Analysis of Vibration Characteristics of Electro-hydraulic 3-UPS/S Parallel Stabilized Platform

Abstract With the development of fluid power transmission and control and control technology, using electro-hydraulic driven can significantly improve the load-carrying capacity, stiffness, and control accuracy of the stabilization platforms. However, compared to mechanical driven, electro-hydraulic driven parallel stabilization platform needs to consider the stiffness and damping of the fluid, as well as the coupling effect between the fluid and the structure, making the modal and dynamic response characteristics of the mechanism more complex. Aiming at the above problems, taking the electro-hydraulic driven 3-UPS/S parallel stable platform as the research object, considering the hinge stiffness, the vibration characteristic equation of the mechanism was established by using the virtual work principle. Then the variation characteristics of natural frequency and vibration response with the position of mechanism were analyzed basing on the dynamic equation. Finally, the correctness of the model was verified by modal test and Runge-Kutta methods. This study can provide a theoretical basis for the dynamic design of electro-hydraulic driven parallel mechanisms.