Design of a Compliant Robotic Hand Actuated by Shape Memory Alloy Wires

• Main Authors: You-Nien Yang, 楊祐任
• Other Authors: Chao-Chieh Lan
• Format: Others
• Language: en_US
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/51603525403802930074

碩士 === 國立成功大學 === 機械工程學系碩博士班 === 96 === A five-fingered compliant hand is designed in this thesis to mimic the motion of a human hand. As traditional robotic hands require numerous relative-moving mechanical parts to achieve dexterous manipulation, we design a compliant robotic hand the manipulation of which relies on finger deflections. To mimic muscle-activated human fingers, three independent shape memory alloy (SMA) wires are applied to actuate each finger. The combination of compliant members with embedded SMA wires makes the finger more compact and lightweight. Various SMA wire layouts are investigated to improve their response time while maintaining sufficient output force. The mathematical model for finger large deflection caused by SMA contraction is derived along with experimental validation. As finger shapes are essential to the range of deflected motion, we design finger shapes based on the model for larger deflection. We further illustrate our method by designing a compliant finger that is capable of three-dimensional manipulation. Finally, a prototype of humanoid compliant hand is presented. The proposed compliant hand has the advantage of grasping external objects with a range of geometry variation without using sophisticated feedback sensors. It is also lightweight, compact, and requires low power consumption. We expect that the design formulations provided here would have wide applications from prosthetics to industrial and medical robotic manipulations.