Underwater terrain-aided navigation is used to complement the traditional inertial navigation employed by autonomous underwater vehicles during lengthy missions. It can provide fixed estimations by matching real-time ...Underwater terrain-aided navigation is used to complement the traditional inertial navigation employed by autonomous underwater vehicles during lengthy missions. It can provide fixed estimations by matching real-time depth data with a digital terrain map, This study presents the concept of using image processing techniques in the underwater terrain matching process. A traditional gray-scale histogram of an image is enriched by incorporation with spatial information in pixels. Edge comer pixels are then defined and used to construct an edge comer histogram, which employs as a template to scan the digital terrain map and estimate the fixes of the vehicle by searching the correlation peak. Simulations are performed to investigate the robustness of the proposed method, particularly in relation to its sensitivity to background noise, the scale of real-time images, and the travel direction of the vehicle. At an image resolution of 1 m2/pixel, the accuracy of localization is more than 10 meters.展开更多
This paper develops a method which can be used to assist aerial navigation by determining the spatial position and posture of the aerial photographic plane. After the method, aerial images match known DEM to capture t...This paper develops a method which can be used to assist aerial navigation by determining the spatial position and posture of the aerial photographic plane. After the method, aerial images match known DEM to capture the spatial position and posture. Some aerial images and terrain data are used to testify our method. Compared with those of analytic and stereo mappers, the results by our method are correspondent to real measurements well.展开更多
A surgical simulation and evaluation method in the anterior cruciate ligament(ACL)reconstructionwith image-free navigation was presented.Firstly,video tracking module,bone surface reconstructionmodule and virtual simu...A surgical simulation and evaluation method in the anterior cruciate ligament(ACL)reconstructionwith image-free navigation was presented.Firstly,video tracking module,bone surface reconstructionmodule and virtual simulation module of this system were discussed.Secondly,the coordinate relations ofseveral surgery objects(including surgical instrument,anatomical,camera and screen)in the surgicalenvironment,the tracking based on MicronTracker with two cameras and the bone surface real-time recon-struction based on the Delaunay algorithm were introduced in detail.Finally,experiments of anisometrymeasurement and virtual simulation on two plastics were carried out to verify the validity of the proposedmethod.The anisometry value of reconstructed ACL was 8.970039mm.The effectiveness of ACL recon-struction has been proved by preliminary evaluation trials.展开更多
基金Supported by the National Natural Nature Science Foundation of China （Grant No. 41376102）, Fundamental Research Funds for the Central Universities （Gant No. HEUCF150514） and Chinese Scholarship Council （Grant No. 201406680029）.
文摘Underwater terrain-aided navigation is used to complement the traditional inertial navigation employed by autonomous underwater vehicles during lengthy missions. It can provide fixed estimations by matching real-time depth data with a digital terrain map, This study presents the concept of using image processing techniques in the underwater terrain matching process. A traditional gray-scale histogram of an image is enriched by incorporation with spatial information in pixels. Edge comer pixels are then defined and used to construct an edge comer histogram, which employs as a template to scan the digital terrain map and estimate the fixes of the vehicle by searching the correlation peak. Simulations are performed to investigate the robustness of the proposed method, particularly in relation to its sensitivity to background noise, the scale of real-time images, and the travel direction of the vehicle. At an image resolution of 1 m2/pixel, the accuracy of localization is more than 10 meters.
基金uisition of Directional Funded by the National 973 Project (No.2003CB415205).
文摘This paper develops a method which can be used to assist aerial navigation by determining the spatial position and posture of the aerial photographic plane. After the method, aerial images match known DEM to capture the spatial position and posture. Some aerial images and terrain data are used to testify our method. Compared with those of analytic and stereo mappers, the results by our method are correspondent to real measurements well.
基金Supported by the National High Technology Research and Development Programme of China (No. 2004AA421022)National Science Fund for Distinguished Young Scholars of P. R. China (No. 60525314)National Science & Technology Pillar Program in the Eleventh Five-year Plan ( No.2006BAI03A16)
文摘A surgical simulation and evaluation method in the anterior cruciate ligament(ACL)reconstructionwith image-free navigation was presented.Firstly,video tracking module,bone surface reconstructionmodule and virtual simulation module of this system were discussed.Secondly,the coordinate relations ofseveral surgery objects(including surgical instrument,anatomical,camera and screen)in the surgicalenvironment,the tracking based on MicronTracker with two cameras and the bone surface real-time recon-struction based on the Delaunay algorithm were introduced in detail.Finally,experiments of anisometrymeasurement and virtual simulation on two plastics were carried out to verify the validity of the proposedmethod.The anisometry value of reconstructed ACL was 8.970039mm.The effectiveness of ACL recon-struction has been proved by preliminary evaluation trials.
