Namkon Lee Norihiro Kamamichi Hongyi Li Katsuhisa Furuta Control system design and experimental verification of Capsubot. 1927-1932 2008 IROS http://dx.doi.org/10.1109/IROS.2008.4650933 conf/iros/2008 db/conf/iros/iros2008.html#LeeKLF08