Abstract:
Weakness is inherently associated with ageing society. In fact, Exoskeleton robotic
technology can be used to provide assistance for age society to perform activities of daily
living (ADL) without depending on others.
Upper limb exoskeleton robots are much suitable to perform ADL. Typically, upper limb
exoskeleton robot consists of number of joints and links which are corresponding to joints
and limbs of human upper limb. Further, exoskeleton robots differ from other conventional
robots due to present of close interaction with wearer. In general, two types of interaction
can be seen in exoskeleton robots: physical human robot interaction (pHRI) and cognitive
human robot interaction (cHRI).Strengthening features of cHRI can be seen on recent
developments of upper limb exoskeleton robots. However, there exists a vacuum to identify
aspects of pHRI relating to performance of exoskeleton robots.
The research work of this thesis is focused to design an upper limb exoskeleton robot for
motion assist taking effect of kinematic redundancy. The proposed exoskeleton robot (6-
REXOS) has four active degree of freedom (DOF) and two passive DOF in its kinematic
chain. Two passive DOF are provided to 6-REXOS by means of flexible bellow coupling
and those are positioned at wrist and elbow joint of the 6-REXOS to keep their axes parallel
to each other. This configuration enhances kinematic redundancy in 6-REXOS. The effect of
redundancy is verified with respect to dexterity measures, such as manipulability index,
minimum singular value, and condition number. Further, manipulation of end-effector of 6-
REXOS due to kinematic redundancy in operational space is presented base on
manipulability ellipsoids.
4DOF kinematic model for human lower arm is proposed in thesis. Manipulability measure
of human kinematic model is used to benchmark the performance of 6-REXOS. Different
measures are taken into account in design of 6-REXOS to ensure smooth pHRI. Passive
compliance of bellow coupling in order to reduce kinematic discrepancy as well as improve
the manipulation of 6-REXOS is highlighted in this thesis.
