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Design and control of a novel variable stiffness actuator based on antagonistic variable radius principle
Xiantao Sun1, Xiaoyu Xiong1, Wenjie Chen1
1School of Electrical Engineering and Automation, Anhui University, Hefei 230601, China.
ISA Transactions
|February 20, 2024
Summary
This study introduces a novel rotary variable stiffness actuator (VSA) using an antagonistic Hoberman linkage mechanism (AHLM). This compact VSA offers independent control over position and stiffness, enhancing safe human-robot interaction.
Area of Science:
- Robotics
- Mechanical Engineering
- Human-Robot Interaction
Background:
- Variable stiffness actuators (VSAs) are crucial for safe human-robot interaction.
- Existing VSAs often face limitations in stiffness range or structural compactness.
Purpose of the Study:
- To propose and demonstrate a novel rotary VSA utilizing an antagonistic Hoberman linkage mechanism (AHLM).
- To achieve a large stiffness range and compact structure for enhanced robotic applications.
Main Methods:
- The VSA-AHLM employs antagonistic quadratic springs connected via cables to a Hoberman linkage mechanism (HLM).
- Stiffness is varied by adjusting HLM radius and spring preload, with independent control via two rotary motors.
- Geometric parameters of spiral cams were optimized for linear stiffness-elongation behavior.
Main Results:
- The developed VSA-AHLM prototype demonstrated significant stiffness variations.
- Independent control of position and stiffness was achieved.
- Excellent positioning and trajectory tracking performance were experimentally validated.
Conclusions:
- The proposed VSA-AHLM offers a promising solution for safe and adaptable human-robot interactions.
- The novel design provides a large stiffness range within a compact structure.
- Independent control capabilities enhance the actuator's versatility in robotic systems.
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