Abstract:
A cleaning apparatus includes: an accommodation unit that accommodates a cleaning cloth; a drawing-out unit that draws out the cleaning cloth; a cleaning clot setting mechanism unit including an ascend/descend member that ascends and descend together with the cleaning cloth drawn out by the drawing-out unit; and a projection unit that upwardly projects as far as a position between an ascended position and a descended position of the ascend/descend member. When the ascend/descend member is located at the ascended position, the cleaning cloth can be drawn out, and when the ascend/descend member is located at the descended position, the projection unit engages the cleaning cloth, and a robot causes an optical device to be pressed against the cleaning cloth engaged by the projection unit, thereby cleaning the optical device.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Technical Field 
         [0002]    The present invention relates to a cleaning apparatus and also to a system including such a cleaning apparatus. 
         [0003]    2. Description of Related Art 
         [0004]    A system has been widespread in which a workpiece is imaged by an optical device such for example as a camera attached to a robot, and the imaged image is analyzed to operate the robot. Using such a system for a long period of time tends to cause the optical device, e.g., the lens of the camera to be stained due to external environment or the like, and therefore it is possible that a clear image cannot be imaged. Consequently, analysis of the image becomes unable to be performed satisfactorily. Hence, it may happen that the robot is frequently stopped so that the operating rate of the system is lowered. Thus, in the prior art, it was necessary for the operator to clean the optical device at regular intervals. 
         [0005]    In this regard, a cleaning apparatus for automatically cleaning an optical component is disclosed in Japanese Laid-open Patent Publication No. 2001-075241. In Japanese Laid-open Patent Publication No. 2001-075241, a spraying device, a humidifying device, and a wiping device are arranged in the named order along the conveying direction of a conveyor. High-pressure air is sprayed by the spraying device onto an optical component conveyed on the conveyor, subsequently the optical component is humidified by the humidifying device, and finally the optical component is wiped by a wiping member of the wiping device. 
         [0006]    However, in Japanese Laid-open Patent Publication No. 2001-075241, since it is necessary to arrange the spraying device, humidifying device and wiping device along the conveying direction of the conveyor, the space occupied by these devices is increased, and therefore the entire system is excessively large. 
         [0007]    The present invention has been made in view of such circumstances, and an object thereof is to provide a cleaning apparatus having an increased operating rate without being excessively large and a system including such a cleaning apparatus. 
       SUMMARY OF THE INVENTION 
       [0008]    In order to achieve the above object, according to a first aspect of the present invention, there is provided a cleaning apparatus including: an accommodation unit that accommodates a cleaning cloth; a drawing-out unit that draws out the cleaning cloth from the accommodation unit; a cleaning cloth setting mechanism unit including an ascend/descend member that ascends and descends between the accommodation unit and the drawing-out unit together with the cleaning cloth drawn out by the drawing-out unit; and a projection unit that upwardly projects as far as a position between an ascended position and a descended position of the ascend/descend member, wherein when the ascend/descend member is located at the ascended position, the cleaning cloth can be drawn out, and wherein when the ascend/descend member is located at the descended position, the projection unit engages the cleaning cloth, and cleaning is performed using the cleaning cloth engaged by the projection unit. 
         [0009]    According to a second aspect of the invention, the cleaning apparatus according to the first aspect further includes a cleaning liquid ejection unit that ejects a cleaning liquid onto the cleaning cloth in the cleaning cloth setting mechanism unit when the ascend/descend member is located at the ascended position. 
         [0010]    According to a third aspect of the invention, there is provided a system including a robot, an optical device, and the cleaning apparatus according to the first or second aspect, wherein the robot causes the optical device to be pressed against the cleaning cloth engaged by the projection unit, thereby cleaning the optical device. 
         [0011]    According to a fourth aspect of the invention, in the third aspect, the cleaning apparatus is attached to the robot, and the optical device is located at a fixed position. 
         [0012]    According to a fifth aspect of the invention, in the third aspect, the optical device is attached to the robot, and the cleaning apparatus is located at a fixed position. 
