Patent Publication Number: US-2020293050-A1

Title: Mobile robot and method of controlling the same

Description:
TECHNICAL FIELD 
     The present disclosure relates to a mobile robot and a method of controlling the same, and more particularly, to a recognizing technology of a mobile robot. 
     BACKGROUND ART 
     Robots have been developed for industrial use to administrate some parts of factory automation. Recently, the application fields of robots have further expanded, leading to the development of medical robots, aerospace robots, etc. and the manufacture of robots used in general homes for domestic uses. Among such robots, an autonomous mobile robot is referred to as a mobile robot. A representative example of a mobile robot used in a home is a robot cleaner. 
     Technologies of autonomously learning and mapping a traveling area by a mobile robot and recognizing a current position thereof on a map have been known. 
     Various smart functions using a mobile robot have been known. The related art (Korean Patent Publication No. 10-2013-0030932) discloses a technology of finding a lost article by doing photography using an image acquirer and transmitting information acquired through photography to a user terminal when an obstacle is detected during cleaning or there is an obstacle to traveling. 
     Patent Document 
     Korean Patent Publication No. 10-2013-0030932 (published on Mar. 28, 2013) 
     DISCLOSURE 
     Technical Problem 
     In the above related art, the possibility that a mobile robot moves in all places of a traveling area without priority in order to search for an object is high, and thus, there is a problem in that a long time takes to find the object. A first objective of the present disclosure is to overcome the problem to enable the mobile robot to effectively find the object. 
     A second objective of the present disclosure is to allow a user to immediately go to a corresponding position and to acquire a discovered object through information on the discovered object detected by a mobile robot. 
     A third objective of the present disclosure is to effectively search for an object in consideration of the characteristics of each lost article even if there is a plurality of lost articles. 
     A fourth objective of the present disclosure is to allow a user to easily input an area in which a mobile robot is supposed to search for an object. 
     In the above related art, an object may be searched for without specifying a lost article that is a target article of a mobile robot, and thus, there is a problem in that unnecessary discovered object information is indiscreetly transmitted to a user. A fifth objective of the present disclosure is to overcome the problem. 
     A sixth objective of the present disclosure is to allow a user to easily input a lost article to be detected by a mobile robot. 
     A seventh objective of the present disclosure is to smartly assist information input of a user using pre-stored information. 
     In the above related art, a mobile robot transmits an image of a discovered object, and thus, there is a problem in that privacy of a user is exposed to an image of a discovered object. An eighth objective of the present disclosure is to overcome the problem. 
     Technical Solution 
     To overcome the problems, in an aspect of the present disclosure, a mobile robot includes a traveling unit configured to move a main body, a sensing unit configured to detect a surrounding object while the mobile robot travels, a communication module configured to get input or receive information and to output or transmit information, and a controller configured to perform control to search for an object while the mobile robot travels in an area specified according to area information input or received from the communication module, and to perform control to output or transmit identification information and position information of a detected discovered object through the communication module. 
     A partial area may be divided from a traveling area. The controller may perform control to search for an object while the mobile robot travels in the partial area specified according to the area information. 
     The communication module may get input or receive a plurality of pieces of object information and may get input or receive area information matched with each of the pieces of object information. 
     The controller may perform control to change an object that is searched for depending on an area to which a current position belongs. 
     The controller may perform control to search for an object specified according to the object information that is input or received from the communication module. 
     The controller may perform control to compare object information that is newly input or received from the communication module with pre-stored object information and to propose the pre-stored object information through the communication module when the newly input object information is matched with the pre-stored object information. 
     The controller may perform control to search for an object using an image acquired from the sensing unit and may perform control to output or transmit information except for an image of the discovered object through the communication module. 
     To overcome the problems, in another aspect of the present disclosure, a method of controlling a mobile terminal includes an input operation of receiving information for traveling, a travel operation of searching for an object while the mobile robot travels in an area specified according to the area information, and an output operation of outputting identification information and position information of a discovered object, detected in the travel operation. 
     A partial area may be divided from a traveling area. The input operation may include specifying the partial area according to the area information. 
     The input operation may include specifying an area below furniture according to input of the area information. 
     The area information may include information on a height to an outer upper limit surface. 
     The area information may include an image of a partial area. 
     The input operation may include receiving a plurality of pieces of object information and receiving area information matched with each of the pieces of object information. The travel operation may include changing an object that is searched for depending on an area to which a current position belongs. 
     The input operation may include receiving object information. The travel operation may include searching for an object specified according to the object information. 
     The object information may include information on a volume of an object. 
     The object information may include a name of a type or an image of an object. 
     The input operation may include comparing newly input object information with pre-stored object information and proposing the pre-stored object information to a user when the newly input object information is matched with the pre-stored object information. 
     The input operation may include comparing newly input object information with pre-stored object information and proposing selection of any one of the newly input object information and the pre-stored object information when the newly input object information is matched with the pre-stored object information. 
     The output operation may include outputting discovery time information of a discovered object. 
     The method may further include searching for an object using an image acquired in the travel operation, wherein the output operation may include outputting information except for an image of a discovered object. 
     The object information may include an image of an object. 
     Advantageous Effects 
     An object may be searched for while a mobile robot travels in an area specified according to area information, and thus, the mobile robot may preferentially search for a partial area with high possibility that there is a lost article. 
     Identification information and position information of a discovered object may be output to a user, and thus, a user may immediately recognize a position of a corresponding discovered object to easily acquire the discovered object. 
