Patent Publication Number: US-10786133-B2

Title: Robot cleaner

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the priority benefit of Korean Patent Application No. 10-2017-0012265, filed on Jan. 25, 2017 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a robot cleaner, more particularly to a robot cleaner adapted to drive a spin mop. 
     2. Description of the Related Art 
     In recent years, the use of robots at home has increased gradually. An exemplary home robot is a cleaning robot. The cleaning robot, as a robot cleaner, moves without human control, and provides autonomous cleaning operations by sucking foreign substances such as dust accumulated on a floor. The cleaning robot can not only move, but also clean the floor simultaneously, by the operation of a spin mop. 
     An example of the robot cleaner for the simultaneous moving and cleaning operations, by the spin mop, is a robot cleaner including two spin mops, by which cleaning operations can be performed while moving. 
     However, the robot cleaner driven by two spin mops has the disadvantage of unstable moving thereof. 
     Moreover, in the case of the robot cleaner including two spin mops, there is another disadvantage that only a single type of cleaning operation is performed while moving. 
     SUMMARY OF THE INVENTION 
     It is an object of the invention to provide a robot cleaner capable of two types of cleaning operations on a floor at one time traveling when the robot cleaner moves for cleaning operations. 
     It is another object of the invention to provide a robot cleaner capable of more stable moving while moving by driving of spin mops. 
     In some embodiments, the above and other objects can be accomplished by the provision of a robot cleaner comprising a main body, a plurality of spin mop assemblies disposed at a lower portion of the main body and configured to include at least one mop pad attached at lower portions of the plurality of spin mop assemblies, a driving assembly configured to drive the plurality of spin mop assemblies, a first supply assembly configured to store a first liquid inside the main body and supply the first liquid to at least one mop pad of some of the plurality of spin mop assemblies by adjusting a first valve, and 
     a second supply assembly configured to store a second liquid inside the main body and supply the second liquid to at least one mop pad of the others of the plurality of spin mop assemblies by adjusting a second valve. Thus, each or some of the plurality of spin mop assemblies may be utilized as a different usage from the others, by dividing the plurality of spin mop assemblies into several groups. 
     In some embodiments, the first liquid and the second liquid may be water or cleaning liquid respectively, and thus some of the plurality of spin mop assemblies may be used for a cleansing operation and the others of the plurality of spin mop assemblies may be used for a wet cleaning operation. 
     In some embodiments, there are provided a plurality of spin mop assemblies comprising a first direction spin mop assembly disposed at a front portion of the main body, to which a first supply assembly may supply a first liquid, and a second direction spin mop assembly disposed at a back portion of the main body, to which a second supply assembly may supply a second liquid. Thus, the plurality of spin mop assemblies can be utilized as various usages. 
     In some embodiments, there are provided a plurality of spin mop assemblies comprising a third direction spin mop assembly disposed at a left portion of the main body, and a fourth direction spin mop assembly disposed at a right portion of the main body. In some embodiments, at least four spin mop assemblies can provide more stable moving to a robot cleaner. 
     In some embodiments, there is provided a robot cleaner including a dry-cleaning mode in which a plurality of spin mop assemblies are driven in a dry status, a wet-cleaning mode in which some of the plurality of spin mop assemblies are supplied water and the others of the plurality of spin mop assemblies are driven in a dry status, a cleansing mode in which some of the plurality of spin mop assemblies are supplied water and the others of the plurality of spin mop assemblies are supplied a cleaning liquid, and a controller configured to control the plurality of spin mop assemblies and a first and second valves, according to a mode of operation. Thus, according to a mode of operation, water or the cleaning liquid can be supplied to the spin mop assemblies and a moving direction of the robot cleaner can be controlled. 
     In accordance with the disclosure, the robot cleaner can selectively supply water or a cleaning liquid to a plurality of spin mop assemblies respectively, and thus the robot cleaner has the advantage of providing at least two types of cleaning operations at one time traveling. 
     In accordance with the disclosure, at least four spin mop assemblies are disposed at a low portion of the main body of the robot cleaner, and there is therefore the advantage of providing more stable moving. 
