In order to address the limitations of existing tip clearance measurement methods in complex outdoor environments, this paper proposes a real-time measurement method based on deep learning networks. The method utilizes the YOLOv3-tiny network to locate the rotor tip area in collected rotor tip images. The OTSU algorithm is then applied to segment the rotor tip from the background, and the rotor tip contour is extracted to locate the pneumatic center points of the upper and lower rotor tips. The rotor tip clearance is calculated based on the located center points. Experimental results conducted in both simulated and real environments demonstrate the high accuracy of the proposed method. The maximum error in tip clearance measurement is 1.99 mm when the camera is positioned 20 meters away from the tip. The proposed method has been successfully applied in real experiments involving tip clearance measurements under various complex background and illumination conditions, where the method exhibits strong adaptability and fast processing speed with a frame rate of 50 fps.
ZENG Leping, XIONG Bangshu, YI Hui, OU Qiaofeng, YU Lei
. Real-Time Measurement for Tip Clearance of Twin-Rotor Helicopter under Complex Background and Illumination[J]. Journal of Applied Sciences, 2024
, 42(2)
: 314
-322
.
DOI: 10.3969/j.issn.0255-8297.2024.02.012
[1] 周云, 胡和平, 孟微. 共轴刚性旋翼桨尖间距建模与参数影响研究[J]. 动力学与控制学报, 2020, 18(4):52-60. Zhou Y, Hu H P, Meng W. Modeling and parametric study of tip clearance of coaxial rigid rotor [J]. Journal of Dynamics and Control, 2020, 18(4):52-60. (in Chinese)
[2] Cameron C, Sitohi J, Feil R, et al. Measurement of transient loads and blade deformation in a coaxial counterrotating rotor [C]//73th Annual Forum of the American Helicopter Society, 2017.
[3] 陈焕, 余莹, 汪文涛, 等. 一种共轴旋翼桨尖间距实时估算方法:113086244B [P]. 2022-07-29.
[4] 欧巧凤, 肖佳兵, 陈垚锋, 等. 直升机桨叶挥舞量的全场景视觉测量及分析[J]. 仪器仪表学报, 2021, 42(1):146-156. Ou Q F, Xiao J B, Chen Y F, et al. Full-scene measurement and analysis of helicopter blade flaps based on vision [J]. Chinese Journal of Scientific Instrument, 2021, 42(1):146-156. (in Chinese)
[5] 汤永, 秦强, 郭聪, 等. 一种基于相位测距原理的高速共轴双旋翼桨尖距测量方法:202011114673.1[P]. 2022-06-21.
[6] 罗霄, 薛亚洲, 王爽, 等. 一种双层旋翼桨叶间距测量装置:213633822U [P]. 2021-07-06.
[7] 曾小明. 基于机器视觉的共轴刚性双旋翼桨尖偏移量实时测量系统研究[D]. 南昌:南昌航空大学, 2019.
[8] Yao Z X, Song X P, Zhao L, et al. Real-time method for traffic sign detection and recognition based on YOLOv3-tiny with multiscale feature extraction [J]. Proceedings of the Institution of Mechanical Engineers, Part D:Journal of Automobile Engineering, 2021, 235(7):1978-1991.
[9] Pang L, Liu H, Chen Y, et al. Real-time concealed object detection from passive millimeter wave images based on the YOLOv3 algorithm [J]. Sensors, 2020, 20(6):1678-1692.
[10] 张育斌, 熊邦书, 欧巧凤, 等. 基于YOLOv3与分水岭的直升机桨叶欠曝光图像圆形标记点检测[J]. 应用科学学报, 2020, 38(6):906-915. Zhang Y B, Xiong B S, Ou Q F, et al. Circular marker detection of under-exposed images of helicopter blades based on YOLOv3 and watershed [J]. Journal of Applied Sciences, 2020, 38(6):906-915. (in Chinese)
