the processor  180  may control the traveling motors  206  and  208  which will be described later according to the signal transmitted from the sensor. 
     The robot  100   a  may further include a display  700 . The display  700  may be disposed on at least one of the pair of armrests  330  and  340 . The display  700  may be disposed to rotate about a horizontal rotation center. The display  700  may be an output interface capable of displaying various information such as traveling information. 
     The display  700  may be rotatably connected to the steering housing  360 . The display  700  may be connected to the front end of the steering housing  360 . 
     The display connection portion  364  to which the display  700  is rotatably connected may be provided in the steering housing  360 . 
     The display connection portion  364  may be spaced apart from the steering body  610  in a horizontal direction when the steering body  610  ascends. 
     The robot  100   a  may further include a display rotator  370  that allows the display  700  to rotate. The display rotator  370  may be a rotating mechanism for allowing the display  700  connected to the display  700  to rotate. The display rotator  370  may include a display motor connected to the display  700  to allow the display  700  to rotate. Hereinafter, for convenience, like the display rotator  370 , the display motor will be described with reference numeral  370 . The display motor  370  may be disposed to be accommodated in the display connection portion  364 . A motor space in which the display motor  370  is accommodated may be defined in the display connection portion  364 . 
     The display motor  370  may be provided with a rotation shaft that allows the display  700  to rotate, and the rotation shaft may be disposed horizontally. The rotation shaft may be lengthily disposed in the left-right direction Y. The display motor  370  may allow the display  700  to rotate so that the display  700  is erected about a rotation axis, or the display  700  is laid down. 
     In this specification, the display  700  is not limited to being vertically erected, but may be defined to include being erected at a predetermined angle. 
     The display  700  may include a front surface  701  facing a front side and a rear surface  702  facing a rear side with respect to the standing display  700 . A screen that is capable of providing a variety of information to the user may be disposed on the rear surface  702  of the display  700 . A touch screen may be disposed on the rear surface  702  of the display  700 , and the user may input various commands through the touch screen. 
     The display  700  may rotate side by side with the top surface of the armrest on the armrest. In this case, the front surface  701  when the display  700  is erected may be a top surface of the display  700 , and the rear surface  702  when the display  700  is erected may be a bottom surface of the display play  700 . 
     When the display  700  is laid horizontally, the screen of the display  700  is hidden from the outside, and the screen of the display  700  may be protected. 
     The robot  100   a  may further include at least one accessory that provides convenience to the user. 
     The accessory may be provided on the armrest or the main body  200 , and a plurality of accessories may be provided on the robot  100   a.    
     The robot  100   a  may include an accessory  800  (armrest accessory) provided on the armrest. The robot  100   a  may include an accessory  900  provided on the main body  200  (body accessory). The robot  100   a  may include both the accessory  800  provided on the armrest and the accessory  900  provided on the main body  200 . 
     For example, the accessory  800  provided on the armrest may be a cup holder into which a cup is seated. For another example, the accessory  800  provided on the armrest may be a sub armrest having the same size and shape as the steering housing  360  but without an opening  362  defined in an upper portion thereof. 
     The steering housing  360  according to this embodiment may be selectively disposed on the armrest body  350  of the left armrest  340  or the armrest body  350  of the right armrest  330  for the convenience of the user. That is, the accessory such as the cup holder or a sub armrest may be disposed on the armrest body  350  of the armrest, in which the steering housing  360  is not disposed, among the left armrest  340  and the right armrest  330  and may support the user&#39;s arm together with the armrest body  350 . 
     The accessory  800  provided on the armrest is not limited to the cup holder or the sub armrest, and also is not limited to the kind thereof as long as it provides the user&#39;s convenience and is accommodated in the accommodation portion  352 . 
