【作者】 卢明明；

【导师】 周晓勤；

【作者基本信息】 吉林大学 ， 机械制造及其自动化， 2014， 博士

【摘要】 三维椭圆振动辅助切削（EVAC）是一种十分有发展潜力的加工方法，不仅在改善切削加工性等方面获得了验证、而且可形成微加工运动创成表面，受到了国内外的学术界和工程界的高度关注。三维EVAC能否在加工中实现最佳的性能，其关键还在于三维EVAC装置及其控制。迄今为止，前人的研究在三维EVAC装置及其控制等方面还存在着一些问题有待研究解决，例如三维EVAC装置的设计、三维椭圆运动轨迹的可控制性、以及三维椭圆运动对驱动的非线性等问题。本学位论文将主要针对这几个方面的问题进行深入研究。论文详细评述了三维EVAC装置及其控制方法的国内外研究现状。在此基础上，系统研究了三维EVAC装置的设计，三维EVAC装置的辨识方法、三维EVAC装置的控制方法，通过离线实验测试、在线切削加工实验，理论分析以及仿真进行了考证，具体包括如下五个方面。（1）研制了一种基于柔性铰链的并联驱动三维EVAC装置针对当前已有的三维椭圆振动辅助切削装置存在的问题，研制了一种能够满足要求的三维EVAC装置，该装置采用四个压电叠堆平行驱动，两两对称，装置刀座与柔性铰链采用一体式加工，减小了由于装配造成的误差，在装置的底座上增加了楔形块式高度微调设计，根据三维EVAC装置中压电叠堆的空间运动配置，所研制的装置可以实现普通车削、二维椭圆振动辅助车削和三维椭圆振动辅助切削，本文对装置的柔性铰链刚度进行了计算、关键部件进行有限元分析，然后对装置简化模型进行刀位点轨迹建模，并通过仿真分析研究了三维椭圆运动参数对于三维椭圆轨迹的影响，通过调整椭圆生成参数使其能够满足三维椭圆运动轨迹的要求。（2）对所研制的三维EVAC装置进行了相关性能测试针对所研制的三维EVAC装置进行了性能测试，测试的内容主要包括静刚度测试、固有频率测试、阶跃响应和正弦响应测试、分辨率测试和最大行程测试、串扰测试。装置的静刚度测试结果与设计值和仿真结果接近；固有频率测试的结果与仿真值差别较小，满足本实验的使用要求；阶跃响应和正弦响应测试可以看出装置的响应速度和跟踪误差都满足设计要求；分辨率测试和最大行程测试可以看出所研制的三维EVAC装置分辨率为100nm以下，可以实现的最大行程为13.97μm；最后对各个压电叠堆驱动时产生的串扰情况进行测试。通过对三维EVAC装置的各项性能测试，对所设计三维EVAC装置的整体性能进一步熟悉，为后续控制研究打下基础。（3）提出了一种基于非线性Wiener系统的三维EVAC装置辨识方法对三维椭圆振动辅助切削系统进行了描述，针对压电驱动装置的特点和压电自身的非线性迟滞特性，本文的系统描述选择的是非线性Wiener系统，同时提出了有针对性的辨识策略，研究了系统的辨识方法，对memetic算法进行了改进，本文改进的memetic算法在全局搜索过程中能够避免出现局部受限问题，在局部细化过程中能够提高搜索效率和精度，通过两个常用的算法测试函数对本文改进memetic算法进行了测试，将测试结果与GA、CMA、PSO的测试结果进行对比，从全局收敛几率，搜索的时间上能够看出改进的memetic算法具有一定的优越性。采用基于改进memetic算法的系统辨识器对三维椭圆振动辅助切削系统进行了系统辨识，辨识的数据是实验采集的真实数据，辨识的信号有常用的正弦信号和方波信号，辨识的结果拟合度高达97.55%。（4）针对辨识的三维EVAC系统设计了一种模糊自适应滑模控制器针对三维椭圆振动辅助切削系统的非线性特征，对系统辨识结果采用模糊自适应滑模控制器来进行控制，设计了滑模控制律，并用Lyapunov定律证明了所设计控制器的稳定性，最后进行了控制器的仿真，仿真的结果显示，模糊自适应滑模控制器可以有效的抑制抖振问题，具有很强的鲁棒性。（5）搭建三维EVAC实验平台进行切削实验首先搭建了三维EVAC加工实验平台，通过参数设定后实际采集的数据，合成了加工使用的三维椭圆运动轨迹，验证了第二章中刀位点建模的理论的正确性；采用普通车削、二维椭圆振动辅助车削、三维椭圆振动辅助切削各加工同一类样件，然后对切削痕迹、表面粗糙度以及刀具磨损这三个方面进行检测，并进行了对比分析，结果表明三维椭圆振动辅助切削在提高表面粗糙度和减小刀具磨损方面具有优越性，同时也进一步验证了本文设计装置的加工性能。更多还原