     In accordance with the disclosure, the robot cleaner has the advantage of providing cleaning operations suitable for a floor to be cleaned at one time traveling, by supplying water or a cleaning liquid to the spin mop assembly according to a mode of operation and controlling a moving direction. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other objects, features and other advantages of the embodiments will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a perspective view illustrating a robot cleaner according to some embodiments; 
         FIG. 2  is a bottom view illustrating the robot cleaner according to some embodiments; 
         FIG. 3  is a front view illustrating the robot cleaner according to some embodiments; 
         FIG. 4  is a view illustrating a plurality of spin mop assemblies of the robot cleaner according to some embodiments; 
         FIG. 5  is a view illustrating a rotary plate and a mop pad of a spin mop assembly of the robot cleaner according to some embodiments; 
         FIG. 6  is a perspective view illustrating the spin mop assembly and a driving assembly of the robot cleaner according to some embodiments; 
         FIG. 7  is a side view illustrating the spin mop assembly and the driving assembly of the robot cleaner of  FIG. 6  according to some embodiments; 
         FIG. 8  is a view illustrating the rotary plate and a liquid collecting guider of the mop pad of the spin mop assembly according to some embodiments; 
         FIG. 9  is a cross-sectional view of the spin mop assembly, vertically taken along line IX-IX′ in  FIG. 8 ; 
         FIG. 10  is a perspective view illustrating the spin mop assembly and the driving assembly of the robot cleaner, as viewed from a different side in  FIG. 6 ; 
         FIG. 11  is a view illustrating a configuration of a plurality of bumper assemblies according to some embodiments; 
         FIG. 12  is a view illustrating a configuration of a bumper assembly according to some embodiments; 
         FIG. 13  is a cross-sectional view of the robot cleaner, horizontally taken along line XIII-XIII′ of  FIG. 3 ; 
         FIG. 14  is a view illustrating a configuration of a liquid supply assembly and a cleansing assembly according to some embodiments; 
         FIG. 15  is a block diagram illustrating a configuration in conjunction with a controller according to some embodiments; 
         FIG. 16A  is a view illustrating spinning of the plurality of spin mop assemblies when the robot cleaner moves straight in a first direction according to some embodiments; 
         FIG. 16B  is a view illustrating spinning of the plurality of spin mop assemblies when the robot cleaner moves straight in a second direction according to some embodiments; 
         FIG. 16C  is a view illustrating spinning of the plurality of spin mop assemblies when the robot cleaner makes a large radius turn according to some embodiments; 
         FIG. 16D  is a view illustrating spinning of the plurality of spin mop assemblies when the robot cleaner makes a small radius turn according to some embodiments; 
         FIG. 17  is a view illustrating driving of the robot cleaner in a dry-cleaning mode according to some embodiments; 
         FIG. 18  is another view illustrating driving of the robot cleaner in the dry-cleaning mode according to some embodiments; and 
         FIG. 19  is another view illustrating driving of the robot cleaner in the dry-cleaning mode according to some embodiments. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Advantages, features and demonstration methods of the disclosure will be clarified through various embodiments described in more detail below with reference to the accompanying drawings. 
     The disclosure may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art. Further, the present invention is only defined by scopes of claims. Wherever possible, the same reference numbers will be used throughout the specification to refer to the same or like parts. 
     Hereinafter, a robot cleaner according to some embodiments will be described with reference to the accompanying drawings. In the following description, the terminology “front” refers to the primary direction of motion of the robot cleaner  10 . 
       FIG. 1  is a perspective view illustrating a robot cleaner according to some embodiments.  FIG. 2  is a bottom view illustrating the robot cleaner according to some embodiments.  FIG. 3  is a front view illustrating the robot cleaner according to some embodiments. 
     Hereinafter, a main body of a robot cleaner and elements disposed on the inside and outside of the main body are described with reference to  FIGS. 1 to 3 . 
     In accordance with some embodiments, a robot cleaner  10  comprises a main body  20 , a plurality of spin mop assemblies  100   a ,  100   b ,  100   c ,  100   d  disposed at a lower portion of the main body and each configured to include mop pad attached at lower portions of each of the plurality of spin mop assemblies, at least one driving assembly  130  configured to drive the plurality of spin mop assemblies, a first supply assembly configured to store water inside the main body and supply the stored water to the mop pad of some of the plurality of spin mop assemblies by adjusting a first valve, and a second supply assembly configured to store a second liquid in the main body, and supply the second liquid to the mop pad of the others of the plurality of spin mop assemblies by opening or closing a second valve. In accordance with some embodiments, the robot cleaner  10  may further comprise at least one bumper assembly  140  disposed on a portion of an enclosure of the main body  20 , and configured to detect or reduce an external impact generated on the main body  20 . 
     The robot cleaner  10 , which has an outer surface, comprises the main body  20  disposed at the upper portion of at least one spin mop assembly  100 , a container  30  disposed inside the main body  20  and configured to store liquid which is supplied to the spin mop assembly  100 , and a container cover  36  disposed at a portion of the container  30  and configured to open or close an upper portion of the container  30 . The robot cleaner  10  may further comprise a spin mop guider  26  disposed at a lower portion of the main body  20  and configured to prevent interference among a plurality of spin mop assemblies. 
