Real-time visual sensing system achieving high-speed 3D particle tracking with nanometer resolution.
Real-time visual sensing system achieving high-speed 3D particle tracking with nanometer resolution.
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DOI：
10.1364/ao.52.007530
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发表时间：
2013-11
期刊：
影响因子：
1.9
通讯作者：
Peng Cheng;S. Jhiang;C. Menq
中科院分区：
文献类型：
--
作者：
Peng Cheng;S. Jhiang;C. Menq
本文提出了一种实时视觉传感系统，旨在以纳米分辨率实现水溶液中微小球形颗粒的高速三维（3D）运动跟踪。该系统包括互补金属氧化物半导体（CMOS）相机、现场可编程门阵列（FPGA）和实时图像处理程序。 CMOS相机具有高感光度和优越的信噪比。它在标准 100 W 卤素灯白光照明下以高达每秒 10,000 帧 (fps) 的帧速率获取 128×120 像素的图像。实时图像流从相机直接下载到 FPGA，其中实施 3D 粒子跟踪算法来实时计算目标粒子的 3D 位置。实现了两个重要目标，即实时估计 3D 位置与相机的最大帧速率相匹配，以及精确控制系统输出数据流的时序。进行了两组实验来验证系统的性能。首先，视觉传感系统用于跟踪 2 μm 聚苯乙烯珠的运动，其运动由三轴压电运动台控制。展示了在所有三个轴上以纳米分辨率跟踪长距离运动的能力。其次，它用于测量 2 μm 聚苯乙烯珠的布朗运动，该珠通过激光捕获系统稳定在水溶液中。
This paper presents a real-time visual sensing system, which is created to achieve high-speed three-dimensional (3D) motion tracking of microscopic spherical particles in aqueous solutions with nanometer resolution. The system comprises a complementary metal-oxide-semiconductor (CMOS) camera, a field programmable gate array (FPGA), and real-time image processing programs. The CMOS camera has high photosensitivity and superior SNR. It acquires images of 128×120 pixels at a frame rate of up to 10,000 frames per second (fps) under the white light illumination from a standard 100 W halogen lamp. The real-time image stream is downloaded from the camera directly to the FPGA, wherein a 3D particle-tracking algorithm is implemented to calculate the 3D positions of the target particle in real time. Two important objectives, i.e., real-time estimation of the 3D position matches the maximum frame rate of the camera and the timing of the output data stream of the system is precisely controlled, are achieved. Two sets of experiments were conducted to demonstrate the performance of the system. First, the visual sensing system was used to track the motion of a 2 μm polystyrene bead, whose motion was controlled by a three-axis piezo motion stage. The ability to track long-range motion with nanometer resolution in all three axes is demonstrated. Second, it was used to measure the Brownian motion of the 2 μm polystyrene bead, which was stabilized in aqueous solution by a laser trapping system.