The Study On Influence Of Shock Absorber On The Stabilization Accuracy Of Airborne Pod

Airborne pod is a sophisticated equipment that can be loaded with a variety of photoelectric load.In military fields,it can be used for air surveillance,target tracking,firepower guiding;in civilian fields,it can be used for monitoring forest fires,rescue at sea and mapping environment.As more and more attention is taken to competition for controlling the air,airborne,as an important means of aerial reconnaissance and surveillance,is required increasingly high performance.As an important indicator to measure the performance of aircraft pod,improving stabilization precision is essential to improve the performance of the pod.Because vibration is an important factor of stabilization accuracy,its effective isolation is meaningful for improving stabilization precision.The means of vibration isolation include active and passive isolation.Active vibration isolation can only isolate vibration that less than the bandwidth of servo control system,while passive vibration isolation by installing vibration damper is chosen to isolate vibration more than it.Design of passive vibration isolation system requires a rational selection of the type,parameters installation layout programs of the damper.The main contents of this paper are as follows:Firstly,it is studied that the mechanism of imaging blur from motion,comparing the different influence of line vibration and angular vibration to motion imaging.According to the results of the analysis,it is known that the focus should be angular vibration isolation and avoiding the vibration coupling from line vibration to angular vibration.Secondly,the working principle of stabilization platform and the important meaning of improving the stabilization precision to improve the aircraft pods' performance are introduced.Then the factors affecting the stabilization precision is analyzed and a further study of the relationship between the angular vibration's period,amplitude and the perturbations to the detector caused by angular vibration.Then,the damping system of the pod is designed.Began with the equations of motion,the conditions for the elimination of vibration coupling is studied and the layout of shock absorber of the two-axis,two-frame stabilization platform is determined.The type of shock absorber is determined to be the metal damper that has equal stiffness in three-dimensional,and the stiffness and damp of the absorber is calculated.Finally,finite element analysis of the whole platform is made.The simplification of the platform,definition of material properties,meshing and model connection are done.Modal analysis of the model is made,comparing the natural frequency of the system between whether absorbers are installed.The result shows that the fundamental frequency of system can be effectively reduced by adding absorbers.Random vibration analysis of the model is made,comparing the response spectrum between whether absorbers are installed.Random vibration analysis is made,comparing the overall displacement,overall stress and response spectrum between whether absorbers are installed when excitation spectrum is given.Random vibration experiment and flight test are done to identify the rationality of design of the damping system.The impact of vibration on the stabilization precision of a two-axis,two-frame stabilization platform is analyzed in this paper.The damping system of the platform is designed.The overall finite element model is established and modal analysis,random vibration analysis is made.It has a reference value to similar design in the future and a definite guidance to the development of the platform.