Daisuke Chugo Wataru Matsuoka Songmin Jia Kunikatsu Takase Rehabilitation walker system for standing-up motion. 3367-3372 2007 IROS http://dx.doi.org/10.1109/IROS.2007.4399079 conf/iros/2007 db/conf/iros/iros2007.html#ChugoMJT07