Research Of On-ship Active Vibration Isolation System Based On Parallel Mechanism

Ships sailing on the surface of the water in the process, due to the role of thewind, waves and other environmental conditions, will produce of up-down,back-forth, rolling, pitching and bowing motions, the ships, the military activities,communications, satellite data receiving and so on, all will have a great effect. Thevibration isolation of shipboard vibration isolation platform between the shipboardequipment and carrier, realizing the function of protection and stability, has wideapplication.Based on the characteristics of ship motion, this paper proposes a new type of3rotations and2translations5degree of freedom4-CPS/RPS parallel mechanismwhich suites for shipboard active vibration isolation. First of all, its degrees offreedom is calculated strictly by using the screw theory, this paper analyzed thekinematics inverse solution, based on that, the velocity and acceleration ofkinematics analysis is analyzed, the kinematics analysis is the foundation of allmechanism analysis; Secondly, in this paper, the singularity, workspace, dexterityand positioning accuracy of the4-CPS/RPS parallel mechanism must be analyzed,the feature analysis of the mechanism is the basis of mechanism optimization; Then,this paper adopted the Lagrange method to establish the dynamic model of the4-CPS/RPS parallel mechanism, the dynamics equation is obtained, which laid afoundation for the next step for vibration isolation control; The single degree offreedom active vibration isolation system model is established on the basis ofanalyzing the different feedback control under the different conditions of vibrationtransmissibility, it provides a theoretical basis for active control; Then, according tothe existing wave theory, it has carried on the ship motion simulation, get themotion of the ship, and used the multi-layer hierarchical forecast method toestablish the forecasting system, implementation the prediction of the ship motionposture in advance; Finally, on the basis of the existing parallel mechanism controlstrategy research, respectively the branch closed-loop PID control strategy and theforce/position redundant control strategy of4-CPS/RPS parallel mechanism isestablished, and using the method of Adams-Simulink joint simulation to have control simulations for the above two kinds of control strategies, to verify the twomethods can realize the shipboard active vibration.