Page 251 - Mechatronics for Safety, Security and Dependability in a New Era
P. 251

Ch48-I044963.fm  Page 235  Tuesday, August 1, 2006  4:04 PM
                      Page 235
                            Tuesday, August
                                      1, 2006
            Ch48-I044963.fm
                                           4:04 PM
                                                                                          235
                                                                                          235
                          GENERATED      IMAGE    FEATURE     BASED    SELECTIVE
                      ATTENTION      MECHANISM       BY VISUO-MOTOR         LEARNING


                    1
                      Department of Adaptive Machine Systems, Graduate  School of Engineering, Osaka  University,
                                      2-1 Yamada-oka,  Suita, Osaka 565-0871 Japan




                  ABSTRACT
                  Visual attention  is an essential mechanism  of an intelligent robot. Existing research typically  specifies
                  in advance the attention control  scheme required  for  a given robot to perform  a specific task. However,
                  a  robot  should  be  able  to  adapt  its  own  attention  control  to  varied  tasks.  In  our  previous  work,  we
                  proposed  a  method  of  generating  a  filter  to  extract  an  image  feature  by  visuo-motor  learning.  The
                  generated  image feature  extractor  is considered to be generalized knowledge to accomplish a task of a
                  certain  class.  We  propose  an  attention  mechanism,  by  which  the  robot  selects  the  generated  feature
                  extractors based  on its task-oriented  criterion.


                  KEYWORDS

                  Mobile Robot, Selective attention, Image feature generation, Image feature  selection, Task-oriented


                  INTRODUCTION

                  Attention  control  is  an  essential  mechanism  for  an  intelligent  robot  to  avoid  processing  enormous
                  amounts  of  data.  It  is  a  data  reduction  process  to  facilitate  decision  making.  With  regard  to  visual
                  attention  control,  it involves  selection  of focus,  image  features,  and  so on. Existing  research  typically
                  specifies  in advance the attention  control  scheme required  for a given  robot to perform  a specific  task.
                  However, a robot should be able to adapt its own attention control to varied tasks and environments.

                  We have focused  on visual  attention  control related to a robot's actions to accomplish  a given task  and
                  proposed  a method  in which  a robot  generates  an  image  feature  extractor  (i.e., image  filter)  which  is
                  necessary  for the selection of actions through visuo-motor map learning (Minato & Asada, 2003). The
                  robot's learning depends  on the experience gathered while performing  a task. In this method, the robot
                  uses  only  one  feature  extractor  for  a  given  task.  For  more  complex  tasks,  however,  multiple  feature
                  extractors are necessary to accomplish the tasks and a method of selecting them should be addressed.

                  Some research  has focused  on a method of feature  selection based  on task-relevant  criteria. McCallum
                  (1996)  proposed  a  method  in  which  a  robot  learns  not  only  its  action  but  feature  selection  using
   246   247   248   249   250   251   252   253   254   255   256