Abstract
Aiming at the non-uniform strain in the welding of airship skin, this paper studies the traditional digital image correlation algorithm, optimizes the shape and size of the subset, and presents an adaptive subset algorithm. Under the premise of ensuring a substantially constant subset area, the modified algorithm uses the initial u and v values to optimize the shape of the subset, find the optimal aspect ratio. Besides, the modified digital image correlation dynamically adjusts the shape of the subset according to the threshold value, making the algorithm better applicable to non-uniform deformation and large deformation. As the results show, in the simulation experiment, under the different strains such as 1000 μɛ, 5000 μɛ, and 9000 μɛ, the standard error measured by the modified method is reduced to more than 50% compared with the traditional method. Meanwhile, during the real speckle experiment, the error in the modified digital image correlation algorithm was reduced from 9.3e−04 to 7.2e−04. Furthermore, the modified digital image correlation only costs 3% more time, has a little effect on computational efficiency. Therefore, the modified method can smooth the measured strain, and make the robustness and accuracy better during the airship skin measurement.
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References
Zhao XJ, Zhang W (2019) Strain measurement of airship gasbags material based on digital image technology. Sci Technol Eng 19(28):378–383
Nayler A (2003) Airship activity and development world-wide 2003: AIAA 2003–6727. AIAA, Denver
Sun JK, Wang QB, Zhao HT et al (2016) The strain monitoring of stratospheric airship envelope based on wireless sensor network. Comput Simul 33(9):77–80
Dai ML, Xu XY, Yang FJ et al (2016) Measurement of continuous deformation of thin-walled spheres compressed by a rigid plate. Opt Precis Eng 24(5):993–1000
Yoneyama S, Kitagawa A, Iwata S et al (2007) Bridge deflection measurement using digital image correlation. Exp Tech 31(1):34–40
Shao X, Dai X, Chen Z et al (2016) Real-time 3D digital image correlation method and its application in human pulse monitoring. Appl Opt 55(4):696
Huang WH, Wang RQ, Xu WC et al (2015) Robust digital imaging Spearman’s Rho correlation for pepper and salt noise. Opt Precis Eng 23(6):1800–1806
Li BJ, Wang Q, Duan DP et al (2017) Modified digital image correlation for balancing the influence of subset size choice. Opt Eng 56(5):054104
Pan B, Xie H, Wang Z et al (2008) Study on subset size selection in digital image correlation for speckle patterns. Opt Express 16(10):7037–7048
Wang Y, Shen H, Xia HS et al (2018) An dynamic strain subset selection algorithm in digital image correlation method. Laser Optoelectron Prog 55(09):119–124
Pan B, Da FW, Yong X (2012) Incremental calculation for large deformation measurement using reliability-guided digital image correlation. Opt Lasers Eng 50(4):586–592
Zhou Y, Sun C, Chen J (2014) Adaptive subset offset for systematic error reduction in incremental digital image correlation. Opt Lasers Eng 55:5–11
Cheng ZJ (2017) Application of digital image correlation for deformation measurement of aerostat skin. Shanghai Jiaotong University, Shanghai
Pan B, Qian KM, Xie HM et al (2009) Two-dimensional digital image correlation for in-plane displacement and strain measurement: a review. Meas Sci Technol 20(6):62001-0
Pan B, Yu LP, Zhang QB (2018) Review of single-camera stereo-digital image correlation techniques for full-field 3D shape and deformation measurement. Sci China Technol Sci 61(1):2–20
Hu H, Liang J, Tang ZHZ et al (2012) Measurement of full-field deformations in metal sheet welding process by image correlation method. Opt Precis Eng 20(7):1636–1644
Dong YL, Pan B (2017) A review of speckle pattern fabrication and assessment for digital image correlation. Exp Mech 57:1161–1181
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The paper was funded by the National Natural Science Foundation of China (NSFC) (Grant nos. 51205253 and 51906141).
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Ruan, Jk., Wang, Qb., Zhao, Ly. et al. Airship skin strain measurement based on adaptive digital image correlation. AS 3, 181–188 (2020). https://doi.org/10.1007/s42401-020-00052-z
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DOI: https://doi.org/10.1007/s42401-020-00052-z