Design and Construction of a Cost-Effective Dexterous Robotic Hand for Research and Development

Human-Robot Interaction (HRI) is increasingly becoming commonplace in various fields, including service robotics, industrial automation, and healthcare. Public acceptance and positive interaction with these robots are heavily influenced by the appearance and human likeness of these robots. To enable interaction with human beings, robots need manipulators that support high dexterity, cost-efficiency, and ease of development. This study presents the design and development of EvoGrip, a humanoid dexterous robotic hand aimed at supporting research and development in HRI. EvoGrip is a cost-effective and easy-to-build robotic hand, adapted from the open-source project Inmoov, enhanced with actuators, sensors and other added value features. The mechanical design changes to the hand include improvements for movement repeatability and the addition of a degree of freedom in the thumb to enable greater dexterity. The development and integration of a custom string potentiometer system, enables precise finger position tracking while simultaneously reducing design complexity. Furthermore, the study develops two distinct modeling approaches for EvoGrip's finger dynamics: a mathematical model based on first principles and a data-driven model using system identification techniques. Both modeling strategies demonstrated high accuracy, with the system identification model showing superior performance in compensating for complex, nonlinear behaviors. This work establishes a foundation for future research and advancements in robotic hands, focusing on real-time control, advanced pressure excursion and applications in human-centric tasks.