机电专业外文翻译---研究基于小波变换的直线电机驱动系统.docx

附录a research on linear motor driving systembased on wavelet transformabstractend-effect is a main reason of influence on the characteristic of linear motor driving system, its direct impact is nonstable and undulate edges magnetic field. the wavelet transform is applied to analyze the linear motor driving system performance in this paper. the improving thrust response system has been presented based on choice wavelet function and wavelet transform. simulation results indicate that the proposed control strategy can abate the thrust ripple problem caused by end effect in linear motor control system, and make the system have good performances.keywords wavelet transform; linear motor; end effect； direct thrust control system introductionfrance physicist morlet first applied the wavelet to analyzing the partial characteristic of earthquake wave in 1984. because wavelet transform is a kind of analysis method for time-scale (frequency) signal, in time-domain and frequency-domain, which has the ability of exploring signal features with partial characteristic. therefore, in the last years, the special analysis method has made itself theories rapid development and extensive application, especially in the aspects of signal analyzing and image processing areas. linear motor has longitudinal edge and transverse edge, for this reason the linear motor exist special end-effect. longitudinal end-effect is caused by finite length primary iron-core. transverse end-effect is caused by finite width of primary and secondary, secondary current and secondary plates affecting the air-gap magnetic field. this is the main difference between the linear motor and the rotating machine. longitudinal end-effect not only causes motor losses, lower electric efficiency and thrust, but also leads to motor work characteristic aggravation. therefore, key factor is to analyze the longitudinal end effect in this paper.traditional analysis method, fourier transform, has localization contradiction of time-domain and frequency-domain, some messages while analyzing nonstable signal will be usually lost. therefore, it is necessary to research a new method that can solve this problem reasonably and effectively so as to improve linear motor driving system performance.single dimension continuous wavelet transform has higher sensitivity, stronger ability of denoising and lower demand of the input signal, and doesnt need objects mathematic model. the single dimension continuous wavelet transform is used for analysis the performance of linear motor driving system.single dimension continuous wavelet transformthe continuous wavelet sequence can be described as, (1)where is scale parameter， is shift parameter. the square-integrable function is called mother wavelet. a wavelet sequence can be obtained by dilation and shift transformation of the mother wavelet. the continuous wavelet transform of arbitrary function is expressed by (2). (2)the mother wavelet formed wavelet sequence has an observable window function, so should satisfy following constraint condition: (3)is a continuous function which must be zero at the initial point for satisfying (2), then, (4)and its fourier transform is , when fulfills the admissible condition: (5)it is shown that single dimension continuous wavelet transform uses both scale dilations and time shifts to analyze the signal. the signal is expanded in window area *, where and represent the time-span and the frequent-span of window respectively. the time-frequency analysis is multi-resolution if varying the window area. the high frequency signal is suitably analyzed by the gradually exquisite time step, and the low frequent signal is finely analyzed by the exquisite frequency step. the windows of the time and frequency are adjusted through changing the signal frequency. time-frequency localization analysis of signal can be achieved.conclusionscomparing with the fourier transform analysis method, the wavelet transform technique has the characteristics that it analyzes the signal combining time domain with frequency domain together, for this reason it can effectively solve the problem of time-domain and frequency-domain limitation. it is important to search a new method that can solve the problem in linear motor driving system so as to improve linear motor servo characteristic. through correct choice wavelet function, it is possible to consider both the frequency spectrum of mother wavelet and the characteristics of original signal. the result of signal analyzed is beneficial for abating the end effect influence on linear motor driving system. simulation results indicate that the proposed control strategy can reasonably and effectively abate the thrust ripple problem of linear motor control system, and make the control system have good performance.references1 liu lili, xia jiakuan and jiang ping. study on the end effect and compensation technique of permanent magnetic linear synchronous motor. journal of shenyang university of technology. vol. 27, pp.261-266, 2005. 2 s. nornaka, “simplified fourier transform method of lim analyses based on space harmonic method”, linear drives for industry application, pp.187-190, 1998. 3 yoshihiko. mori, “end-effect analysis of linear induction motor based on the wavelet transform technique”, ieee transactions on magnetics, 35(5), pp.3739-3741, 1999.4 li. haodong, “research on the end-effect and control of the pm linear motor used in the electric discharge machining”, shenyang university of technology, 2003.5 guo. qingding and wang. chengyuan and zhou. meiwen and sun. yanyu, “precision control of linear ac serve system”, china machine press, pp.30-37, 2000.6 hu. changhua, li. guohua, and liu.tao, “the system analysis and design based on matlab6.x- wavelet transform”, xian university of electron science & technology press, pp.15-17, 2004.7 liu lifeng. research of direct thrust force control system of linear motor based on dsp. shenyang university of technology. 2005.研究基于小波变换的直线电机驱动系统摘要年底效应是一个主要的原因的影响的特点，直线电机驱动系统，其直接影响是nonstable和起伏的边缘磁场。小波变换是适用于分析直线电机驱动系统的性能在这方面的文件。改进推力响应系统已提交的基础上选择小波函数和小波变换。仿真结果表明，所提出的控制策略，可以减轻推力纹波问题所造成的端部效应在直线电机控制系统，使系统具有良好的性能。关键词 小波变换;直线电机;月底效应;直接推力控制系统简介法国物理学家，第一次申请的morlet小波分析部分的特点，地震波在1984年。因为小波变换是一种分析方法的时间尺度（频率）信号，在时间域和频域，其中有能力探索信号特征与局部特征。因此，在过去的几年中，特别分析方法，取得了理论本身的迅速发展和广泛应用，尤其是在方面的信号分析和图像处理的领域。直线电机有纵向和横向边缘的边缘，为此，直线电机存在特别月底生效。纵向月底的效果是有限所造成的长度小学铁芯。横向月底的效果是有限所造成的宽度，小学和中学，中学和中学目前的板影响气隙磁场。这是主要区别直线电机和旋转机械。纵向年底效应不仅造成汽车损失，降低电力的效率和推力，但也导致电机工作特性恶化。因此，关键因素是分析纵向边端效应在这方面的文件。传统的分析方法，傅立叶变换，有本地化的矛盾的时域和频域，一些讯息，而分析nonstable信号通常