Model Predictive Control of a Shipborne Hydraulic Parallel Stabilized Platform Based on Ship Motion Prediction
Hongbin Qiang, Song Jin, Xinyu Feng, Dapeng Xue, Lijie Zhang
Abstract
Shipborne stabilized platform is an important equipment to ensure the stability of shipborne equipment relative to inertial coordinate system. This paper presents a model predictive control strategy based on ship motion prediction (MPMPC) for ship stabilization platform. Firstly, the ship motion is simulated, and the autoregressive prediction model (AR model) is used to predict the ship motion. Then the kinematics analysis of the Shipborne stabilized platform is carried out and the mathematical model of the hydraulic drive unit (HDU) of the stable platform is established. Then the predicted ship motion is combined with model predictive control (MPC). The predicted trajectory of HDU can be obtained by the kinematics calculation of predicted ship motion. One part of the predicted trajectory is used to compensate the time delay of HDU, and the other part is used as the reference trajectory of the rolling optimization of MPC, instead of the reference trajectory using the measured ship motion at the current moment in traditional model predictive control. Compared with the reference trajectory using the measured ship motion at the current moment, the predicted trajectory of AR model can reflect the future state of the system better, and a better control sequence will be obtained by minimizing the objective function. Finally, the simulation and experiment show that the MPMPC has higher tracking accuracy than traditional MPC.