Patent Publication Number: US-2011058800-A1

Title: Humanoid robot recognizing objects using a camera module and method thereof

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of Korean Patent Application No. 2009-84011, filed on Sep. 7, 2009 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference. 
     BACKGROUND 
     1. Field 
     Example embodiments relate to a humanoid robot and method, in which a best one of lenses or filters of a camera module is selectively substituted to improve object recognition performance. 
     2. Description of the Related Art 
     In general, robots are machinery, which automatically conduct a work or operation, and are widely used as substitutes for humans or to assist humans in various fields. 
     Among these robots, industrial robots have the highest utilization. The industrial robots allow a production line to be automated and unmanned to improve productivity, and conduct dangerous operations on behalf of humans to protect humans from industrial disasters. 
     Recently, humanoid robots, which have an external appearance similar to humans and conduct motions similar to those of humans, have been developed. In the same manner as the industrial robots, these humanoid robots are supplied to various industrial spots and are used to conduct dangerous operations on behalf of humans. The most important advantage of the humanoid robots is to provide various services while living with humans in daily life rather than to substitute for humans. 
     Each of the humanoid robots includes a camera module mounted on its head, which serves as a visual sensor in order to recognize conditions around a position of an object (for example, a human face, an article, environment, etc). The camera module includes lenses, and image sensors to form images signal using light from the lenses. 
     The humanoid robot accurately recognizes a size of an object or a distance to an object through the camera module. However, the lenses of the camera module may not accurately recognize the object due to limitations of angles of view and focal lengths thereof. 
     SUMMARY 
     Therefore, it is one aspect of the example embodiments to provide a humanoid robot, in which a best one of lenses or filters of a camera module are selectively substituted so as to improve object recognition performance. 
     Additional aspects will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the disclosure. 
     The foregoing and/or other aspects are achieved by providing a humanoid robot including a torso, a head connected to the torso, and a camera module installed on the head, wherein the camera module includes at least one of a lens member and a filter member, which selectively substitutes a part thereof according to a recognition state of an object. 
     The camera module may further include an image sensor member to capture images projected by the lens member, the lens member may include a lens holder rotated right and left around the image sensor member, and a plurality of lenses fixed to the lens holder and rotated in connection with rotation of the lens holder, and the lens holder may cause any one of the plurality of lenses to be selectively connected to the image sensor member. 
     The camera module may further include an image sensor member to capture images projected by the lens member, the lens member may include a lens holder fixed to the head, and lenses detachably connected to the lens holder, and the lens holder may include a lens connection groove, to which the lenses are selectively connected. 
     The camera module may further include an image sensor member to capture images projected by the lens member, the lens member may include a plurality of lens holders rotated upward and downward around the image sensor member, and a plurality of lenses respectively fixed to the plurality of lens holders and rotated in connection with rotation of the plurality of lens holders, and the plurality of lens holders may cause any one of the plurality of lenses to be selectively connected to the image sensor member. 
     The filter member may include a filter holder rotated right and left around the lens member, and a plurality of filters fixed to the filter holder and rotated in connection with rotation of the filter holder, and the filter holder may cause any one of the plurality of filters to be selectively connected to the lens member. 
     The filter member may include a filter holder fixed to the head, and filters detachably connected to the filter holder, and the filter holder may include a filter connection groove, to which the filters are selectively connected. 
     The filter member may include a plurality of filter holders rotated upward and downward around the lens member, and a plurality of filters respectively fixed to the plurality of filter holders and rotated in connection with rotation of the plurality of filter holders, and the plurality of filter holders may cause any one of the plurality of filters to be selectively connected to the lens member. 
     The lens holder may include a base part having a flat shape installed at the inside of the head, and support parts extended from the base part to support the plurality of lenses. 
     The humanoid robot may further include a driving device connected to the base part, and the base part may rotate the base part right and left according to images formed by the image sensor member such that the plurality of lenses is selectively substituted. 
     The humanoid robot may further include a lens storage unit provided within the torso. 
     The lens storage unit may be formed in a vacant space of one side of the torso. 
     Further, the lens storage unit may be formed in a bag on the rear surface of the torso. 