     The main body  20  comprises a top cover  22  forming an upper portion and an enclosure of the main body  20 , and a base  24  forming a lower portion of the main body  20 . The container  30  (see  FIG. 13 ) configured to store a first liquid and a second liquid which are supplied to spin mop assemblies  100  and the container cover  36  configured to open or close the container  30  may be disposed inside the main body  20 . 
     In accordance with some embodiments, the container  30  may comprise a first container  32  and a second container  34 . The first container  32  may be configured to store a first liquid, and the second container  34  may be configured to store a second liquid. The first liquid may have the same properties as the second liquid, or different properties from the second liquid. In accordance with some embodiments, the first liquid may be water, and second liquid may be a cleaning liquid, which may be a liquid mixed with water and a detergent and cleanse dust or filth on the floor by chemical reactions. The detergent used with water may be in the form of a powder or a liquid. 
     A sterilization module  40  for sterilizing some stored substances may be disposed inside the container  30 , as illustrated in  FIG. 13 . The sterilization module  40  can sterilize a liquid stored in the container  30  and the inside thereof as well. 
     The spin mop guider  26  is disposed at the lower portion of the base  24 , and can prevent interference among the plurality of spin mop assemblies  100 . The spin mop guider  26  may be disposed at the center of one set of four spin mop assemblies  100 . The spin mop guider  26  prevents enclosures of at least two spin mop assemblies  100  from touching each other. 
       FIG. 4  is a view illustrating a plurality of spin mop assemblies of the robot cleaner according to some embodiments.  FIG. 5  is a view illustrating a rotary plate and a mop pad of the spin mop assembly of the robot cleaner according to some embodiments.  FIG. 6  is a perspective view illustrating the spin mop assembly and a driving assembly of the robot cleaner according to some embodiments.  FIG. 7  is a side view illustrating the spin mop assembly and the driving assembly of the robot cleaner of  FIG. 6  according to some embodiments.  FIG. 8  is a view illustrating the rotary plate and a liquid collecting guider of the mop pad of the spin mop assembly according to some embodiments.  FIG. 9  is a cross-sectional view of the spin mop assembly, vertically taken along line IX-IX′ in  FIG. 8 .  FIG. 10  is a perspective view illustrating the spin mop assembly and the driving assembly of the robot cleaner, as viewed from a different side in  FIG. 6 . 
     Hereinafter, referring to  FIGS. 3 to 10 , a spin mop assembly and a driving assembly are described according to some embodiments. 
     Referring to  FIG. 4 , the robot cleaner  10  according to some embodiments may move in a first direction or a second direction. The first direction is opposite to the second direction. In addition, the robot cleaner  10  may move in a third direction or a fourth direction. The third and fourth directions may be generally vertical to the first direction or the second direction respectively, and the third direction is opposite to the fourth direction. In the following description, the first, second, third, and fourth directions define the front, back, left and right directions of the robot cleaner respectively. It should be understood, however, that, although the terms first, second, etc. are used herein to describe directions, the scope of the invention should not be limited by these terms. 
     The robot cleaner  10  may include at least one spin mop assembly  100 . The spin mop assembly  100  may be disposed at the lower portion of main body  20 . The spin mop assembly  100  may be configured to cause the main body  20  to move and clean the floor by spinning thereof. 
     In accordance with some embodiments, the robot cleaner  10  may include a plurality of spin mop assemblies  100 , but not limited to, a first spin mop assembly  100   a , a second spin mop assembly  100   b , a third spin mop assembly  100   c  and a fourth spin mop assembly  100   d . The robot cleaner  10  may include five or more spin mop assemblies. 
     Referring to  FIG. 4 , the first, second, third, and fourth spin mop assemblies  100   a ,  100   b ,  100   c ,  100   d  are disposed at the front left, front right, back left, and back right portions of the robot cleaner  10  respectively. It should be understood, however, that, although the front left, the front right, etc. are used herein to describe locations, the scope of the invention should not be limited by these terms. 
     In accordance with some embodiments, the spin mop assembly  100  may include a first direction spin mop assembly disposed at the front of the lower portion of the main body  20 , and a second direction spin mop assembly disposed on the back of the lower portion of the main body  20 . The first direction spin mop assembly may include at least two spin mop assemblies, and hereinafter is defined to include one set of the first spin mop assembly  100   a  and the second spin mop assembly  100   b . The second direction spin mop assembly may include at least two spin mop assemblies, and hereinafter is defined to include one set of the third spin mop assembly  100   c  and the fourth spin mop assembly  100   d.    
