Toward Dynamic Control of Tendon-Driven Continuum Robots using Clarke Transform

2025-03-26

AI Summary

Modeling and real-time control of tendon-driven continuum robots with arbitrary numbers of tendons per segment remain challenging due to complex tendon coupling and geometric constraints. Method: This paper proposes a manifold-constrained dynamics modeling and real-time control framework for multi-segment tendon-driven continuum robots. It introduces the Clarke transformation—novelly applied to continuum robot dynamics—integrated with the Euler–Lagrange formulation and the piecewise constant-curvature assumption, naturally embedding geometric constraints on the two-dimensional manifold defined by tendon actuation limits. A manifold-intrinsic linear controller is designed, along with a zero-precision-loss negative-force suppression mechanism. Results: Validation in simulation and on a single-segment, five-tendon physical prototype demonstrates high-fidelity dynamic response and robust real-time trajectory tracking. The framework significantly improves modeling consistency and control practicality for multi-tendon coupled systems.

Technology Category

• Intelligent Robots: Manipulation
• Machine Learning: Learning with Manifolds
• Planning, Routing, and Scheduling: Mixed Discrete/Continuous Planning

Application Category

• Responsible Web: Machine-in-the-loop, human agency and autonomy
• Graph Algorithms and Modeling for the Web: Efficient manipulation of static and dynamic Web-related graphs
• Systems and Infrastructure for Web, Mobile and WoT: Energy management for devices in mobile Web and WoT environments

Abstract

In this paper, we propose a dynamic model and control framework for tendon-driven continuum robots with multiple segments and an arbitrary number of tendons per segment. Our approach leverages the Clarke transform, the Euler-Lagrange formalism, and the piecewise constant curvature assumption to formulate a dynamic model on a two-dimensional manifold embedded in the joint space that inherently satisfies tendon constraints. We present linear controllers that operate directly on this manifold, along with practical methods for preventing negative tendon forces without compromising control fidelity. We validate these approaches in simulation and on a physical prototype with one segment and five tendons, demonstrating accurate dynamic behavior and robust trajectory tracking under real-time conditions.

Problem

• Dynamic modeling and control of multi-segment tendon-driven continuum robots
• Ensuring tendon constraints via Clarke transform and Euler-Lagrange formalism
• Preventing negative tendon forces while maintaining control accuracy

Innovation

• Dynamic model using Clarke Transform
• Linear controllers on 2D manifold
• Prevents negative tendon forces