In this paper, we propose a control system for object grasping tasks performed by the multifingered robot hand. Unlike previous systems, which were built using force control based on mechanical and dynamic analyses, this system is built using position control. The variable stiffness compliance control we propose is used as the grasp controller, and the system is able to perform all approach, co...

This study uses theory and experiments to investigate the relationship between the passive stiffness of series elastic actuators and torque tracking performance in lower-limb exoskeletons during human walking. Through theoretical analysis with our simplified system model, we found that the optimal passive stiffness matches the slope of the desired torque-angle relationship. We also conjectured ...

Vibration is omnipotent, universal and multifaceted phenomena. It is an interdisciplinary field where physicist, mathematician and engineer interact in a closed loop. Vibration absorption is a method of adding a tuned springmass absorber to a system to create anti-resonance at a resonance of the original system. Most real-world phenomena exhibit nonlinear behavior. In these paper overviews of v...

This paper addresses control of structural vibrations using semi-active actuators that are capable of manipulating stiffness and/or producing variable stiffness. Usually vibration suppression is achieved using damping devices rather than stiffness ones. However, stiffness devices can produce large forces and have significant advantages for shock isolation purposes. In this work we use a passivi...

This work is focused on the analysis of manipulators with both joint and link flexibility. Due to the different order of joint and link stiffness, the full-order nonlinear system can be decomposed into different time-scale subsystems, namely, slow subsystem, mid-speed subsystem, and fast subsystem. It is shown that when the link stiffness is much greater than joint stiffness 01when the two kind...