     An area below furniture with high possibility that there is a lost article may be specified to effectively find the lost article. 
     Area information may be input using information on the height to an outer upper limit surface and/or an image of a partial area, and thus, a user may easily specify a partial area for searching of a mobile robot. 
     A plurality of pieces of object information and area information matched with each piece of object information may be received, a search range may differ for each lost article while a plurality of lost articles is simultaneously searched for, thereby effectively searching for a lost article. 
     Object information may be received, and thus, a mobile robot may intensively search for a lost article that a user wants to find, and it may be convenient that the user does not necessarily receive unnecessary information. 
     Object information may be input using information on the volume of an object, a name of a type of the object, and/or an image, and thus, the user may easily specify a target object of a mobile robot. 
     When newly input object information is matched with pre-stored object information, the pre-stored object information may be proposed to a user, and thus, a user may check whether the newly input object information is already pre-stored. 
     When newly input object information is matched with pre-stored object information, selection of any one of the newly input object information and the pre-stored object information may be proposed, and thus, a user may conveniently input object information using the pre-stored object information, and when the user intends to newly input other similar object information, an error of misrecognizing the new object information as the pre-stored object information by a controller may be prevented. 
     In addition, discovery time information may be output, and thus, a user may recognize a time point when information on a discovered object is generated, thereby more conveniently using output information. 
     An object may be detected using an image acquired in the travel operation, and information except for an image of a discovered object may be output in the output operation, and thus, the accuracy of detection through image acquisition may be enhanced while privacy of the user is protected. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a mobile robot  100  and a charging stand  200  for charging the mobile robot  100  according to an embodiment of the present disclosure. 
         FIG. 2  is a diagram of the mobile robot  100  of  FIG. 1  viewed from the above. 
         FIG. 3  is a diagram of the mobile robot  100  of  FIG. 1  viewed from the front. 
         FIG. 4  is a diagram of the mobile robot  100  of  FIG. 1  viewed from the below. 
         FIG. 5  is a block diagram showing a control relationship of main components of the mobile robot  100  of  FIG. 1 . 
         FIG. 6  is a flowchart showing a control method of a mobile robot according to an embodiment of the present disclosure. 
         FIG. 7A  is a flowchart showing a control method of a mobile robot according to a first embodiment of the present disclosure. 
         FIG. 7B  is a flowchart showing a control method of a mobile robot according to a second embodiment of the present disclosure. 
         FIG. 7C  is a flowchart showing a control method of a mobile robot according to a third embodiment of the present disclosure. 
         FIG. 8  is a flowchart showing a control method of a mobile robot according to another embodiment of the present disclosure. 
         FIG. 9  is a flowchart showing an input operation S 100  according to another embodiment of the present disclosure. 
         FIGS. 10 to 16  are diagrams showing a user environment of a control method according to an embodiment of the present disclosure.  FIGS. 10 to 14  show a user environment for user input in the input operation S 100 , and  FIGS. 15 and 16  show a user environment for output to a user in an output operation S 300 . 
         FIG. 10  is a diagram showing a main image for inputting object information and area information. 
         FIGS. 11A and 11B  are diagrams showing an image for inputting detailed area information. 
         FIG. 11A  shows an image of a state in which an entire traveling area is selected. 
         FIG. 11B  shows an image of a state in which a partial area of a traveling area is selected. 
         FIG. 12  is a diagram showing an image that receives detailed information of a partial area. 
         FIGS. 13A and 13B  are diagrams showing an image for inputting detailed object information. 
         FIG. 13A  shows an image for capturing a photo (image) or selecting a photo. 
         FIG. 13B  shows an image for Internet search. 
         FIGS. 14A and 14B  are diagrams of an image showing a procedure in which some of a plurality of objects is selected in an input image. 
         FIGS. 15 and 16A and 16B  are diagrams showing an image for outputting identification information and position information of a discovered object. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A mobile robot  100  according to the present disclosure may be a robot that autonomously moves using a wheel or the like and may be a domestic helper robot, a robot cleaner, and the like. 
     Hereinafter, with reference to  FIGS. 1 to 5 , a robot cleaner  100  of the mobile robot will be exemplified, but the present disclosure is not limited thereto. 
     The mobile robot  100  may include a main body  110 . Hereinafter, when portions of the main body  110  are defined, a portion directed toward a ceiling in a traveling area may be defined as an upper surface portion (refer to  FIG. 2 ), a portion direction toward a bottom in the traveling area may be defined as a bottom surface portion (refer to  FIG. 4 ), and a portion of a circumference of the main body  110  between the upper surface portion and the bottom surface portion, which is directed in a traveling direction, may be defined as a front surface portion (refer to  FIG. 3 ). A portion directed in an opposite direction to the front surface portion of the main body  110  may be defined as a rear surface portion. The main body  110  may include a case  111  that forms a space for accommodating various components included in the mobile robot  100 . 
     The mobile robot  100  may include a sensing unit  130  for detecting a surrounding object. The sensing unit  130  may detect information on the surrounding object while the mobile robot  100  travels. The sensing unit  130  may detect surrounding environment information of the mobile robot  100 . The sensing unit  130  may detect information on a surrounding environment such as a cliff or an obstacle. The mobile robot  100  may search for an object through a surrounding object detection function of the sensing unit  130 . 
     The surrounding objet may refer to furniture or a lost article which is positioned on a traveling surface, an external upper object, and the like. The external upper object may be a ceiling positioned in an upward direction of the mobile robot  100 , a bottom surface of furniture, or the like. 
     The information on the surrounding object may include information on an image captured by the mobile robot  100 . The information on the surrounding object may include information on a distance to the surrounding object from the mobile robot  100 . 
     The sensing unit  130  may be installed at an upper surface portion and/or front portion of the main body  110 . A detection direction of the sensing unit  130  may be an upward direction, a forward and backward direction, and/or a lateral direction. 
     The sensing unit  130  may detect an image of a surrounding object or may detect a distance to the surrounding object. The sensing unit  130  may detect the information on the surrounding object at each position over time during movement. 
