Design And Simulation Research Of 2-DOF Parallel Stable Platform For Ship

The ship in the process of navigation have 6 degree of freedom movements under the influence of waves,wind and etc, including rolling, pitching, heading, yawing, swaying, surging and heaving, and this badly influenced the safe landing of helicopter, the ship-based weapons'firing accuracy and the crew's work and life. In all the 6 degree of movements which most influence other things on ship are rolling and pitching, so a 2-DOF of parallel platform was designed to isolate the rolling and pitching movement. This paper for the study of the parallel platform contains 3 parts, the attitude detection of the ship, the kinematic and dynamic analysis of the platform, and the third part-the controlling section.The attitude detection and prediction of the ship. In this paper , the theory of how to detect the attitude of ship is analyzed with two methods, i.e. differential equation method and the quaternion method. And the equation for real-time detecting is obtained. At same time, the advantages, disadvantages and the errors of both methods are compared by simulation with Matlab. This section of study would provide theoretical basis for the attitude detection. The attitude prediction has been analyzed with the prediction method which is based on the ARMA(autoregressive moving average) model, then was stimulated in Eviews.Mechanism analysis. The structure of the platform is designed in Pro-E. The kinematics of the mechanism including the inverse position kinematics solutions of the mechanism has been analyzed, and the velocity and acceleration has been analyzed based on first order and second order impact factor method. Finally, the dynamic model of the mechanism is established with the Lagrangian method. The validity of all the kinematics analysis are verified through the programming of Matlab, and the curves of the inverse position kinematics solutions, the velocity and acceleration of the mechanism in particular enter are obtained.Controlling. A pose big loop serve control strategy based on attitude prediction was present in this section, and the related hardware is introduced. A synovial variable structure controller based on the dynamic model of the mechanism is designed. Finally, the feasibility of the controller is verified by stimulating with Matlab programming.