         [0013]    According to a sixth aspect of the invention, in the fourth aspect, the cleaning apparatus is attachable to and detachable from the robot. 
         [0014]    According to a seventh aspect of the invention, in the third aspect, it is configured such that in accordance with a program of the robot, the optical device is cleaned at each predetermined cycle or when the number of detection errors by the optical device exceeds a predetermined number of times. 
         [0015]    The above objects, features, and advantages, as well as other objects, features, and advantages, of the present invention will become more apparent from a detailed description of exemplary embodiments of the invention illustrated in the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]      FIG. 1  is a view illustrating a system including a cleaning apparatus and a robot; 
           [0017]      FIG. 2  is a perspective view of the cleaning apparatus illustrated in  FIG. 1 ; 
           [0018]      FIG. 3  is another perspective view of the cleaning apparatus illustrated in  FIG. 1 ; 
           [0019]      FIG. 4  is a flow chart illustrating the operation of the system including the cleaning apparatus and the robot based on the present invention; 
           [0020]      FIG. 5  is a perspective view for explaining the operation of the system; 
           [0021]      FIG. 6  is a first perspective view for the optical device being cleaned; 
           [0022]      FIG. 7  is a second perspective view for the optical device being cleaned. 
       
    
    
     DETAILED DESCRIPTION 
       [0023]    Embodiments of the present invention will now be described with reference to the accompanying drawings. Throughout the drawings, like reference numerals are assigned to like members. The scale of the drawings is appropriately changed in order to facilitate understanding. 
         [0024]      FIG. 1  is a view illustrating a system including a cleaning apparatus and a robot based on the present invention. The system  1  illustrated in  FIG. 1  includes mainly a robot  1 , an optical device  12  attached to a hand of the robot  11 , and a cleaning apparatus  20  for cleaning the optical device  12 . The optical device  12  may be a camera or a visual sensor, and in the following description, it is assumed that the optical device  12  is a camera  12 . Further, the robot  11  and the cleaning apparatus  20  are connected to a control apparatus  10  that controls the robot  11  and the cleaning apparatus  20 . 
         [0025]      FIG. 2  is a perspective view of the cleaning apparatus illustrated in  FIG. 1 , and  FIG. 3  is another perspective view of the cleaning apparatus  20  illustrated in  FIG. 1 . The cleaning apparatuses illustrated in  FIGS. 2 and 3  are in substantially the same state, and different in that a cleaning cloth  33  illustrated in  FIG. 3  is eliminated in  FIG. 2 . 
         [0026]    As illustrated in  FIGS. 1 through 3 , the cleaning apparatus  20  includes a base  21  having a plurality of openings formed therein. In the illustrated embodiment, the cleaning apparatus  20  is fixed to a floor unit or the like, for example, with bolts or the like inserted through the openings of the base  21 . 
         [0027]    On the base  21  of the cleaning apparatus  20  is mounted an accommodation unit  22  as illustrated. In the accommodation unit  22 , there is accommodated a winding roller  31  for the cleaning cloth  33 . Further, on the base  12 , there is mounted a drawing-out unit  34  for drawing out the cleaning cloth  33  from the winding roller  31 . The drawing-out unit  34  includes a take-up roller  32  onto which the drawn cleaning cloth  33  is wound. The cleaning cloth  33  may be either a woven cloth or a non-woven cloth, and, alternatively, it may be of any other configuration. 
         [0028]    Further, a first guide unit  23  is located adjacent to the accommodation unit  22  for causing the cleaning cloth  33  unwound from the accommodation unit  22  to be inclined upwardly. Also, a second guide unit  24  is located adjacent to the drawing-out unit  34  for causing the cleaning cloth  33  to be inclined downwardly. 
