3D Printed Prosthetic Robot Arm with Grasping Detection System for Children

Abstract

Prosthetic robot arms have been an alternative replacement for upper limb-related disability, especially among children as it helps them perform regular activities such as holding tools, eating, and drinking. This research aims to develop a 3D prosthetic robot arm using SolidWorks and 3D printer, using a low-cost and straightforward mechanism for children. This paper proposes a close loop control system with position control for the prosthetic robot arm to achieve an appropriate grasping force focusing on solid-shaped objects using PID control. The PID controller controls the system's response to perform in the most efficient path. Force-sensitive resistors (FSR) are attached to all fingers to measure the grasping force acting on objects with different surfaces, dimensions, and weights. The controller results showed improvement in the overshoot percentage of 0.902%, as overshoot is essential in preventing the grasped object's deformations. The analysis of the experiment shows that the mean grasping force and static coefficient friction of each object are different regardless of the material the object is made of and the object's mass. For example, a cube-shaped object made of wood requires 0.5288 N of grasping force to grasp the object firmly compared to a plastic-made cube that only requires 0.3245 N to hold the cube. On the other hand, the static coefficient friction for the wood cube is 3.1708 and 0.4725 for the plastic cube. Further research can be done by designing the prosthetic robot arm with independent motorized and multi-degree movement of fingers.

3D Printing in the Design and Fabrication of Anthropomorphic Hands: A Review

“…[74,[79][80][81] Force sensing resistors at the fingertips is a more direct way of sensing because it is not a position but it measures force being applied to the hand by the grasped object. [82] Some use a camera to detect an object being securely grasped at the palm of the anthropomorphic hand [83] or a gyroscope for fingertip angle measurements. [84] For a prosthetic hand, intention detection from the user is mandatory as it cannot automatically make decisions in regard to object manipulation.…”