Modeling And Simulation Of Passive Vibration Isolation Technology For Optoelectronic Equipment Visual Axis

Motion platform on the optoelectronic equipment equipped with visible TV,infrared thermal imaging camera and other imaging methods to obtain target image information,and because of its high mobility,high timeliness and high economy and other advantages,is widely used in maritime rescue,environmental mapping,forest detection and military reconnaissance and other civilian or military fields.Image quality is one of the most important indicators to measure the performance of optoelectronic equipment.With the continuous development of science and technology,the most important factor limiting the imaging quality is no longer the optical system or electronic system,but the vibration in the working environment of optoelectronic equipment.Vibration is divided into line vibration and angular vibration,of which angular vibration on the imaging quality is much greater than the impact of line vibration.In the ideal situation,as long as the elastic center of the damping system and the center of mass of the optoelectronic device coincide to ensure that the decoupling between linear and angular vibration.In actual application,due to the limitation of photoelectric equipment shape,mass distribution and installation space,there is always eccentricity,and the actual damping system always has vibration coupling.Therefore,the analysis of the influence of the mass center offset on the dynamic characteristics of the damping system and the degree of coupling is of certain guidance for the design of the damping system.Firstly,the sources and causes of angular vibration are analyzed and discussed,and it is determined that both the direct angular vibration excitation of the external environment and the coupling of the line vibration through the damping system will lead to the angular vibration response of the optoelectronic equipment.For the coupling of line vibration and angular vibration of the damping system,a six-degree-of-freedom damping system model of the optoelectronic equipment is established,the elastic coordinate system and the center-of-mass coordinate system are defined,and the coupling characteristics of the damping system are analyzed and discussed according to the position and attitude relationship between the two coordinate systems.The results show that the non-coincidence of the center of mass of the photoelectric device and the elastic center of the damping system leads to the coupling between the line vibration and the angular vibration,and the inertia product of the photoelectric device in the center of mass coordinate system leads to the coupling between the angular vibration,and there is no coupling between the line vibration.Secondly,a two-degree-of-freedom damping system model is established,and the mathematical relationships between the unidirectional center-of-mass offset and the inertia product for the modal frequency and the modal vibration mode of the coupled system are derived respectively.The results indicate that as the mass offset or inertia product increases,the lower order frequency of the coupled system decreases while the higher order frequency increases,and the decoupling rate decreases.Then,for the two different damper layouts,the simulations were performed for the six-degree-of-freedom damping system with the center of mass offset in one direction,offset in two directions and offset in all three directions,and the graphs and clouds of the frequency and decoupling rate changes were obtained,showing that the effect of the center of mass offset on the frequency and decoupling rate of the system is negatively related to the system elastic radius,and the larger the elastic radius is,the less the frequency and decoupling rate is changed.The larger the radius of elasticity is,the less the frequency and decoupling rate of the system can be changed.Finally,the line vibration response and angular vibration response of optoelectronic equipment under line vibration excitation and angular vibration excitation are given for different eccentric situations of the damping system of optoelectronic equipment.For the line vibration excitation,in order to reduce the angular vibration response generated by the coupling,the corresponding damping measures are given.One is to adjust the position of the center of mass of the equipment,such as adding counterweights or adjusting the equipment tooling structure;the second is to adjust the position of the elastic center of the damping system,such as adjusting the installation position of the damper or stiffness parameters.For angular vibration excitation,you can adjust the installation position of the damper,stiffness parameters or change the equipment tooling structure to get the appropriate angular vibration resonance frequency to reduce the angular vibration response of the equipment.