         [0029]    Further, a cleaning cloth setting mechanism unit  40  is located between the first guide unit  23  and the second guide unit  24 . Referring to  FIG. 2 , the cleaning cloth setting mechanism unit  40  includes mainly a flat unit  41  located at substantially the same height as the upper ends of the first and second guide units  23  and  24 , and an ascend/descend member  42  that ascends and descends above the flat unit  41 . The ascend/descend member  42  is caused by an ascend/descend unit  45  to ascend and descend between an ascended position depicted in  FIG. 1  and a descended position depicted in  FIG. 3 . 
         [0030]    Further, as can be seen from  FIG. 2 , the ascend/descend member  42  has a substantially rectangular through hole  43  formed at the center thereof. Further, the flat unit  41  is provided with a projection unit  49  that extends through the through hole  43  of the ascend/descend member  42 . While the cross section of the projection unit  49  illustrated in  FIG. 2  is substantially circular, the cross section of the projection unit  49  may be otherwise shaped, e.g., may be of a rectangular shape proportional to the through hole  43 . The projection unit  49  projects upwardly from the flat unit  41  to a position between the ascended position and the descended position of the ascend/descend member  42 . Preferably, the projection unit  49  projects as far as a position that is slightly lower than the ascended position of the ascend/descend member  42 . 
         [0031]    As can be seen from  FIGS. 1 and 2 , a first roller  51  is provided at one side of the flat unit  41  adjacent to the first guide unit  23 . A second roller  52  is provided at one side of the through hole  43  adjacent to the first roller  51 , and a third roller  53  is provided at the other side of the through hole  43 . In addition, a fourth roller  54  is provided at the other side of the flat unit  41  adjacent to the first guide unit  24 . 
         [0032]    The cleaning cloth  33 , which has been drawn out from the winding roller  31  by the drawing-out unit  34 , extends as far as the take-up roller  32  in engagement with all of the first to fourth rollers  51  to  54 . As can particularly be seen from  FIG. 1 , the cleaning cloth  33  passes below the first roller  51 , above the second roller  52  and the third rollers  53 , and blow the fourth roller  54 . 
         [0033]    Further, as illustrated in  FIG. 1 , a bracket  37  extends horizontally from a part of the ascend/descend member  42 . Attached to the distal end of the bracket  37  is an inclined member  38 . Further, a cleaning liquid ejection unit  39  that ejects a cleaning liquid is mounted perpendicularly to the inclined member  38 . It is assumed that the cleaning liquid ejection unit  39  is connected to an unillustrated cleaning liquid source. The cleaning liquid is ejected when the camera  12  contains stains that cannot be removed merely by dry wiping with the cleaning cloth  33 , for example. 
         [0034]      FIG. 4  is a flow chart illustrating the operation of the system including the cleaning apparatus and the robot based on the present invention. Further,  FIG. 5  is a perspective view for explaining the operation of the system. With reference to these drawings, description will now be made of the operation of the system including the cleaning apparatus of the present invention. Meanwhile, it is assumed that the operation illustrated in  FIG. 4  is performed at each predetermined control cycle. 
         [0035]    Initially, at step S 11  of  FIG. 4 , the robot  11  is driven to move the camera  12  to an imaging position. The imaging position is a position above an unillustrated workpiece, for example. Subsequently, at step S 12 , a determination is made as to whether a predetermined cycle has ended or a predetermined time has elapsed. The predetermined cycle refers to the cycle or another predetermined cycle of a predetermined operation performed using the robot  11  and the camera  12 . When the predetermined cycle has not ended or when the predetermined time has not elapsed, the procedure proceeds to step S 13 . 
         [0036]    At step S 13 , a workpiece or the like is imaged by the camera  12 . At step S 14 , a determination is made as to whether the imaged image is satisfactory. Whether an image is satisfactory is determined based on whether image processing can be appropriately performed by an image processing unit (not illustrated) in the control apparatus  10 , for example. When a satisfactory image is acquired, it can be determined that the camera  12  is not stained at all. In such an instance, the procedure proceeds to step S 16 , and the predetermined operation is performed. 
