Analysis And Optimization Of Compact6-DOF Shaking Table Mechanism

As the primary means of seismic performance and reliability verificationproducts, Hdraulic shaking experimental system is a key equipment in the fieldof engineering research, and is widely used in aviation, aerospace, steel,automotive, construction and other industrial sectors. This subject studystructural property, the kinematics analysis, dynamics model, frequencycharacteristics, structural optimization and base control strategy of compact6-DOF shaking table, which is being researched by HIT institute of electro-hydraulic servo simulation&testing system. The main contents are as follows:Firstly, the paper introduces the structural features of such high-frequencyvibration table, according to the structural characteristics of compact shakingtest table, drawing the analysis method of parallel-series mechanism, the paperestablishs the kinematics model, deduces the closed-form solution of inversekinematics and the Jacobi matrix of velocity, and verifys the correctness of themodel. Considering the table is a light load, we can not ignore the mass ofpistons and connecting rods. So the multi-rigid body dynamics model should bebuilt using Kane method. The model validation is completed by the Matlab/Simulink model, which lays the foundation for structural optimization andselection of the power sectors.Secondly, stiffness matrix of the compact shaker is deduced under the pre-load conditions. Then the paper gives the natural frequency of the table for eachdegree of freedom, combined inertia matrix. Analysis of major structuralparameters on the natural frequency of vibration table is completed in this paper.On this basis, optimize the structure parameter by the target of expanding thebandwidth, isotropic and decoupling. Then determine the selection of thehydraulic cylinders and servo valves, and verify the reasonableness of the curveusing the maximum power function curve and optimized matching.The structural parameters of the compact6-DOF freedom shaking table is Designed, refering to the structural parameters of foreign similar vibration table,combined with the specific design specifications, drawing the mature designexperience of HIT Institute of electro-hydraulic servo system simulation and testin six degrees of freedom simulation platform and large-scale shaking table.Finally, the paper establishes a common mathematical model for thesymmetrical cylinder controlled by servo valve, and derives the transfer function.The PID control of hinge point in space is analyzed in detail for the hydraulicdriving shaker. A virtual prototype of the table is established using ADAMS, andthen make a co-simulation with Matlab/Simulink to verify the kinematics andcontrol system analysis of the shaking table are correct, which provides certaindesign basis for manufactureing the real table.