Patent Publication Number: US-2015088359-A1

Title: Mobile robot with returning mechanism

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     The present invention claims priority of Korean Patent Application No. 10-2013-0114335, filed on Sep. 26, 2013, which is incorporated herein by reference. 
     FIELD OF THE INVENTION 
     The present invention relates to a mobile robot having a returning mechanism, and more specifically, to a method and apparatus for returning a mobile robot to an initial location from a hazardous area at a situation where the mobile robot cannot be remotely controlled. 
     BACKGROUND OF THE INVENTION 
     In recent years, there has been proposed a method to deploy a mobile robot in an area where people do not access directly because of a lot of hazardous factors such as radioactive area and remotely control the mobile robot to accomplish the intended task. 
     After that, a method of returning the mobile robot to an origin point is performed by a method using image information. In connection with the method of returning a moving body, a prior art of Korean Patent Registration No. 10-0645814, which is registered on Nov. 23, 2006, discloses a method to control the moving body to return to the origin point by using the infrared image information of an infrared module inputted from a camera module. 
     However, in the provision of the method to return the mobile robot, the aforementioned prior art does not disclose how to return a mobile robot to an initial starting point when the communication between a moving body and a remote control device is disconnected. Further, the prior art is silent to disclose any configuration in which the mobile robot is controlled to independently move in the direction of the initial starting location when it is located in the hazardous area but personnel cannot access the hazardous area. 
     SUMMARY OF THE INVENTION 
     In view of the above, the present invention provides a mobile robot having a returning mechanism that includes a returning member having a rigidity stronger than a cable member of the mobile robot and one or more moving members and that is capable of returning the mobile robot to an original location by using the returning member and tension thereof even when the mobile robot falls in a deadlock. However, the technical subjects of the embodiment of the present invention are not limited to the aforementioned subjects, and there may be other technical subjects. 
     In accordance with an embodiment of the present invention, there is provided a mobile robot having a returning mechanism. The mobile robot includes one or more moving members mounted on a body of the mobile robot; a cable member connected to one side of the mobile robot so as to supply the mobile robot with electrical power; a returning member having a rigidity stronger than the cable member and disposed to wrap the cable member so that the cable member is placed within the returning member; and a take-up unit configured to pull the returning member to keep it taut. 
     In accordance with any one of solutions to the subject described above, it is possible to implement a method to return the mobile robot by use of the tension of the returning member even if the mobile robot is placed in a situation where it cannot be controlled, thereby prevent safety accidents in advance since personnel need not to put in the hazardous area. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other objects and features of the present invention will become apparent from the following description of the embodiments given in conjunction with the accompanying drawings, in which: 
         FIG. 1  shows a perspective view of a mobile robot having a returning mechanism in accordance with an embodiment of the present invention; 
         FIG. 2  is a sectional view of a returning member and cable member of a mobile robot having a returning mechanism shown in  FIG. 1 ; 
         FIGS. 3A and 3B  show perspective views of a mobile robot having a returning mechanism in accordance with a first embodiment of the present invention; 
         FIG. 4  is a side view of a mobile robot having a returning mechanism in accordance with a second embodiment of the present invention; 
         FIGS. 5A and 5B  show a mobile robot having a returning mechanism in accordance with a third embodiment of the present invention, wherein  FIG. 5A  is a side view of a mobile robot having a returning mechanism and  FIG. 5B  illustrates a state where the mobile robot is enveloped by the returning collection mechanism; 
         FIGS. 6A and 6B  are side views of a mobile robot having a returning mechanism in accordance with a fourth embodiment of the present invention; and 
         FIGS. 7A and 7B  show perspective views of a mobile robot having a returning mechanism in accordance with a fifth embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that they can be readily implemented by those skilled in the art. 
     Throughout the specification and the claims, when an element is described as being “connected” to another element, this implies that the elements may be directly connected together or the elements may be connected through one or more intervening elements. Furthermore, when an element is described as “including” one or more elements, this does not exclude additional, unspecified elements, nor does it preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and/or groups thereof. 
     Hereinafter, the embodiments of the present invention will be described in detail with reference to the accompanying drawings. 
       FIG. 1  shows a perspective view of a mobile robot having a returning mechanism in accordance with an embodiment of the present invention, and  FIG. 2  is a sectional view of a returning member and a cable member of the mobile robot having a returning mechanism shown in  FIG. 1 . 
