共查询到19条相似文献,搜索用时 187 毫秒
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《仪表技术与传感器》2017,(10)
针对有感无刷直流电机中测速周期长、精度低、硬件电路复杂等问题,文中给出了一种滚动测速与软件倍频相结合的改进测速方法。在分析霍尔传感器测速原理的基础上,采用软件编程实现霍尔信号输出六倍频处理,以提高测速分辨率、提高可移植性;采用滚动测速法实现速度检测,可提高系统测速精度、缩短测速时间间隔;进行了系统硬件和软件设计。所设计系统在全自动酶免分析仪上的实验表明,该测速方法精度可达±0.36%。 相似文献
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本文介绍了周期余数法测速的原理,分析了其性能。采用周期余数法的智能测速系统具有相对分辨率高、动态范围宽的特点,可用于各种实时控制系统。 相似文献
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本文提出一种采用单片机和变T测速法的高精度、宽范围速度控制的直流电机数控系统,并带有参数预报的PI速度调节器,使系统在极低速运转时也可选用较高的采样频率,扩大了调速范围,提高了低速控制的稳定性和精度。 相似文献
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樊学能 《机械制造与自动化》2011,(3)
该设计方案以STC12C4052单片机和MOS管组成的H桥为硬件基础而设计的PID算法直流电动机调速系统.STC12C4052单片机能输出两路占空比可控的PWM(脉宽调制)信号,通过改变占空比从而达到直流电动机调速的目的.测速传感器采用霍尔传感器测速,通过单片机中断采集传感器产生的脉冲以实现闭环控制. 相似文献
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This article introduces the development of a Frequency Division Duplexing Long Term Evolution (FDD-LTE) scanning measurement system which can quickly scan FDD-LTE cells and measure the quality of wireless signals. In this system development, a low complexity frame synchronization method is proposed for efficiently reducing the resource usage of the FPGA, and a co-channel cell detection scheme is also proposed and implemented. The success probability of this frame synchronization method is simulated and its effectiveness is verified with experimental testing. By using the co-channel cell detection scheme, co-channel cells can be correctly detected in practical measurement. Experimental testing results show that this FDD-LTE scanning measurement system can detect and measure a cell at a very high speed. The Physical Broadcast Channel (PBCH) decoding function is also included in this scanning measurement system and verified in field testing. Using this scanning measurement system, FDD-LTE system operators can launch the cell coverage measurement more conveniently and speed up the wireless network optimization process. 相似文献
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在某些对测频精度要求较高的场合,如惯导系统的信号测量,人工采用计数器测频法存在着耗时长、更换通道步骤繁琐、测量不方便的缺陷。本文给出一种用FPGA编程替代计数器的自适应测频方法,该方法可在宽频段(0.1Hz-200KHz范围内)实现同时、连续对多个通道快速、高精度测量,并能根据被测频率的变化自动实时输出测量结果,大大简化了测频步骤、节省了测量时间。使用此方法研制的某惯导信号测频系统经实际测量检验精度达到10~(-7)。 相似文献
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针对列车制动防滑系统的速度测量在测量精度和实时性两方面的要求,介绍了一种可变测速时区的速度测量方法.与传统测速方法相比,消除了测速齿轮加工偏差带来的测量误差,提高了测量精度,而且能将高、低速的测量统一于同一个计算公式,编程简单可靠;采用数字信号处理器(DSP)实现该测速功能,提高了速度和减速度的运算速度,满足了防滑控制的实时性要求. 相似文献
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The continuous instantaneous flow field in pump impeller is vital for studying the mechanism of some complex flow phenomenon. In this paper, a high frequency PIV system with maximum sampling frequency 10 k Hz is built and used to measure the continuous flow field in impeller. In order to reduce the minimum sampling frequency required for PIV while ensuring the accuracy of flow field measurement, an image rotation method was proposed for calculating the relative velocity flow field in impeller. This method removed the particle displacement caused by impeller rotation in circumferential direction before the FFT calculation was performed. The relative velocity value calculated by velocity triangle method and image rotation method are compared and analyzed at different sampling line positions for different experimental conditions. The results show the image rotation method can not only obtain a more accurate velocity field near the blade area, but also has a lower requirement for the sampling frequency of the PIV system. The relative velocity error between two methods shows a trend of decreasing and then increasing when the sampling frequency decreases from 10 k Hz to 1 k Hz. Meanwhile, the relationship between the impeller speed and optimal sampling frequency range is established, which provides guidance for the selection of the appropriate PIV sampling frequency used for the measurement of the flow field in impeller. 相似文献
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空间滤波测速法具有结构简单、稳定性好和适用性强等优点,但传统线阵CCD空间滤波测速法要求CCD阵列方向与待测物体的运动方向一致,因此不适合测量复杂的流场。针对这一问题,本文提出了基于面阵CCD相机的空间滤波测速方法。对采集到测量区域的一系列面阵CCD输出图像进行处理,在图像水平方向和垂直方向分别进行隔行采样,模拟多狭缝空间滤波特性,实现了对障碍流颗粒速度的光学非接触式测量。针对复杂流场功率谱密度的特点,利用能量重心校正频谱提高了系统测量精度。通过调节传送带速度对本系统进行标定,实现了不同速度下的流速测量,平均误差小于4%。利用本系统还测量了由玻璃砂模拟的泥石流速度场分布,最后讨论了空间周期和测量时间对测量结果的影响。结果表明,采样时间大于0.5s时,测量结果趋于稳定,空间分辨率最小可达1.28mm。 相似文献
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微机控制电机实时测速系统 总被引:1,自引:0,他引:1
在很多与电机控制相关的工业过程中.都需要有一个在较大速度范围内具有分辨率高、响应快捷准确的测速系统。本文给出了一种AT89S52单片机控制的数字式电机实时测速系统.在实际应用中获得了较好的效果。文中详细介绍了测速系统的基本原理.同时给出了系统的软硬件设计方法。 相似文献
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针对宽口径专业人才培养模式下新的教学要求,从教学内容、教学方法两个方面,阐述了《互换性与技术测量》课程教学改革的思路,提出了优化教学内容、以精度设计作为课程的主线、精讲多练、多媒体与板书结合、网络辅助教学、重视与加强实践环节的教改方法,对提高课程的教学效果和教学品质做了有益的探讨。 相似文献