双光路对称补偿的激光三角法位移测量系统

发布时间：2018-04-16 11:23

本文选题：激光三角法 + 双光路　；参考：《浙江大学》2017年硕士论文

【摘要】：激光三角测距法作为一种较新型的非接触式的位移测量技术,目前常被应用于各领域工业自动化生产中。本文针对传统的激光三角位移测量方法在测量不均匀表面时的成像光斑畸变问题,提出了双光路对称补偿的激光三角法位移测量方法,该方法可有效补偿单光路成像的不足,提高系统的抗干扰能力和测量精度。最终研制出实验样机,标定和比对试验的结果表明,系统在±3mm的量程中,采样频率为88KHz,线性度为±0.13%F.S.,重复精度为1μm,相关参数达到了设计目标。论文的主要工作内容如下:1、阐述激光三角测量方法的基本背景,分析相关技术的国内外研究现状,阐述激光三角位移测量方法的基本工作原理及激光光斑中心亚像素定位方法。本文利用灰度质心法来确定光斑中心位置,该方法精度较高,计算复杂度较低,易于硬件语言编程实现。2、提出双光路对称成像的光路结构,设计准直聚焦镜头和成像镜头,完成系统的机械设计。系统采用双远心境头作为激光光斑的成像镜头,其对微小的物距和像距变化均不敏感,能较好地消除被测物体成像的畸变,使得被测物体的位置发生改变时,图像传感器感光面上接收到的光斑图像的成像大小和形状保持稳定。3、设计基于ARM微控制器的激光二极管驱动控制电路,应用PID控制方法实现激光功率针对不同发射率表面的自适应控制;设计基于FPGA的高速数据采集电路,实现图像传感器上光斑图像的亮度与位置信息的获取与处理;使用MATLAB实现与测量设备的通信与数据分析处理。4、通过标定实验,确定系统的测量性能参数,并与KEYENCE的LK-G30传感器进行比对测试。
[Abstract]:As a new non-contact displacement measurement technique, laser triangulation is widely used in various fields of industrial automation.In this paper, aiming at the problem of spot distortion in the traditional laser triangulation displacement measurement method for measuring uneven surfaces, a laser triangulation displacement measurement method with symmetrical compensation of double optical paths is proposed, which can effectively compensate for the shortcomings of single optical path imaging.Improve the anti-interference ability and measurement accuracy of the system.The results of calibration and comparison tests show that the system has a sampling frequency of 88kHz, a linearity of 卤0.13F.S. and a repetition accuracy of 1 渭 m in the range of 卤3mm. The related parameters reach the design goal.The main work of this paper is as follows: 1. The basic background of laser triangulation measurement method, the research status of related technology at home and abroad, the basic working principle of laser triangulation displacement measurement method and the sub-pixel location method of laser spot center are expounded.In this paper, the center of light spot is determined by gray centroid method. This method has the advantages of high precision, low computational complexity and easy to be realized by hardware programming. The optical path structure of symmetrical imaging with double optical paths is proposed, and the collimation focusing lens and imaging lens are designed.Complete the mechanical design of the system.The system uses double remote motif head as the imaging lens of laser spot, which is insensitive to the small object distance and the change of image distance, which can eliminate the distortion of the image of the object under test and make the position of the object under test change.The image size and shape of the spot image received on the photosensitive surface of the image sensor remain stable. 3. The laser diode drive control circuit based on ARM microcontroller is designed.The PID control method is applied to realize the adaptive control of laser power for different emissivity surfaces, and the high-speed data acquisition circuit based on FPGA is designed to obtain and process the luminance and position information of the spot image on the image sensor.MATLAB is used to realize the communication and data analysis with the measuring equipment. Through the calibration experiment, the measurement performance parameters of the system are determined and compared with the LK-G30 sensor of KEYENCE.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TH744.5

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