     For example, the accessory  900  provided on the main body  200  may be a supporter on which a user&#39;s baggage (e.g., a carrier) is placed. For another example, the accessory  900  provided on the main body  200  may be a holder on which a medical device (e.g., crutches, medicines, etc.) to assist user&#39;s walk. The accessory  900  provided on the main body  200  is not limited to the holder, and also, the accessory  900  is not limited in kind as long as the accessory  900  moves with the user. Various kinds of accessories  900  may be separably attached to the main body  200 . 
     An opening  362  may be defined in the armrest, and an inner space S in which a portion of the steering  600  is accommodated may be defined in the armrest. When the robot  100   a  includes a pair of armrests  330  and  340 , the steering  600  may be disposed on one of the pair of armrests  330  and  340 . 
     At least one of the pair of armrests  330  and  340  may be an assembly of a plurality of members, and at least one of the pair of armrests  330  and  340  may include the armrest body  350  and the steering housing  360 . 
     One of the pair of armrests  330  and  340   330  may include the armrest body  350  and the steering housing  360  disposed on the armrest body  350 . An accommodation portion  352  in which the steering housing  360  is accommodated may be defined in the armrest body  350 . 
     The accommodation portion  352  may be provided in a shape that is recessed in the armrest body  350 . A top surface of the accommodation portion  352  may be opened. Each of the top and front surfaces of the accommodation portion  352  may be opened. 
     The steering housing  360  may be inserted into and accommodated in the accommodation portion  352  and may be protected by the accommodation portion  352 . 
     The steering housing  360  may surround at least a portion of the steering  600  and may protect the steering  600 . 
     The other one of the pair of armrests  330  and  340  may include the armrest body  350  and may further include an accessory  800  disposed on the armrest body  350 . The armrest body  350  may be provided with the accommodating portion  352  in which the accessory  800  is accommodated. 
     The pair of armrests  330  and  340  may include the armrest body  350  having the same structure, and the steering housing  360  and the accessory  800  may be disposed symmetrical to each other in the horizontal direction. Each of the pair of armrests  330  and  340  may be provided with the accommodation portions  352  having the same shape and the same size. 
     The accessory  800  and the steering housing  360  may have the same size and outline shape. 
     The steering housing  360  and the accessory  800  may have the same shape and size and may be disposed symmetrical to each other with respect to the seating body  300 . 
     The steering housing  360  may constitute a steering assembly together with steering  600 . The steering assembly may be selectively disposed together with the accessory  800 . 
     When the steering housing  360  is disposed on the armrest body  350  of the right armrest  330 , the accessory  800  may be disposed on the armrest body  350  of the left armrest  340 , and vice versa. When the steering housing  360  is disposed on the armrest body  350  of the left armrest  340 , the accessory  800  may be disposed on the armrest body  350  of the right armrest  330 . 
       FIG.  8    is a perspective view of the steering body and the display when the steering body of  FIG.  4    descends,  FIG.  9    is a perspective view illustrating a state in which the display of  FIG.  8    covers the steering body,  FIG.  10    is a cross-sectional view taken along line A-A of  FIG.  4   ,  FIG.  11    is a cross-sectional view taken along line B-B of  FIG.  8   , and  FIG.  12    is a cross-sectional view taken along line C-C of  FIG.  9   . 
     An opening  362  may be defined in an upper portion of the steering housing  360 , and an inner space S may be defined in the steering housing  360 . A vertical length L 1  of the inner space S may be longer than a vertical length L 2  of the steering body  610 . 
     The vertical length L 1  of the inner space S may be longer than the vertical length L 2  of the steering body  610 . The steering housing  360  may be coupled to the armrest body  350 , particularly, the accommodation portion  352 , by a coupling member such as a screw. 
     The steering housing  360  may include a lower housing  366  having an inner space S defined therein and a steering top cover  368  disposed on an upper end of the lower housing  366  to cover the inner space S. 
     A wire through-hole  367  through which a wire connected to a motor  622 , which will be described later, or extending to the inside of the steering housing  360  passes may be defined in the lower housing  366 . 
     The lower housing  366  may be provided with a coupling portion such as a coupling boss to which the coupling member such as the screw is coupled. 
