Building the control signal model for design of 3DOF motion platform of marine simulation system

In this article, the dynamics of a 3DOF motion platform which supports the bridge and imitates the motion of the ship is studied that introduces a new control signal model. This research is based on a Stewart platform in three degrees of freedom (roll, pitch and heave). The platform deck is moved by three frequency-controlled servo drives. A new approach is presented to deal with this issue, namely "the exact control signal model estimation method". Based on Newton-Raphson iterative method, simulation of this approach is conducted, their demerits and merits are compared in detail. It is concluded that the improved estimation model, when providing good initial iteration values, shows the exact simulation of the nonlinear kinematics of the considered parallel manipulator 3DOF motion platform.