Atsushi Kamiyoshi

Application of USP to Steam Generator Nozzles

An effective countermeasure against stress corrosion cracks in pipe welds is to improve the residual stress. A new ultrasonic shot peening (USP) technique for steam generator (SG) nozzles will be introduced as a means to improve the residual stress of SG nozzles with Alloy 600 welds. This method changes the residual stress on the inner surface from tensile stress to compressive stress by applying plastic strain to the surface via the collision force of the shot material during the shot peening. Our group has successfully performed 14 USP operations in actual plants in Japan.© 2011 ASME

Position-detecting device for measurement of human motion in human-machine interaction

In this study, a human-machine interface device and a motion controller are developed for a human-machine interactive system. The interface device can simultaneously detect relative positional data as well as force data generated between the human operator and the robot during their interaction. Our proposed modified admittance controller is designed to handle the detected positional data as well as force data in order to generate familiar and intuitive robot motion for a human operator. The proposed control system enables the human operator to interact with the robot intuitively and with stability. In particular, the proposed interface device mechanism, which provides an adequate stiffness for the human-robot interaction, improves the stability of the control system. To confirm that the performance of the proposed system, power assistance experiments for a human forearm are carried out. Experimental results show that the proposed interface device and proposed controller are effective for human-robot interaction.

Development of Human Motion Detecting Device for Human-Machine Interface

This paper presents the development of a human-robot interface and a modified impedance controller, which generate robot motion which is appropriate for a human-robot interaction. The proposed control system enables a human operator to interact with the robot intuitively and stably. The proposed interface can simultaneously detect relative motion data as well as force data between the human operator and the robot during a human-robot interaction. The modified impedance controller, which is designed to handle not only the relative motion data but force data as well, generates familiar and intuitive motion for the human operator. In addition, the proposed interface mechanism, which provides an adequate stiffness, improves the stability of the control system. In order to confirm that the effectiveness of the proposed system, a supporting human operators forearm experiment is carried out. Experimental results illustrate that the proposed interface and the proposed controller are effective for the human-robot interaction.