     A mobile robot having a returning mechanism in accordance with an embodiment of the present invention includes one or more moving members  100 , a cable member  200 , a returning member  300 , and a take-up unit  400 . However, the mobile robot having a returning mechanism is merely an example and the present invention is therefore not construed to be limited to that illustrated in  FIG. 1 . 
     The one or more moving members  100  are mounted on a body of the mobile robot  1  having a returning mechanism. The moving member  100  may be modified depending on various embodiments of the present invention, which will be discussed later. Herein, the mobile robot  1  having a returning mechanism and the mobile robot  1  are defined to indicate the identical entity. 
     The cable member  200  is coupled to one side of the mobile robot  1  so that an electrical power can be supplied to the mobile robot  1 . 
     The returning member  300  has rigidity stronger than the cable member  200  and wraps the cable member  200  to place the cable member  200  within the returning member  300 . Referring to  FIG. 2 , the returning member  300  may be substituted with a fire hose of a fire fighting robot (not shown) or a wired communication cable of a nuclear robot (not shown). That is to say, the fire fighting robot is equipped with a fire hose and the nuclear robot is equipped with a wired communication cable, and these firefighting and nuclear robots may take advantage of the fire hose and the wired communication cable as a returning rope, instead of equipping with a separate returning rope. For that reason, the returning member  300  of the embodiment may also be embodied in the fire hose or the wired communication cable. Accordingly, even if the returning member  300  is severely pulled under high tension, the returning member  300  is able to withstand the pulling tension without being cut off. In this case, the cable member  200  may include a cladding having the rigidity stronger than the cable member  200 . 
     Referring back to  FIG. 1 , the take-up unit  400  takes care of the returning member  300 , e.g., by pulling on the returning member  300  to keep it taut. 
     The mobile robot  1  having a returning mechanism in accordance with an embodiment of the present invention can be returned by pulling on the returning member  300  in case where it cannot move by itself due to breakdown. 
       FIGS. 3A and 3B  show perspective views of a mobile robot having a returning mechanism in accordance with a first embodiment of the present invention. Referring to  FIGS. 3A and 3B , the moving member  100  may be one of ballcasters, wheel-based ballcasters and fixed flippers. 
     The mobile robot  1  having a returning mechanism in accordance with an embodiment of the present invention can be returned by pulling on the returning member  300  in a situation where it cannot move by itself due to breakdown. However, because the gear ratio between a motor and wheels that are engaged is high, the wheels do not rotate easily once the motor is stopped, which leads to a difficult of returning the mobile robot. 
     In accordance with a first embodiment of the present invention, therefore, a plurality of the moving members  100  enable to easily move without employing the wheels. For example, although the mobile robot  1  having a returning mechanism falls down on its side, it is possible to return the mobile robot  1  by the roll motion of a plurality of the moving members  100  which are provided on the front and rear sides, and left and right sides of the mobile robot  1  during pulling on the returning member  300 . 
       FIG. 4  is a side view of a mobile robot having a returning mechanism in accordance with a second embodiment of the present invention. Referring to  FIG. 4 , the mobile robot  1  having a returning mechanism of the second embodiment of the present invention further includes a lower panel  500 , a control unit  600  and a linear motor  700 . 
     The lower panel  500  is arranged below the mobile robot  1 . The moving member  100  is mounted on the bottom of the lower panel  500 . 
     The control unit  600  detects a state that the mobile robot  1  is not able to move, and the linear motor  700  allows the lower panel  500  to descend by pushing the lower panel in a downward direction when the control unit  600  detects a state that the mobile robot  1  is not able to move. Therefore, the moving member  100  is protruded downwardly further than a moving unit of the mobile robot  1  by the linear motor  700  so that it can step on land. Here, the moving unit may be one or more wheels of the mobile robot  1 . 
     With the configuration of the returning mechanism included in the mobile robot  1 , it is possible to return the mobile robot  1  having a returning mechanism by protruding the lower panel  500  or lowering the lower panel  500  on which the moving member  100  is mounted on the bottom of the mobile robot  1  and pulling on the returning member  300  when the mobile robot  1  breaks down and is not able to move. In other words, since a rolling motion may not occur when the mobile robot  1  falls in a deadlock during the motor and the wheels are engaged with each other, the mobile member  100  which is capable of rolling is protruded to step on land, whereby the mobile robot  1  can be returned even when it remains stationary. 