     The sensing unit  130  may include an image detector  135  for detecting an image of a surrounding object. The image detector  135  may include a digital camera for photographing a traveling area. The digital camera may include an image sensor (e.g., a CMOS image sensor) including at least one optical lens, and a plurality of photodiodes (e.g., pixels) on which an image is formed by light passing through the optical lens, and a digital signal processor (DSP) for configuring an image based on a signal output from the photodiodes. The DSP may generate a video image including frames including still images as well as a still image. 
     The sensing unit  130  may include a distance detector  131  for detecting a distance to a surrounding object. The distance detector  131  may be disposed at the front surface portion of the main body  110 . The distance detector  131  may detect a front obstacle. The sensing unit  130  may include the plurality of distance detectors  131 . The distance detector  131  may be embodied using ultrasonic waves or infrared rays. The distance detector  131  may be embodied using a camera. 
     The sensing unit  130  may include a cliff detector  132  for detecting whether a cliff is present on a bottom in the traveling area. The sensing unit  130  may include the plurality of cliff detectors  132 . 
     The sensing unit  130  may further include a lower image sensor  137  for acquiring an image of the floor. 
     The mobile robot  100  may include a traveling unit  160  for moving the main body  110 . The traveling unit  160  may move the main body  110  along the floor. The traveling unit  160  may include at least one driving wheel  166  for moving the main body  110 . The traveling unit  160  may include a driving motor. The driving wheel  166  may be installed on the left and right of the main body  110  and, hereinafter, will be referred to as a left wheel  166 (L) and a right wheel  166 (R). 
     The left wheel  166 (L) and the right wheel  166 (R) may be driven by one driving motor but, as necessary, may include a left wheel driving motor for driving the left wheel  166 (L) and a right wheel driving motor for driving the right wheel  166 (R). A driving direction of the main body  110  may be changed to the left or to the right by forming a difference of rotation speed between the left wheel  166 (L) and the right wheel  166 (R). 
     The mobile robot  100  may include a cleaner  180  for cleaning the floor. The mobile robot  100  may perform a clean while moving in the traveling area. The cleaner  180  may include a suction device for sucking foreign substances, brushes  184  and  185  for sweeping with a broom, a dust canister (not shown) for storing foreign substances collected by the suction device or the brushes, and/or a mopping unit (not shown) for mopping. 
     A suction inlet  180   h  for sucking air may be formed in the bottom surface portion of the main body  110 . The main body  110  may include a suction device (not shown) that provides suction force to suck air through the suction inlet  180   h , and a dust canister (not shown) that collects sucked dust along with air through the suction inlet  180   h.    
     An opening for inserting and removing the dust canister may be formed in the case  111 , and a dust canister cover  112  for opening and closing the opening may be rotatably installed on the case  111 . 
     The main body  110  may include a main brush  184  with a roll type, which has brushes exposed through the suction inlet  180   h , and an auxiliary brush  185   135  that is positioned at a front side of the bottom surface portion of the main body  110  and has brushes including a plurality of wings that radially extends. Dusts may be removed from the floor in a traveling area via rotation of the brushes  184  and  185 , and dusts separated from the floor may be sucked through the suction inlet  180   h  and may be collected in the dust canister. 
     A battery  138  may supply power required for an overall operation of the mobile robot  100  as well as the driving motor. When the battery  138  is discharged, the mobile robot  100  may drive to return to a charging stand  200  for charging, and during driving to return, the mobile robot  100  may autonomously detect a position of the charging stand  200 . 
     The charging stand  200  may include a signal transmitter (not shown) for transmitting a predetermined return signal. The return signal may be an ultrasonic signal or an infrared (IR) signal, but is not limited thereto. 
     The mobile robot  100  may include a communication module  170  for getting input or receiving information and outputting or transmitting information. The communication module  170  may include a communication unit  175  for transmitting and receiving information to and from other external devices. The communication module  170  may include an input unit  171  for inputting information. The communication module  170  may include an output unit  173  for outputting information. 
     For example, the mobile robot  100  may directly receive information from the input unit  171 . In another example, the mobile robot  100  may receive information input to a separate terminal  300  through the communication unit  175 . 
     For example, the mobile robot  100  may directly output information to the output unit  173 . In another example, the mobile robot  100  may transmit information to the separate terminal  300  through the communication unit  175 , and the terminal  300  may output information. 
     The communication unit  175  may be configured to communicate with an external server, the terminal  300 , and/or the charging stand  200 . The communication unit  175  may include a signal detector for receiving the return signal. The charging stand  200  may transmit an infrared (IR) signal through the signal transmitter, and the signal detector may include an infrared sensor for detecting the IR signal. The mobile robot  100  may be moved to a position of the charging stand  200  and may be docked on the charging stand  200  according to the IR signal transmitted from the charging stand  200 . Through such docking, charging may be performed between a charging terminal  133  of the mobile robot  100  and a charging terminal  210  of the charging stand  200 . 
     The communication unit  175  may receive information input from the terminal  300  such as a smartphone or a computer. The communication unit  175  may transmit information to be output to the terminal  300 . The terminal  300  may output information received from the communication unit  175 . 
     The communication unit  175  may receive various pieces of command signals from the terminal  300 . The communication unit  175  may receive area information for traveling from the terminal  300 . The communication unit  175  may receive information on a target object from the terminal  300 . The communication unit  175  may transmit information on a discovered object that is detected during traveling to the terminal  300 . The communication unit  175  may transmit identification information of the discovered object to the terminal  300 . The communication unit  175  may transmit information on a position of the discovered object to the terminal  300 . 
     The input unit  171  may receive On/Off or various commands. The input unit  171  may receive the area information. The input unit  171  may receive the object information. The input unit  171  may include various buttons or touch pads, a microphone, or the like. 
     The output unit  173  may notify a user about various pieces of information. The output unit  173  may include a speaker and/or a display. The output unit  173  may output information on a discovered object that is detected during traveling. The output unit  173  may output identification information of the discovered object. The output unit  173  may output information on a position of the discovered object. 
     The mobile robot  100  may include a controller  140  for processing and determining various pieces of information, e.g., mapping and/or localization of a current position. The controller  140  may control an overall operation of the mobile robot  100  through control of various components included in the mobile robot  100 . The controller  140  may map a traveling area and may localize a current position on a map through the image. That is, the controller  140  may perform a simultaneous localization and mapping (SLAM) function. 
