A Soft-Rigid Tendon-Driven Continuum Robot with Multi-Curvature Actuated by a Single Set of Tendons
Liuming Qiu, Luiza Labazanova, David Navarro-Alarcon, Dan Zhang
AI summary
Problem
Achieving multiple curvatures in tendon-driven continuum robots typically requires additional tendon sets or complex mechanical locking mechanisms, which increases system complexity and control difficulty.
Approach
The design integrates modular subsegments filled with low-melting-point alloy that switch between soft and rigid states through localized thermal phase transitions, allowing independent curvature control with a single tendon drive.
Key results
- Demonstrated C-, J-, and S-shape configurations in 2D and 3D space
- Achieved independent multi-curvature control using only one set of actuation tendons
- Maintained high structural rigidity in thermally locked subsegment states
- Developed and validated a hybrid kinematic model for the variable-stiffness backbone
Why it matters
Simplifies the mechanical and control architecture of continuum robots, advancing their practical deployment in confined-space tasks like minimally invasive surgery and pipeline inspection.
Abstract
This work presents a novel design of achiev- ing multiple curvatures in a tendon-driven continuum robot (TDCR) system with only a single set of acturation tendons. The TDCR used in this work is assembled from multiple sub- sections made of low-melting point alloy (LMPA), which each of them has independent binary stiffness by localized thermal phase transitions. Through localized thermal phase transitions, the robot can dynamically ”lock” or ”release” specific sub- sections, enabling multi-curvature configurations, enabling in- dependent curvature control with only one set of actuation tendons. is approach eliminates the need for additional segments or complex locking mechanisms, significantly reducing mechan- ical complexity and control challenges. Experimental validation confirms the system’s ability to execute complex shapes (C/J/S- shape configurations), maintain structural rigidity in locked states, as well as different spatial movements can be achieved by changing the configuration of subsegments. The SR-TDCR demonstrates potential for confined-space applications merging dexterity with actuation efficiency.