     In alternative embodiments, the spin mop assembly  100  may include a third direction spin mop assembly disposed at the left of the lower portion of the main body  20 , and a fourth direction spin mop assembly disposed at the right of the lower portion of the main body  20 . The third direction spin mop assembly may include at least two spin mop assemblies, and hereinafter is defined to include one set of the first spin mop assembly  100   a  and the third spin mop assembly  100   c . The fourth direction spin mop assembly may include at least two spin mop assemblies, and hereinafter is defined to include one set of the second spin mop assembly  100   b  and the fourth spin mop assembly  100   d.    
     A first container  32  is connected to the first direction spin mop assembly  100   a ,  100   b . Accordingly, a first liquid being stored in the first container  32  may be supplied to at least one mop pad  102  of the first direction spin mop assembly. A second container  34  is connected to the second direction spin mop assembly. Thus, a second liquid being stored in second container  34  may be supplied to at least one mop pad  102  of the second direction spin mop assembly. 
     In accordance with some embodiments, the first container of the robot cleaner may be connected to a first supply assembly, which will be described below, the second container may be connected to a second supply assembly. In accordance with some embodiments, the first liquid stored in the first container  32  may be water, and the second liquid in the second container  34  may be a cleaning liquid. In accordance with some embodiments, the first supply assembly  150  connected to the first direction spin mop assembly may be used as a liquid supply assembly, and a second supply assembly  160  connected to the second direction spin mop assembly may be used as a cleansing assembly. In alternative embodiments, both the first supply assembly  150  and the second supply assembly  160  may be used as the liquid supply assembly or the cleansing assembly. 
     In accordance with some embodiments, the first and third spin mop assemblies  100   a ,  100   c  of the third direction spin mop assembly may be driven at the same rotational direction and rotational speed. In accordance with some embodiments,  FIG. 4  illustrates that the first and third spin mop assemblies  100   a ,  100   c  of the third direction spin mop assembly may be driven by separate driving motors  132 . It should be noted, however, that the third direction spin mop assembly may be driven at the same rotational direction and rotational speed by a single driving motor  132 . 
     The second and fourth spin mop assemblies  100   b ,  100   d  of the fourth direction spin mop assembly may be driven at the same rotational direction and rotational speed. In this case, as illustrated in  FIG. 4 , The second and fourth spin mop assemblies  100   b ,  100   d  of the fourth direction spin mop assembly may be driven by a single driving motor  132 , or by separate driving motors  132 . 
     Next, referring to  FIGS. 5 to 10 , a configuration of the spin mop assembly is described in detail. In accordance with some embodiments, the plurality of spin mop assemblies may include the same configuration or different configurations, but hereinafter, for convenience of description, description will be given in instances where the same configuration is applied to them. Therefore, the same reference number will be used to respective parts of the spin mop assemblies. That is, a reference number used on the spin mop assembly identifies respective parts of one or more spin mop assemblies. 
     The spin mop assembly  100  includes a rotary plate  104  which is connected to a driving assembly  130  and rotated by it, and a mop pad  102  attached to a lower portion of the rotary plate  104 . The rotary plate  104  may include an attaching member by which the mop pad  102  can be attached to the rotary plate  104  or detached from it, and the attaching member may be made of an elastic fabric, such as Velcro-like material. 
     Referring to  FIG. 7 , the spin mop assembly  100  may be inclined relative to the floor at a predetermined angle. The spin mop assembly  100  may include a suspension base  110  which is connected to the rotary plate  104  and configured to adjust an inclination angle of the rotary plate  104 , and an elastic member  112  which is configured to apply an elastic force to a portion of the suspension base  110  and adjust an inclination angle of the rotary plate  104 . The suspension base  110  is connected by means of a hinge to a suspension frame  114  which is disposed on the base  24  of the main body  20 . One portion of the elastic member  112  is connected on the suspension frame  114  and configured to apply an elastic force to the suspension base  110  to which another portion of the elastic member  112  is connected. In instances where a separate external force is not applied to the spin mop assembly  100 , the rotary plate  104  of the spin mop assembly may be inclined relative to the floor at a predetermined angle by an elastic force of the elastic member  112 , as illustrated in  FIG. 7 . 
     Referring to  FIG. 3 , an inclination angle of the third direction spin mop assembly relative to the floor, which is resulted from the elastic member  112  and the suspension base  110 , may be generally symmetrical relative to an inclination angle of the fourth direction spin mop assembly relative to the floor. 