     The controller  140  may receive information from the communication module  170  and may process the information. The controller  140  may receive information from the input unit  171  and may process the information. The controller  140  may receive information from the communication unit  175  and may process the information. The controller  140  may receive detection information from the sensing unit  130  and may process the detection information. The detection information may refer to information on the surrounding object. 
     The controller  140  may transmit information to the communication module  170  for output. The controller  140  may transmit information to the communication unit  175 . The controller  140  may control output of the output unit  173 . The controller  140  may control driving of the traveling unit  160 . The controller  140  may control an operation of the cleaner  180 . 
     The mobile robot  100  may include a storage unit  150  for storing various data. The storage unit  150  may record various pieces of information required to control the mobile robot  100  and may include a volatile or non-volatile recording medium. 
     The storage unit  150  may store a map of a traveling area. The map may be input by an external terminal that exchanges information with the mobile robot  100  through the communication unit  175  and may be generated via autonomous learning of the mobile robot  100 . In the former case, the external terminal  300  may be, for example, a remote controller, a PDA, a laptop, a smart phone, or a tablet PC, in which an application for map setting is installed. 
     An actual traveling area may correspond to a traveling area on a map. The traveling area may be defined as the range obtained by summing an entire planar area on which the mobile robot  100  has traveled and an entire planar area on which the mobile robot  100  currently travels. 
     The controller  140  may also recognize a moving path of the mobile robot  100  based on an operation of the traveling unit  160 . For example, the controller  140  may recognize the current or past moving speed or a traveling distance of the mobile robot  100  based on a rotation speed of the driving wheel  166  and may also recognize a current or past procedure of changing a direction depending on a rotation direction of each of the driving wheels  166 (L) and  166 (R). A position of the mobile robot  100  on a map may be updated based on recognized traveling information of the mobile robot  100 . The position of the mobile robot  100  on the map may also be updated using the image information. 
     The controller  140  may control the mobile robot  100  to travel in an area specified by the area information input or received from the communication module  170 . The controller  140  may control the mobile robot  100  to travel and search for an object in the specified area. The controller  140  may control the mobile robot  100  to search for an object based on object information input or received from the communication module  170 . The controller  140  may control the communication module  170  to output identification information and position information of the detected discovered object and to transmit the identification information and the position information to the terminal  300 . 
     Hereinafter, a method of controlling the mobile robot  100  according to embodiments of the present disclosure will be described with reference to  FIGS. 6 to 9 . Repeated descriptions in flowcharts are denoted by the same reference numerals and, thus, a repeated description will be omitted. 
     The control method may be performed by the controller  140 . The present disclosure may be related to the control method of the mobile robot  100  or the mobile robot  100  including the controller  140  for performing the control method. The present disclosure may be related to a computer program including each operation of the control method and may be related to a recording medium with a program recorded thereon for executing the control method by a computer. The ‘recording medium’ refers to a computer readable recording medium. The present disclosure relates to a mobile robot control system including both hardware and software. 
     Operations of flowcharts of the control method and combinations of the flowcharts may be performed according to computer program instructions. The instructions may be installed in a general-purpose computer, a special-purpose computer, or the like and may generate elements for performing functions described in operations of the flowcharts. 
     In some embodiments, the functions described in the operations may be generated irrespective of their order. For example, two operations that are continually illustrated may be substantially simultaneously performed or the operations may be frequently performed in reverse order depending on corresponding functions. 
     Referring to  FIG. 6 , the control method may include an input operation S 100  of inputting information to the mobile robot  100  by a user. The control method may include a travel operation S 200  for traveling based on information received in the input operation S 100 . The control method may include an output operation S 300  of outputting the information acquired in the travel operation S 200 . The input operation S 100 , the travel operation S 200 , and the output operation S 300  may be sequentially performed. 
     The controller  140  may receive object information. The controller  140  may receive area information. The controller  140  may control traveling of the mobile robot  100  based on the object information and the area information. The controller  140  may perform control to output identification information of a discovered object. The controller  140  may perform control to output information on a position of the discovered object. 
     In the input operation S 100 , the object information may be received. In the input operation S 100 , the object information may be received in order to specify a target object. 
     For example, the object information may be selected in a database (DB) for storing information. The DB for storing information may be updated. The DB may be updated using information that is received or input through the communication unit  175  or the input unit  171 . In another example, the object information may also be selected from the DB that is provided through a wired and wireless network. In another example, the object information may also be directly input by the user. 
     The object information may include a name of a type of an object. For example, the name of the type of the object may include a key, a key including a key ring, a car key, a remote controller, a car remote controller, a lock, a cellular phone, a wireless telephone, a tablet PC, paper money (Korean currency or foreign currency), a coin (Korean currency or foreign currency), a book (a notebook, a diary, or a delivery food menu), or the like. 
     The name of the type of the object may be directly input by a user. The name of the type of the object may be selected from the stored DB. The name of the type of the object may be selected on the Internet. 
     The name of the type of the object may be selectively input among a general name and a detailed name. The name of the type of the object may be input as a high-ranking concept or may also be input as a low-ranking concept. For example, the name of the type of the object may be input as ‘paper money’ or ‘dollar paper money’ or ‘US paper money’. 
     The name of the type of the object may be selectively input among a name without a condition and a name with a condition. For example, the name of the type of the object may be input as a ‘key’ without a condition or may be input as a ‘key including a key ring’ with a condition. 
     The object information may include an image of an object. The image of the object may be a photo or a picture. 
     The image may be a photo that is directly captured by a user. The image may be selected from the stored DB. The image may be selected on the Internet. 
     In the input operation S 100 , all of a plurality of object images on the selected or captured image may be input. In the input operation S 100 , any one of the plurality of object images on the selected or captured image may be selected and input (refer to  FIG. 14 ). 
