Research On The Spacecraft Vibration Isolation Platform Based On The Five-dof Parallel Mechanism

In recent years China actively researched and launched the space-craft such asmanned spaceflight, moon exploration spacecraft. According to NASA Statistics, thereason of most spacecraft launch failure, caused by the vibration of the harshmechanical environments.Rresearching the whole-spacecraftisolation technology has acrucial role for satellites and space-craft launch. In this paper based on the analysis ofthe space-craft during the launching load, proposed the parallel vibration isolationmechanism comprising flexible joints.Parallel vibration isolation mechanism as theresearch background, the kinematics, dynamics and the vibration response of theparallel vibration isolation mechanism is analyzed.First, this paper analyzed the load characteristicsofthe spacecraft launching process.According to selection principle of the vibration isolation mechanism, selectedthe3-CPA/UPU parallel mechanism with5DOF as the vibration isolation mechanism. TheDOF of this mechanism had been calculated. The direction of the constraint degree offreedom had been defined, and the magneto rheological damper had been selected.Second, the classification and advantages of the flexible joints had beenintroduced.Derived rotational stiffness formulas of four typical flexible hinges toanalyzed the impact of various parameters on the rotational stiffness.The sizes of theflexible hingeswere designed. The static of the flexible hinges had been analyzed andthe strength of the flexible hinges had been checked.Third, the inverse solution of analytical geometry vibration isolation parallelmechanismobtained by derivation. The first-order influence coefficient matrix andsecond-order influence coefficient matrix of the vibration isolation parallel mechanismcan be obtained by the method of the loop equation. The geometry of the flexible hingescan be analyzed and the dynamic modeling equations of the flexible hinges wereconstructed. The dynamic modeling equations of the vibration isolation parallelmechanism can be constructed by the Kane method. The inverse kinematics simulationof the vibration isolation parallel mechanism can be took by using MATLAB program.Finally, the stiffness matrix and damping matrix of the vibration isolation parallelmechanism were solved by the virtual displacement method. The free vibration equationwithout damping of the vibration isolation parallel mechanism was solved to get thenatural frequency of the vibration isolation system. The various parameters whichimpacted of the natural frequency of the vibration isolation system can be analyzed. Thevibration equation with the damping and force was decoupled be using positivematrix.The vibration response of the vibration isolation system under sinusoidalperiodic excitation and random excitation can be solved. In this paper, based on the parallel vibration isolation mechanism comprisingflexible joints, the kinematic, dynamic and the vibration response of the vibrationisolation system were be solved. The design method and analysis of the spacecraftmultidimensional vibration isolation mechanism were provided in this paper.