     The spin mop assembly  100  may include a nozzle  120 , which is connected to a first hose  154  connected to the first container  32  or a second hose  164  connected to the second container  34 , and a liquid collecting guider  122  for guiding or collecting some substances supplied from the nozzle  120 . An upper part of rotary plate  104  may include a rotary plate hole  124  which is configured to supply the substances collected in the liquid collecting guider  122  to the mop pad  102 . 
     A nozzle which is disposed on the first direction spin mop assembly is connected to the first hose  154 , and supplies the first liquid stored in the first container  32 , and another nozzle which is disposed on the second direction spin mop assembly is connected to the second hose  164 , and supplies the second liquid stored in the second container  32 . 
     The driving assembly  130  is configured to rotate the rotary plate  104  of the spin mop assembly  100 . The driving assembly  130  may be disposed on each of the third direction spin mop assembly and the fourth direction spin mop assembly, or on each of four spin mop assemblies  100 . 
     Next, referring to  FIG. 10 , the driving assembly  130  disposed on the spin mop assembly  100  is described. 
     The driving assembly  130  includes a driving motor  132  for providing a driving force to rotate the spin mop, a first gear  134  connected to a driving shaft  106  of the driving motor  132 , and a second gear  136  which is engaged with the first gear  134  and configured to transfer the driving force to the rotary plate  104 . 
     In accordance with some embodiments, the first gear  134  may be a worm gear for transferring the driving force to the second gear  136  to which the first gear  134  is generally vertically disposed relative. The second gear  136  which is engaged with the worm gear may receive the driving force from it. 
     The upper surface of rotary plate  104  includes a rotation shaft  106 , which is protruded from the center toward upward, and the upper end of the rotation shaft  106  is connected to the second gear  136 . The driving assembly  130  is disposed on an upper portion of the suspension base  110 . Accordingly, even if an inclined angle of the rotary plate  104  is changed, the rotary plate  104  can be driven stably. 
       FIG. 11  is a view illustrating a configuration of a plurality of bumper assemblies according to some embodiments.  FIG. 12  is a view illustrating a configuration of a bumper assembly according to some embodiments. 
     Hereinafter, referring to  FIGS. 11 to 12 , the bumper assembly is described in accordance with some embodiments. 
     The bumper assembly  140  is disposed on an enclosure of the main body  20 , such as a protruded or groove portion, an edge portion of the outer surface thereof. The bumper assembly  140  can detect an external impact which is generated while the robot cleaner  10  is moving, or reduce it. Referring to  FIG. 11 , the bumper assembly  140  according to some embodiments may be disposed on an enclosure of an upper portion of the spin mop assembly  100 , such as a protruded or groove portion, an edge portion of the outer surface thereof. 
     In accordance with some embodiments, the robot cleaner  10  may include a plurality of bumper assemblies  140   a ,  140   b ,  140   c ,  140   d . In accordance with some embodiments, the robot cleaner  10  may include a first bumper assembly  140   a , a second bumper assembly  140   b ), a third bumper assembly  140   c , and a fourth bumper assembly  140   d . The number of the bumper assemblies is not limited to this. It is, therefore, possible that five or more bumper assemblies are employed. 
     Referring to  FIG. 11 , the first, second, third and fourth bumper assemblies  140   a ,  140   b ,  140   c ,  140   d  may be disposed on enclosures of the first, second, third, and fourth spin mop assemblies  100   a ,  100   b ,  100   c ,  1200   d  respectively. 
     Hereinafter, referring to  FIG. 12 , a configuration of the bumper assembly is described. In accordance with some embodiments, each of the plurality of bumper assemblies may include the same configuration, therefore the same reference number will be used to respective parts of the bumper assemblies. That is, a reference number used on the bumper assembly may identify respective parts of one or more bumper assemblies. 
     The bumper assembly  140  may include a bumper  142  which is disposed to be protruded on an enclosure of the main body  20 , an impact detection sensor  144  which detects the movement of the bumper  142 , and a pressure member  146  which puts pressure on the impact detection sensor  144  when the bumper  142  moves. The bumper assembly  140  may further include a movement guider member  148  which guides the movement of the bumper  142 . 
     The bumper assembly  140  may include two impact detection sensors  144 . Each of the bumper assemblies  140  may include impact detection sensors  144 , which detect impact within a range of at least two directions which are generally vertical to each other. 
     In accordance with some embodiments, the robot cleaner  10  may apply at least two impact detection sensors  144  to each of the four bumper assemblies. Accordingly, it is possible that impacts generated not only in the first, second, third and fourth directions, but also in directions defined among the first, second, third or fourth directions are detected. 
