1991 Fiscal Year Final Research Report Summary

Giant Magnetostrictive Acturator for Aerospace Robotics

Research Project

Project/Area Number	02805021
Research Category	Grant-in-Aid for General Scientific Research (C)
Allocation Type	Single-year Grants
Research Field	機械要素
Research Institution	Tokyo Insitute of Technology
Principal Investigator	HAYASHI Iwao Tokyo Institute of Technology, Associate Professor, 精密工学研究所, 助教授 (80016790)
Co-Investigator(Kenkyū-buntansha)	YOSHIDA Kazuhiro Tokyo Institute of Technology, Research Associate, 精密工学研究所, 助手 (00220632) IWATSUKI Nobuyuki Tokyo Institute of Technology, Research Associate, 精密工学研究所, 助手 (70193753) HAYASHI Teru Tokyo Institute of Technology, Professor, 精密工学研究所, 教授 (40016762)
Project Period (FY)	1990 – 1991
Keywords	Robotics / Actuator / Magnetostriction / Piezoelectricity / 圧電
Research Abstract	The fundamental output characteristics of a giant magnetostrictive alloy (abbreviates as GMA hereafter) element was experimentally investigated and the rotational performance of a rotating actuator for aerospace robotics was experimentally and theoretically investigated in this report. From the experiments on the output characteristics of the GMA element such as the static displacement characteristics, the frequency response and so on, the followings were found : (1) the maximum strain of the GMA element was smaller than or equal to 10^<-3>, and the amount is also smaller than the strain of piezoelectric ceramics, (2) since the material is metal, its Young modulus is twice larger than the piezoelectric ceramics, and large power is expected on the GMA element, (3) since driving coil is required, driving the GMA element is not effective ; hence the GMA element is appropriate for the field in which very small displacement is required to control as well as large power is required. Instead of the GMA element, a rotational actuator was made using piezoceramics and its fundamental output characteristics were experimentally and theoretically investigated. The results obtained are as follow : (1) the motor rotated at a speed which was determined theoretically from the rotational principle, the error of rotational speed was less than one percent, then the rotational principle of the rotational actuator is effective, (2) the output torque increased as the driving frequency increased, and it also increased after the driving frequency became higher than the resonance frequency of its driving unit up to its maximum driving frequency, (3) the motor kept its rotational speed even if its load was increased until it reached the maximum load. Summarizing these results, the rotational actuator proposed in this report had a useful and effective output characteristics for aerospace robotics.