The Design Of Ship Simulator With Three Degrees Of Freedom And Its Hydraulic Control System

Ship simulator platform can simulate ship motions in different waves conditions, and provide test conditions of dynamic property and static property for research of seasick disease, training for resistance to get seasick disease and testing of various of equipments equipped on ship overland. Compare to the ship of the actual test at sea, it is more economic, safe, controllable, flexible and so on.In order to better simulate the condition of the ship sail on the sea, I design a new kind of ship simulator with three degrees of freedom while consider the actual conditions which various of tests need. The simulator platform can achieve severe vertical movement by forficiform hydraulic lift platform. It also can achieve roll and longitudinal wave motion with construction of seesaw which is driven by two different hydraulic cylinders. By analyzing platform’s kinematics and dynamics, I get the basic parameters of the platform and the driving force which hydraulic system needs.Hydraulic system uese one pump to supply oil to three hydraulic cylinders, so the platform can achieve swing motion, roll movement and longitudinal wave motion at the same time. Also according to test’s need, one of the three hydraulic cylinders can move without being affected by others. The platform uses the proportional position closed-loop control method and it not just responses more quickly but also can get higher control precision compare with the normal switch valve controlling cylinder system.Establish mathematical model of the proportional valves controlled asymmetrical hydraulic cylinder system. Simulate and analysis the model by using simulation software Matlab/Simulink. The results of the simulation show that the system has good stability and response characteristics. For making the system getting better dynamic characteristics, I use the conventional PID control strategy to improve the control effect of the proportional valves controlled asymmetrical hydraulic cylinder system.Last establish the virtual prototype of the platform by using the simulation software ADAMS to simulate and study seasick disease trail. The preliminary test results show that the platform’s motion has achieved the index and it can meet the requirements of practical application.