Designing Of Three-axis Swing Bench And Its H_∞ Control

Three-axis ship motion simulation table can simulate ship's roll, pitch, and yaw motion very well, and it can provide the ship equipments with the real ship motion environment. The table simulates ship motion when the ship motion trajectory of computer simulation is used as input signal. The designed table is a typical UOO table, the inner frame and middle frame can swing in limited angle range, and the outer frame can swing at random position of 360°range. According to requirement of response speed , loading, and precision, the AC servo system and reduction gears are used for driving the table, compared with direct drive control type, the precision is relatively poor, but the load and response speed are relatively well when the power and small dimension.First, analyze the theory of how the table works and set up the mechanic model. Then, using MATLAB to simulate the coupling effect among the three frames, and analyze the response ability of the table when receives the random motion signal of the ship. To satisfy the stability and real time need of the table, and to improve the response ability, control strategy based on the H_∞theory is designed and tested before the simulation.Based on the conclusion of the model simulation, drive system of the table is selected. In order to satisfy the requirement of big load, fast response and control precision relatively not very high, ANCHUAN AC servo system and high precision planet decelerate engine are selected to drive the table. Control computer adopts the control mode of industrial computer and multi-axial motion control card PMAC. To meet the real time need and precision requirement of the angle measuring system, high precision angle encoders are installed at the side of the table axis. And the angle is outputted based on the PLC system of the CANopen bus. In the end, the monitor system of the Control computer is designed in Visual Basic and through OPC technology to exchange data with the PLC.Through testing on site, the response speed, control resolution and angle measurement precision could satisfy the requirement when the table has loading.