     The object information may include information on the volume of an object. The volume information may include information on an occupied area. The volume information may include height information. The volume information may include a horizontal length, a vertical length, and a height. 
     In the input operation S 100 , the area information may be received. In the input operation S 100 , area information for traveling may be received. 
     For example, the area information may be selected from the stored DB. Any one of a plurality of areas in the DB may be selected and area information may be received. The DB of the plurality of areas may be updated. When a map is updated using information acquired while the mobile robot  100  travels, the DB of the plurality of areas may also be updated. The area information may also be selected as a predetermined area by a user on a map of the stored traveling area. 
     In another example, the area information may be information on the characteristics of a specific area that is directly input by a user. 
     A partial area of the traveling area may be divided. The traveling area on a map may be divided into a plurality of partial areas, and a partial area of the traveling area on the map may be separately specified and may be divided into partial areas. 
     A partial area of the traveling area may be divided using information that is detected while the mobile robot  100  travels. For example, a partial area of the traveling area may be divided using an image detected by the mobile robot  100 , distance information, or the like. 
     A partial area of the traveling area may be divided according to a predetermined division reference. In the input operation S 100 , the partial area may be specified based on the area information. 
     For example, the predetermined division reference may be configured to divide each room of the traveling area into partial areas. In another example, the predetermined division reference may be configured to divide an area having a height to an outer upper limit surface of the traveling area, which is equal to or less than a predetermined value. 
     According to the area information in the input operation S 100 , an area below furniture (a desk, a table, a chair, or a bed) having a low height to the outer upper limit surface may be selected. The area below furniture may be configured to be specified according to the input of the area information in the input operation. 
     The area information may include information on the height to the outer upper limit surface. The outer upper limit surface may be an outer surface that the mobile robot  100  is directed upward and may be a ceiling surface of an indoor area, a bottom surface of furniture, or the like. The height to the outer upper limit surface may be a height to the outer upper limit surface from the floor of the traveling area or may be a height to the outer upper limit surface from the mobile robot  100 . For example, when a user inputs a specific value as the height information of the outer upper limit surface, a partial area having a height to the outer upper limit surface of the traveling area, which is equal to or less than a predetermined value, may be specified. 
     The area information may include information on an area below specific furniture. For example, a user may select an area below specific furniture to specify a partial area. 
     The area information may include an image of a partial area. A partial area corresponding to the image of the partial area may be specified using the input image of the partial area. For example, the user may input an image of an area below a bed to specify the area below the below as a partial area. 
     In the travel operation S 200 , the mobile robot  100  may travel in the traveling area. In the travel operation S 200 , the mobile robot  100  may travel an area specified according to the area information. In the travel operation S 200 , the mobile robot  100  may travel in the partial area specified according to the area information. 
     In the travel operation S 200 , the mobile robot  100  may search for an object. That is, in the travel operation S 200 , the mobile robot  100  may search for (detect) the object. In the travel operation S 200 , the mobile robot  100  may search for an object specified according to the object information. In the travel operation S 200 , the mobile robot  100  may search for an object while traveling in the partial area specified according to the area information. 
     The mobile robot  100  may be moved in the specified partial area on in a stored map and may search for an object while traveling in the specified partial area. The controller  140  may compare the detected object with the object specified according to the object information and may determine similarity therebetween. When determining that the detected object corresponds to the specified object, the controller  140  may consider the detected object as a discovered object. In the travel operation S 200 , the mobile robot  100  may store information on the discovered object. When a plurality of discovered objects is detected in the travel operation S 200 , information on a discovered object, corresponding to each discovered object, may be stored. 
     In the travel operation S 200 , when an object specified according to the object information is discovered, even if the mobile robot  100  does not travel in an entire specified area, the mobile robot  100  may be configured to return to a charging stand. 
     In the output operation S 300 , information on the stored discovered object may be output. When a plurality of discovered objects is detected, information on a discovered object, corresponding to each discovered object, may be output in the output operation S 300 . As such, the user may verify a discovered object that is found by the mobile robot  100  through the travel operation S 200 . 
     Information on the discovered object may include identification on the discovered object. The identification information of the discovered object may include a name indicating a type of the discovered object. 
     In the output operation S 300 , the identification information of the discovered object may be output to be matched with the input name of the type of the object. For example, the identification information may be output to indicate the discovered object matched with the input object information. 
     For example, the identification information of the discovered object may include an image of the discovered object. In another example, the identification information of the discovered object may include only other information except for the image of the discovered object. 
     An object may be searched for using the image acquired in the travel operation S 200 , and in this case, information except for the image of the discovered object may be output in the output operation S 300 . As such, the accuracy of detection through image acquisition may be enhanced while privacy of the user is protected. 
     The identification information of the discovered object may include the volume of the discovered object. For example, the volume information of the discovered object may include a horizontal length, a vertical length, and a height. 
     Information on the discovered object may include information on a position of the discovered object. The position information may be output as a position on a map (refer to  FIGS. 15 and 16 ). For example, a map of the traveling area and the position of the discovered object on the map may be displayed and output. 
     The information on the discovered object may include discovery time information. The discovery time information may include a discovery date and/or time of a corresponding discovered object. 
     In the output operation S 300 , identification information of the discovered object may be output. In the output operation S 300 , position information of the discovered object may be output. In the output operation S 300 , the discovery time information of the discovered object may be output. 
