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分析了一种百纳米级位移分辨率的双级衍射光栅测量系统, 建立了衍射叠栅(莫阿)信号与对应位移的数学模型, 并通过计算机仿真对叠栅信号的位移特性进行了研究。在此基础上设计了一套基于双级衍射光栅的精密定位装置, 利用两组衍射光栅, 取其透射零次激光叠栅信号的差信号为控制信号, 由微机控制实现高精度位置检测及精密自动定位。系统采用的差动光栅技术, 极大地提高了位置检测信号的灵敏度及定位精度。通过粗定位和精定位相结合的两段式复合定位, 可在高精度定位的同时, 缩短定位时间, 实现高速高精度定位。实验结果表明, 基于衍射光栅的精密定位装置可获得±0.5 μm的定位精度, 对精密加工工程领域具有重要的实用价值。 相似文献
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为满足半导体精密设备步进速度和精度的控制要求,步进运动轨迹应具备精度高、冲击小、速度快等特征。根据其运动轨迹特征,设计出四阶S型运动轨迹规划算法,但在实际应用中,一种轨迹规划通常并不能完全覆盖所有的使用场景。为实现能够根据实际需求提前停止的运动轨迹,在四阶运动轨迹基础上,通过使用轨迹拼接的方式设计出平滑停止算法。根据测试结果,四阶运动轨迹可以根据外部触发信号在任意时刻转为平滑停止轨迹,达到快速停止的目的,且轨迹不会产生额外的冲击力,确保了四阶运动轨迹原有的特征。 相似文献
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当前涂胶机器人存在不够智能、新工件涂胶路径设定较复杂等缺点。针对此,通过引入数字摄像技术和图像信息处理技术实现图像的实时捕获;将获取图像转换成匹配特征矢量,与标准图库进行比较,通过相似性正确判断工件型号;通过零件骨架提取和零件骨架拟合,实现零件信息矢量化;结合NC代码生成技术,实现自动产生喷头行走轨迹的NC代码;在涂胶过程中应用视觉伺服,把视觉系统嵌入涂胶机器人系统的反馈回路中,实现机器人高精度控制;在图像信息中提取胶线曲线,用形态学的方法细化胶线曲线,提取胶线骨架信息,判断胶线闭合性,检测胶线的质量。实验证明,所设计的算法效率较高,所研制的系统功能强、效果好。 相似文献
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数控机床加工零件,通常在零件加工后采用另外的仪器进行加工误差测量,重复装夹必然造成精度降低和工时延长.数控机床通过控制走刀路径使其按照特定轨迹运动,因此工件的加工误差可通过测量轨迹误差得到.文中运用非均匀B样条曲线拟合及曲线特征点提取的方法,将测量轨迹与理想轨迹进行拟合实现工件加工误差的在机测量.通过在数控机床上试验一直线圆弧样品加工验证了该方法的可行性. 相似文献
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本文介绍了一种基于32位高性能处理器的视觉精密测量系统的软硬件设计.图像传感器采集的条码图像通过精密定位算法得到绝对位移值,由以太网接口实现高速图像采集.该系统适用于高精度定位的各种位移测量. 相似文献
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提出一种用光纤传感器测量高速旋转构件微小位移量的新方法,实现了非接触式高速、高精度的位移测量。在介绍光纤传感器测量原理的基础上,得出光强与测距之间关系式。将光强转为电压信号,建立电压商值与测距之间的拟合公式。设计V带参数测量实验台,对V带稳定运转时其在轮槽中的径向位移进行测定,进而得出V带在带轮中的轨迹,测量出滑动角的大小。针对原有V带滑动角计算公式中的不足进行优化,得出新的滑动角计算公式。对比实验结果,新公式更接近实验结果,误差更小,为V带的精确设计提供理论依据。 相似文献
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《Mechatronics》2023
The high-speed rotating machinery equipped with active magnetic bearings (AMBs) always suffers from rotor unbalance and displacement sensor runout, which produce periodic fluctuations in current and cause power amplifier saturation and severe harmonic vibration. The harmonic vibration suppression, especially under variable rotational speed, requires the speed information, but the problem of no installation conditions for speed measurement sensors in some applications may rise with conventional suppression approaches. This paper presents a novel multi-notch filters (MNFs) method with frequency estimator to suppress the harmonic vibration. Firstly, the harmonic vibration dynamic modeling is described and the expressions of current and vibration force affected by harmonic displacement disturbance are obtained. The structure and notch characteristic of the MNFs are then presented, the frequency estimator based on one single channel displacement signal is developed and its convergence is analyzed. Moreover, the stability of the whole system with MNFs is investigated and the compensation phases are implemented according to system identification to maintain the closed-loop stability. Simulation and experiments are conducted on an AMB-rotor setup and validate the effectiveness of the proposed method on eliminating the harmonic current and suppressing the harmonic vibration under the variable rotational speed. 相似文献
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An intelligent maximum power extraction algorithm for inverter-based variable speed wind turbine systems 总被引:17,自引:0,他引:17
Quincy Wang Liuchen Chang 《Power Electronics, IEEE Transactions on》2004,19(5):1242-1249
This paper focuses on the development of maximum wind power extraction algorithms for inverter-based variable speed wind power generation systems. A review of existing maximum wind power extraction algorithms is presented in this paper, based on which an intelligent maximum power extraction algorithm is developed by the authors to improve the system performance and to facilitate the control implementation. As an integral part of the max-power extraction algorithm, advanced hill-climb searching method has been developed to take into account the wind turbine inertia. The intelligent memory method with an on-line training