To address the challenges of varied aircraft skin hole detection types and susceptibility to noise,this paper proposes a method based on the perspective of dual contour edge information fusion.The core method combines...To address the challenges of varied aircraft skin hole detection types and susceptibility to noise,this paper proposes a method based on the perspective of dual contour edge information fusion.The core method combines stereoscopic vision and structured light dual contour information consistently,focusing on extracting edge point information around the hole edge to achieve precise detection of circular holes.In this approach,a line multi-directional gradient feature detector (LMGFD) is introduced for locating the holes from plane stereoscopic image.Furthermore,we establish a three-dimensional (3D) circular hole detection method (BPCircle) based on the dual contour edge information fusion.Finally,experiments demonstrate that our proposed method achieves superior accuracy and robustness based on public benchmark dataset and our own collected standard IPCDS dataset (including two-dimensional (2D)images,3D point clouds,and measured data of three-coordinate measuring machine).The dataset and code can be found from https://github.com/Nicholsdqw/123.展开更多
To better analyzing the temperature oscillation and the two-phase behavior inside a flat loop heat pipe,visual studies were conducted.Under the 20℃ water cooling and horizontal orientation,the effects of the filling ...To better analyzing the temperature oscillation and the two-phase behavior inside a flat loop heat pipe,visual studies were conducted.Under the 20℃ water cooling and horizontal orientation,the effects of the filling ratio and heat loads on the temperature oscillation were analyzed.Based on the experimental data,the results indicate that owing to the increased system pressure,the temperature oscillation decays as the filling ratio increases from 34%to 58%.Meanwhile,during the startup process,temperature oscillation tends to occur during the boiling and steady stages due to the more violent two-phase behavior,while the temperature curves are smooth during the slow evaporation stage.Moreover,as the heat load increases,the evaporation becomes more intense at the active zone of evaporator,leading to a faster startup process and a higher oscillation frequency.Besides,owing to the synergistic effect of two-phase flow in the compensation chamber caused by heat leak and subcooled liquid backflowing,a“breathing”oscillation behavior of the vapor-liquid interface is observed at the compensation chamber,which further leads to the unstable operation behavior of the loop heat pipe system.展开更多
基金supported by the National Natural Science Foundation Youth (No.62303330)。
文摘To address the challenges of varied aircraft skin hole detection types and susceptibility to noise,this paper proposes a method based on the perspective of dual contour edge information fusion.The core method combines stereoscopic vision and structured light dual contour information consistently,focusing on extracting edge point information around the hole edge to achieve precise detection of circular holes.In this approach,a line multi-directional gradient feature detector (LMGFD) is introduced for locating the holes from plane stereoscopic image.Furthermore,we establish a three-dimensional (3D) circular hole detection method (BPCircle) based on the dual contour edge information fusion.Finally,experiments demonstrate that our proposed method achieves superior accuracy and robustness based on public benchmark dataset and our own collected standard IPCDS dataset (including two-dimensional (2D)images,3D point clouds,and measured data of three-coordinate measuring machine).The dataset and code can be found from https://github.com/Nicholsdqw/123.
基金This work was supported by National Natural Science Foundation of China(NSFC)(Grant No.51878254)National Key R&D Program of China(Grant No.2018YFE0111200)+1 种基金Key Research and Development Plan of Hunan Province(2020WK2012)Hunan Provincial Science and Technology Department(2020GK4057).
文摘To better analyzing the temperature oscillation and the two-phase behavior inside a flat loop heat pipe,visual studies were conducted.Under the 20℃ water cooling and horizontal orientation,the effects of the filling ratio and heat loads on the temperature oscillation were analyzed.Based on the experimental data,the results indicate that owing to the increased system pressure,the temperature oscillation decays as the filling ratio increases from 34%to 58%.Meanwhile,during the startup process,temperature oscillation tends to occur during the boiling and steady stages due to the more violent two-phase behavior,while the temperature curves are smooth during the slow evaporation stage.Moreover,as the heat load increases,the evaporation becomes more intense at the active zone of evaporator,leading to a faster startup process and a higher oscillation frequency.Besides,owing to the synergistic effect of two-phase flow in the compensation chamber caused by heat leak and subcooled liquid backflowing,a“breathing”oscillation behavior of the vapor-liquid interface is observed at the compensation chamber,which further leads to the unstable operation behavior of the loop heat pipe system.
