- The paper presents a novel hand design that leverages underactuated fingers and passive mechanics to perform both robust power and adaptive fingertip grasps.
- The design employs a minimalist five-actuator system with compliant, elastomeric fingers optimized through task-centric methodologies for efficient manipulation.
- Experimental results validate its effectiveness in unstructured environments, providing actionable insights for future developments in robotic manipulation.
Overview of the i-HY Hand: A Compliant, Underactuated Robotic Manipulator
This paper introduces the i-HY Hand, a robotic hand engineered with a minimalist, underactuated design driven by five actuators. It is capable of executing an array of grasping and in-hand manipulation tasks, tailored for mobile robotic applications requiring durability, cost-effectiveness, and moderate dexterity. The paper focuses on the innovation in underactuated fingers, enabling adaptive power and fingertip grasps through passive mechanics.
Design Approach and Features
The i-HY Hand diverges from traditional, top-down design methodologies often centered around anthropomorphic or kinematic principles. Instead, a task-centric, bottom-up approach is adopted, optimizing the hand's design based on a defined set of representative tasks. This strategy prioritizes functionality and efficiency over comprehensive anthropomorphic replication.
Key Characteristics:
- Underactuated Fingers: Designed to perform both robust power grasps and delicate fingertip manipulations by leveraging passive mechanics.
- Actuation: Utilizes minimal actuators (five in total) to facilitate both finger flexion and independent thumb positioning.
- Compliance and Robustness: Features compliant, modular fingers with elastomeric pads, offering resilience in unstructured environments.
Task and Mechanical Design Implications
The i-HY Hand's design is underpinned by its capability to tackle specific challenge tasks, such as picking keys and using tools. The design process distilled these tasks into core grasping and manipulation operations, informing the hand's layout and actuation strategy. The compliant nature of the fingers allows for effective collision mitigation and adaption to varying object geometries, simplifying control and enhancing robustness.
Sensing and Control
The hand incorporates a modest yet efficient sensor system, comprising tactile arrays, magnetic encoders, and accelerometers, focused on grasping kinematics and contact localization. Notably, it employs novel low-cost, MEMS-based tactile sensors to further integrate the hand’s operation with its mechanical intelligence.
Experimental Validation
Experiments conducted demonstrate the hand's functionality across a range of grasping scenarios:
- Power Grasp Acquisition: The hand successfully envelops objects by initially maintaining finger alignment and subsequently adapting to object contours through elastic deformation.
- Fingertip Grasping: By tuning underactuated compliance, the i-HY Hand maintains stability in fingertip engagements, demonstrating sufficient stiffness for reliable manipulation under varied conditions.
Implications and Future Directions
The i-HY Hand represents a significant evolution in the field of robotic manipulation by utilizing simple yet effective design paradigms, offering insights into achieving dexterity through underactuated mechanics. This approach may inform future developments in robotic hands, emphasizing practical implementations in unstructured and cost-sensitive applications. Further exploration may involve refining sensor integration and expanding the range of environmental interactions to enhance adaptability and precision in real-world settings.