     The lower housing  366  may include a portion facing the armrest body  350 , and the wire through-hole  367  may be defined in a portion facing the armrest body  350 . On the other hand, a wire through-hole  357  which communicates with the wire through-hole  367  and through which the wire passes may be defined in the armrest body  350 . 
     An opening  362  may be defined in one side of the steering top cover  368  to pass in the vertical direction. 
     A handle  612  may be disposed on an upper portion of the steering body  610 . The steering body  610  may pass through the opening  362 . A lower portion of the steering body  610  may be accommodated in the inner space S. 
     The steering  600  may include an elevator  620 . 
     The elevator  620  may be accommodated in the inner space S to elevate the steering body  610 . The elevator  620  may be connected to the lower portion of the steering body  610  to elevate the steering body  610 . 
     The elevator  620  may allow the handle  612  to ascend above the opening  362  at a height higher than the opening  362  and may allow the handle  612  to descend to the opening  362 . When the handle  612  descends to the opening  362 , the opening  362  of the steering housing  360  may surround an outer circumference of the handle  612 . 
     In the elevator  620 , when the steering body  610  descends, a height of an upper end of the handle  612  matches a height of the top surface of the steering housing  360 , or a height of an upper end of the handle  612  is greater than a height of the top surface of the steering housing  360  so that the steering body  610  descends. 
     The elevator  620  may allow the steering body  610  to ascend when the steering body  610  ascends so that the height of the upper end of the handle  612  is higher than the height of the top surface of the steering housing  360 . 
     The elevator  620  may include a motor  622  and at least one power transmission member connected to the motor  622 . The power transmission member may include at least one lever  624 . 
     The motor  622  may be accommodated in the inner space S defined in the armrest. The motor  622  may be accommodated in the steering housing  360  of the armrest. 
     The lever  624  may be connected to the steering body  610  to allow the steering body  610  to descend or ascend. The lever  624  may be connected to a rotation shaft  623  of the motor  622  to rotate. The lever  624  may be connected to a lower portion of the steering body  610 . The lever  624  may be connected to a connection shaft  618  disposed under the steering body  610 . The connection shaft  618  may be disposed horizontally under the steering body  610 . 
     A guide hole  626  that guides the connection shaft  618  to be movable may be defined in the lever  624 . The guide hole  626  may be lengthily defined in a longitudinal direction of the lever  624 . 
     The steering  600  may further include an inner cover  630 . 
     The inner cover  630  may be connected to the steering body  610 . The inner cover  630  may be elevated together with the steering body  610  when the steering body  610  is elevated. 
     An area of the inner cover  630  may be greater than an opening area of the opening  362 . 
     The inner cover  630  may block the opening  362  when the steering body  610  ascends. When the inner cover  630  ascends, an edge of the inner cover  630  may contact a peripheral bottom surface of the opening  362  of the steering housing, and the inner cover  630  may be disposed below the opening  362  to block the opening  362 . That is, the inner cover  630  may limit the upward travel of the steering  610  by contacting an inner surface of the top surface  361  of the steering housing  360 . 
     The inner cover  630  may descend below the opening  362  when the steering body  610  descends, and the edge of the inner cover  630  may be spaced apart from the peripheral bottom surface of the opening  362  of the steering housing  360  in the vertical direction. 
     The accommodation portion  352  in which the steering housing  360  is inserted and accommodated may be recessed in the armrest body  350 . 
     The display  700  may have a size larger than a size of the opening  362 . A length L 3  of the display  700  may be longer than a distance L 4  between the display connection portion  364  and the opening  362 . 
     The display  700  may cover the opening  362  when the display  700  rotates to cover the top surface  361  of the steering housing  360 . 
     The display  700  may be larger than the top surface  361  of the steering housing  360 . When the display  700  rotates to cover the top surface  361  of the steering housing  360 , the display  700  may have a size that is enough to cover a boundary  358  between the steering housing  360  and the armrest body  350 . 
