Design And Implementation Of Vibration Isolation System For Inertial Navigation Equipment Of Underground Roadheader

The inertial navigation system of underground roadheader takes the underground shield machine as the carrier,and combines with the initial position information to measure the real-time velocity,azimuth and attitude of the carrier,which is the key equipment to realize the autonomous navigation with high precision and resolution.However,the vibration excitation caused by the environment will seriously affect the navigation accuracy of the inertial navigation system,and the severe vibration shock will even damage the precision inertial elements inside the inertial navigation system.So the high performance inertial navigation damping system is the key to protect the safety of inertial navigation equipment and ensure the navigation accuracy of inertial navigation system.In this thesis,a new vibration reduction system is proposed to meet the space constraints and performance indicators for inertial navigation system of underground roadheader.The main research work and innovation of this paper are as follows:Firstly,a 6-DOF dynamic model of the system was established based on six common shock absorber spatial configurations,and the dynamic characteristics of the system under different vibration absorber configurations were analyzed.In order to avoid vibration coupling of inertial navigation system,the optimal spatial layout of vibration damping system is determined.Taking the three-way resonant frequency and the vibration transmissibility at the key frequency points of the inertial navigation system as parameter indexes,the position of the connection point of the stiffness and damping module of the vibration damping system was determined,and the parameter matching of the stiffness and damping module was completed.Then,according to the matching results of the stiffness and damping parameters of the module,the stiffness and damping module design of the inner rubber strip of the cylindrical helical tension spring was proposed.Based on the stiffness design requirements of the vibration damping system in three directions,a cylindrical helical tensile spring was designed to meet the performance requirements by considering the use strength and fatigue strength of the spring,and the reliability of the design was verified by simulation and test.Friction damping characteristics between spring and rubber strip were analyzed,damping characteristics tests were carried out,and damping parameters were identified.Then the key structural parts of the damping system are designed and verified by simulation.Finally,the prototype of inertial navigation vibration damping system is developed,and the effectiveness of the design is confirmed by the vibration damping performance test.The results show that the three-direction resonant frequencies of the vibration damping system are respectively: transverse 2.15 Hz,longitudinal 2.20 Hz and vertical 2.25 Hz,and the measured results are all around 2Hz.At the key working frequency point(7Hz),the vibration transmissability in three directions of the damping system is: transverse-22.38 d B,longitudinal-19.84 d B and vertical-22.61 d B,and the errors with the theoretical values are8.91%,1.39% and 9.91%,respectively.The experimental results show that the new inertial navigation vibration damping system basically meets the performance requirements of inertial navigation vibration damping.To sum up,the inertial navigation damping system of underground roadheader designed and developed in this thesis has good vibration damping performance in the working frequency band,which provides a relatively stable working environment for inertial navigation system and guarantees the navigation accuracy of inertial navigation system.The design and research method of inertial navigation damping system in this thesis also lays a foundation for its application in engineering practice.