Takanori Masuda

Development of micro manipulation system with two-finger micro hand

A dexterous micro manipulation system is developed for the application in assembling micro machine, manipulating cell, and micro surgery. We have proposed a concept of a two-finger micro hand, and designed and built two types of hand modules based on parallel mechanisms. In this paper, we mainly discuss the structure of a two-finger micro hand. The structure of the two-finger micro hand is strongly related to the effective work space, or the common work space of two fingers as well as its cooperation control algorithms. We design a structure to be suitable for a two-finger micro hand and made a prototype. Development of useful master device to operate the two-finger micro hand is important issue for the dextrous micro manipulation system. We developed a master device which is operated by one hand. The forefinger and thumb is generally used to manipulate objects by one hand. However, motion of each finger cannot be directly used to move the micro manipulator operational signal. We observed difference between the manipulation by two-finger hand like chopsticks and the manipulation by forefinger and thumb in human hand, and discuss operational algorithm for easy manipulation. By using this system for the micro manipulation, we evaluated effectiveness of the two-finger micro hand. In the actual micro manipulation, we succeeded to pick up, place and rotate a micro glass ball having size of 2 microns. The positioning accuracy is less than 0.1 micron.

Mechanism configuration evaluation of a linear-actuated parallel mechanism using manipulability

The linear-actuated parallel mechanism that changes the motion characteristic according to the actuator configuration is known. The authors previously (2000) reported on the kinematics and the motion characteristic on the basis of the motion transmissibility. In this report, we analyze the changed in motion characteristics using the measures of manipulability. Indices of manipulability are given with components of the value determined by the singular value decomposition. The typical index is a volume of the manipulability ellipsoid. We clarify the features of the motion characteristics according to a change in the actuator configuration using these indices. Finally, we show the recommended application examples that are designed for mechanisms using the obtained result.