Modeling and stability analysis for autonomous surface manipulator systems

Abstract

An Autonomous Surface Manipulator System (ASMS) is a versatile system with a robotic manipulator installed onto an Unmanned Surface Vehicle (USV), which can bring important technological innovations and efficiency improvements to various ocean applications. To develop a high-performance ASMS, an accurate model of the ASMS is required. However, existing models have limitations, such as neglecting the dynamic coupling between manipulators and USVs and not being suitable for stability analysis of ASMS. Hence, this paper proposed a modeling method for ASMS considering the dynamic coupling between the manipulator and the USV and performed stability analysis of the ASMS with the proposed model. Firstly, a six-degree-of-freedom ASMS model is introduced using the Newton-Euler equations. Then, an ASMS prototype is developed to validate the model, with its parameters identified through experiments. Subsequently, the motions of the USV are measured and compared with the calculated values under various motions of the manipulator. The accuracy of the proposed ASMS model is validated by the calculated errors of maximum roll angles and stable roll angles of the USV, which are less than 2deg and 1.1deg, respectively. Finally, a stability indicator is proposed, and the stability of the ASMS is analyzed.