Observer-based Adaptive Robust Control of Soft Pneumatic Network Actuators

Fabricated by elastomer materials, soft pneumatic network actuators (PNAs) not only enable versatile applications but also bring challenges to the high-performance control. This study presents new observer-based adaptive robust controllers for PNAs subjected to system uncertainties and unavailable states. First, a sliding patch-based observer and an observer-based controller are addressed for PNAs with known upper bounds, and stability of closed-looped systems is proved by the Lyapunov method. Second, a novel disturbance observer is proposed for the case of prior unknown bounds of uncertainties, and the stability of the closed-looped system controlled by an adaptive robust controller is also analyzed by the Lyapunov method. Finally, the effectiveness of the proposed controllers is verified by simulations and experiments.