구간분할 바이너리 제어기반 로봇핸드의 메커니즘에 관한 연구

Abstract

Actuators are the key technologies underpinning robotics. Breakthroughs in actuator technology, particularly in terms of power-to-weight ratio, or energy-density, will have significant impacts upon the way we design and control robotic systems. In recent years, as the robot technology is developed, the researches on the artificial muscle actuator that enables robot to move dexterously like biological organ become active. Non electro-mechanical actuators, such as Shape Memory Alloys(SMA) and Electro-active Polymer(EAP) actuators, convert the source energy to mechanical energy based on inherent material properties that exhibit actuator functionality. Although these actuator materials have an order of magnitude higher energy-density compared to electro-mechanical actuators, numerous difficulties persist in using them reliably and suitably as robot actuators. SMA has the hysterically dynamic characteristics. In this thesis, A new approach to design and control of shape memory alloy(SMA) actuators is presented. SMA wire are divided into many segments and their thermal states are controlled individually in a binary manner. Thermo-electric module(TEM) is used for heating and cooling individual segments of the SMA. Unlike the traditional way of controlling the wire length by driving a current to the entire SMA wire, the new method controls the binary state(hot and cold) of each segment. The total displacement is then proportional to the number of the segments having the heated state with the austenite phase. This control manner will drastically reduce the hysteresis that the SMA material has and it becomes the fundamental technology to develop the anthropomorphic robotic hand. Accordingly, in this research, the mechanism in the digital step motor of the shape memory alloy that is driven by the segmented binary control, which is a new control technique, is studied. By using ADAMS, the robotic hand is designed. In order to find out the dynamical characteristics, the simulation is made in respect of the various forms of the robotic hand. By manufacturing the actual robotic hand, the experiment on the dynamical characteristics of the robotic hand is accomplished in the method of segmented binary control.