     Hereinafter, a control method according to first to fourth embodiments will be described with reference to  FIGS. 7A to 8 .  FIGS. 7A to 8  sequentially show input operations S 101 , S 102 , and S 110 ), travel operations S 201 , S 202 , S 203 , S 211 , and S 212 , and an output operation S 310 . 
     Referring to  FIG. 7A , the control method according to the first embodiment may include operation S 101  of receiving the area information. After operation S 101 , the mobile robot  100  may travel in an area specified according to the area information and may perform operation S 201  of searching for an object. Information on a discovered object through the operation S 201  may be stored in the storage unit  150 . After operation S 201 , operation S 310  of outputting the identification information and the position information of the discovered object may be performed. According to the first embodiment, object information may not be input in the input operation S 101 , and all objects detected in the travel operation S 201  may be determined as a discovered object. 
     Referring to  FIG. 7B , the control method according to the second embodiment may include operation S 102  of receiving the object information. After operation S 102 , the mobile robot  100  may travel and may perform operation S 202  of searching for an object specified according to the object information. In operation S 202 , the mobile robot  100  may travel in the entire traveling area. Alternatively, in operation S 202 , the mobile robot  100  may also travel in the entire traveling area until the mobile robot  100  discovers the specific object. After operation S 202 , operation S 310  of outputting the identification information and the position information of the discovered object may be performed. According to a second embodiment, in the input operation S 102 , area information may not be input, and in the travel operation S 202 , the mobile robot  100  may travel in the entire traveling area and may determine only a specific object as a discovered object. 
     Referring to  FIG. 7C , the control method according to the third embodiment may include operation S 110  of receiving the object information and the area information. After operation S 110 , the mobile robot  100  may travel in an area specified according to the area information and may perform operation S 203  of searching for an object specified according to the object information. In operation S 203 , the mobile robot  100  may travel in the specified partial area. Alternatively, in operation S 203 , the mobile robot  100  may also travel in the entire traveling area until the mobile robot  100  discovers the specific object. After operation S 203 , operation S 310  of outputting the identification information and the position information of the discovered object may be performed. According to a third embodiment, in the input operation S 110 , both the area information and the object information may be input, and in the travel operation S 203 , the mobile robot  100  may travel in the specified area and may determine only the specific object as the discovered object. 
     Referring to  FIG. 8 , the control method according to another embodiment may include operation S 110  of receiving information. Based on the received area information, operation S 120  of determining whether a partial area of the traveling area is selected may be performed. In operation S 120 , when it is determined that the partial area is selected, operation S 211  in which the mobile robot  100  travels in the selected partial area may be performed. In operation S 120 , when it is determined that the partial area is not selected, operation S 212  in which the mobile robot  100  travels in the entire traveling area may be performed. In operations S 211  and S 212 , a specified object may be searched based on the received object information. After operations S 211  and S 212 , operation S 310  of outputting the identification information and the position information of the discovered object may be performed. 
     Operation S 211  may be set to enable a function of searching for an object only in a specified partial area. When an object positioned on the floor in the specified partial area is detected, the detected object may be set to be stored as information on the discovered object. When the mobile robot  100  detects the object positioned on the floor in the specified partial area, an output signal may be transmitted to the user. When the mobile robot  100  detects the object positioned on the floor in an area that is not the specified partial area, the detected object may not be stored as the information on the discovered object. When the mobile robot  100  detects the object positioned on the floor in an area that is not the specified partial area, an output signal may not be transmitted to the user. 
     In the input operation S 100 , object information may be input using a method of selecting one of stored object information. In the input operation S 100 , information on a new object to be selectable by the user may be stored. The newly stored object information may be stored as one of various pieces of object information, and then, information may be selected in the input operation S 100 . For example, the user may newly store object information of a key owned by the user, and may then input object information using a method of selecting object information of a key, which is pre-stored when the key is lost. 
     In the input operation S 100 , the expression ‘object information is received’ may generally mean that i) object information is selected in a DB, and ii) information on a new object that is not present in the DB is received. In the input operation S 100 , object information may be newly received by directly capturing/uploading a photo or typing a name of a type of an object by a user. 
     With reference to  FIG. 9 , the input operation S 100  according to another embodiment will be described. In the input operation S 100 , operation S 151  of newly receiving the object information may be performed. 
     Operation S 153  of determining whether the information on the new object input in operation S 151  is matched with pre-stored object information may be performed. In operation S 153 , the newly input object information and the pre-stored object information may be compared with each other. In operation S 153 , the new object information may be compared with each of a plurality of pieces of pre-stored object information. In operation S 153 , similarity between the new object information and any one of the pre-stored object information is equal to or greater than predetermined similarity, it may be determined that the new object information is matched with the pre-stored object information. 
     When the newly input object information is matched with the pre-stored object information in operation S 153 , operation S 154  of proposing the pre-stored object information to a user may be performed. The pre-stored object information matched in operation S 154  may be output to the user through a display or the like. As such, the user may check whether the newly input object information is already pre-stored. 
     When the newly input object information is matched with the pre-stored object information in operation S 153 , operation S 155  of proposing selection of any one of the newly input object information and the pre-stored object information may be performed. In operation S 155 , any one of the newly input object information and the pre-stored object information may be selected according to user intention. Operation S 155  may be an operation of determining whether the pre-stored object information is selected. As such, convenience may be provided to allow the user to input object information using pre-stored object information, and when the user intends to newly input information on another similar object, an error of misrecognizing the new object information as the pre-stored object information by a controller may be prevented. 
     According to the present embodiment, operation S 155  may be performed after operation S 154 . In detail, when the new object information is matched with the pre-stored object information in operation S 153 , operation S 155  of proposing the pre-stored object information to the user and selecting any one of the newly input object information and the pre-stored object information may be performed. 
