Dynamic characteristics analysis and multi-source disturbances rejection control of a 6-PUS parallel stabilization mechanism on floating base

Abstract

The safety and efficiency of marine transfers are significantly influenced by the vessel motion under random wave excitations. The conventional ship-mounted stabilization platforms based on the Stewart-Gough platform design face limitations such as inadequate vertical workspace and additional inertial forces. To overcome these challenges, this study introduces a novel parallel stabilization mechanism, with kinematic and dynamic models that incorporate the motion of the floating base and the inertia characteristics of the limbs. To tackle the control difficulties posed by various marine disturbances, an innovative composite control scheme is proposed. This scheme employs a non-singular terminal sliding mode control, designed using a double power reaching law, to enhance tracking speed and vibration suppression. Additionally, a disturbance estimator is developed to mitigate external disturbances by generating a compensatory signal on the input channel that counteracts the effects of these disturbances. Theoretical analysis confirms the stability of the proposed approach, while simulation results further demonstrate its effectiveness and superior performance.