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针对永磁同步直线电机具有的非线性,扰动敏感的特点,提出基于自适应滑模电流控制算法的滑模控制.通过在电流环引入自适应律,进行在线估计系统内部参数摄动以及模型不确定性扰动,来改善永磁同步直线电机驱动系统中的电流环响应速度、追踪性能,并将正弦饱和函数代替常规sign函数,来削弱系统抖振,提高系统的鲁棒性和稳定性.同时设计二阶扩张观测器预测系统的负载扰动,二阶扩张观测器中利用提出的新型sigfal函数,改善了传统扩张观测器的预测精度和稳定性,然后将预测值前馈到电流环对其进行补偿,来减小滑模控制增益.仿真结果证明,所提出的方法可以提高永磁同步直线电机驱动系统的抗干扰性和动态响应性能. 相似文献
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分析了直线电机的位置角度误差对直线电机的输出电流的影响;为了消除直线电机的位置角度误差,作者在基于模型参考自适应控制方法的基础上设计了一套直线电机的位置角度校正系统.由于该校正系统中的位置角度误差补偿器采用不受位置角度影响的输入量对位置角度进行校正,所以可以在现有位置角度测量的基础上实现对位置角度的准确校正,为在现有直线电机和低精度光栅尺的情况下获得尽可能高的控制精度提供了保证.仿真和实验结果显示,采用位置角度校正后,直线电机可以实现对力矩电流的精确控制,而且位置角度误差能够被校正. 相似文献
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为了精确检测应用于航空航天领域的电磁阀驱动电源的电流,设计了一个高精度电流检测系统并对其精度进行了分析.通过对电流检测系统各部分精度的计算以及系统误差的合成,得到整个检测系统的理论精度.对电流检测系统进行试验研究,计算实际检测系统的精度,结果表明系统精度都在理论计算范围内,所设计的电流检测系统满足精度要求,所述检测系统精度分析方法正确,也可用于分析其他检测系统. 相似文献
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本文提出以AT89C52为控制器所设计逆变器检测系统.系统测试项目有多路高频交流电流,直流电流,频率,逆变器的效率等.该文重点阐述了高频交流电流,直流电流,频率检测实现的软硬件设计方法及系统在使用中的优越性. 相似文献
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无功电流检测方法是谐波抑制和无功补偿领域的核心技术之一.分析了ip-iq理论的原理,给出了检测系统的框图,应用Matlab/Simulink平台建立仿真模型进行仿真分析,给出了电流检测波形,该方法可以对无功电流快速有效检测. 相似文献
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人体测量学并不是现代社会的产物。有着很长发展历史的人体比例理论中就包含了现代人体测量学的基本内容,尽管其还不够系统完整,但至少说明了在艺术创作中诞生的人体比例理论对现代人体测量学的影响。并随着时间的推移而不断的完善发展,为现代人体测量学的系统提出奠定了坚实的基础。 相似文献
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M. G. Zotov 《Journal of Computer and Systems Sciences International》2006,45(5):714-717
By examples of the design in the input-output relations of control devices with various configurations, the dependence on the configuration of the value of the criteria characterizing the system quality is shown. The complexity of solving the problem in the state space is illustrated. 相似文献
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分析了在长江水质的评价和预测建模过程中出现的一些问题,利用灰色模型的指数特性,建立预测长江水质的GM(1,1)的改进模型。根据数据的周期波动特性,采用灰色系统理论建立了残差序列周期修正GM(1,1)模型,用复合残差来修正预报数据,提高了数据预报的准确程度和模型的适用性。 相似文献
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Weihua Ge Khaled Alkhaledi David Cochran Mohamed Amar 《International Journal of Industrial Ergonomics》2014
Even though using the hand as a hammer causes injury, the practice continues, and may be increasing, in industry and in jobs that require intensive manual labor. This was an exploratory study aimed at measuring the relationships between the forces of strikes, the relative angles of strikes, and/or the number of strikes (up to 3) with the perception of severity of strikes when using the base of the palm of the hand. Eight subjects struck a metal force plate with the base of the palm of the hand at three levels of force, three levels of angle with respect to the surface of a force plate, and with three different numbers of times in a trial. Subjects were then asked to give a psychophysical rating after each trial. The subjective perception of the severity of each impact and force-time curves were recorded. From each force-time curve, peak force, maximum acceleration of force application, and the area of the force curve from initiation to peak were determined. Sixteen ANOVA models were analyzed. 相似文献
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用JSP实现基于中值排序基数法的BBS树状结构,给出数据结构的设计以及具体的算法实现。 相似文献
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沈嘉 《数字社区&智能家居》2007,(17)
为了能够解决学生网络实验的可操作性和实验室安全管理的稳定性之间的矛盾,引入VMware,从而在单机上实现虚拟网络实验平台,提高网络实验教学的课堂效果. 相似文献
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沈嘉 《数字社区&智能家居》2007,(9):1307-1308
为了能够解决学生网络实验的可操作性和实验室安全管理的稳定性之间的矛盾,引入VMware,从而在单机上实现虚拟网络实验平台,提高网络实验教学的课堂效果。 相似文献
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郭林林 《数码设计:surface》2009,(10):170-171
紫禁城是我国古代建筑的精品,显示着古代匠师们在建筑上的卓越成就。其苦心经营的屋顶建构更是彰显了宫殿壮丽的威严和飞动的气势。随着我国城市化建设的加速发展,正确地认识中国传统建筑文化并设计具有中国文化的建筑迫在眉睫。本文将从紫荆城屋顶的造型和色彩两方面探析紫禁城的屋顶文化。 相似文献
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A. S. Rybakov 《Automatic Control and Computer Sciences》2010,44(1):11-21
The peculiarities of the interpolation method based on digital signal processing are considered. It is shown that the transfer
function of the interpolator may be represented by the composition of two functional components. A nonstatistical method of
reconstruction of the form of the corrective component of the transfer function based on processing of the scatter diagram
of the ordered pairs of the experimental and predicted data is investigated. It is shown that such pairs may be obtained in
the process of periodic event flow timing with estimations of the time positions of the signal and the predetermined instants
of the event occurrence being elements of the ordered pairs. The efficiency of the reconstruction method is illustrated by
the experimental results. 相似文献
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David Smith 《AI & Society》2003,17(1):1-11
The paper questions the ability of current university systems to respond appropriately to the complex demands of an Information
Economy. It argues that new relationships between creative subjects and technology require new thinking about the nature and
purpose of universities per se. In particular, attention is drawn to the growing involvement of the private sector in higher
education. It is argued that it may not be appropriate to think of the `university of the future' in terms of current public
sector and quasi public sector institutions, but rather in terms of an emporium, based on an international trade in educational
services, and with the `University' as we now understand it occupying the functions of licensing, quality assurance and cultural
custodianship.
Accepted: 25 June 2002 相似文献