Model Predictive Control Considering Load Disturbance of Ship-Borne Hydraulic Parallel Platform

Abstract

The ship stabilization platform effectively compensates for the ship’s multi-dimensional rocking motion, ensuring the stability of onboard equipment relative to the inertial system. The irregular shaking motion of high-inertia ship equipment introduces significant load disturbances to the hydraulic drive unit of the stabilization platform, thereby affecting its compensation performance. This paper proposes a model predictive control (MPC) strategy for the ship stabilization platform that accounts for load disturbances. Firstly, the kinematic model of the stabilization platform and the feedback linearization model of the hydraulic drive unit system, inclusive of load forces, are established and verified through simulation. Secondly, a predictive model for the hydraulic drive unit that incorporates load disturbances is developed. Utilizing the hydraulic drive unit’s force balance equation, a sliding mode disturbance observer is employed to monitor and estimate the load disturbances, leading to the design of a predictive controller for the hydraulic drive unit that considers these disturbances. Thirdly, this load-disturbance-aware hydraulic drive unit model predictive controller is applied to regulate the motion of Stewart ship stabilization platform based on joint space control. The efficacy of this proposed method, in comparison to traditional MPC, is validated through simulation and experimental results.

Keywords

• Ship-borne parallel platform
• hydraulic drive unit
• model predictive control
• load disturbance
• sliding mode disturbance observer