     The foregoing and/or other aspects are achieved by providing a humanoid robot including a torso, a head connected to the torso, and a camera module installed on the head, wherein the camera module includes an image sensor member to capture images, a lens member optically connected to the image sensor member to project images to the image sensor member, and a filter member installed in front of the lens member, and at least one of the lens member and the filter member, which selectively substitutes a part thereof according to a recognition state of an object. 
     Any one of the lens member and the filter member may be configured such that lenses or filters are connected to a lens holder or a filter holder rotated right and left to be selectively substituted. 
     Any one of the lens member and the filter member may be configured such that lenses or filters are detachably connected to the lens member or the filter member to be selectively substituted. 
     Any one of the lens member and the filter member may be configured such that lenses or filters are respectively connected to lens holders and filter holders rotated upward and downward to be selectively substituted. 
     The foregoing and/or other aspects are achieved by providing a method including capturing images using an image sensor member, a lens member optically connected to the image sensor member to project images to the image sensor member, and a filter member installed in front of the lens member; and selectively substituting at least one of the lens member and the filter member according to a recognition state of an object. 
     Additional aspects, features, and/or advantages of embodiments will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and/or other aspects will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which: 
         FIG. 1  is a view illustrating an external appearance of a humanoid robot in accordance with example embodiments; 
         FIG. 2  is a view schematically illustrating a configuration of the humanoid robot of  FIG. 1 ; 
         FIG. 3  is an enlarged top view of a head of the humanoid robot in accordance with example embodiments; 
         FIG. 4  is a longitudinal-sectional view taken along the line IV of  FIG. 3 ; 
         FIG. 5  is a view illustrating a modification of the humanoid robot in accordance with example embodiments shown, for example, in  FIG. 3 ; 
         FIG. 6  is a view illustrating a head of a humanoid robot in accordance with example embodiments; 
         FIG. 7  is an enlarged view of a lens member shown in  FIG. 6 ; 
         FIG. 8  is a view illustrating a modification of the humanoid robot of  FIG. 6 ; 
         FIG. 9  is a view illustrating a head of a humanoid robot in accordance with example embodiments; and 
         FIG. 10  is a view illustrating a modification of the humanoid robot of  FIG. 9 . 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. 
       FIG. 1  is a view illustrating an external appearance of a humanoid robot in accordance with example embodiments, and  FIG. 2  is a view schematically illustrating a configuration of the humanoid robot of  FIG. 1 . 
     As shown in  FIGS. 1 and 2 , a humanoid robot (hereinafter, simply referred to as a ‘robot’)  1  includes a torso  10 , legs  20 R and  20 L connected to both sides of the lower portion of the torso  10 , arms  30 R and  30 L connected to both sides of the upper portion of the torso  10 , and a head  40  connected to the upper end of the torso  10 . The arms  30 R and  30 L are respectively connected to the torso  10  through shoulders  50 R and  50 L, and the head  40  is connected to the torso  10  through a neck  60 . Here, R and L respectively represent a right side and a left side. 
     The inside of the torso  10  is protected by a cover  11 . A control unit  12 , a battery  13 , and an inclination sensor  14  (shown in  FIG. 2 ) may be installed in the torso  10 . The inclination sensor  14  detects an angle of inclination of the torso  10  relative to a vertical axis and its angular velocity. 
     The torso  10  is divided into a breast part  10   a  and a waist part  10   b , and a joint  15  causing the breast part  10   a  to be relatively rotated against the waist part  10   b  is installed between the breast part  10   a  and the waist part  10   b .  FIG. 2  briefly illustrates the torso  10  as a torso link. 
     Both legs  20 R and  20 L respectively include thigh links  21 , calf links  22 , and feet  23  (shown in  FIG. 2 ). The thigh links  21  are connected to the torso  10  through thigh joint units  210 . The thigh links  21  and the calf links  22  are connected to each other by knee joint units  220 , and the calf links  22  and the feet  23  are connected to each other by ankle joint units  230 . 
     The thigh joints units  210  respectively have three degrees of freedom. In particular, the thigh joint units  210  respectively include rotary joints  211  rotated in a yaw direction (around the Z-axis), rotary joints  212  rotated in a pitch direction (around the Y-axis), and rotary joints  213  rotated in a roll direction (around the X-axis). 
     The knee joint units  220  respectively include rotary joints  221  rotated in the pitch direction, and thus have one degree of freedom. The ankle joint units  230  respectively include rotary joints  231  rotated in the pitch direction and rotary joints  232  rotated in the roll direction, and thus have two degrees of freedom. 