process is described in this paper. The developed maximum wind power extraction algorithm has the capability of providing initial power demand based on error driven control, searching for the maximum wind turbine power at variable wind speeds, constructing an intelligent memory, and applying the intelligent memory data to control the inverter for maximum wind power extraction, without the need for either knowledge of wind turbine characteristics or the measurements of mechanical quantities such as wind speed and turbine rotor speed. System simulation results and test results have confirmed the functionality and performance of this method. 相似文献
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Jiandong Duan Shaogui Fan Kai Zhang QunTao An Li Sun Guanglin Wang 《International Journal of Electronics》2013,100(9):1562-1577
By analysing the loss model of high-speed permanent magnet synchronous generator (PMSG), the analytic formula of loss using quadrature–direct axis current and speed is established. It shows that the total loss is concave function with respect to d-axis current and speed so that the mathematical method of solving the extreme value can be applied and then the explicit expression of the two independent variables direct axis current and the speed at the minimum loss point can be achieved. Considering the effect of the maximum current limitation of the hardware circuit on the system speed operation mode, the minimum loss speed and direct current integrated control strategy are raised. The results show that compared with the traditional algorithm, the algorithm has obvious advantages, and the efficiency of the algorithm is improved by 16.91% compared with the traditional algorithm. 相似文献
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高速机动目标会在短时间内跨越距离单元(Range Migration, RM),并且由于目标机动性产生跨多普勒单元(Doppler Spread, DS)等问题。基于搜索的传统处理算法通过时间和计算量换取积累性能,不利于工程应用。本文提出一种通过分段处理方式对回波进行相参积累的算法。该算法在保证子片段内回波RM和DS问题可以忽略的前提下,将积累时间划分为若干个子片段。在该分段准则下通过Radon-Fourier Transform(RFT)对子片段进行处理。随后,根据各子片段RFT积累峰值位置分布特性和相位差异,设计一种子片段间的相参积累方案,实现多个子片段间峰值能量的相参积累。所提算法在子片段内可以忽略目标机动性的影响,避免了子片段内目标机动参数(加速度项)的搜索,可在积累性能和计算效率之间取得良好平衡。 相似文献
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针对试验中高速摄像技术在远距离测量振动响应精度较低的问题,提出结合双三次 插值法与Sobel算子边缘检测图像技术的方法,用其处理测得图像来提高测量精度。首先,设计了采 用高速摄像与加速度计两种测量系统的管系振动台试验。然后,对高速摄像系统测得的图像 与加速度计测得的加速度振动响应进行处理并提取位移振动响应数据。最后,从时域和频域 两个角度对比高速摄像与加速度计两种测量系统测得的位移振动响应数据,对高速摄像系统 测得数据的准确性进行分析。结果表明,结合双三次插值法与Sobel算子边缘检测图像处理 技术优化高速摄像技术测得的图像可以获得满足测量与使用要求的高精度位移振动响应数 据。 相似文献
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In order to change the path candidates, reduce the average list size, and make more paths pass cyclic redundancy check (CRC), multiple CRC-aided variable successive cancellation list (SCL) decoding algorithm is proposed. In the decoding algorithm, the whole unfrozen bits are divided into several parts and each part is concatenated with a corresponding CRC code, except the last part which is concatenated with a whole unfrozen CRC code. Each CRC detection is performed, and only those satisfying each part CRC become the path candidates. A variable list is setup for each part to reduce the time complexity. Variable list size is setup for each part to reduce the time complexity until one survival path in each part can pass its corresponding CRC. The results show that the proposed algorithm can reduce the average list size, and the frame error rate (FER) performance, and has a better performance with the increase of the part number. 相似文献
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一种改进的变步长LMS自适应算法 总被引:1,自引:0,他引:1
为了提高LMS自适应算法的性能,在对一些变步长LMS算法分析的基础上,提出了步长因子μ(n)与误差信号e(n)之间一种新的非线性函数关系,该算法比固定步长LMS算法收敛速度快,稳定性好,另外与文[5]中算法相比,不需要进行指数运算.将该算法应用于自适应噪声抵消系统的仿真中,计算机仿真结果与实际分析相一致. 相似文献
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针对OFDM系统中传统信道估计算法在冲击噪声环境中性能急剧下降的问题,提出了一种基于韦伯分布函数的顽健型变步长符号算法进行信道估计。在深入研究冲击噪声特性及韦伯分布函数性质的基础上,提出了采用估计误差绝对值的韦伯分布函数控制步长的低复杂度变步长符号算法。该算法在利用传统符号算法顽健性的基础上,采用估计误差的韦伯分布函数动态地改变迭代符号算法的步长,从而能够以较低的复杂度提高变步长符号算法在冲击噪声环境中的收敛速度。算法复杂度分析及仿真结果表明,在冲击噪声环境下所提算法相较于传统自适应滤波信道估计算法能够以更低的复杂度、更快的收敛速度达到相同的信道估计均方误差。 相似文献