Design of a low-cost five-finger anthropomorphic robotic arm with nine degrees of freedom

The aim of this work was to design and demonstrate a dexterous anthropomorphic mobile robotic arm with nine degrees of freedom using readily available low-cost components to perform different object-picking tasks for immobile patients in developing nations. The robotic arm consists of a shoulder, elbow, wrist and five-finger gripper. It can perform different gripping actions, such as lateral, spherical, cylindrical and tip-holding gripping actions using a five-finger gripper; each finger has three movable links. The actuator used for the robotic arm is a high torque dc motor coupled with a gear assembly for torque amplification, and the five-finger gripper consists of five cables placed like tendons in the human arm. The robotic arm utilizes a controller at every link to trace the desired trajectory with high accuracy and precision. Digital implementation of the control algorithm is done on an Atmel Atmega-16 microcontroller using trapezoidal approximation and Newton's backward difference methods. The arm can be programmed or controlled manually to perform a variety of object-picking tasks. A prototype of the robotic arm was constructed, and test results on a variety of object-picking tasks are presented.

► The paper presents a low-cost five finger robotic arm with nine degrees of freedom.
► The robotic arm can perform dexterous gripping actions like the human hand.
► An inverse model was used to determine the trajectory of the robotic arm.
► The robotic arm performed well on a variety of object picking tasks.