高频高精快刀伺服系统优化  

Optimal design of high frequency and high precision fast tool servo system

作　　者：张建国 李江 黄凯 郑正鼎 杨辉[2] 许剑锋[1] ZHANG Jianguo;LI Jiang;HUANG Kai;ZHENG Zhengding;YANG Hui;XU Jianfeng(School of Mechanical Science and Engineering,Huazhong University of Science and Technology,Wuhan 430074,China;Beijing Institute of Aeronautical Precision Machinery,Beijing 100076,China)

机构地区：[1]华中科技大学机械科学与工程学院,湖北武汉430074 [2]北京航空精密机械研究所,北京100076

出　　处：《光学精密工程》2022年第1期78-88,共11页Optics and Precision Engineering

基　　金：华中科技大学学术前沿青年团队资助项目(No.2019QYTD12)。

摘　　要：研制了一款高频响、高精度及大驱动力的压电驱动型快速刀具伺服(Fast Tool Servo,FTS)装置,采用广义圆锥线拟合的柔性铰链构造新颖的柔性机构,通过对称布置的结构消除柔性刀架工作过程中在非期望运动方向的耦合误差,并对机构的运动学特性进行了综合建模。综合考虑装置行程和固有频率的设计目标,基于改进的BP神经网络优化算法,对柔性机构的结构尺寸进行了多目标优化设计。使用优化后的结构参数建立FTS装置的三维模型并通过ANSYS软件进行有限元分析,分析结果表明,优化后的柔性机构可以达到预期性能要求,验证了该优化算法的可行性。最后,进行了实验样机的制造和性能测试,进一步验证了FTS装置的优化设计结果。测试结果表明:FTS装置的固有频率超过7.6 kHz,标称行程约为6.4μm,分辨率约为12 nm,跟随精度约为0.3μm,静态和动态性能均符合设计目标。An innovative design for a fast tool servo(FTS)system exhibiting high response frequency,high precision,and a high driving force was proposed herein.A flexible hinge fitted with a generalized conic line was applied to construct a novel flexible mechanism.The coupling error of the undesired movement direction of the flexible tool holder was decreased efficiently using a symmetrically arranged structure.Moreover,the kinematic characteristics of the mechanism were comprehensively modeled.Subsequently,based on an improved BP neural network,a multi-objective optimization design for the structural size of the flexible mechanism was performed.The stroke and natural frequency of the designed structure was analyzed to balance these two conflicting design objectives.The three-dimensional model of this device was established based on structural parameters obtained via optimization.Furthermore,a finite element analysis was performed.It is demonstrated that the algorithm affords a perfect optimization effect.The flexible mechanism designed via optimization could achieve advanced performances and was hence suitable for the FTS flexible mechanism.Finally,a prototype of the device was manufactured,and performance tests were conducted to verify the optimization design process.Experimental results show that the static and dynamic performances of the proposed device satisfy the design requirements.Its natural frequency exceeds 7.6 kHz,the nominal stroke is approximately 6.4μm,the resolution is approximately 12 nm,and the following accuracy is approximately 0.3μm.In addition,the experimental results verify the feasibility of the designed FTS system for ultraprecision machining.

关 键 词：超精密加工 快速刀具伺服装置 柔性刀架 优化设计 有限元分析 

分 类 号：TH703[机械工程—仪器科学与技术] TP27[机械工程—精密仪器及机械]