Experiments on resolved acceleration control of a 3-link dual-arm underwater robot with model error compensator

Underwater environments provide significant challenges for humans, thus researchers have focused on controlling underwater robots equipped with manipulators known as Underwater Vehicle-Manipulator System (UVMS) that perform underwater tasks instead of humans. To achieve high-precision control of UVMS, an accurate mathematical model must be developed. However, there are modeling errors between the UVMS model used for control system and the fluid forces that actually act on the robot. In conventional studies, control methods based on joint space have been used as a compensation controller for disturbances, including modeling errors. This paper proposes a Resolved Acceleration Control (RAC) method for UVMS that incorporates a Model Error Compensator (MEC), a control method based on task space, designed to minimize these model errors. The proposed method aims to achieve robust trajectory tracking control for UVMS by suppressing the uncertainties in modeling of fluid forces and the effects of disturbances. Furthermore, unlike many prior studies that demonstrate the effectiveness of their methods through simulations, this study validates the proposed method through position control experiments of a robot under wave disturbances. The experimental results confirm the robustness of the control system against modeling errors and wave disturbances, demonstrating the usefulness of the proposed method.