Metrology & Measurement Technology, Volume. 45, Issue 3, 45(2025)
Design and implementation of high precision laser self⁃focusing control system
Fig. 5. Simulation results of focused diffuse spots in the 635 nm band at different measurement distances
Table 1.
Specification parameters for stepper motors and motor drivers View tableView in ArticleTable 1.
Specification parameters for stepper motors and motor drivers 参数 电压 外形尺寸 步距角 / 细分设定 保持力矩 步进电机 2.5 V 21 mm × 21 mm × 28 mm 1.8° ≥ 0.12 kgf·cm 电机驱动器 18 ~ 40 V直流电压 55 mm × 86 mm × 21 mm 128细分（二进位） -
Table 2.
Core components list of self⁃focusing control system View tableView in ArticleTable 2.
Core components list of self⁃focusing control system 组件名称 型号规格 核心参数描述 指示激光器（可见光） 635 nm红光激光模块 输出功率60 mW
连续模式
用于目标对准与聚焦辅助
成像相机组件 CMOS ICR一体机芯 帧率 ≥ 20 f / s
30倍光学变焦
变焦镜组 前端镜组、动镜组、后置镜组 聚焦光斑尺寸：衍射极限
通光直径 ≥ 40 mm
镜组长度 ≤ 200 mm
设计波长：635 nm
步进电机 + 丝杆模组 21 mm × 21 mm × 28 mm 步距角：1.8°
最小控制步距：5 μm
保持力矩 ≥ 0.12 kgf·cm
导程：0.050"
螺杆直径：4.78 mm
光栅尺及编码器（位置反馈） RESOLUTE绝对式光栅 + 编码器 分辨力1 nm
测量速度100 m / s
控制器 树莓派 + 步进电机驱动模块 支持脉冲⁃方向 / 双脉冲控制
通信接口支持RS485 / UART
支持光电隔离输入
Table 3.
Theoretical size of laser spot at different working distances View tableView in ArticleTable 3.
Theoretical size of laser spot at different working distances 工作距离 / m 束腰光斑直径 / μm 0.5 19.4 1 38.7 3 116.2 5 193.7 10 387.4 30 1 162.1 60 2 324.1
Table 4.
Dispersion spot diameter and theoretical value of light spot at different working distances View tableView in ArticleTable 4.
Dispersion spot diameter and theoretical value of light spot at different working distances 工作距离 / m 理论直径 / mm 弥散斑直径 / mm 0.5 0.019 0.002 1 0.039 0.008 3 0.116 0.007 5 0.194 0.024 10 0.387 0.067 30 1.162 0.240 60 2.324 0.499
Table 5.
635 nm laser spot parameters at different working distances View tableView in ArticleTable 5.
635 nm laser spot parameters at different working distances 测试点 / m 光束宽度X / µm 光束宽度Y / µm 椭圆率 质心偏移量 / μm 1.95 210.35 250.70 0.83 0.00 14.95 540.82 600.51 0.90 19.60 20.95 770.46 880.12 1.04 34.50 26.95 1 160.00 1 165.00 0.94 41.80 32.95 1 500.25 1 410.33 0.81 62.70
Table 6.
Laser spot parameters in different states View tableView in ArticleTable 6.
Laser spot parameters in different states 状态 光束宽度X / px 光束宽度Y / px 等效束腰直径 / px 椭圆率 Tenengrad清晰度 失焦1 87.23 99.13 92.99 1.136 1.27 × 107 失焦2 70.32 75.17 72.70 1.069 2.48 × 107 失焦3 61.78 63.89 62.83 1.034 3.04 × 107 失焦4 39.36 39.12 39.24 0.994 4.18 × 107 聚焦 24.38 24.96 24.67 0.977 7.26 × 107
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Jiangping WANG, Chunbo ZHAO, Yu ZHANG, Danni MA. Design and implementation of high precision laser self⁃focusing control system[J]. Metrology & Measurement Technology, 2025, 45(3): 45
Category: New Techniques for Precision Measurement
Received: Mar. 19, 2025
Accepted: --
Published Online: Jul. 31, 2025
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