共查询到19条相似文献,搜索用时 156 毫秒
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基于脉动阵列的自适应光学实时波前处理机设计 总被引:1,自引:0,他引:1
针对自适应光学系统对波前处理机高计算量、高实时性的要求,本文提出了一种基于脉动阵列的自适应光学实时波前处理方法.该方法将脉动阵列的概念引入波前处理机设计,完成了波前斜率计算、复原运算和控制运算向脉动阵列的映射,合理地建立了数据的深度流水线,同时分析了以FPGA技术实现时系统的计算延时.对于48个子孔径,61单元的自适应光学系统,以一片Xilinx Virex-Ⅱ XC2V3000芯片实现了基于脉动阵列的实时波前处理机,实验测得计算延时仅8.6μs,结果表明该方法能极大地提高系统的实时性,集成度、通用性和扩展性. 相似文献
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37单元自适应光学系统实时波前处理 总被引:1,自引:0,他引:1
讨论了37单元自适应光学系统中子孔径排布、CCD相机的图象输出方式及波前处理算法的特点,并介绍了针对系统中帧频为380/秒的波前探测器研制的用5片TMS320C25并行处理的、峰值运算速度达1亿次/秒的高速数字处理器-波前处理机的原理和实现。该机对一帧图象的采集和处理延时为3.4ms。 相似文献
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本文叙述了超声波全息成像的数学模型、超声远场波分布的记录方法,以及从数字图像复原和增强的观点,给出了复原起声图像的最佳估计模型与算法。文中还例举了一个小型超声全息记录成像系统,分析了其主要参数的作用。实验过程中得到了很好的原始数据与复原的图象,并给出了处理的图片。 相似文献
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通过对软件无线电体系结构中的实时操作系统的分析,选用了性能可靠、实时性好的VxWorks作为系统的实时操作系统.然后构建了基于多DSP处理器4通道软件无线电硬件平台.使软件无线电的运算能力达到12 000 MFLOPS,很好地满足了系统的运算速度的要求.整个系统具有处理数据量大、传输速度快、实时性好、可扩展性好等诸多优点. 相似文献
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基于绝对差分算法的相关HS波前处理机设计 总被引:2,自引:1,他引:1
在太阳自适应光学系统中,通常采用绝对差分或者互相关因子算法进行哈特曼波前探测.本文给出了一种基于绝对差分算法的相关HS(Hartmann-Shack)波前处理机的设计结果.针对子孔径阵列呈6×6方形排布,单个子孔径大小为32 pixels×32 pixels,参考模板大小为16 pixels×16 pixels的相关HS渡前传感器,采用绝对差分算法在单片FPGA内实现了对波前的实时处理.实验结果表明,该处理机峰值运算量超过230亿次/s,系统延时120μs,能够满足1 000 Hz的CCD采样要求.本设计在单片FPGA内实现,具有成本低、易维护、集成度高的特点. 相似文献
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We propose a new recursive filtering algorithm for wave-front reconstruction in a large-scale adaptive optics system. An embedding step is used in this recursive filtering algorithm to permit fast methods to be used for wave-front reconstruction on an annular aperture. This embedding step can be used alone with a direct residual error updating procedure or used with the preconditioned conjugate-gradient method as a preconditioning step. We derive the Hudgin and Fried filters for spectral-domain filtering, using the eigenvalue decomposition method. Using Monte Carlo simulations, we compare the performance of discrete Fourier transform domain filtering, discrete cosine transform domain filtering, multigrid, and alternative-direction-implicit methods in the embedding step of the recursive filtering algorithm. We also simulate the performance of this recursive filtering in a closed-loop adaptive optics system. 相似文献
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Multilevel quality-guided phase unwrapping algorithm for real-time three-dimensional shape reconstruction 总被引:1,自引:0,他引:1
A multilevel quality-guided phase unwrapping algorithm for real-time 3D shape measurement is presented. The quality map is generated from the gradient of the phase map. Multilevel thresholds are used to unwrap the phase level by level. Within the data points in each level, a fast scan-line algorithm is employed. The processing time of this algorithm is approximately 18.3 ms for an image size of 640x480 pixels in an ordinary computer. We demonstrate that this algorithm can be implemented into our real-time 3D shape measurement system for real-time 3D reconstruction. Experiments show that this algorithm improves the previous scan-line phase unwrapping algorithm significantly although it reduces its processing speed slightly. 相似文献
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Justh EW Vorontsov MA Carhart GW Beresnev LA Krishnaprasad PS 《Journal of the Optical Society of America. A, Optics, image science, and vision》2001,18(6):1300-1311
A wave-front control paradigm based on gradient-flow optimization is analyzed. In adaptive systems with gradient-flow dynamics, the output of the wave-front sensor is used to directly control high-resolution wavefront correctors without the need for wave-front phase reconstruction (direct-control systems). Here, adaptive direct-control systems with advanced phase-contrast wave-front sensors are analyzed theoretically, through numerical simulations, and experimentally. Adaptive system performance is studied for atmospheric-turbulence-induced phase distortions in the presence of input field intensity scintillations. The results demonstrate the effectiveness of this approach for high-resolution adaptive optics. 相似文献
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基于DSP技术的钢管内直径及内表面检测 总被引:2,自引:0,他引:2
提出了一种新的检测钢管内直径及内表面质量的方法。该方法采用高分辨力面阵CCD成像, 通过数字信号处理(DSP)系统进行图像采集,图像处理及计算。该方法速度快,精度高,实时性好,可以有效地检测钢管内表面的各种缺陷及钢管内直径。采用像素细分技术,测量精度可达0.05mm。 相似文献
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We study the performance of an adaptive optics (AO) system with four laser guide stars (LGSs) and a natural guide star (NGS). The residual cone effect with four LGSs is obtained by a numerical simulation. This method allows the adaptive optics system to be extended toward the visible part of the spectrum without tomographic reconstruction of three-dimensional atmospheric perturbations, resolving the cone effect in the visible. Diffraction-limited images are obtained with 17-arc ms precision in median atmospheric conditions at wavelengths longer than 600 nm. The gain achievable with such a system operated on an existing AO system is studied. For comparison, performance in terms of achievable Strehl ratio is also computed for a reasonable system composed of a 40 x 40 Shack-Hartmann wave-front sensor optimized for the I band. Typical errors of a NGS wave front are computed by use of analytical formulas. With the NGS errors and the cone effect, the Strehl ratio can reach 0.45 at 1.25 microm under good-seeing conditions with the Nasmyth Adaptive Optics System (NAOS; a 14 x 14 subpupil wave-front sensor) at the Very Large Telescope and 0.8 with a 40 x 40 Shack-Hartmann wave-front sensor. 相似文献