三轴摄影测量中折射误差修正模型的精度分析  

Accuracy Analysis of Refraction Error Correction Models in Three-axis Photogrammetry

作　　者：张博 牟春梅[1,2] 潘强 李燕霞 阳瑾 ZHANG Bo;MU Chunmei;PAN Qiang;LI Yanxia;YANG Jin(College of Civil Engineering,Guilin University of Technology,Guilin,Guangxi 541004,China;Guangxi Key Laboratory of Geomechanics and Geotechnical Engineering,Guilin,Guangxi 541004,China)

机构地区：[1]桂林理工大学土木工程学院,广西桂林541004 [2]广西岩土力学与工程重点实验室,广西桂林541004

出　　处：《计量学报》2024年第11期1654-1664,共11页Acta Metrologica Sinica

基　　金：广西自然科学基金(2020GXNSFAA297247);南方石山地区矿山地质环境修复工程技术创新中心资助项目(cxzx2020-002)。

摘　　要：摄影测量技术应用于三轴试验可以实现土样变形的非接触式测量,然而该方法的测量精度易受到不同介质的折射影响。为了解决此问题,首先在空气中通过测量平面人工编码点的距离和刚性圆柱体的轴向及径向长度,验证摄影测量法在无折射影响下具有较高的测量精度;但在压力室中光线会受到空气、有机玻璃罩和水等不同介质的折射影响,造成较大的测量误差。为消除折射的影响,将三维折射误差修正模型应用于饱和混合土三轴试验,从轴向和径向对试验结果进行精度分析。试验结果表明:1)折射放大效应对三轴土样轴向测量精度的影响较小,可忽略不计,但对径向测量的影响较大,需进行折射误差修正;2)经误差修正后,三轴土样径向测量值的绝对误差和相对误差分别为0.120 mm和0.59%,表明折射误差修正模型可以提高三轴摄影测量的精度。Photogrammetric technique applied to triaxial test can realize the non-contact measurement of soil sample deformation,however the measurement accuracy of the method is susceptible to the refraction influence of different media.To solve the problem,firstly,the photogrammetric method is verified to have high measurement accuracy without the influence of refraction by measuring the distance of the plane artificial coding points and the axial and radial lengths of the rigid cylinders in air;but the light will be affected by the refraction of different mediums,such as the air,the organic glass cover and water in the pressure chamber,which results in a large measurement error.In order to eliminate the effect of refraction,the three-dimensional refraction error correction model is applied to the triaxial test of saturated mixed soil,and the test results are analyzed for accuracy from axial and radial directions.The test results show that:1)the effect of refraction amplification on the axial measurement accuracy of triaxial soil samples is very small and negligible,but the effect on the radial measurement is larger,which needs to be corrected by the refraction error;2)after the error correction,the absolute and relative errors of the radial measurements of triaxial soil samples are 0.120 mm and 0.59%,respectively,indicating that the refraction error correction model can improve the accuracy of triaxial photogrammetry.

关 键 词：光学计量 摄影测量 土样变形 三轴试验 折射误差修正模型 精度分析 

分 类 号：TB96[机械工程—光学工程]