MRE-based Variable Stiffness Design And Performance Of Compliant Micro-motion Stage

In recent years,the rapid development of micro-nano technology has greatly promoted the progress of modern industrial civilization.The micro-motion platform based on flexible mechanism is widely used in precision scientific instruments and high-end equipment fields such as ultra-precision processing,semiconductor preparation,optical measurement,biological operation,etc.due to its high motion accuracy,fast response speed,low energy consumption and compact structure.And become a key core component of related instruments and equipment,restricting the performance improvement of instruments and equipment.With the expansion of the application of related instruments and equipment,it has put forward more and more stringent requirements on the motion characteristics of the micro-motion platform,especially the dynamic performance.It is no longer just a single nano-positioning requirement within a certain range of motion,but is oriented toward Comprehensive performance optimization across scales,variable loads,multiple working conditions,multiple motion modes,etc.The inherent contradiction between the deformation range of the flexible mechanism and the mechanical stiffness greatly limits the performance improvement of the micro-motion platform and the application range of precision scientific instruments.Therefore,in response to the above technical challenges,the research on the variable stiffness design of the flexible micro-motion platform,realizes the multi-mode movement of large-stroke cross-scale movement and high-rigidity ultra-precision fast movement positioning,and meets the application requirements of different working conditions.It has important engineering significance and research value.In response to the above challenges,this article starts with the deformation mechanism of the flexible mechanism,combined with the material properties of the magnetorheological elastomer,designed and prepared a "sandwich" flexible guiding mechanism based on the magnetorheological elastomer,and studied the deformation of the guiding mechanism under the action of a magnetic field.Based on the principle and characteristics of stiffness,the static and dynamic models of the micro-motion platform are established.With the help of finite element analysis and experimental verification,the active adjustment of the dynamic performance of the micro-motion platform under the action of an external magnetic field is realized.The main research contents of the thesis are as follows:Firstly,the characteristics and preparation process of magnetorheological elastomer,the key material for the variable stiffness design of the micro-motion platform,are studied and analyzed.From the raw materials to be prepared,the equipment used and the process flow of the preparation,the whole process of the preparation of the magnetorheological elastomer is introduced in detail.The working mode and mechanical model of the magnetorheological elastomer are discussed and analyzed,combined with experimental tests,the relationship between the change in the modulus of the magnetorheological elastomer and the magnetic induction intensity is obtained.Secondly,a "sandwich" flexible guide mechanism based on magnetorheological elastomers is designed to realize the variable stiffness design of the flexible micro-motion platform.Based on the elastic beam theory and the magnetorheological elastomer chain model,a variable magnetic-solid coupling statics model of the flexible micro-motion platform is established,which accurately describes the variable stiffness behavior of the micro-motion platform under the action of a magnetic field.On this basis,the characteristics of the energy(kinetic energy and potential energy)of the micro-motion platform are further analyzed.Based on the Lagrangian equation,a dynamic model of the flexible micro-motion platform is established,and the characteristics of the natural frequency of the micro-motion platform under the action of a magnetic field are analyzed.Combined with the finite element analysis method,the validity and accuracy of the established statics and dynamics models are limitedly verified.Finally,a prototype of a flexible micro-motion platform based on magnetorheological elastomers was fabricated,and a semi-physical real-time rapid control experimental system for platform performance testing was built.The flexible micro-motion platform was designed and prepared in a magnetic field and a magnetic field.The open loop characteristics are tested.Experimental results show that under the action of an external magnetic field,the rigidity and dynamic characteristics of the flexible micro-motion platform are significantly improved.Among them,under the action of a 50 m T magnetic field,the rigidity is increased by 14.28%,and the natural frequency is increased by17.81%,which effectively verifies the proposal in this paper.Variable stiffness design of flexible micro-motion platform based on magnetorheological elastomer.