Design and control of a compliant robot hand with soft fingers

• Main Author: Tham, Brenda Jia Hui
• Other Authors: Yeo Song Huat
• Format: Final Year Project
• Language: English
• Published: 2019
• Subjects: DRNTU::Engineering::Mechanical engineering
• Online Access: http://hdl.handle.net/10356/78615
• Institution: Nanyang Technological University

This project presents a robotic gripper with soft compliant fingers that is capable of simple grasping motions. Due to its compliant property, soft gripping ensures greater safety in service settings and allows for gripping without extensive planning, reducing mechanical and control complexity. This is in comparison to a traditional gripper where rigid links and joints make it dangerous and unadaptable to unforeseen circumstances due to its lower tolerance for uncertainty. In this project, an existing finger design was adapted, improved upon and evaluated via simulations to determine an optimal design. The fluidic elastomer design of the fingers was found to be optimal with a certain configuration of wall thickness, chamber height, base thickness and number of chambers. The fingers were then fabricated by curing a soft material in a 3D printed mold. Thereafter, a palm design was conceptualised and fabricated via 3D printing to house the fingers in a modular way. To actuate the fingers, a pneumatic approach was chosen. As such, a control system comprising valves, switches, pumps and a microprocessor was implemented to deliver varying air pressures. To characterise the configuration of the actual gripper, image processing software and resistive bend sensors were used. The prototype has been demonstrated to be capable of two basic grasping modes, namely the pinch grip and the encompassing grip, with various objects. However, there is room for improvement. Recommendations for future work are included in the final chapter.