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介绍了一种高分辨率宽频域方波脉冲的产生方法。用此方法设计的方波脉冲发生器使用方便.灵活。它不用变档即可实现高低不同频域方波脉冲的控制,且具有较高的分辨率,可实用于具有特殊要求的步进电动机驱动控制系统中。 相似文献
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鉴于多/高光谱遥感数据同源同点多波段同时获取的特点,提出了基于灰度级差关联概率矩阵
( Gray Level Difference Associated Possibility matrix.GLDAP)的视觉差异分析方法,以有效地利用图像底层数
据及数据之间的相关性.根据地物的波谱特性,统计两波段图像灰度协同变化的规律并记录在GLDAP矩阵
中,基于此矩阵提取了遥感数据的类立体纹理特征.将该方法与灰度共生矩阵( GLCM)纹理分析方法的遥感
地物分类性能比较,实验结果表明:基于GLDAP的纹理提取及分析表现出良好的性能,3种地物分类效果
明显优于GLCM方法,能够减少因单波段中地物可分性差而导致的误识,克服了GLCM方法对图像统计描述
的局限性,在相同时间开销下GLDAP右法较GLCM有更优的解译分析精度 相似文献
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Virtual test system for permanent—magnet DC motor 总被引:1,自引:0,他引:1
In order to obtain the primary parameters and operating characteristics of a DC motor without directly measuring its torque and rational speed,it is proposed to use a PC and a data acquisition card to acquire both the dynamic and static data of armature current to establish the performance of a DC permanent-magnet motor.The accuracy and validity of this virtual test system proposed were verifield by comparing the measurements made with the system proposed with the measurements made with conventional torque meters.It is concluded from the results of comparison that from the mathematic model established for the DC permant-magnet motors,both major parameters and operating characteristics can be directly established for the DC motors without measuring their torques and rotational speed,a perfect on-line measurement and test system has been established for the DC permanent-magnet motors using the theory of virtual test system.The system proposed feature shorter test time,higher efficiency and lower cost. 相似文献
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分析了HB型步进电动机迭步铁心对电机性能的影响,提出了等效模型修正法,及在转子永磁体两侧设置适当厚度的高导磁材料的块状轭铁和采用轴向补偿线圈等提高转矩的对策,并实验验证了方法的有效性。 相似文献