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In order to reduce the influence of temperature on the image point coordinates of industrial cameras in visual measurement, the image point drift caused by the self-heating of the camera was studied, and a compensation method for the thermal image point drift of industrial cameras was proposed. The finite element simulation analysis of the industrial camera model through Ansys Workbench shows that the self-heating of the industrial camera will cause the imaging optical path change and sensor expansion change, quantitatively the influence of the optical path change and sensor expansion on the image point coordinates was analyzed, and the image point drift compensation model was established. A large number of experiments have shown that the image point drift error compensated by the model is reduced from 0.4-0.6 pixel to 0.1-0.2 pixel, which is equivalent to the image point drift suppression effect achieved by hardware thermal control. However, compared with the thermal control device, the method of using the model for compensation has obvious advantages of simple structure and low cost. The temperature compensation model proposed in this research provides a theoretical basis for reducing the image point drift error caused by the self-heating of the camera in the visual measurement. 相似文献
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在大型风电叶片动态摄影测量中,为了对相机的站位进行优化,采用一种变异操作改进型遗传算法作为摄影测量网络优化方法,通过光线束前方交会的误差传递建立测量误差模型,以空间坐标测量误差的标准差为网络优化的目标,同时根据被测风电叶片几何结构和实际环境确定了相应的约束条件进行仿真实验,得到了最优的相机站位。结果表明,在以叶片长度为40m的风机为被测物的仿真实验中,最优站位的空间坐标测量误差标准差为2.7mm;通过对叶片长度为3.5m的风机模型进行实测实验验证,最优站位的相对测量误差为0.009%,最大误差为0.617mm。该研究为风电叶片摄影测量的网络优化提供了参考。 相似文献
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An optical fiber sensor for strain and temperature measurement based on long period fiber grating (LPFG) cascaded with fiber Bragg grating (FBG) structure has been proposed and realized both theoretically and experimentally. Theoretical analysis shows that two microstructures with similar sensitivities cannot be used for double parameters measurement. The LPFG is micromachined by the CO2 laser, and the FBG is micromachined by the excimer laser. For the validation and comparison, two FBGs and one LPFG are cascaded with three transmission valleys, namely FBG1 valley at 1 536.3 nm, LPFG valley at 1 551.2 nm, and FBG2 valley at 1 577.3 nm. The temperature and strain characteristics of the proposed sensor are measured at 45—70 °C and 250—500 με, respectively. The sensitivity matrix is determined by analyzing wavelength shifts and parameter response characterization of three different dips. The proposed optical fiber sensor based on LPFG cascaded with FBG structure can be efficiently used for double parameters measurement with promising application prospect and great research reference value. 相似文献