       FIG. 13  is a cross-sectional view of the robot cleaner, horizontally taken along line XIII-XIII′ of  FIG. 3   FIG. 14  is a view illustrating a configuration of a fluid supply assembly and a cleansing assembly according to some embodiments. 
     Hereinafter, in accordance with some embodiments, a first supply assembly and a second supply assembly will be described with referring to  FIGS. 13 to 14 . 
     The robot cleaner  10  includes the first supply assembly  150  configured to supply the first liquid to the spin mop assembly  100  and the second supply assembly  160  configured to supply the second liquid to the spin mop assembly  100 . 
     The first supply assembly  150  is configured to supply the first liquid to at least one mop pad of some of the plurality of spin mop assemblies  100   a ,  100   b . In accordance with some embodiments, the first supply assembly  150  is configured to supply the first liquid to the first direction spin mop assembly. 
     The first supply assembly  150  includes a first container  32  configured to store the first liquid which is supplied to the spin mop assembly  100 , a first pump  152  for supplying the first liquid stored in the first container  32  to the spin mop assembly  100 , and a first hose  154  forming a channel for guiding the flow of the first liquid from the first container  32  to the spin mop assembly  100 . The first supply assembly  150  may further include a first valve  156  which is disposed on the first hose  154  and configured to adjust the flow of the first liquid. The robot cleaner  10  can open or close the first valve  156  in accordance with a mode of operation for moving thereof. 
     In accordance with some embodiments, the first hose  154  is connected to a nozzle of the first direction spin mop assembly. The first hose  154  is configured to supply the first liquid to a liquid collecting guider of the first direction spin mop assembly. 
     The second supply assembly  160  is configured to supply the second liquid to at least one mop pad of the others of the plurality of spin mop assemblies  100   c ,  100   d . In accordance with some embodiments, the second supply assembly  160  is configured to supply the second liquid to the second direction spin mop assembly. 
     The second supply assembly  160  includes a second container  34  configured to store the second liquid which is supplied to the spin mop assembly  100 , a second pump  162  for supplying the second liquid stored in the second container  34  to the spin mop assembly  100 , and a second hose  164  forming a channel for guiding the flow of the second liquid from the second container  34  to the spin mop assembly  100 . The second supply assembly  160  may further include a second valve  166  which is disposed on the second hose  164  and configured to adjust the flow of the second liquid. The robot cleaner  10  can open or close the second valve  166  in accordance with a mode of operation for moving thereof. 
     In accordance with some embodiments, the second hose  164  is connected to the second direction spin mop assembly. The second hose  164  is configured to supply the second liquid to a liquid collecting guider of the second direction spin mop assembly. 
     In accordance with some embodiments, the first supply assembly  150  may be used as a liquid supply assembly  150  which uses water as the first liquid. In accordance with some embodiments, the second supply assembly  160  may be used as a cleansing assembly  160  which uses cleaning liquid as the second liquid. 
     The liquid supply assembly  150  is configured to supply water to the mop pad  102  of the spin mop assembly  100 . In accordance with some embodiments, the liquid supply assembly  150  is configured to supply water to the first direction spin mop assembly. 
     The cleansing assembly  160  is configured to supply the cleaning liquid to the mop pad  102  of the spin mop assembly  100 . The cleansing assembly  160  is configured to supply the cleaning liquid to the second direction spin mop assembly. 
     Referring  FIG. 13 , in accordance with some embodiments, the first container  32  of the first supply assembly  150  is disposed in a separate space from the second container  34  of the second supply assembly  160 . It should be noted, however, that this is an example, and as an alternative embodiment, the first container  32  and the second container  34  may be integrated into one single container  30  in which the same liquid may be stored. 
       FIG. 15  is a block diagram illustrating a configuration in conjunction with a controller according to some embodiments. 
     Hereinafter, in accordance with some embodiments, a sensor and a controller for driving the robot cleaner will be described with reference to  FIG. 15 . 
     In accordance with some embodiments, the robot cleaner  10  includes an obstacle detection sensor  210  configured to detect obstacles near the robot cleaner  10 . The robot cleaner  10  may include a plurality of the obstacle detection sensor  210   a ,  210   b ,  210   c , as illustrated in  FIG. 3 . In accordance with some embodiments, the obstacle detection sensor  210  of the robot cleaner  10  may be disposed on a front surface and a back surface of the main body  20 . It should be noted, however, that this is an example, and as an alternative embodiment, the obstacle detection sensor  210  may be disposed on a side surface thereof. 
