Design And Analysis Of Precision Tip-tilt Stage Based On Additive Manufacturing Spatial Compliant Mechanism

Devices with nanometer-level moving and positioning accuracy are the basic key devices in ultra-precision machining,modern medical engineering,aerospace and other high-tech fields,among which precision tip-tilt motion stages have become the core of high-end complex devices such as nanolithography,laser weapons and space commu-nication because they can realize precise scanning,tracking and pointing actions.The traditional subtractive processing-based flexible motion platform is unable to meet the increasingly demanding demand for compactness and integration of the system be-cause of its large size,vibration and clearance due to structural assembly.As a manu-facturing technology based on the discrete-stacking principle,additive manufacturing has the advantage of spatially fabricated structures,and has achieved breakthrough ap-plications in many military and civil fields after several years of development.In view of the challenges faced by the current precision tip-tilt motion platform,it is urgent to carry out research on the design of a new tip-tilt stage based on additive manufac-turing processing method.In this paper,we design a tip-tilt motion stage based on spacial flexure mechanism,which has excellent additive manufacturability,and carry out research on measurement,design,modeling,and experimental methods.The main research contents include:First,the research of PSD-based precision comer measurement method.Starting from precision corner measurement,a common problem in precision inspection,we lay the foundation for platform design and inspection analysis.The current PSD-based corner measurement method is analyzed,which has problems such as inconsistent for-ward and reverse comer measurement results,limited measurement range and approx-imation.A new precision corner measurement method is proposed,which can real-ize the simultaneous measurement of two-axis deflection and one-axis displacement,with the advantages of no theoretical approximation and large measurement range,etc.Based on this,a simplified measurement model is proposed,and an experimental system based on the proposed method is built.Secondly,the design method of the tip-tilt motion platform of the spacial flexure mechanism is studied.For the goal of additive manufacturing spatially flexible tip-tilt stage,two sets of new flexible mechanisms are designed by borrowing the vine bionic in nature,and two sets of structures are connected in parallel using the asymmetric stiffness mechanism to obtain a platform that can achieve single-axis precision deflec-tion motion under a single input,with compact structure and additive-friendly features.The stiffness models of the two sets of substructures are established by using the sec-ond law of Castigliano and the theory of Timoshenko beams,and the hydrostatic model of the single-axis tip-tilt platform is obtained by model assembly.Then,the simulation and experimental analysis of the uniaxial tip-tilt stage were carried out.The simulation of the uniaxial tip-tilt stage based on ANSYS software was carried out to analyze the static dynamic performance of the platform and verify the accuracy of the theoretical static model,and further analyze the influence of axial drift and additive manufacturing errors on the platform motion performance during the deflection motion.The results were compared with those of several measurement methods,and the accuracy of the proposed measurement method was verified while showing the actual motion travel of the platform.Finally,the design and study of the three-axis tip-tilt motion stage.A tip-tilt stage that can realize three-axis motion is obtained by connecting three sets of single-axis tip-tilt stages in parallel,and the necessity of hinge material flexibility is judged using sim-ulation analysis methods to obtain a dual-material three-axis tip-tilt motion stage with decoupled large-stroke motion.A set of composite manufacturing processes based on additive manufacturing and injection molding is developed,which can realize inte-grated tip-tilt stage manufacturing and has the prospect of integrated electromechanical manufacturing of multi-material complex structures.Further the internal defects of the structure were observed using tomography,and the motion performance of the tip-tilt stage was analyzed by simulation and experiment.In this paper,the structural design of single-axis and three-axis tip-tilt stage based on additive manufacturing is carried out to solve the contradiction between the low processing accuracy of additive manufacturing and the high processing accuracy of precision mechanism.A static model is established for the single-axis tip-tilt stage,and a multi-material spatial structure manufacturing process is developed for the three-axis tip-tilt stage.In addition,a three-axis motion detection method is established,and on this basis,the properties of the two tip-tilt stages are analyzed by combining model simulation and tomography technology.This paper has wide reference significance for the topics of additive manufacturing precision platform,precision motion sensing detection,and integrated manufacturing process of electromechanical structures.