     The display  700  may be disposed above the opening  362  to cover the opening  362  when the steering body  610  descends, and the display  700  rotates to cover the top surface of the steering housing  360 . The opening  362  and the handle  612  may be covered by the display  700 . 
     The motor  622  and the display motor (i.e., display rotator)  370  of the elevator  620  may operate at the same time or at a time difference. 
     In use of the steering  600 , before the motor  622  allows the lever  624  to rotate upward, the display motor  370  may be driven to allow the display  700  to rotate in a direction in which the display  700  opens the opening  322 , and also, when the display motor  370  is erected upward, the display motor  370  may be stopped. 
     When the display  700  is erected upward, the motor  622  may allow the lever  624  to rotate upward, and the handle  612  of the steering body  610  may ascend higher than the opening  362 . When the steering body  610  completely ascends, the motor  622  may be stopped. 
     In the use of the steering  600 , if the display motor  370  is driven first and then stopped, the motor  622  may be driven and then stopped. In the use of the steering  600 , when the display motor  370  and the motor  622  are sequentially driven/stopped, damage or breakage of the display  700  by the steering body  610  may be minimized. 
     When the steering  600  is not used, the motor  622  may allow the lever  624  to rotate downward, and when the steering body  610  completely descend to the inner space S, the display motor  370  may allow the display  700  to rotate so that the display  700  covers the opening  322 . 
     When the steering  600  is not used, if the motor  622  is driven first and then stopped, the display motor  370  may be stopped after being driven. When the steering  600  is not used, when the motor  622  and the display motor  370  are sequentially driven/stopped, the damage or breakage of the display  700  by the steering body  610  may be minimized, and also, malfunction of the steering body  610  by the display  700  may be minimized. 
       FIG.  13    is a perspective view illustrating a state in which a sub steering is disposed on an armrest according to an embodiment. 
     An accessory  800 ′ illustrated in  FIG.  13    may include a sub steering  810  provided on the seating body  300  together with the steering  600  and a sub steering housing  820 . The accessory  800 ′ may be installed instead of the accessory illustrated in  FIG.  6   . 
     The sub steering  810  may be disposed symmetrical to the steering  600  in the horizontal direction. 
     The user may alternatively operate either the sub steering  810  or the steering  600  or may operate the sub steering  810  and the steering  600  together. 
     The elevator  620  may allow the steering body  610  of the steering  600  to descend into the steering housing  360 . In this case, the user may operate the robot  100   a  using the sub steering  810 . 
     According to an embodiment, when the steering body  610  is used, the steering body  610  may ascend to assist the user&#39;s traveling operation. When the steering body  610  is not used, the steering body  610  may ascend to minimize the contamination or damage to the steering body  610 . 
     Also, when the display  700  is erected, and the steering body  610  ascends, the display  700  may protect the steering body  610  and the user&#39;s hands in front of the steering body  610 . 
     Also, if the steering body  610  descends, and the display  700  covers the top surface of the steering  600 , the steering body  610  may be hidden by the display  700  so that the outer appearance of the robot  100   a  is simply shown, and also, the attachment of the foreign substances such as the dust to the steering housing  610  or the steering  600  may be minimized. 
     Also, when the display  700  covers the top surface of the steering housing  610 , the opening  362  may be covered to minimize penetration of the foreign substances such as the dusts into the steering housing  610  through the opening  361 . Therefore, the screen of the display  700  may be protected by the steering housing  360 . 
     Also, since positions of the steering and accessory are changeable to the left and right sides, there is an advantage that the operation convenience of the steering is high. 
     The above-disclosed subject matter is to be considered illustrative, and not restrictive, and the appended claims are intended to cover all such modifications, enhancements, and other implementations, which fall within the scope of the present disclosure. 
     Thus, the implementation of the present disclosure is to be considered illustrative, and not restrictive. 
     Therefore, the scope of the present disclosure is defined not by the detailed description of the invention but by the appended claims, and all differences within the scope will be construed as being included in the present disclosure.