     In accordance with some embodiments, the robot cleaner  10  includes a cliff sensor  220  which detects whether a cliff is exist or not within an area to be cleaned. The robot cleaner  10  may be provided with a plurality of the cliff sensors  220 . In accordance with some embodiments, the cliff sensor  220  may be disposed at a front portion and a back portion of the robot cleaner  10 , as illustrated in  FIG. 2 . 
     In accordance with some embodiments, the robot cleaner  10  includes a controller  200  which controls operation of the robot cleaner  10 . The controller  200  includes a printed circuit board disposed inside the main body  20 . The controller  200  can process a signal from obstacle detection sensor  210  or the cliff sensor  220 . The controller  200  can control the driving assembly  130  for moving of the robot cleaner  10 . The controller  200  can cause the robot cleaner  10  to move forward or backward, or turn. The controller  200  can process a signal from the impact detection sensor  144  which detects an impact created by the bumper  142  while the robot cleaner  10  is moving. The controller  200  may control the driving assembly  130  based on a signal from the impact detection sensor  144  or the obstacle detection sensor  210 . 
     The controller  200  may open or close the first valve  156  or the second valve  166 , which are disposed on the first hose  154  or the second hose  164  respectively. The controller  200  may open or close the first valve  156  or the second valve  166  according to a mode of operation for moving of the robot cleaner  10 . 
     In accordance with some embodiments, the robot cleaner  10  may include an input unit  230  for inputting a user&#39;s instruction. A mode of operation for moving of the robot cleaner  10  or the driving assembly  130  can be changed by an instruction through the input unit  230 . The input unit  230  may be disposed on the robot cleaner  10 , or on a mobile handset to which the robot cleaner  10  can communicate wirelessly or through a wired connection. The controller  200  may process some signals from the input unit  230  and control the robot cleaner  10 . 
     In accordance with some embodiments, the robot cleaner  10  may further include a charger  38  for charging a battery for providing power with the robot cleaner  10 . The charger  38  is configured to charge from external power source and supply the charged power to a driving motor  132  or a pump. 
       FIG. 16  is a view illustrating spinning of the plurality of spin mop assemblies when the robot cleaner makes a small radius turn according to some embodiments. 
     Hereinafter, referring to  FIG. 16A to 16D , a description will be given of a rotational direction and a rotational speed of the spin mop assembly according to moving of the robot cleaner. 
     In accordance with some embodiments, each of the third direction spin mop assembly and the fourth direction spin mop assembly may be configured to enable the robot cleaner  10  to move. In instances where the robot cleaner  10  moves straight in the first or second direction, the third direction spin mop assembly and the fourth direction spin mop assembly have the same rotational speed, but rotational directions thereof are different to each other. 
     Referring to  FIG. 16A , in accordance with some embodiments, in instances where the robot cleaner  10  moves straight in the first direction, the third direction spin mop assembly may turn counterclockwise, and the fourth direction spin mop assembly may turn clockwise. 
     Referring to  FIG. 16B , in instances where the robot cleaner  10  moves straight in the second direction, the third direction spin mop assembly may turn clockwise, and the fourth direction spin mop assembly may turn counterclockwise. 
     In instances where the robot cleaner  10  turns, the third direction spin mop assembly and the fourth direction spin mop assembly have the same rotational direction or rotational speed, or it is possible that rotational speeds thereof are different to each other. The robot cleaner  10  may adjust a turning radius thereof by adjusting a difference between the rotational speeds of at least one spin mop of the third direction spin mop assembly and at least one spin mop of the fourth direction spin mop assembly. 
     Referring to  FIG. 16C , in instances where the robot cleaner  10  turns, and a rotational speed of a spin mop assembly, among the plurality of spin mop assemblies  100 , that is located far from a turning radius of the robot cleaner  10  is faster than that of the others, a turning radius of the robot cleaner  10  becomes small. In addition, referring to  FIG. 16D , in instances where the robot cleaner  10  turns, and a rotational speed of a spin mop assembly, among the plurality of spin mop assemblies  100 , that is located far from a turning radius of the robot cleaner  10  is slower than that of the others, a turning radius of the robot cleaner  10  becomes large. 
       FIG. 17  is a view illustrating driving of the robot cleaner in a dry-cleaning mode according to some embodiments.  FIG. 18  is another view illustrating driving of the robot cleaner in the dry-cleaning mode according to some embodiments.  FIG. 19  is another view illustrating driving of the robot cleaner in the dry-cleaning mode according to some embodiments. 
     Hereinafter, Referring to  FIGS. 17 to 19 , a description will be given of controls of the driving assembly, the liquid supply assembly and the cleansing assembly in accordance with a mode of operation for moving of the robot cleaner  10 . 
