Research On Design Method Of Flexible Support Structure In Broadband Inertial Reference

With the gradual improvement of the detection distance of high-precision spacecraft and airborne system,higher requirements are put forward for the stability and pointing accuracy of the Los of acquisition,tracking and pointing(ATP)system instruments.It is urgent for high-precision LOS stabilization system to stabilize the Los of ATP system in the inertial space.As one of the important parts of the high-precision LOS stabilization system,the wide-band inertial reference system is equipped with an inertial sensor which feeds the sensitive angular disturbance back to the controller.The controller drives the motor to drive the platform to move in the reverse direction,so as to realize the inertial stabilization of the platform.Inertial reference can provide ATP system with high-precision Los reference in broadband,which is of great significance to its research.The flexible supporting structure of the mechanical part of the broadband inertial reference plays the role of carrying the main load of the system and distributing the system degrees of freedom.The anisotropic stiffness of the flexible support structure determines the resonance characteristics of the system structure,and then determines the achievable bandwidth of the system.The accuracy of the stiffness model of flexible supporting structure directly affects the reliability of structural design.In this paper,based on the stiffness equivalent relationship between the flexible support structure and the flexible hinge,a stiffness model which can accurately and efficiently design the size of the flexible support structure is established.The main contents of this paper are as follows:1.This paper makes a detailed discussion on the research results of broadband inertial reference at home and abroad,summarizes the design methods of flexible support structure,analyzes the shortcomings of the existing design methods of flexible support structure applied to the structural design of broadband inertial reference,and expounds the necessity of this paper.2.According to the application requirements of the wide-band inertial reference,the performance indexes of the system are put forward;from the system composition and working principle,the performance index requirements of the wide-band inertial reference for the flexible support structure are further put forward.3.The topological relationship between a flexible support structure and a single flexible hinge is analyzed.The results show that the stiffness characteristics of the flexible support structure mainly depend on the stiffness characteristics of the basic unit flexure hinge;by introducing the new design parameters of the flexure hinge,a new stiffness design formula of the flexure hinge is derived;compared with the finite element simulation results of a single flexure hinge,the error between the stiffness design formula derived in this paper and the finite element analysis result is less than5%,The correctness of the new stiffness design formula is verified.4.Based on the topological relationship of the structure and the new formula of flexure hinge stiffness design,the key dimension parameters of the flexure support structure are determined.The finite element analysis of the stiffness and stress distribution of the flexure support structure is carried out.At the same time,the modal analysis of the inertial reference system based on the flexure support structure is carried out.5.According to the characteristics of the flexible support structure designed in this paper,an experimental test device for the anisotropic stiffness of the flexible support structure is designed,and the experimental test for the anisotropic stiffness of the flexible support structure is carried out,and compared with the theoretical calculation results and the finite element simulation results,thus verifying the effectiveness of the design method of the flexible support structure in this paper.