Research On Parameterized Dynamical Models And Isolation Performance Of Stewart Platform

The continual progress and innovation of vibration isolation technology hasa significant role in the performance of advanced equipment, regardless ofpromising excellent function at the beginning, those good design targets are hardto get if no good vibration environment is guaranteed in the practical application,which is especially important for high-precision instruments in aerospacebecause of its high-cost, so the vibration isolator platform for spacecraft has beenextensively studied. However, most studies are carried out on Stewart Platformfor active vibration isolation, despite of fruitful results, active vibration isolationdevice has been limited in this field because of its complicated structure andenergy dependence, it is necessary to have an in-depth study on Stewart Platformfor passive vibration isolation appliations.In this thesis, we construct the dynamic equations of Stewart Platform withtwo\three parameters legs in inertial coordinate system, considering the legs’quality, moment of inertia and the basestation movement, discussion about theinfluence by some parameters on natural frequency’s distribution andtransmission rate has been made, meanwhile the theoretical model was validatedand deeply discussed through the virtual model by some commercial softwares,the main work are as follows.Firstly, based on spaceful rigid body dynamic equations, taking the legs’mass, inertia characteristics and the displacement excitation of basement intoconsideration,we build the dynamic equations of two/three parameters isolationplatform in inertial coordinate system and gives both the linearized eigenequation and the methods for solving the nonlinear response.Secondly, after establishment of the Adams simulation model and comparingthe simulation results with the theoretical ones, we verified the correctness of thetheoretical results, then with the help of the natural frequency,response andtransmission rate analysis of two/three parameters isolation platform,thevibration isolator characteristics of different vibration isolation platform wereobtained.Finally, by comparing the theoretical results with ANSYS model analysisand harmonic response analysis of the flexible vibration isolation platform finiteelement model, what effects structural flexibility will have on the transmissionrate and the corresponding improvement are obtained.