【Abstract】 Three-dimensional elliptical vibration assisted cutting (EVAC) is a very potentialprocessing methods, not only be verified to improving material machinability,but alsocan formed into a surface by micromachining movement,and then,3D EVAC gets highconcerned by academic and engineering all of the world.The ability to obtain the bestperformance of3D EVAC in actual processing based on the develop of3D EVACappratus and its control.State-of-the-art,there are still some issues of the previous studiesin3D EVAC appratus and its control to be resolved by studies,such as the controllabilityof three-dimensional elliptical trajectory,the nonlinear motion of three-dimensionalelliptical trajectory,and so on.This dissertation will focus on the problem of these twoaspects in-depth study.This dissertation detailed reviews the research status of three-dimensional EVACappratus and its control method. On this basis, the design of three-dimensional EVACappratus,the identification method of three-dimensional EVAC system and the controlmethod for three-dimensional EVAC appratus was studied,and the theories were verifiedthrough offline experimental testing,cutting experiments,theoretical analysis andsimulation.This dissertation contains the following five parts.(1) Designed a three-dimensional EVAC appratus based on parallel driver the parallelflexible hingeAimed to solve the current problems existing in3D EVAC appratus,developed athree-dimensional EVAC appratus to meet the requirements.The developedthree-dimensional EVAC appratus uses four piezoelectric actuators place parallelly andsymmetrically.The knife block in the appratus and the flexible hinges integratedprocessing to reduce the errors caused assembly,the appratus has a wedge-block designto fine-tune the height of the diamond tool.According to the movement of thepiezoelectric actuators configuration,the appratus can achieve cutting experiment bycommon turning, two-dimensional and three-dimensional elliptical vibration assisted turning. This dissertation calculate the stiffness of the flexible hinge portion in thedeveloped appratus and the finite element analysis of key components.Modeling theknife sites trajectory by simplify the designed appratus and simulation analysis theaffecting of the trajectory parameters on the trajectory shape, and generate athree-dimensional elliptical trajectory by adjusting the parameters of the trajectoryparameters to meet the processing requirements.(2) Carried ou the performance test of the developed3D EVAC apparatusThis dissertation carried out the performance test of the developed3D EVACapparatus to enable it to meet requirements of the precision ultra-precision machining.The test content includes the static stiffness test, the test of natural frequency,the testingof step response and sinusoidal response, the test of resolution testing and maximumstroke and the test of crosstalk.The test results of the Static stiffness is close to the designvalue and the simulation results,the test Results of natural frequency is not very differentfrom the simulated values,basically meet the requirements of this experiment. The stepresponse and sinusoidal response testing of the developed appratus can be seen that thedriving motion error of the piezoelectric stack satisfies the design requirements.Theresults of the resolution test can be seen that the resolution of the developed appratus is100nm or less.The maximum stroke test reaults of the developed appratus can be seenthat the maximum stroke can be achieved as13.97μm, the crosstalk test between thepiezoelectric stacks was carried out finally.The overall performance of the designedthree-dimensional EVAC appratus have a comprehensive grasp by the performancetest,can be targeted the subsequent control process.(3) Proposed a system identification method for three-dimensional EVAC appratus basedon nonlinear Wiener system.This dissertation described the developed three-dimensional EVAC appratus systemusing a nonlinear Wiener system due to the nonlinear hysteresis characteristics of thepiezoelectric actuators, and proposed a targeted identification strategy,researchidentification of the system, improved the memetic algorithm.This paper improvedmemetic algorithm framework global search strategy chosen is genetic particle swarm optimization algorithm,the local refinement strategy uses a only perception mode ofparticle swarm algorithm.So that not only the local convergence problems ofconventional algorithms can be solved,but also improve the chances of search efficiencyand success.The improved algorithm was tested through two commonly used algorithmstest functions,the test results were compared with GA, CMA and PSO,verified thesuperiority of the improved algorithm. This dissertation proposed a system identifierbased on the improved memetic algorithm and carried ou the system identification of thedeveloped three-dimensional EVAC appratus.The data for identification was collectedby experimental,the signals for identification selected as sinusoidal signal and the squarewave signal.The fit of the system identification result can be up to97.55%.(4) Proposed a adaptive fuzzy sliding control method for three-dimensional EVACappratusA fuzzy adaptive sliding mode controller was proposed to control the developedthree-dimensional EVAC appratus according to the nonlinear characteristics of theEVAC system. The control law of sliding mode was designed through the results ofsystem identification,and system stability was proved by Lyapunov law,finally thesimulation of fuzzy adaptive sliding mode controller was carried out.The simulationresults shows that the fuzzy adaptive sliding mode controller can effectively suppresschattering problem, which has strong robustness.(5) Carried out the processing experiments by the developed three-dimensional EVACappratusThis dissertation carried out the processing experiments by the developedthree-dimensional EVAC appratus.Firstly, introduced the experimental conditions of thecutting experiment.Synthesis three-dimensional elliptic trajectory through the parametersetting of three-dimensional elliptical trajectory,also to verify the theoretical ofmodeling knife sites modeling in the chapter2.The cutting experiments results of by thedeveloped three-dimensional EVAC appratus were comparison with the conventionalcutting and two-dimensional EVAC of YOZ plane.The photo of machined parts weregiven firstly,then described the advantages of three-dimensional EVAC by cut traces,surface roughness and tool wear,also authentication the theoretical research in thefront.更多还原