Research On Three-degree-of-freedom Large-stroke Micro-nano Positioning Platform Based On Compliant Mechanism

In micro-nano manufacturing and micro-nano measurement,it is very important to study the micro-nano positioning platform with a large stroke.This dissertation mainly designs and studies the positioning platform with three-degree-of-freedom large stroke,complete the structural design.The flexibility matrix method is used for static analysis,and the mechanical vibration and finite element method are used for dynamic analysis.In the design of the micro-nano positioning platform,the compliant mechanism is used as the design concept,and a three-degree-of-freedom large-stroke micro-nano positioning platform is completed by using the columnar rhombic flexible hinge,the composite parallel four-bar guiding mechanism and the structural integration design mode.The platform consists of two parts in parallel: the upper mechanism is connected to the four sides of the central working platform by four composite compliant four-bar mechanisms to realize the motion guidance of the platform in the X or Y direction,the four-bar mechanism also embeds a rectangular flexible unit.,and the upper compliant mechanism isolates the driver from the central working part of the platform,thereby reducing the influence of additional motion on the driver;the lower mechanism adopts an eight-column structure,which can realize the movement of the platform in the vertical direction,and have the ability to move in the X and Y directions.The positioning platform adopts a symmetrical design,which can effectively suppress the coupling displacement of the platform.In the theoretical modeling and dynamics analysis of the micro-nano positioning platform,this paper uses the flexibility matrix method to theoretically model the platform.The diamond-shaped flexible hinge and the compliant guiding mechanism are calculated theoretically.The Lagrangian method and the finite element method are used to obtain the dynamic model of the working platform,and the natural frequency of the working platform is solved.In this paper,the finite element analysis software is used to simulate and verify the micro-positioning platform.The output displacement,coupling displacement error,stiffness and dynamic performance of the working platform are studied systematically.The physical model of micro-nano positioning platform is obtained.Simulation experiments show that the micro-nano positioning platform can achieve three-degree-of-freedom motion with good carrying capacity,and the stroke in three directions is on the order of millimeters.