     In accordance with some embodiments, the robot cleaner  10  moves in a first direction or a second direction. Moving of the robot cleaner  10  in the first direction or the second direction includes a moving forward in the first direction or the second direction and a turning. 
     Hereinafter, an exemplary first supply assembly  150  is used as a liquid supply assembly which uses water as the first liquid, and an exemplary second supply assembly  160  is used as a cleansing assembly  160  which uses the cleaning liquid as the second liquid. In this case, a description will be given of the operation of the robot cleaner in accordance with a mode of operation in instances where these exemplary embodiments are applied. 
     In accordance with some embodiments, the robot cleaner ( 10 ) includes the first direction spin mop assembly, which is disposed at a lower portion of main body  20  in the first direction, the second direction spin mop assembly, which is disposed at a lower portion of main body  20  in the second direction, a liquid supply assembly  150  configured to supply water to the first direction spin mop assembly, and a cleansing assembly  160  configured to supply a liquid mixed with water and a cleaning liquid to the second direction spin mop assembly. 
     In accordance with some embodiments, the liquid supply assembly  150  is configured to store water in a first container  32 . The liquid supply assembly  150  is connected to the first direction spin mop assembly through a first hose  154 . The liquid supply assembly  150  is configured to adjust the supply of water to the first direction spin mop assembly, by opening or closing a first valve  156  which are disposed on the first hose  154 . 
     In accordance with some embodiments, the cleansing assembly  160  is configured to store a cleaning liquid in a second container  34 . The cleansing assembly  160  is connected to the second direction spin mop assembly through a second hose  164 . The cleansing assembly  160  is configured to adjust the supply of cleaning liquid to the second direction spin mop assembly, by opening or closing a second valve  166  which are disposed on the second hose  164 . 
     The robot cleaner  10  may operate in a dry-cleaning mode in which the spin mop assembly  100  is driven in a dry status, a wet-cleaning mode in which some of a plurality of spin mop assemblies  100  are supplied water and the others of the plurality of spin mop assemblies  100  are driven without the supply of water or in a dry status, or a cleansing mode in which some of the plurality of spin mop assemblies  100  are supplied a liquid mixed with water and a cleaning liquid and the others of the plurality of spin mop assemblies are supplied water. 
     In instances where the dry-cleaning mode is implemented, the controller  200  of the robot cleaner  10  is configured to cause the first valve  156  and the second valve  166  to be closed. The controller  200  controls moving of the robot cleaner  10  by controlling the driving assembly  130 . The robot cleaner  10  moves in the first direction or the second direction, and thus mops the floor. 
     In instances where the wet-cleaning mode is implemented, the controller  200  of the robot cleaner  10  is configured to cause the first valve  156  to be opened and the second valve  166  to be closed. The controller  200  is configured to cause the robot cleaner  10  to move in the first direction by controlling the driving assembly  130 . The robot cleaner  10  moves in the first direction or turns, in a state where the first valve  156  only is opened and water is supplied to the first direction spin mop assembly. 
     In instances where the wet-cleaning mode is implemented, the robot cleaner  10  moves in the first direction. In this case, the second direction spin mop assembly of the robot cleaner  10  moves on the floor through which the first direction spin mop assembly already passed. Accordingly, the second direction spin mop assembly mops with dry mops the wet floor which the first direction spin mop assembly moped with water. Also, the robot cleaner  10  can perform simultaneously two types of cleaning operations on the floor, a wet mopping and a dry mopping, at one time traveling. 
     In instances where the cleansing mode is implemented, the controller  200  of the robot cleaner  10  is configured to cause all the first valve  156  and the second valve  166  to be opened. The controller  200  is configured to cause the robot cleaner  10  to move in the second direction by controlling the driving assembly  130 . The robot cleaner  10  is configured to open the first valve  156  and the second valve  166 . Water is supplied to the first direction spin mop assembly and a cleaning liquid is supplied to the second direction spin mop assembly. 
     In instances where the cleansing mode is implemented, the robot cleaner  10  moves in the second direction. In this case, the first direction spin mop assembly of the robot cleaner  10  moves on the floor through which the second direction spin mop assembly already passed. Accordingly, the first direction spin mop assembly mops with water the floor which the second direction spin mop assembly mopped with the cleaning liquid. Also, the robot cleaner  10  can perform simultaneously two types of cleaning operations on the floor, a cleansing mopping operation and a wet mopping operation. 
     It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. The scope of the invention is defined not by the detailed description of the invention but by the appended claims, and all differences, variations and modifications within the scope will be construed as being included in the present invention concepts or prospects of the present disclosure.