       FIGS. 5A and 5B  show a mobile robot having a returning mechanism in accordance with a third embodiment of the present invention, wherein  FIG. 5A  is a side view of a mobile robot having a returning mechanism and  FIG. 5B  illustrates a state where the mobile robot is enveloped by the returning collection mechanism. Referring to  FIGS. 5A and 5B , the mobile robot  1  having a returning mechanism in accordance with a third embodiment of the present invention further includes an airbag module  800  and a control unit  600 . 
     The airbag module  800  is mounted to envelope an entire body of the mobile robot the mobile robot  1 , which may be embodied in the moving member  100 . 
     The control unit  600  detects a state that the mobile robot  1  is not able to move. The airbag module  800  envelopes the mobile robot  1  in the form of a sphere when it is activated. The airbag module  800  protects the mobile robot  1  while providing high elasticity and less friction. 
       FIGS. 6A and 6B  are a side view of a mobile robot having a returning mechanism in accordance with a fourth embodiment of the present invention. Referring to  FIG. 1  and  FIGS. 6A and 6B , the mobile robot  1  having a returning mechanism further includes one or more gears  900 , a primary motor  930  and a control unit  600 . 
     The one or more gears  900  are coupled to a moving unit  910  of the mobile robot  1 . The moving unit  910  may be one or more wheels of the mobile robot  1 . 
     The primary motor  930  is engaged with the gear  900  to drive the moving unit  910 . 
     The control unit  600  detects a state that the mobile robot  1  is not able to move. When the control unit  600  detects the state that the mobile robot  1  is not able to move, it forces the primary motor  930  to be separated from the gear  900  by moving the primary motor  930  in one side direction. 
     The mobile robot  1  having a returning mechanism in accordance with the fourth embodiment of the present invention separates the primary motor  930  from the gear  900  to disconnect between the moving unit  910  and the primary motor  930 . As a result, the moving unit  910  which is disconnected with the primary motor  930  can freely roll, thereby returning the mobile robot  1  with the pulling tension of the returning member  300 . 
       FIGS. 7A and 7B  show perspective views of a mobile robot having a returning mechanism in accordance with a fifth embodiment of the present invention. The operation of the mobile robot of  FIGS. 7A and 7B  will be explained with reference to  FIG. 1  as below. The mobile robot  1  having a returning mechanism includes a caterpillar  910  as the moving unit, and further includes a control unit  600  and linear motor  700 . 
     The caterpillar  910  includes one or more main moving rollers  911 , an at least subsidiary moving roller  913 , and a belt assembly  915  in which a plurality of plates is coupled using pins enclosing the main moving roller  911  and the subsidiary moving roller  913 . 
     The control unit  600  detects a state that the mobile robot  1  is not able to move, and a linear motor  700  is connected with the caterpillar  910 . When the control unit  600  detects the state that the mobile robot  1  is not able to move, it drives the linear motor  700  to remove the pins on the belt assembly  915 . Or, when the control unit  600  detects the state that the mobile robot  1  is not able to move, it drives the linear motor  700  to remove the main moving roller  911  or the subsidiary moving roller  913 . 
     The mobile robot  1  having a returning mechanism in accordance with a fifth embodiment of the present invention removes the belt assembly  915  of the caterpillar  910  so that the main moving roller  911  cannot contact ground. As a result, the mobile robot  1  can be returned by the roll of the subsidiary moving roller  913  and the pulling tension of the returning member  300 . 
     With the mobile robot  1  having a returning mechanism in accordance with an embodiment of the present invention, when performing fire suppression, mine detection and monitoring and operation of a nuclear facility, even if the mobile robot is not able to move, it is possible to to return the mobile robot without the direct access the hazardous area of the personnel. 
     Description of the present invention as described above are intended for illustrative purposes, and it will be understood to those having ordinary skill in the art that this invention can be easily modified into other specific forms without changing the technical idea and the essential characteristics of the present invention. Accordingly, it should be understood that the embodiments described above are exemplary in all respects and not limited thereto. For example, respective components described to be one body may be implemented separately from one another, and likewise components described separately from one another may be implemented in an integrated type. 
     While the invention has been shown and described with respect to the embodiments, the present invention is not limited thereto. It will be understood by those skilled in the art that various changes and modifications may be made without departing from the scope of the invention as defined in the following claims.