Eventos Anais de eventos
COBEM 2017
24th ABCM International Congress of Mechanical Engineering
Robotic Hand Operated With Super-Elastic Memory Wires
Submission Author:
Priscila Lima , PE , Brazil
Co-Authors:
Miguel Neto, Asafe Silva, Maycon Ferreira Silva, Sylwerton Santos, Alexander Sena, Priscila Lima
Presenter: Priscila Lima
doi://10.26678/ABCM.COBEM2017.COB17-2790
Abstract
This work proposes the activation, by means of an embedded system, of a prototype of a robotic hand consisting of five fingers, using Shape memory alloys (SMA) wires. Each finger will have its bending and traction movement determined by thin wires of a superelastic Nickel-Titanium (Ni-Ti) type SMA, activated by cooling using Seebek-Peltier-based thermoelectric inserts, and deactivated by Joule effect. Specifically, from the control of the voltage sent to Peltiers pellets (TEC1-12706), the cooling of the SMA wires indirectly was achieved by cooling a chamber containing alcohol gel and glycerin. With cooling of the wires immersed to the cooled fluid (without freezing), the alloy returned to its treated format. The activation of the Peltiers occurred by means of a power circuit that receives the PWM control signals from an embedded microcontrolling system with PIC18F4550. The heating of each SMA wire by joule effect (referring to each finger) occurred by means of a power circuit that also received PWM signals from the microcontroller. For control purposes a temperature sensor of the NTC (Negative Temperature Coefficient) type was introduced in the refrigerated environment. The fingers were triggered individually from application in Smartphone, communicating by bluetooth with embedded system. The assembly provided a cooling of the wires at a temperature of approximately 4°C, causing the fingers to open, and heating generated a finger closing time of approximately 4s, these results being considered satisfactory.
Keywords
Prototype, Remote Control, Shape Memory Alloy, Heat treatment, Robotic hand
