Garra robótica teleoperada com realimentação de força

Abstract

In order to manipulate objects, the human hand faces problems related to physical limitations: arm length, tremors, fatigue and maximum reach. In a surgery robots can manipulate small surgical instruments with high precision, while guided by visual non-invasive equipments like tomographs. They can also operate in hostile ambients, such as depths in the ocean, space, amongst other applications and possibilities. Unfortunately, the systems available on the market still haven’t shown significant results concerning response to touch sensation, force, and texture to the operator. Therefore, this project aims at developing a working prototype composed by a two-fingered teleoperated claw and a device attached to the human hand that is able to provide force feedback, so-called controller. The project has been divided in stages, being the main ones: study of technologies, development of the main base, firmware, and development of isolated blocks to be integrated and tested during the project. Servo and stepper motors were used to move de claw, and give force feedback to the user, as well as mechanical components were used for the construction of the tweezers. Force sensor resistors and micro load cells were used for reading the force excerced by the claw and the operator hand. The Arduino Uno board was used for controlling the system, which is an open-source plataform based on Atmega328 microcontroller. The prototype is able to follow the movement of the thumb and forefinger of the user, as well as to monitor the rotation of the wrist, creating resistence proportional to the readings obtained by the teleoperated claw sensors, as the latter is positioned according to the position of the controller. This project can be adapted to other pratical applications, and also as a plataform for teaching robotics.