     Since the legs  20 L and  20 R respectively include six rotary joints for three joint units  210 ,  220 , and  230 , twelve rotary joints are provided for the two legs  20 L and  20 R. Although not shown in the drawings, motors to drive the rotary joints are respectively installed on the legs  20 R and  20 L. The control unit  12  properly controls the motors provided on the legs  20 R and  20 L, thereby achieving various motions of the legs  20 R and  20 L including walking of the robot  1 . 
     Multi-axis force and torque (F/T) sensors  24  are respectively installed between the feet  23  and the ankle joint units  230  of the two legs  20 L and  20 R. The multi-axis F/T sensors  24  measure three directional components (Mx, My, Mz) of moment and three directional components (Fx, Fy, Fz) of force transmitted from the feet  23 , and thus detect whether or not the feet  23  are on the ground or loads are applied to the feet  23 . 
     A camera module  100  serving as the sense of sight of the robot  1  and microphones  42  serving as the sense of hearing of the robot  1  are installed at the head  40 . 
     The head  40  is connected to the torso  10  through a neck joint unit  410 . The neck joint unit  410  includes a rotary joint  411  rotated in the yaw direction, a rotary joint  412  rotated in the pitch direction, and a rotary joint  413  rotated in the roll direction, and thus has three degrees of freedom. 
     Head rotating motors (not shown) are respectively connected to the rotary joints  411 ,  412 , and  413  of the neck joint unit  410 . The control unit  12  controls the respective motors and thus drives the rotary joints  411 ,  412 , and  413  at proper angles, thereby allowing the head  40  to move in a desired direction. 
     Both arms  30 R and  30 L respectively include upper arm links  31 , lower arm links  32 , and hands  33 . The upper arm links  31  are connected to the torso  10  through shoulder joint assemblies  310 . The upper arm links  31  and the lower arm links  32  are connected to each other through elbow joint units  320 , and the lower arm links  32  and the hands  33  are connected to each other through wrist joint units  330 . 
     The elbow joint units  320  respectively include rotary joints  321  rotated in the pitch direction and rotary joints  322  rotated in the yaw direction, and thus have two degrees of freedom. The wrist joint units  330  include rotary joints  331  rotated in the pitch direction and rotary joints  332  rotated in the roll direction, and thus have two degrees of freedom. 
     Five fingers  33   a  are installed at each of the hands  33 . Each of the fingers  33   a  includes plural joints (not shown), respectively driven by motors. The fingers  33   a  perform various motions, such as gripping of an object and indicating of a special direction, in connection with the motion of the arms  30 R and  30 L. 
       FIG. 3  is an enlarged top view of the head of the humanoid robot in accordance with the example embodiments, and  FIG. 4  is a longitudinal-sectional view taken along the line IV—of  FIG. 3 . 
     As shown in  FIGS. 3 and 4 , the head  40  of the humanoid robot includes a helmet part  40   a  formed from the central portion thereof to a rear surface thereof, and a face part  40   b  formed at the front surface thereof. The helmet part  40   a  may be made of opaque plastic, and the face part  40   b  may be made of transparent plastic. 
     The camera module  100  used as a vision sensor of the humanoid robot is installed at the inside of the face part  40   b . The camera module  100  includes a lens member  110 , an image sensor member  120  to capture images projected by the lens member  110 , and a connection member  130  to optically connect the lens member  110  and the image sensor member  120 . 
     The image sensor member  120  is fixed to the inside of the face part  40   b  within the head  40 , and images first formed by the image sensor member  120  are used as a signal to drive a driving device  140  such that the lens member  110  may be substituted. 
     The connection member  130  includes a lens connection part  131  facing the lens member  110 , first and second reflection parts  132  and  133  installed in the lens connection part  131 , central reflection parts  134  installed at a center between the first and second reflection parts  132  and  133 , and a sensor connection member  135  facing the image sensor member  120  such that images reflected by the central reflection parts  134  are captured by the image sensor member  120 . 
     Although the drawings illustrate that the connection member  130  includes the lens connection part  131 , the first and second reflection parts  132  and  133 , the central reflection parts  134 , and the sensor connection member  135 , since the connection member  130  serves only to optically connect the lens member  110  and the image sensor member  120 , it would be appreciated by those skilled in the art that the lens member  110  and the image sensor member  120  may be optically connected using various methods. 
