Research On Design And Key Technology Of Large Longitudinal Ratio Flexible Hinge Micro-motion Platform

Compared with the traditional sports platform,the micro-motion platform has the characteristics of flexible configuration,good controllability and high rigidity,and plays an important role in the field of precision positioning.At present,the research on micro-motion platform is mostly based on plane and linear drive.The micro-motion platform of this structure can achieve high-precision positioning,but the range of motion is very limited,and it is difficult to achieve nano-level positioning accuracy.In view of this,this paper proposes a large aspect ratio flexible hinge,which aims to solve the limitations of the traditional flexible hinge with small range of motion and low positioning accuracy under small deformation.The research carried out is summarized as follows:Firstly,the overall design requirements of the large aspect ratio flexible micro-motion platform are proposed,and the overall design scheme of the platform is given.Structurally,the hinges and branches of the platform are flexible,and the driver selects a high-resolution,high-precision piezoelectric ceramic driver.The control system of the platform uses the STM32 series single-chip microcomputer as the main control module,combined with the fuzzy self-tuning PID control strategy,and the closed-loop control of the platform through the attitude detection device.Then optimize the analysis of the overall structure and key components of the platform based on the platform structure design.Designing the flexible hinge structure of the platform,using the large aspect ratio structure,for the small deformation of the flexible hinge under low load,using the combination of theoretical calculation and Abaqus finite element analysis,the large aspect ratio flexible hinge Size optimization.For the micro-motion platform designed with large aspect ratio flexible hinge,the kinematics analysis such as degree of freedom analysis,shaft analysis and positional inverse solution are carried out,and the working space of the platform is verified by numerical search method.Analyze the static force of the platform,establish the mechanical model from the virtual work principle to obtain the work balance between the driving force and the binding force and the external load,verify the correctness of the spiral theoretical analysis result,and obtain the force balance equation of the platform.According to the static stiffness theory,the overall stiffness equation of the micro-motion platform is derived,and the forces and moments applied in different directions are analyzed.Through the modal analysis,the sixth-order mode diagram of the platform is obtained,and the natural frequency range of the platform is known to ensure the stability under external excitation.Finally,it is difficult to establish an accurate mathematical model for the piezoelectric ceramic driver.Based on the fuzzy self-tuning PID control algorithm,the micro-motion platform is used to control the operation,ensuring that the platform can cope with the complex conditions such as nonlinear,multivariable and time-varying during operation.The Simulink is used to model and simulate the control system,and the system parameters are corrected by the fuzzy theory to achieve the nano-level positioning accuracy of the control system.