Page 303 - Handbook of Biomechatronics

Upper and Lower Extremity Exoskeletons 295

Fig. 5 Lower-limb exoskeleton with permission of open access articles with unrestricted
use permission (Fleerkotte et al., 2014; Sawicki and Ferris, 2009; Schmidt et al., 2007).
(A) LOPEZ, (B) KAFO, (C) gait trainer GTI, and (D) haptic walker.

In the ATLAS project, an active orthosis has been developed for gait
assistance, in particular among children suffering from quadriplegia
(Merodio et al., 2012). The first prototype of the ATLAS exoskeleton
provided active motion for the hip and knee f/e, with the ankle f/e
underactuated, by connecting to a linkage between the thigh and shank.
The aim of the designers is that the device could to be a completely auton-
omous assistive orthosis, in which the user only supply locomotion maneu-
ver triggers, for example, start and stop, stand up, and sit down. The IHMC
Mobility Assist Exoskeleton presented in Kwa et al. (2009) has three actuated
DOFs on the hip a/a and f/e and knee f/e, and two passive DOFs on the hip
rotation and ankle d/p. The anthropomorphic design and its series of elastic
actuators (SEA), enable the IHMC exoskeleton to work in different modes,
like zero assistance mode, performance augmentation mode, and gait
rehabilitation mode. The wearable walking helper (WWH) is a wearable
gravity-compensating hip-knee (HK) exoskeleton developed to assist the
locomotion activities of disabled and elderly people (Nakamura et al.,
2005). The assistive torques provided by the WWH are proportional to
the torques calculated based on an approximated human body model, user’s
postures and motions. Experiments with a subject standing up and sitting
down showed a reduction of EMG activities at the rectus femoris, thus
proving efficacy to the WWH as an antigravity exoskeleton. The XoR pro-
totype has been developed for the postural control of elderly people and
persons with mobility disability (Hyon et al., 2011). The XoR is
implemented with a hybrid driving concept combining pneumatic artificial
muscles (PAMs) and electric motors—the former acts as a gravity balancer
while the latter acts as a dynamic compensator. The user’s posture is defined
by joint angles and ground reaction forces while the motion intention is