     The lens member  110  includes a lens holder  111  rotated right and left around the image sensor member  120  within the face part  40   b , and a plurality of lenses  112  having different focal lengths, fixed to the lens holder  111 , and rotated in connection with the rotation of the lens holder  111 . Although the drawings illustrate that the lens member  110  is installed at the inside of the face part  40   b , the lens member  110  may be installed at the outside of the face part  40   b  as well as at the inside of the face part  40   b.    
     Among these lenses  112 , a lens disposed at the front portion of the head  40  of the humanoid robot is referred to as a first lens  112   a , a lens disposed at the left portion of the head  40  of the humanoid robot is referred to as a second lens  112   b , a lens disposed at the rear portion of the head  40  of the humanoid robot is referred to as a third lens  112   c , and a lens disposed at the right portion of the head  40  of the humanoid robot is referred to as a fourth lens  112   d.    
     Although the drawings illustrate that four lenses  112  are connected to the lens holder  111 , the number of the lenses  112  connected to the lens holder  111  is not limited to four. 
     The lens holder  111  is rotated such that any one of the first to fourth lenses  112   a ,  112   b ,  112   c , and  112   d  is selectively connected to the image sensor member  120 . 
     The lens holder  111  may be provided in a flat shape within the face part  40   b . The first to fourth lenses  112   a ,  112   b ,  112   c , and  112   d  are respectively fixed to the edge of the flat lens holder  111 . The lens holder  111  is connected to the driving device  140 , and the driving device  140  causes the lens holder  111  to be rotated along the inner circumference of the face part  40   b.    
     The first to fourth lenses  112   a ,  112   b ,  112   c , and  112   d  have different angles of view and different focal lengths, and are connected selectively to the connection member  130  and the image sensor member  120  according to the right and left rotation of the lens holder  111 . 
     For example, in order to clearly recognize an object under a first recognition state, the humanoid robot may connect the first lens  112   a  to the connection member  130  and the image sensor member  120 . Further, under a second recognition state, the humanoid robot may connect the second lens  112   b  to the connection member  130  and the image sensor member  120 . In such a manner, the humanoid robot may selectively substitute a best one of the lenses  112  in order to clearly recognize an object according to various recognition states. 
     The lens holder  111  includes a base part  111   a  formed in a flat shape, and a plurality of support parts  111   b  extended from the base part  111   a  to support the plural lenses  112  such that the lenses  112  are respectively connected to the support parts  111   b . The base part  111   a  of the lens holder  111  is connected to the driving device  140  at the central portion thereof. The driving device  140  includes a rotary shaft  141 , which is the center of the right and left rotation of the lens holder  111 . 
     Therefore, the lens holder  111  selects any one of the plural lenses  112  according to images formed on the image sensor member  120 , thereby being capable of varying an angle of view and a focal distance of the camera module  100 . 
     Accordingly, this selective substitution of the lenses  112  provides a zoom function and a wide function to the camera module  100 , and thus reduces an unnecessary moving distance of the humanoid robot in order to clearly recognize an object. 
     Reference numeral  150  represents an image input board, by which an image signal from the camera module  100  is input and various forms of image processing are achieved. 
       FIG. 5  is a view illustrating a modification of the humanoid robot in accordance with example embodiments shown, for example, in  FIG. 3 . As shown in  FIG. 5 , a camera module  100  in accordance with this modification includes a filter member  160  disposed such that the filter member  160  moves relative to a lens member  100   a . The lens member  100   a  of the camera module  100  may include lenses of a well-known camera module. 
     The filter member  160  includes a filter holder  161  rotated right and left within the head  40 , and a plurality of filters  162  connected to the filter holder  161 . 
     The filters  162  of a small thickness are made of plastic having a property of absorbing rays of respective wavelengths. The filters  162  are provided in front of the lens member  100   a , and serve to transform the color and shape of an object and to disperse light. 
     The filter holder  161  causes any one of the plural filters  162  to be selectively connected to the lens member  100   a . The filter holder  161  is connected to a driving device  170 , and the driving device  170  causes the filter holder  161  to be rotated right and left around the lens member  100   a . Therefore, the humanoid robot may clearly recognize an object through the selective substitution of the filters  162 . 
