Kinematic Modeling and Workspace Amplification of a Novel Cable-Driven Hybrid Robot via Configuration-Based Decoupling

Resolving inverse kinematics and evaluating constrained workspace remain challenging for multi-module cable-driven robots. This paper analyzes a dual-module cable-driven hybrid robot inspired by inchworm locomotion and proposes a new configuration-based decoupling strategy in which a scalar decoupling factor relates the dominant bending variables of the two modules and organizes the redundant inverse kinematics into C-shaped and S-shaped configuration sets. A physically constrained workspace evaluation framework that combines the decoupling rule with cable-stroke, unilateral-cable, joint-deflection, and anti-winding constraints is established. Monte Carlo sampling is used to extract the admissible position and orientation workspaces. The results show that the dual-module topology increases the lateral reach from 65.2 mm to 180.6 mm relative to a single module while retaining a yaw range of about ±80°. In addition, the workspace subsets associated with positive and negative values of the decoupling factor correspond to boundary-reaching motion and lateral body adjustment, respectively. These results show that the proposed decoupling parameterization provides a valid way to organize redundant configurations and to evaluate the workspace amplification introduced by serial coupling.