Research Of A 3-Dof Coupling Parallel Mechanism For Stabilized Platform

In the process of navigation,slips will have the movement of rolling, pitching, yawing, swaying, surging and heaving because of the influences of storms or other environmental conditions, this motion seriously affects safety of ship-based helicopter and launching precision of ship-based weapons. Ship-based stabilized platform is used to isolate the ship motion, which is of great strategic significance. The existing studies were aimed at stabilized platform with series structure. Based on the characteristics of ship motion and its influence on the helicopter, a new coupling parallel platform is proposed. Degrees of freedom, motion characteristics, kinematics, workspace and modeling of dynamics are analyzed.Firstly, coupling characteristics of ship motion and level of its influence on helicopter are analyzed. Based on these, a new coupling parallel platform is proposed. Degrees of freedom and motion characteristics are analyzed based on screw theory, and the rationality of input joints choosing is discussed, performance of the combinations of actuating inputs is evaluated. Secondly, the method of equivalent motion of coordinte is given, the forward and inverse position kinematics of stabilized platform mechanism and numerical examples based on wave motion are given. The workspace of the parallel mechanism is discussed by inverse solutiong search, influence of geometric parameters on workspace is analyzed, geometric parameters are optimized based on volume of workspace. Based on kinematic influence coefficient theory, the kinematics of its mechanism is analyzed, the curves of the inputs'velocity and acceleration in case of basic and complex motion are discussed, the velocity performance map is drawed.Finally, the model of dynamics is set up by Lagrange method, input torque is reasonably distributed based on principle of energy optimization. The entity modeling and simulation are carried out by ADAMS software, and the simulative results and theoretic results are compared. The correctness of inverse position kinematics solutions and kinematics are checked.