     Further example embodiments will be described with reference to  FIGS. 6 and 7 . Some parts in  FIGS. 6 and 7 , which are substantially the same as those in the former embodiment of  FIG. 3 , are denoted by the same reference numerals even though they are depicted in different drawings, and a detailed description thereof will thus be omitted because it is considered to be unnecessary.  FIG. 6  is a view illustrating a head of a humanoid robot in accordance with this embodiment, and  FIG. 7  is an enlarged view of a lens member shown in  FIG. 6 . 
     As shown in  FIGS. 6 and 7 , a camera module  100  is installed at the inside and outside of a face part  40   b  of a head  40  of a humanoid robot in accordance with this embodiment. 
     The camera module  100  includes a lens member  110 , an image sensor member  120  to capture images projected by the lens member  110 , and a connection member  130  to optically connect the lens member  110  and the image sensor member  120 . 
     The lens member  110  includes a lens holder  111  fixed to a helmet part  40   a , and a lens  112  selectively inserted into the lens holder  111 . The lens holder  111  includes a lens connection groove  111   a , which causes the lens  112  to be selectively connected to the image sensor member  120 . 
     The humanoid robot judges a recognition state of an object according to images formed on the image sensor member  120  under the condition that the lens  112  is inserted into the lens connection groove  111   a , and then separates the lens  112  from the lens connection groove  111   a  and selects another lens  500 , which is the best or most proper for the recognition state of the object, and inserts the lens  500  into the lens connection groove  111   a . Therefore, the lens  500  may be selectively substituted. 
     If the lens holder  111  is not fixed to the helmet part  40   a , an integral assembly of the lens holder  111  and the lens  112  may be selectively connected to the helmet part  40   a  of the head  40  according to the recognition state of an object. 
     The humanoid robot may be provided with a lens storage unit (not shown) storing a plurality of lenses  112  and  500  on the torso (not shown). The lenses  112  and  500  stored in the lens storage unit have different angles of view and different focal lengths, and the lens storage unit may be located at a position, which the arm (not shown) of the humanoid robot easily accesses. 
     For example, the lens storage unit may be located in a vacant space of one side of the torso of the humanoid robot, or may be located in a bag on the rear surface of the torso. 
     Therefore, the humanoid robot first judges a recognition state of an object, and selectively substitutes another lens  112  or  500  taken out of the side of the torso or the bag for the lens, which was already inserted into the lens connection groove  111   a , thereby reducing an unnecessary moving distance in order to clearly recognize the object. 
       FIG. 8  is a view illustrating a modification of the humanoid robot of  FIG. 6 . As shown in  FIG. 8 , a camera module  100  in accordance with this modification includes a filter member  160  disposed such that the filter member  160  is detachably attached to a lens member  110   a . The lens member  110   a  of the camera module  100  may include lenses of a well-known camera module. 
     The filter member  160  includes a filter holder  161  fixed to the helmet part  40   a , and a filter  162  selectively inserted into the filter holder  161 . The filter holder  161  includes a filter connection groove  161   a , which causes the filter  162  to be selectively connected to the lens member  110   a.    
     For example, the humanoid robot separates the filter  162  from the filter connection groove  161   a  using arms and hands thereof, and then selects another filter  600 , which is the best or most proper for a recognition state of an object, from a filter storage unit (not shown) and inserts the filter  600  into the filter connection groove  161   a . Therefore, the filter  600  may be selectively substituted. Therefore, the humanoid robot may clearly recognize an object through the selective substitution of the filter  600 . 
     Example embodiments will be described with reference to  FIG. 9 . Some parts in  FIG. 9 , which are substantially the same as those in the former embodiment of  FIG. 3 , are denoted by the same reference numerals even though they are depicted in different drawings, and a detailed description thereof will thus be omitted because it is considered to be unnecessary.  FIG. 9  is a view illustrating a head of a humanoid robot. 
     As shown in  FIG. 9 , a camera module  100  is installed at the inside and outside of a face part  40   b  of a head  40  of a humanoid robot in accordance with this embodiment. The camera module  100  includes a lens member  110 , an image sensor member  120  to capture images projected by the lens member  110 , and a connection member  130  to optically connect the lens member  110  and the image sensor member  120 . 
