基于DXF文件的自由曲面可视化

三维数据的可视化问题是计算机图形学、计算机辅助设计、计算机视觉等领域的重要课题。论文提出了一种基于DXF文件的编程方法,将由视觉传感器测得的三维数据转为DXF格式,交由逆向工程软件快捷地实现可视化的方法。初步探讨了视觉检测过程中的自适应采样问题。     

An optical sensor for hydrogen sulfide detection in open path using WMS-2f/1f technique

An optical hydrogen sulfide (H2S) sensor based on wavelength modulation spectroscopy with the second harmonic (2f) corrected by the first harmonic (1f) signal (WMS-2f/1f) is developed using a distributed feedback (DFB) laser emitting at 1.578 µm and a homemade gas cell with 1-m-long optical path length. The novel sensor is constructed by an electrical cabinet and an optical reflecting and receiving end. The DFB laser is employed for targeting a strong H2S line at 6 336.62 cm-1 in the fundamental absorption band of H2S. The sensor performance, including the minimum detection limit and the stability, can be improved by reducing the laser intensity drift and common mode noise by means of the WMS-2f/1f technique. The experimental results indicate that the linearity and response time of the sensor are 0.999 26 and 6 s (in concentration range of 15.2—45.6 mg/m3), respectively. The maximum relative deviation for continuous detection (60 min) of 30.4 mg/m3 H2S is 0.48% and the minimum detection limit obtained by Allan variance is 79 μg/m3 with optimal integration time of 32 s. The optical H2S sensor can be applied to environmental monitoring and industrial production, and it has significance for real-time online detection in many fields.     

一种三维数据的可视化方法

本文提出了一种基于DXF文件编程的三维数据可视化方法将由视觉传感器测得的三维数据转换为DXF格式,交由逆向工程软件方便地实现可视化.针对实际采样过程,对自由曲面的自适应采样问题进行了初步的探讨,并提出了一种基于导数的自适应采样策略.     

基于单幅图像三维形貌恢复测量不确定度分析

基于单幅图像三维形貌恢复的研究尚未进行系统的测量不确定度分析.文章在已获得的三维测量结果的基础上,提出并使用了“全面像素不确定度评价方法”,改变传统的以物体关键部位不确定度代替全貌不确定度的评价方法,将被检三维物体形貌恢复结果的每个像素,均参与到测量不确定度评价过程中.通过全面测量不确定度的研究可以全面了解三维形貌恢复的状况,有助于进行精度的改进,并可根据精度分布状况,进行有针对性的测量.     

3D defect detection of connectors based on structured light

In order to realize the rapid detection of three-dimensional defects of connectors, this paper proposes a method for detecting connector defects based on structured light. This method combines structured light with binocular stereo vision to obtain three-dimensional data for the connector. Point cloud registration is used to identify defects and decision trees are used to classify defects. The accuracy of the 3D reconstruction results in this paper is 0.01 mm, the registration accuracy of the point cloud reaches the sub-millimeter level, and the final defect classification accuracy is 94%. The experimental results prove the effectiveness of the proposed three-dimensional connector defect detection method in connector defect detection and classification.     

A non-contact gear measurement method based on laser vision

In order to classify the gears and achieve high precision measurement results, a non-contact gear measurement system based on the laser vision is developed in this paper. The laser vision precision measurement method （LVPMM） is pro- posed to ensure the accuracy. Experimental results indicate that the gear measuring uncertainty is 2.1 /am. The preci- sion can satisfy the gear measurement requirements for two-grade or under two-grade standard gears in industry, and can classifv the gears very well     

Fast 3D reconstruction of dental cast model based on structured light

To quickly obtain accurate 3D data of dental cast model, this paper proposes a 3D reconstruction method for dental cast model based on structured light. This method combines the structured light with the motor turntable to obtain a group of 3D data for the dental cast model from multiple angles, and automatically registers the dental 3D data from multiple angles through the ball calibration of turntable. Compared with the real data of the dental cast model, the maximum error of the 3D reconstruction results in this paper is 0.115 mm. The reconstruction time of this process is about 130 s. The experimental results show that the method has high precision and high scanning speed for the 3D reconstruction of the dental cast model.     

单幅图像形貌恢复在三维数字加工中的应用

仅仅根据一幅照片,就可得到照片内物体每个像素点的三维形貌数据.并可将这些三维数据应用到三维数字加工中,拓宽了数字加工的范围.     

基于三维光学信息的人体姿态快速测量

汽车中人体姿态三维测量对汽车座椅设计的舒适性评价具有重要的意义。为了快速准确地获取车内人体三维数据,文中采用一种基于双目视觉的立体三维数据获取方法,该方法将结构光与标记点相结合,实现了人体三维点云快速重建以及三维姿态(距离、角度)自动快速测量。实验结果表明,该方法在距离2 m以上,测量范围1.5 m×2 m时,人体姿态测量精度可以达到0.03 mm,满足了汽车人体姿态高精度三维数据采集的需求。与传统的汽车人体姿态三维测量方法相比,文中所使用的三维自动测量方法不仅自动化程度高,而且具有测量精度高、速度快、鲁棒性强的优点。     

Quantitative analysis of multicomponent mud logging gas based on infrared spectra

This work deals with quantitative analysis of multicomponent mud logging gas based on infrared spectra. An accurate analysis method is proposed by combining a genetic algorithm (GA) and a radial basis function neural network (RBFNN). The GA is used to screen the infrared spectrum of the mixed gas, while the selected spectral region is used as the input of the RBFNN to establish a calibration model to quantitatively analyze the components of logging gas. The analysis results demonstrate that the proposed GA-RBFNN performs better than FS-RBFNN and ES-RBFNN, and our proposed method is feasible.