     In operation S 153 , when it is determined that the newly input object information and the pre-stored object information are not matched with each other, operation S 158  of storing the newly input object information may be performed. The newly input object information may be stored in the storage unit  150  and may then be compared with newly input another object information. In this case, in the travel operation S 200 , an object specified according to the newly input object information may be searched for. 
     In operation S 155 , when the pre-stored object information is not selected, operation S 158  of storing the newly input object information may be performed. In operation S 155 , when the newly input object information is selected, operation S 158  of storing the newly input object information may be performed. A description of operation S 158  is the same as the above description. 
     In operation S 155 , when the newly input object information is not selected, the newly input object information may not be stored (S 159 ). In operation S 155 , when the pre-stored object information is selected, the newly input object information may not be stored (S 159 ). In this case, a next operation may be performed without storing the newly input object information. In this case, in the travel operation S 200 , an object specified according to the selected pre-stored object information may be searched for. 
     Area information may also be input using a method of dividing a plurality of preset areas on a map and selecting any one of the plurality of areas in the input operation S 100 . In addition, the plurality of areas may be differently divided according to user setting. 
     Hereinafter, with reference to  FIGS. 10 to 16 , an example of a user environment (interface) for embodying the control method will be described.  FIGS. 10 to 16  are diagrams showing an example of a display image, and the terminal  300  is exemplified as a display but the present disclosure is not limited thereto. In order to select a display part and an input part on the image of  FIGS. 10 to 16 , a method of touching a screen is exemplified, but the present disclosure is not limited thereto. 
     According to the present embodiment, information input to the separate terminal  300  may be received through the communication unit  175 , and the image of  FIGS. 10 to 14  is an image of a touchscreen of the terminal  300 . However, in another example, information may be received from the input unit  171  such as a touchscreen or other buttons on the main body  110  of the mobile robot  100 , and the image of  FIGS. 10 to 14  may also be embodied on the touchscreen on the main body  110 . 
     According to the present embodiment, information may be transmitted to the separate terminal  300  through the communication unit  175 , and the image of  FIGS. 15 and 16  may be an output image of the terminal  300 . However, in another example, the mobile robot  100  may directly output information to the output unit  173  such as a display, and the image of  FIGS. 15 and 16  may also be embodied on a screen on the main body  100 . 
     Referring to  FIG. 10 , in the input operation S 100 , a main image for inputting object information and area information may be output. An input unit D 100  for inputting whether the object search function is enabled may be configured. A user may select the input unit D 100  for inputting whether the object search function is enabled using a method of touch and may turn on/off the object search function (lost article search function).  FIG. 10  shows a state in which the object search function is turned on. 
     Referring to  FIG. 10 , in the input operation S 100 , an object indicator D 110  that indicates a target object and an area indicator D 120  that indicates a travelling area may be matched with each other and may be output. An object indicated on the object indicator D 100  may be a lost article to be found. An area indicated on the area indicator D 120  may refer to a place in which a corresponding object is searched for. 
     Referring to  FIG. 10 , the object indicator D 110  and the area indicator D 120  may be matched with each other and may be displayed as one set. The plurality of sets may be configured. The plurality of sets may differ. A set selector D 130  may be configured to allow a user to select only a set for enabling the object search function among the plurality of sets. The set selector D 130  may be touched to enable or disable traveling based on the corresponding set. When traveling based on any one specific set is enabled by the set selector D 130 , the mobile robot  100  may travel in an area based on area information of the specific set and may search for an object according to object information of the specific set.  FIG. 10  shows the case in which a function of searching for a car key only in a registered place (partial area) and a function of searching for money in all places (entire traveling area) are enabled and shows the case in which a function of searching for a remote controller is disabled. 
     In the input operation S 100 , a plurality of pieces of object information may be received. Referring to  FIG. 10 , object information of a plurality of objects (car key and money) may be input by the object indicator D 110  and the set selector D 130 . 
     When a plurality of pieces of object information is received, area information matched with each of pieces of object information may be received in the input operation S 100 . Referring to  FIG. 10 , area information (only a registered place or all places) matched with a plurality of objects (car key and money) may be input by the area indicator D 120  and the set selector D 130 . 
     In the input operation S 100 , when the plurality of pieces of object information and area information matched with each of the pieces of object information are received, a target object may differ for each area to which a current position belongs in the travel operation S 200 . For example, in the travel operation S 200  after the input operation S 100  of  FIG. 10 , a car key and money may be searched for while the mobile robot  100  travels in a specified partial area (registered place), and only money may be searched for while the mobile robot  100  travels in an area that is not a specified partial area. 
     Referring to  FIG. 10 , the object indicator D 110  for each set may be selected through a touch and object information may be changed. In addition, the area indicator D 120  for each set may be selected through a touch and area information may be changed. 
     Referring to  FIG. 10 , an object adder D 150  may be selected through a touch and selectable object information may be additionally generated. The object adder D 150  may be selected to generate a new set. In addition, an area adder D 160  may be selected through a touch and selectable area information may be additionally generated. 
       FIGS. 11A and 11B  are diagrams showing an image for inputting detailed area information.  FIG. 11A  shows an image in the case in which an entire traveling area is selected, and  FIG. 11B  shows an image in the case in which a partial area of a traveling area is selected.  FIGS. 11A and 11B  are diagrams showing an image when the area indicator D 120  is selected in the image of  FIG. 10 . 
     Referring to  FIG. 11A , when an entire area enabling unit D 161  is selected and enabled through a touch, an object of a corresponding set may be searched for from the entire traveling area. 
     Referring to  FIG. 11B , when the entire area enabling unit D 161  is selected and disabled through a touch, an object of a corresponding set may be searched for from the partial area. A name, a feature, or the like indicating a corresponding area may be indicated on an area information identification unit D 163 . The plurality of area information identification units D 163  may be configured, and an area information enabling unit D 164  corresponding to each of the area information identification units D 163  may be configured. Through the area information enabling unit D 164 , a range of the enabled area may be changed. Only area information corresponding to the area information identification unit D 163  selected by the area information enabling unit D 164  may be received, and an object of a corresponding set may be searched for only in a partial area specified according to the input area information. In addition, an area adder D 162  may be selected through a touch, and the selectable area information identification unit D 163  may be additionally generated. 
