This paper shows mechanisms for artificial finger based on a planetary gear system (PGS). Using the PGS as a transmitter provides an under-actuated system for driving three joints of a finger with back-drivability that is crucial characteristics for fingers as an end-effector when it interacts with external environment. This paper also shows the artificial finger employed with the originally de...

In atomic force microscopy (AFM) the imaging speed is strongly limited by the bandwidth of the feedback loop that controls the interaction between the measurement tip and the sample. A significant increase in closed-loop bandwidth can be achieved by combining a long-range, low-bandwidth actuator with a short-range, high-bandwidth actuator, forming a dual actuated system. This contribution discu...

in this paper the design of a biped robot actuated with shape memory alloy (sma) springs with minimum degrees of freedom is presented. sma springs are a class of smart materials that are known for their high power to mass and volume ratios. it was shown that utilizing spring type of smas have many advantages as large deformation, smooth motion, silent and clean movement compared to ordinary typ...

Magnetic resonance imaging (MRI) can be a very effective imaging modality for live guidance during surgical procedures. The rationale of MRI-guided surgery with robot-assistance is to perform surgical interventions utilizing “realtime” image feedback while minimize operation time and improves the surgical outcomes. However, challenges arise from electromagnetic compatibility within the high-fie...

Exoskeleton robots are mechanical constructions attached to human body parts, containing actuators for influencing human motion. One important application area for exoskeletons is human motion support, for example, for disabled people, including rehabilitation training, and for force enhancement in healthy subjects. This paper surveys two exoskeleton systems developed in our laboratory. The fir...

In this paper, we propose a sliding mode controller for a robot manipulator with passive joints. A robot manipulator with passive joints which are not equipped with any actuators is a kind of underactuated system. Underactuated systems have some advantages compared to fully-actuated ones. For example, they weigh less and consume less energy because they have smaller number of components than fu...

Drawing mainly on linear algebra and screw theory, this paper presents a general and systematic approach for force/motion/stiffness transmissibility analyses of redundantly actuated and overconstrained parallel manipulators. A set of normalized transmission indices is proposed for representing the closeness to singularities as well as for dimensional optimization of the redundantly actuated and...

The main contribution of this paper is the development of a linearized model for describing the dynamic hysteresis behaviors of piezoelectrically actuated fast tool servo (FTS). A linearized hysteresis force model is proposed and mathematically described by a fractional order differential equation. Combining the dynamic modeling of the FTS mechanism, a linearized fractional order dynamic hyster...