Technology Research On The Two-Dimensional Ultra-Precision Positioning Platform

Precision positioning techniques play an important role in the modern industry system. In the engineering applications, it is highly desirable for precision positioning with high positioning accuracy, large motion range, and high natural frequency. In the precision positioning system, precision positioning stage is the main carrier to realize precision positioning and flexure precision positioning stage is popular in modern technical field. Compared with traditional rigid mechanisms, compliant mechanisms can have many advantages: high positioning accuracy, no assembly, continuous displacement, negligible stickslip friction, compact structure. Micropositioning systems based on flexure mechanisms inherit the advantages of compliant mechanisms, attracting more interest and attention.This thesis presents a XY flexure micropositioning stage based on basic building blocks. In order to achieve a large displacement and small parasitic errors, a symmetrical flexure structure using compliant beam is utilized within the structure configuration. In addition, based on the properties of building blocks, classic beam theory is utilized to analyze statics and dynamics characteristics of stage and natural frequencies and corresponding vibration modes is analytically illustrated. Furthermore, a precise positioning of the micropositioning system is established and experimental studies reveal the positioning performance of the stage. The main works include:? The development and research status of flexure precision positioning stage is introduced. The advantage of flexure precision positioning stage compared with traditional rigid positioning stage is analyzed. The requirement of precision positioning technology is pointed out and the design requirements and goals of this paper is put forward.? Different solving methods of the nonlinear large-deflection beam are introduced and analyzed on their solving precision and scope of application. Three basic compliant positioning modules are built using compliant beams. Positioning performance and stiffness characteristics of these three modules is further analyzed. In addition, the effects of various factors in module structure on stiffness characteristics of basic compliant modules are discussed.? The basic design criteria is put forward in the design of two translational degrees of freedom positioning stage and flexure precision positioning stage is designed using basic compliant modules according to these criteria. The working stroke of the stage is obtained.Working Principle of the stage is then explained and its decoupling performance?isolation performance at load-point and overall performance of the stage are illustrated.? Statics and dynamics characteristics of stage are analyzed, and natural frequencies, driving characteristic and corresponding vibration modes are analytically illustrated. The finite element analysis software is used for the modal establishment and analysis to obtain the model shape and frequency. The positioning performance of stage is further analyzed and positioning accuracy and error is obtained.? Experimental prototype is manufactured using suitable material and processing method. According to requirement of driving characteristics and positioning accuracy, driving actuator and displacement detecting device are selected. Furthermore, closed loop servo-system is set up.