Characteristics And Control Research Of4-DOF Parallel Shipboard Stabilized Platform

In the process of navigation, ships will have the movement of rolling, pitching,yawing, swaying, surging and heaving because of the effects of weather andwaves or other environmental conditions, These movements directly affect the activitiescarried out on the ship. Stabilized platform for the isolation of ship movements, keep thedevice stable, and improving its adaptability, so it has been widely used in the shipboardequipment. Most of the existing stabilized platform is serial stable platform, which unableto meet the high performance, high accuracy of large heavy equipment. This paper willuse a parallel stabilized platform of folding as ship-based stabilized platform, and analysisof the characteristics of parallel mechanism, kinematics and dynamics and stabilitycontrol.Firstly, according to the ship suffered major and minor disturbance, choose a2-RRS/2-RUS folding four DOF parallel mechanism for stabilized platform that canisolate the roll, pitch, sway and heave four freedom of disturbance. Degrees of freedom,motion characteristics and forward and reverse solutions and workspace are analyzedbased on screw theory.Secondly, combining with the theory of parallel mechanism with the screw theory,the influence coefficient method of stabilized platform mechanism kinematics anddynamics analysis, the platform is given with driving the relation between the input andoutput speed acceleration corresponding torque input relations. Verify the correctness ofthe kinematics and dynamics solved by ADAMS. Co-simulation of ADAMS and Simulinkbased on computed torque control algorithm, validate the dynamics control method aresuccessful.Finally, the analysis identified a stabilized platform for shipboard overall systemhardware and software solutions, using open "PC+motion controller" structure, selectedTRIO EURO209motion controller as a control subject. Building the system interactiveinterface based on Motion Perfect2and LABVIEW software. Depending on theperformance of the motion controller choices feed forward control algorithm PID controlalgorithm as a mechanism, and finally verify the validity of the algorithm by simulation. Experimental studies conducted on the basis of system hardware and software, throughmultiple sets of simulation movement experiments to verify the validity and rationalitystable platform for system software and hardware architecture. Stable tracking experimentcarried out in this system, verified by a square wave and continuous curve modes and usespeed mode and position mode tracking, and through experiments on two models tooptimize position and time error which produce due to smooth processing at speeds,ultimate complete tracking experiment. Learned from the experimental data, the maximumtracking error is0.43%, meet the system design requirements.