Abstract
This thesis investigates the design and functionality of robotic hands, aiming to replicate the versatility and adaptability of the human hand and focusing on linkage-driven fingers known for their impressive capabilities in large-force exertion, high durability, and precision.Drawing inspiration from existing modular concepts, a novel approach that introduces integrated four-bar linkages into phalanx mechanisms aligned with the human finger’s anatomical structure is proposed. The thesis classifies finger components based on function and generates all the potential designs by using graph enumeration and Assur group methods.
The historical evolution of industrial robotics leads to bio-inspired soft robotics, where the pros and cons of rigid-body and soft components are explored. Reconfigurable mechanisms, incorporating underactuation systems, bridge the gap between these two kinds, offering adaptability but also rigidity and precision. A conceptual design of the PRPR axis-constraint-based linkage is presented, resulting in a versatile finger mechanism adopting various configurations. The integration of underactuation enables the reconfigurable finger mechanism to transit from 2-DoF rigid to 3-DoF rigid-compliant and to 4-DoF compliant configurations.
Due to the complexity of topological structure change, the determination of the feasible manipulation workspace of reconfigurable hands is a challenging task. A novel method is introduced to derive the precision manipulation workspace (PMW), focusing on force-closure, singularity avoidance, and collision prevention. This approach serves as a crucial tool for grasp planning, design optimization, and actuation reduction, with a unique emphasis on offline design considerations. The thesis explores grasp performance analysis for three-fingered and four-fingered metamorphic hands. For the four-fingered anthropomorphic metamorphic hand, inspired by human prehension, the research adopts opposition-space modelling and constructs detailed mathematical models for each selected gesture. An extensive evaluation of grasp performance across diverse palm configurations and sizes demonstrates the adaptability of the anthropomorphic hand in various scenarios.
This thesis contributes to the field by presenting innovative design methodologies and comprehensive analyses, enriching the landscape of robotic hand design and operation.
| Date of Award | 1 Apr 2024 |
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| Original language | English |
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| Supervisor | Jian Dai (Supervisor) & Emmanouil Spyrakos Papastavridis (Supervisor) |