Research On Modeling And Control Strategy Of 6-DOF Hydraulic Platform For Ship Handling Simulator

The ship handling simulator is used to train sailors by reappearing the ship’s movement on the sea. The scene simulating system of a typical ship handling simulator is built to imitate the movement of sailing. In recent years, a new kind of ship handling simulator is developed. It can imitate the true movement of the ship on the sea through the moving platform added to the simulator. This article is based on the hydraulic 6-DOF platform of a ship handling simulator.Based on the study of marine simulator’s development, the characteristics of 6-DOF platform, modeling methods and control algorithms, the kinematics of hydraulic 6-DOF platform is studied, including the analysis of inverse kinematics.Then, the mathematical modeling is carried out for the hydraulic system drived by asymmetric valve controlled asymmetric cylinders, and the related experiment and simulation is completed to varify the modeling.In this article, the method of co-simulation of 6-DOF platform for modeling and simulation is adopted. AMESim is used to build the hydraulic system. The parameters of the servo valve model are adjusted according to characteristic curves of frequency response in the servo valve reference. Considering all the inertia effect of the system, the mechanism part of the platform is built in Virtual.Lab Motion. Compared with the typical way of mathematical modeling, this way is much more simple and accurate. Inverse kinematics and hydraulic control system is built in Matlab/Simulink. Then through the interfaces provided by the softwares, a general simulation model including mechanical, hydraulic and control system is constructed.At last, experiment is carried out to study the 6-DOF platform. The simulation results are compared with the test results. A good result shows that the simulation model can exactly reflect the actual work of the whole system. Then, the simulation model is studied much further on control algorithm of hydraulic system. This article contrasts the traditional PID control and the dynamic pressure feedback algorithm. Through simulation model and experiment of 6-DOF platform, it proves that the dynamic pressure feedback algorithm can better improve the dynamic performance of the platform.