Measurement of aspheric surfaces using annular subaperture stitching interferometry based on an automatic positioning method: theory and application

2014 ◽  
Vol 53 (7) ◽  
pp. 074104 ◽  
Author(s):  
Yongfu Wen ◽  
Haobo Cheng
2013 ◽  
Vol 52 (23) ◽  
pp. 5686 ◽  
Author(s):  
Yongfu Wen ◽  
Haobo Cheng ◽  
Hon-Yuen Tam ◽  
Dongmei Zhou

2013 ◽  
Author(s):  
Bing-guo Liu ◽  
Guo-dong Liu ◽  
Na Gong ◽  
Feng-Dong Chen ◽  
Zhi-tao Zhuang

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Hongxing Wang ◽  
Hang Zhou ◽  
Haoran Liu ◽  
Zheng Huang ◽  
Mingduan Feng

During the inspection process of power pole towers, manual positioning is mainly used to select the shooting viewpoints of the drone, which leads to erroneous viewpoint selection and inaccurate shootings of inspected objects. Also, neglecting the effect of the sun’s backlight on photographs contributes to poor photo quality that does not meet inspection requirements. Aiming at the selection of shooting viewpoints during multirotor unmanned aerial vehicles’ inspection on power poles, this paper proposes an automatic positioning method that determines the shooting viewpoints by considering UAV performance, airborne camera parameters, and the size of objects to be measured. Considering the factors of sun illumination, we optimize the method to ensure the positions of the viewpoints and to ensure that the images can be clearly generated so that the observers can check the power pole towers through the images when shooting is also taken into consideration. Finally, the automatic calculation method of the related viewpoints is implemented in the Java language. Experiments show that the method can accurately obtain the positions of the drones’ viewpoints and reduce the number of viewpoints, which significantly improves the efficiency and quality of inspection shooting.


2009 ◽  
Author(s):  
Paul Murphy ◽  
Gary DeVries ◽  
Jon Fleig ◽  
Gregory Forbes ◽  
Andrew Kulawiec ◽  
...  

2021 ◽  
Author(s):  
Biao Yan ◽  
Wenlong Zhang ◽  
Lijing Cai ◽  
Lingxiang Zheng ◽  
Kaiyang Bao ◽  
...  

Abstract At present, dental implant surgery mainly relies on the clinical experience of the doctor and the assistance of preoperative medical imaging. However, there are some problems in dental implant surgery, such as narrow space, sight obstruction, inaccurate positioning, and high requirements of doctors' proficiency. Therefore, a dental implant robot system (DIRS) guided by optical navigation is developed in this study, with an x-shaped tool and an irregular pentagonal tracer are designed for spatial registration and needle tip positioning strategy respectively. The coordinate system of each unit in DIRS is unified through system calibration, spatial registration, and needle tip positioning strategy. Then the surgical path is planned on the Computed Tomography (CT) images in the navigation software before operation. The automatic positioning method and the auxiliary positioning method can be used in the operation to achieve accurate positioning and assist doctors to complete the operation. The errors of spatial registration, needle tip positioning strategy, and the overall accuracy of the system were evaluated respectively, and the results showed that they all met the needs of clinical surgery. This study preliminarily verified the feasibility of the precise positioning method for dental surgery robots and provided certain ideas for subsequent related research.


2011 ◽  
Author(s):  
Po-Chih Lin ◽  
Yi-Chun Chen ◽  
Chung-Min Lee ◽  
Chao-Wen Liang

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