     The lens member  110  includes a plurality of lens holders  111  connected to a helmet  40   a  such that the lens holders  111  are rotated upward and downward around the image sensor member  120 , and lenses  700 ,  701 ,  702 , and  703  respectively connected to the lens holders  111 . 
     The plural lens holders  111  may include a first lens holder  111   a , a second lens holder  111   b , a third lens holder  111   c , and a fourth lens holder  111   d . A first lens  700  is connected to the first lens holder  111   a . A second lens  701  having an angle of view and a focal length, differing from those of the first lens  700 , is connected to the second lens holder  111   b . A third lens  702  having an angle of view and a focal length, differing from those of the first lens  700  and the second lens  701 , is connected to the third lens holder  111   c . A fourth lens  703  having an angle of view and a focal length, differing from those of the first lens  700 , the second lens  701 , and the third lens  702 , is connected to the fourth lens holder  111   d.    
     Any one of the first to fourth lens holders  111  may be selectively connected to the image sensor member  120 . For this reason, the first to fourth lens holders  111  are connected to a driving device (not shown). 
     Any one of the first to fourth lens holders  111  is rotated from the helmet part  40   a  to the face part  40   b  such that the corresponding one of the lenses  700 ,  701 ,  702 , and  703  provided on the lens holders  111  is selectively connected to the connection member  130  and the image sensor member  120 . 
     As shown in  FIG. 9 , in order to selectively connect the first lens  700  to the image sensor member  120 , the first lens holder  111   a  is rotated downward and is located at the face part  40   b . If it is judged that selective connection of any one of the second to fourth lenses  701 ,  702 , and  703  to the image sensor member  120  allows clear recognition of an object, the first holder  111   a  is rotated upward, and then any one of the second to fourth lens holders  111  is rotated toward the face part  40   b  and is selectively connected to the image sensor member  120 . 
     The first to fourth lens holders  111  are connected to a rotary shaft  704  at both sides of the helmet part  40   a  and the face part  40   b . The first to fourth lens holders  111  are fixedly installed on the rotary shaft  704  and they are overlapped. Thus, the lenses  700 ,  701 ,  702 , and  703  are selectively used based on judgment as to a recognition state of an object according to images formed on the image sensor member  120 , thereby varying an angle of view and a focal length of the camera module  100 . Therefore, the humanoid robot may clearly recognize an object through selective substitution of these lenses  700 ,  701 ,  702 , and  703 . 
       FIG. 10  is a view illustrating a modification of the humanoid robot of  FIG. 9 . As shown in  FIG. 9 , a camera module  100  in accordance with this modification includes a filter member  160  disposed such that the filter member  160  moves relative to a lens member  110   a . The lens member  110   a  of the camera module  100  may include lenses of a well-known camera module. 
     The filter member  160  includes a plurality of filter holders  161  connected to a helmet  40   a , and filters  700 ,  701 ,  702 , and  703  respectively connected to the filter holders  161 . Any one of the plural filter holders  161  is rotated upward and downward to face the lens member  110   a  such that the corresponding one of the filters  700 ,  701 ,  702 , and  703  is selectively connected to the lens member  110   a.    
     That is, as shown in  FIG. 10 , in order to selectively connect the first filter  700  to the lens member  110   a , a first filter holder  161   a  is rotated downward. If it is judged that selective connection of any one of the second to fourth filters  701 ,  702 , and  703  to the lens member  110   a  allows clear recognition of an object, the first filter  111   a  is rotated upward, and then any one of second to fourth filter holders  161   b ,  161   c , and  161   d , is rotated downward and is selectively connected to the lens member  110   a.    
     The filter holders  161  are connected to a driving device (not shown), and the driving device selectively rotates the filter holders  161  upward and downward around the lens member  110   a  and thus allows one of the filters  700 ,  701 ,  702 , and  703 , which is the best or most proper for the recognition state of an object, to be connected to the lens member  110   a . Therefore, the humanoid robot may clearly recognize an object through selective substitution of these filters  700 ,  701 ,  702 , and  703 . 
     As is apparent from the above description, in a humanoid robot in accordance with one embodiment, a best or proper one of lenses or filters of a camera module is selectively substituted, thereby improving object recognition performance. 
     Although embodiments have been shown and described, it should be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the disclosure, the scope of which is defined in the claims and their equivalents.