Dynamical Design & Experiment Research Of Inertial Measuring Unit's Vibration System

The Inertial Measuring Unit(Inertial Measuring Unit,IMU), the core part of the navigation system, is widely used in the aviation, astronavigation and navigation industry. Because it's loading equipments usually work in the abominable environments, such as the large extent of vibration frequency, large vibration acceleration, large shock load etc, it is very easy to generate dynamical errors, thus causing very low accuracy for the navigation system to work, along with affecting service life of IMU components. As to solve IMU dynamical errors caused by the vibration and shock, and to guarantee the orientation accuracy of the navigation system,it is essential to optimize IMU vibration system. Therefore, the research of good performance of the vibration system will be of great significance to normal operation of IMU.In this paper, the vibration system of a Inertial Measuring Unit is as the object of research. According to the vibration and shock theory, the vibration system's coupling rates was calculated, the stiffness of the isolator optimized, and the vibration and shock finite analysis of the vibration system conducted with the simulation software ADAMS. Finally, completed the vibration and shock experiments, via the research of this paper, improved the navigation system's vibration system's design and efficiency. The main contents of the dissertation are expressed as follows:â‘ The overall design of the IMU vibration system. After compared the different isolators'arrange styles'advantages and disadvantages, choose the suitable isolators'arrange styles; established the 3D models of the IMU, and adjust its centre of gravity to make it almost coincide with the elasticity center of the vibration system, calculated the vibration system's uncoupling rates; and completed the mounting bracket's modal analysis.â‘¡The design of the IMU isolator. Isolator static tri_stiffness was optimized on equal stiffness with FEM software. Based on the elastic rubber material model, the comparison of tri_stiffness before and after optimization was made, and isolator that has better isoelastic characteristics was designed.â‘¢The FEA analysis of the IMU vibration system. Modal and frequency response IMU vibration system was carried out, and its vibration characteristic was in-depth study. By Z axis impact loading dynamic response , the shock acceleration and displacement response were gained, along with the max stress of the vibration system, isolator and isolator's rubber. On that basis, the random vibration and fatigue analysis Was completed on IMU vibration system, and isolator was checked according to fatigue strength criterionâ‘£IMU vibration system's vibration and shock experiments were completed, as to qualify it's performance in equal tri_stiffness, equal tri_damping, fatigue endure characteristics; and the experiments'result was compared with the analysis result.