Design of a Laser Spot Centroid Detection System Based on NIR CMOS
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摘要: 为实现在复杂背景光照条件下具有较高的光斑探测灵敏度,高精度的坐标计算,及大于1000 fps的结果输出速度,介绍了一种基于近红外CMOS图像传感器,实时计算光斑质心坐标并输出的系统。设计使用安森美半导体公司的Python1300系列近红外图像传感器NOIP1FN1300A对激光光斑成像。利用Cyclone4系列低功耗FPGA对传感器进行驱动和解串,应用可靠的质心算法实时计算光斑坐标。结果输出部分分别采用USB2.0和RS422接口实时输出目标图像和质心坐标。该设计最终具有1500 fps的实时处理能力,软件代码简洁,质心坐标计算精确,系统功耗低等优点。Abstract: To meet the requirements of high detection sensitivity, high-precision calculation of spot coordinates, and a calculated output speed greater than 1000 fps, this study introduces a system based on a near-infrared CMOS image sensor to calculate and output centroid coordinates in real time. We employed the NIR detector NOIP1FN1300A of the Python1300 series produced by the company ONsemiconductor to image the laser spot. The Cyclone4 series low-power FPGA was used to drive the sensor and deserialize the sensor output data, and a reliable centroid algorithm was used to calculate the spot coordinates. The results in the output part, USB2.0, and RS422 interfaces were used to output the target image and centroid coordinates in real time. The design has the following advantageous features: 1500 fps real-time processing capacity, a concise software code, accurate calculation of centroid coordinates, and low-power consumption.
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Key words:
- image sensor /
- FPGA /
- near-infrared /
- spot coordinates
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表 1 NOIP1FN1300A传感器性能
Table 1. Performance of NOIP1FN1300A sensor
Resolution 1280×1024 Pixel size 4.8μm×4.8μm Frame rate
210/165fps@SXGA(ZROT/NROT) 815/545fps@VGA(ZROT/NROT) Analog-to-digital converter(ADC) 10-bit Configuration interface SPI Output format 4 LVDS data channels Power supply 3.3V and 1.8V Dark temporal noise < 9e-(Normal ROT,1× gain) Dark signal 5e-/s,0.5LSB10/s @20℃ Clock rate Master clock 72MHz Max LVDS clock 360MHz Max LVDS data rate 720Mbps Max 表 2 坐标输出结果
Table 2. Coordinate output
X-axis Y-axis 1 1196.36 147.12 2 1196.36 147.13 3 1196.36 147.12 4 1196.35 147.12 5 1196.36 147.12 6 1196.35 147.13 7 1196.35 147.13 8 1196.35 147.12 9 1196.36 147.13 10 1196.36 147.12 -
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