Researching On Coarse-fine Nano-positioning Stage Based On Dual Piezoelectric Drive

With the continuous development of science technology, more and more in-depthstudy is adopted in the microscopic field, such as photonics, MEMS, bio-engineering,nano-materials and so on, and higher positioning accuracy is continuously required, whichleads to the era of micro/nano-accuracy with large stroke at the same time. The large strokemicro/nano-positioning stage will promote the further development of the multipledisciplines, having major scientific significance and practical value.In order to solve the contradiction between large stroke and high precision inmicro/nano-positioning technology, this paper, combined with the national863Project"high-resolution tomography and detection system on fine structure of cross-scale ",studies2-DOF coarse-fine nano-positioning stage driven by dual-piezoelectric units.According to the macro stage’s positioning characteristics and requirements, thepositioning program and the overall structure of the macro stage is designed. Since themacro stage is still in manufacture, this paper focuses on the micro-positioning system.A micro-positioning stage driven by piezoelectric ceramic is designed. The stagestructure is designed with a pair of flexible parallel four-bar linkage, to eliminate couplingdisplacement.The basic theory of piezoelectric ceramics is analyzed. This paper gives a keyresearch on the piezoelectric ceramic’s creep and hysteresis characteristics, which havegreater impact on the micro-positioning accuracy. Creep and hysteresis data is measured inexperiments, and fitted by using MATLAB software, and then the hysteresis functionmodel is obtained. By the method of inverse, the hysteresis feedforward control algorithmis gained. The experiments show that the algorithm reduces hysteresis of the piezoelectricceramic to less than5%.The relationship, between the flexible hinge parameters and the rotational stiffness, isanalyzed by theoretical formula. According to the actual size of the flexible hinge, the rotational stiffness is calculated to3.2144N.m/rad. Stress, displacement and otherperformance of the micro-positioning stage model is analyzed by ANSYS software. Theexperiment proves that the micro-positioning stage has good voltage-displacementperformance, and its’ X-direction’s positioning accuracy is80nm and resolution is18nm.Its’ Y-direction’s positioning accuracy is88nm and resolution is22nm.