Title :
Shape memory alloy servo actuator system with electric resistance feedback and application for active endoscope
Author :
Ikuta, Koji ; Tsukamoto, Masahiko ; Hirose, Shigeo
Author_Institution :
Center for Robotic Syst. in Microelectron., California Univ., Santa Barbara, CA, USA
Abstract :
A control system for a shape memory alloy (SMA) servo actuator, and its application to a unique medical tool, are considered. It is thought that the electric resistance value of an SMA can be utilized to monitor the transformation of the SMA directly. Therefore, an antagonistic transformation control scheme using electric resistance feedback is proposed and is verified by several experiments. This control scheme reduces the open-loop hysteresis of an SMA actuator and improves greatly its robustness against heat disturbance due to changes in the cooling condition. Research into the application of the method in an active endoscope is reported. It consists of five segments of 13 mm diameter, 40 mm length each. The bending angle of each segment can be controlled individually from outside by using antagonistic electric resistance feedback without any motion sensors. A model for smooth insertion to the colon is verified
Keywords :
biomedical equipment; electric actuators; electric resistance; feedback; fibre optic sensors; servomechanisms; shape memory effects; 13 mm; 40 mm; active endoscope; antagonistic transformation control scheme; bending angle; colon; electric resistance feedback; fibre optic instrument; heat disturbance; medical tool; open-loop hysteresis; robustness; servo actuator; shape memory alloy; Actuators; Biomedical monitoring; Control systems; Electric resistance; Feedback; Medical control systems; Open loop systems; Servomechanisms; Shape control; Shape memory alloys;
Conference_Titel :
Robotics and Automation, 1988. Proceedings., 1988 IEEE International Conference on
Conference_Location :
Philadelphia, PA
Print_ISBN :
0-8186-0852-8
DOI :
10.1109/ROBOT.1988.12085
