Design and Nonlinear Modeling of a Modular Cable-Driven Soft Robotic Arm

Area of Science:

• Robotics
• Mechanical Engineering
• Materials Science

Background:

• Soft robotic arms offer high compliance and safety for human-robot interaction.
• Existing models often struggle to accurately capture the complex nonlinear dynamics of cable-driven soft robots.

Purpose of the Study:

• To propose a novel multi-section cable-driven soft robotic arm.
• To develop a new analytical static and kinematic modeling approach for enhanced prediction accuracy and motion planning.

Main Methods:

• Fabrication of a modular soft robotic arm using 3D-printed endcaps and casting.
• Development of an analytical static model to describe bending curvature based on cable lengths.
• Derivation of a kinematic model and motion planning algorithm from the static model.

Main Results:

• The proposed analytical static model demonstrated superior prediction performance compared to a baseline model, especially under large bending conditions.
• Experiments confirmed the soft arm's high flexibility and large workspace.
• The motion planning algorithm based on the new model achieved up to 52% smaller tracking errors.

Conclusions:

• The novel modeling approach accurately captures the nonlinear dynamics of cable-driven soft robotic arms.
• The proposed soft robotic arm exhibits excellent flexibility and workspace, with improved motion control accuracy.