Modeling and Trajectory Tracking Control for a Rope-Driven Soft Robotic Arm Based on State-Attracted Functions

In this letter, a biomimetic rope-driven soft robotic arm (RDSRA) is designed with its kinematic and dynamic modeling, incorporating the bending and adsorption structures of an elephant trunk and the lamellar structure of a gecko toe to grasp objects of various shapes and materials. Then, a state attraction function-based trajectory tracking control (SAF-TTC) approach is proposed by using a one-dimensional vector field with globally bounded and convergent characteristics. This approach ensures consistency between the tracking error convergence direction and the vector field direction, so that the system is insensitive to disturbances and the tracking error converges to a small neighborhood of the origin along the vector field direction. The SAF-TTC approach is analyzed by using the Lyapunov stability theory and validated by simulations and experiments.