     Referring to  FIGS. 11A and 11B , a current state of a corresponding set may be lastly set through selection of confirmation D 168 . Through selection of cancelation D 168 , setting change in the image of  FIGS. 11A and 11B  may be cancelled. 
       FIG. 12  is a diagram showing an image that receives detailed information of a partial area. In the image of  FIG. 11B , when the area adder D 162  or the area information identification unit D 163  is selected, the image of  FIG. 12  may be configured to be output. The image of  FIG. 12  may include a part D 167   a  on which a name of an area is indicated. When an area image input unit D 165  for inputting area information as an image (photo) is selected, an input unit D 165   a  for directly capturing a photo and an input unit D 165   b  for selecting any one of pre-stored photos may be configured. It may be possible to select a search input unit D 166  for searching for area information from information on the Internet. The image of  FIG. 12  may include a part D 167   b  that indicates an input photo. The image of  FIG. 12  may include a height input unit D 167   c  for inputting information on a height to the outer upper limit surface. Through confirmation D 167   d,  changed area information may be lastly set. Through selection of cancelation D 167   e,  setting change may be cancelled in the image of  FIG. 12 . 
       FIGS. 13A and 13B  are diagrams showing an image for inputting detailed object information,  FIG. 13A  shows an image for capturing a photo (image) or selecting a photo, and  FIG. 13B  shows an image for Internet search. 
     When the object indicator D 110  is selected in the image of  FIG. 10 , an image of  FIG. 13A or 13B  may be configured to be output. The image of  FIGS. 13A and 13B  may include a part D 111   a  that indicates a name of an object. When an object image input unit D 112  for inputting object information as an image (photo) is selected, an input unit D 112   a  for directly capturing a photo and an input unit D 112   b  for selecting any one of pre-stored photos may be configured. It may be possible to select a search input unit D 113  for searching for area information from information on the Internet. When the search input unit D 113  is selected through a touch, the image of  FIG. 13B  may be output. Object information may be searched for on the Internet through a search unit D 113   a  on the image of  FIG. 13B . The image of  FIGS. 13A and 13B  may include a part D 111   b  that indicates an input photo. The image of  FIGS. 13A and 13B  may include a volume input unit D 111   c  for inputting volume information of an object. Through selection of confirmation D 111   d,  changed object information may be lastly set. Through selection of cancellation D 111   e,  setting change on the image of  FIGS. 13A and 13B  may be cancelled. 
       FIG. 14  is a diagram of an image showing a procedure in which some of a plurality of objects is selected in an input image. When the input unit D 112   a  or the input unit D 112   b  is selected in the image of  FIG. 13A  to directly capture a photo or select a photo, a corresponding photo (image) may be configured in the image of  FIG. 14 . When the search unit D 113   a  is selected in the image of  FIG. 13B  and a photo is searched for, the corresponding photo (image) may be configured on the image of  FIG. 14 . When there is a plurality of objects in the photo indicated on the image of  FIG. 14 , some of a plurality of objects may be configured to be selected. Referring to  FIG. 14 , a partial image may be divided to select any one of a plurality of objects. 
       FIG. 15  is a diagram showing a main image for outputting identification information and position information of a discovered object. When the travel operation S 200  is terminated in a state in which the object search function is enabled, the image of  FIG. 15 or 16  may be output according to the output operation S 300 . 
     The image of  FIGS. 15 and 16  may include a traveling end notification unit D 301  that indicates that the travel operation S 200  is terminated. The traveling end notification unit D 301  may be indicated in the form of a message. The image of  FIGS. 15 and 16  may include a summary information indicator D 302  indicating summarized information of a discovered object. For example, the number of discovered objects and/or the number of positions of the discovered objects may be indicated on the summary information indicator D 302 . 
     Close D 380  may be selected to terminate output of the image of  FIGS. 15 and 16 . A setting unit D 390  may be selected to output the image of  FIG. 10  while terminating output of the image of  FIGS. 15 and 16 . 
     Referring to  FIG. 15 , a position information selector D 310  may be selected, and a map and a discovered object position indicated on the map may be output. When the position information selector D 310  is selected, a position indication window D 311  indicating a map and position indication on the map may be output. 
     Referring to  FIG. 16 , an identification information selector D 320  may be selected to output identification information of a discovered object. When the identification information selector D 320  is selected, an identification information indicator D 323  may be output. A name of a type of a discovered object may be displayed on the identification information indicator D 323 . The identification information indicator D 323  may indicate a name of a type corresponding to the discovered object among names of types of objects input in the input operation S 100 . In addition, a position information indicator D 322  that indicates position information of a discovered object corresponding to the identification information indicator D 323  may be output. The identification information indicator D 323  and the position information indicator D 322  may be output as a pair. A position indication enabling unit D 321  corresponding to the identification information indicator D 323  may be configured. Among a plurality of discovered object lists, a position may be indicated on a map with respect to only the discovered object enabled through the position indication enabling unit D 321 . In addition, the identification information indicator D 323  and a corresponding position confirmation D 324  may be configured. When a plurality of discovered objects is detected, if the position confirmation D 324  corresponding to a specific discovered object among a plurality of discovered objects is selected, a position of the specific discovered object may be emphasized and indicated on the map. For example, when the corresponding position confirmation D 324  is touched to check a position of a coin that is a discovered object, a map and a coin position D 311   a  may be indicated on the position indication window D 311 . 
     DESCRIPTION OF REFERENCE NUMERALS 
       
     
       
         
           
               
               
               
             
               
                   
                   
               
             
            
               
                   
                 100: mobile robot 
                 120: sensing unit 
               
               
                   
                 140: controller 
                 160: traveling unit 
               
               
                   
                 180: cleaner 
                 200: charging stand 
               
               
                   
                 300: terminal 
                 S100: input operation 
               
               
                   
                 S200: travel operation 
                 S300: output operation