Model-Free Feedback Control of a Hybrid-driven Soft Manipulator

Soft robots offer high compliance and flexibility, enhancing their human and environmental interaction capabilities. However, complex modeling and control hinder the adoption of soft robots. This paper presents a novel model-free control approach for a hybrid-driven soft manipulator. It utilizes a model-free control method to estimate the Jacobian matrix in real time via end position feedback of the soft manipulator. To mitigate operational noise, Huber’s M-estimation technique is incorporated. Furthermore, an inner and outer loop motion controller is designed to effectively govern the soft manipulator and accelerate the pneumatic drive's response within the hybrid drive system. The proposed control approach is demonstrated through experiments. The results substantiate its capability to withstand external disturbances and environmental noise, enabling efficient soft manipulator control.