         [0037]    In contrast, when it is determined at step S 14  that the image is unsatisfactory, the procedure proceeds to step S 15 . At step S 15 , a determination is further made as to whether the number of NG times that it is determined that the image is unsatisfactory exceeds a predetermined number of times. It is assumed that the number of NG times is stored in a storage unit (not illustrated) of the control apparatus  10 . When the number of NG times is not in excess of the predetermined number of times, it can be determined that the camera  12  is not so stained and that a satisfactory image could not be acquired due to another external factor. In such an instance, the procedure returns to step S 13 , and the camera  12  picks up an image again. 
         [0038]    In contrast, when the number of NG times exceeds the predetermined number of times at step S 15 , it can be determined that the camera  12  is considerably stained. Meanwhile, at step S 12 , when the predetermined cycle has ended or the predetermined time has elapsed, it can be determined that the staining of the camera  12  has progressed. In such instances, the procedure proceeds to step S 21 , and the camera  12  is cleaned by the cleaning apparatus  20 . 
         [0039]    At step S 21 , initially, the robot  11  is driven so that the camera  12  is moved to a neighborhood of the cleaning apparatus  20 . Further, at step S 22 , the ascend/descend member  42  of the cleaning cloth setting mechanism unit  40  is ascended to the above-mentioned ascended position in the direction of arrow A 1  in  FIG. 1 . In this manner, the cleaning cloth  33  becomes out of engagement with the distal end of the projection unit  49 . Thus, when the drawing-out unit  34  is driven at step S 23 , a predetermined amount of the cleaning cloth  33  can be drawn out in the direction of arrow A 2   
         [0040]    Subsequently, at step S 24 , a predetermined quantity of the cleaning liquid is ejected from the cleaning liquid ejection unit  39 . As can be seen from  FIG. 1 , the cleaning liquid is ejected onto the cleaning cloth  33  between the second roller  52  and the third roller  53 , i.e., the cleaning cloth  33  at the position corresponding to the distal end of the projection unit  49 . Meanwhile, when it is determined that the degree of the staining of the camera  12  is not so high, the processing at step S 24  may be omitted. 
         [0041]    Subsequently, at step S 25 , the ascend/descend member  42  is descended to the above-mentioned descended position in the direction of arrow A 4  in  FIG. 5 . In this manner, as will be appreciated from a comparison of  FIGS. 2 ,  3 , and  5 , the projection unit  49  is caused to project from the through hole  43  of the ascend/descend member  42 , with the cleaning cloth  33  being engaged with the distal end of the projection unit  49 . When the ascend/descend member  42  is located at the descended position, the distal end of the projection unit  49  is engaged with the cleaning cloth  33  so that the cleaning cloth  33  is prevented from moving. 
         [0042]    Subsequently, at step S 26 , as illustrated by arrow A 5  in  FIG. 5 , the robot  11  is driven so as to dispose the camera  12  into contact with the cleaning cloth  33  engaged with the distal end of the projection unit  49 . Then, at step S 27 , with the cleaning cloth  33  being disposed in contact with the camera  12 , the robot  11  is reciprocated horizontally over a predetermined distance, so that the camera  12  is cleaned. Meanwhile, the robot  11  may clean the camera  12  by another operation. 
         [0043]    Referring again to  FIG. 4 , the procedure proceeds to step S 17  when the camera  12  is cleaned. At step S 17 , since the camera  12  has already been cleaned, the number of NG times used at step S 15  is reset to zero. Then, the procedure returns to step S 11 . 
         [0044]    In this manner, in the present invention, the camera  12  is automatically cleaned at regular intervals through use of the cleaning apparatus  20 . Thus, it is possible to always keep the camera  12  in a non-stained state. Consequently, it is possible to prevent an image from not being analyzed and to prevent the robot from being stopped. In the present invention, therefore, the operation rate of the system  1  can be increased. Also, the burden of the operator can be reduced since there is no need for the operator to manually clean the camera  12 . 
         [0045]    Further, the cleaning apparatus  20  of the present invention is not required to include a spraying device, humidifying device, and wiping device of the conventional technique. Thus, the cleaning apparatus  20  of the present invention is small-sized as compared with the apparatus of the conventional technique in which a spraying device, humidifying device, and wiping device are arranged along the feeding direction of a conveyor. In this manner, in the present invention, the system  1  can be prevented from becoming large-sized. 
