Static And Dynamic Analysis Of Large Stroke Multi-degree Of Freedom Micro-positioning Platform

With the continuous progress and development of micro/nano manufacturing,micro/nano assembly and micro/nano mechanical system and other micro/nano fields,the requirements for positioning accuracy of related manufacturing equipment and detection technology are getting higher and higher.The positioning technology based on traditional mechanical transmission mode has been unable to meet the work needs of micro/nano fields.Therefore,it is urgent to develop a high precision positioning system with large stroke,multiple degrees of freedom and high frequency response to meet the increasingly stringent requirements of practical work.Based on compliant mechanism and piezoelectric ceramic micro/nano positioning platform based on piezoelectric ceramic drive,through the compliant mechanism and the elastic deformation of flexible component implementation force energy transfer,the combination of piezoelectric ceramic ultra high resolution,high stiffness,quick response and large output force mechanism and advantages and the advantages of no cooperation,no wear and high precision has received the widespread attention in the field of precision manufacturing.Therefore,it is of great theoretical significance to carry out the technical research on the precision positioning platform with high precision,large stroke and many degrees of freedom for the precision manufacturing field and China’s manufacturing power.In this paper,based on the State Key Laboratory of Mechanical Transmission,the working principle,static and dynamic composite modeling principle,static and dynamic composite simulation,experimental measurement and improvement design of the micro-positioning platform with large stroke and multi-degree of freedom are studied.The main research contents are as follows:(1)The working principle of micro/nano positioning system is studied.Based on compliant mechanism and elastic deformation theory,the working principle of the large-stroke 6-DOF micro-positioning platform was discussed,and the principles of piezoelectric ceramic actuator and several common compliant displacement amplification mechanisms were analyzed.The analysis method of compliant mechanism was analyzed,and the composite modeling principle of statics and dynamics based on dynamic stiffness matrix for compliant mechanism was explored.The statics and dynamics analysis method of large-stroke multi-degree-of-freedom micro-positioning platform was proposed.(2)The theoretical modeling theory and method of compliant micro-positioning platform are studied.Based on D ’Alembert’s principle,transfer matrix theory,finite element vibration theory and matrix displacement method,an improved multi-level simplified static and dynamic composite modeling method for compliant mechanisms with complex structures was proposed,and the dynamic stiffness matrix of each element was obtained.The equivalent simplifications of the serial and parallel multi-element branched double-node flexible elements and the equivalent simplifications of the symmetric compliant structure are discussed.The input/output two-port statics composite model of the micro-positioning platform is established.The force-displacement relationship of the whole platform is explored,and the static/dynamic characteristics of the platform,such as input/output stiffness model,amplification ratio model and natural frequency model,are derived.(3)The performance analysis and experimental test of the micro-positioning platform were studied.The influences of mechanical structure and main geometric parameters on the input/output stiffness,output displacement and natural frequency of the micro-platform were discussed by using modern design methods and experimental testing techniques.The static and dynamic experimental test platforms of the micro/nano positioning system were built,and the feasibility of the input/output stiffness model,amplification ratio model and natural frequency model of the micro positioning platform was discussed based on the finite element simulation results.The working stroke,input-output characteristics and dynamic response characteristics of the micro-positioning platform were analyzed and evaluated,and the correctness of the static and dynamic analysis method for the large-stroke and multi-freedom micro-positioning platform was verified.(4)The improved design scheme of the micro-positioning platform was studied:the improved design scheme was explored for the performance deficiency of the six-degree-of-freedom micro-positioning platform,and the design method of the large-stroke and high-dynamic frequency response compliant positioning platform was discussed.A new configuration of a hybrid displacement amplifying mechanism with both large displacement and high frequency response was proposed,and a new micro-positioning platform was built.The static and dynamic model of the new micro-platform was established,and the static and dynamic characteristics of the simulation experiment were analyzed.The reliability of the static and dynamic analyzing model for the new micro-platform was verified.