         [0046]    In a factory or the like, a plurality of like robots each equipped with a camera  12  may work. As will be appreciated, even in such an instance, a plurality of the cameras  12  can be cleaned sequentially through use of the single cleaning apparatus  20  of the present invention. 
         [0047]      FIGS. 6 and 7  are perspective views for the optical device being cleaned. As seen from these figures, a lens  13  (optical component) of the camera  12  is usually covered with a light-transmitting cover  12   a.  In  FIG. 6 , the cleaning apparatus  20  is cleaning the cover  12   a  of the camera  12 , whereas in  FIG. 7 , the cleaning apparatus  20  is directly cleaning the lens  13  of the camera  12 , with the cover  12   a  of the camera  12  being removed. As such, the cleaning apparatus  20  of the present invention may clean the cover  12   a  or may clean the lens  13 . As a matter of course, the cleaning apparatus  20  can also clean another part of the camera  12  or a part such, for example, as the hand of the robot  11 . 
         [0048]    In the embodiment illustrated in  FIG. 1  or the like, the camera  12  is attached to the robot  11 , and the cleaning apparatus  20  is fixed. However, in an unillustrated embodiment, the cleaning apparatus  20  may be attached to the robot  11  with bolts or the like inserted through the openings of the base  21 , and the camera  12  may be fixed to a floor unit or the like. In such an instance, the cleaning apparatus  20  is moved to an arbitrary position by the robot so that even when a plurality of cameras  12  are fixed, the single cleaning apparatus  20  can clean the plurality of cameras  12 . 
         [0049]    The cleaning apparatus  20  may be mounted to the floor unit or robot  11  by means other than inserting bolts through the openings of the base  21 . Preferably, the cleaning apparatus  20  is attachable and detachable. In such an instance, the single cleaning apparatus  20  is fixed to the floor unit or the like and cleans the camera  12  provided on the robot  11 . Also, it is possible that the cleaning apparatus  20  may be detached from the floor unit and attached to the robot  11  to clean the camera  12  that is separately fixed. 
       ADVANTAGE OF THE INVENTION 
       [0050]    In the first embodiment, there can be provided the cleaning apparatus that is small-sized as compared with the apparatus of the conventional technique in which a spraying device, a humidifying device, and a wiping device is arranged along the conveying direction of a conveyor. 
         [0051]    In the second embodiment, since the cleaning liquid is used, it is possible to cope with stains that cannot be removed merely by dry wiping. 
         [0052]    In the third embodiment, since the optical device such, for example, as the camera can be cleaned by the cleaning apparatus, there is no possibility that the optical device is stained and that the robot is stopped due to becoming unable to analyze an image; thus, the operating rate of the system can be increased. Further, since there is no need for the operator to manually clean the optical device, the burden of the operator can be reduced. Further, since the cleaning apparatus is relatively small-sized, the system can be avoided from becoming large-sized. 
         [0053]    In the fourth embodiment, since the cleaning apparatus can be moved to an arbitrary position by the robot, a plurality of optical devices can be cleaned by the single cleaning apparatus even when the plurality of optical devices are fixed. 
         [0054]    In the fifth embodiment, even when there are a plurality of robots each equipped with an optical device, the plurality of optical devices can be cleaned by the single cleaning apparatus. 
         [0055]    In the sixth embodiment, since the cleaning apparatus is attachable and detachable, both the optical camera provided on the robot and the optical device located at a fixed position can be cleaned using the cleaning apparatus. 
         [0056]    In the seventh embodiment, since the optical device can be automatically cleaned, it is possible to keep the optical device at all times in a state in which it is not stained. 
         [0057]    While the present invention has been described with reference to exemplary embodiments thereof, it will be appreciated by those skilled in art that the above-mentioned changes, as well as various other changes, omissions, and additions, are possible without departing from the scope of the present invention.