Camera Pose Estimating from point and line correspondences is critical in various applications,including robotics,augmented reality,3D reconstruction,and autonomous navigation.Existing methods,such as the Perspective-...Camera Pose Estimating from point and line correspondences is critical in various applications,including robotics,augmented reality,3D reconstruction,and autonomous navigation.Existing methods,such as the Perspective-n-Point(PnP)and Perspective-n-Line(PnL)approaches,offer limited accuracy and robustness in environments with occlusions,noise,or sparse feature data.This paper presents a unified solution,Efficient and Accurate Pose Estimation from Point and Line Correspondences(EAPnPL),combining point-based and linebased constraints to improve pose estimation accuracy and computational efficiency,particularly in low-altitude UAV navigation and obstacle avoidance.The proposed method utilizes quaternion parameterization of the rotation matrix to overcome singularity issues and address challenges in traditional rotation matrix-based formulations.A hybrid optimization framework is developed to integrate both point and line constraints,providing a more robust and stable solution in complex scenarios.The method is evaluated using synthetic and realworld datasets,demonstrating significant improvements in performance over existing techniques.The results indicate that the EAPnPL method enhances accuracy and reduces computational complexity,making it suitable for real-time applications in autonomous UAV systems.This approach offers a promising solution to the limitations of existing camera pose estimation methods,with potential applications in low-altitude navigation,autonomous robotics,and 3D scene reconstruction.展开更多
In this paper,a second order linear differential equation is considered,and an accurate estimate method of characteristic exponent for it is presented.Finally,we give some examples to verify the feasibility of our res...In this paper,a second order linear differential equation is considered,and an accurate estimate method of characteristic exponent for it is presented.Finally,we give some examples to verify the feasibility of our result.展开更多
Purpose:During fracture fixation,the size of tibial nail is a vital factor affecting the outcomes and thus preoperative estimation of tibial nail length is very important.This study aims to find out whether"olecr...Purpose:During fracture fixation,the size of tibial nail is a vital factor affecting the outcomes and thus preoperative estimation of tibial nail length is very important.This study aims to find out whether"olecranon to 5th metacarpal head"(O-MH)measurement can be used to reliably predict the tibial nail length.Methods:This was a cross sectional study involving 100 volunteers.Measurements were done and recorded by two observers on two separate occasions.Tibial nail length estimation measurement was done from highest point of tibial tuberosity to the tip of the medial malleolus(TT-MM).O-MH measurement was taken from tip of olecranon to the tip of 5th metacarpal head with wrist in neutral position and hand clenched.Statistical analysis was done to find out correlation between two measurements and influence of age,gender and body mass index on them.Results:Paired t-test showed no systematic error between the readings.Intraclass correlation coefficient showed strong agreement in inter and intra observer settings.Strong correlation was found between the TT-MM&O-MH measurements using Pearson's correlation coefficient test(r=0.966).Hierarchical regression analysis showed age,gender and BMI have no statistically significant bearings on these measurements and their correlations.Conclusion:O-MH measurement is a useful and accurate means of estimating tibial nail length preoperatively.展开更多
基金funded by the Jiangsu Province Postgraduate Scientific Research and Practice Innovation Program(SJCX240449)projectthe Nanjing University of Information Science and Technology Talent Startup Fund(2022r078).
文摘Camera Pose Estimating from point and line correspondences is critical in various applications,including robotics,augmented reality,3D reconstruction,and autonomous navigation.Existing methods,such as the Perspective-n-Point(PnP)and Perspective-n-Line(PnL)approaches,offer limited accuracy and robustness in environments with occlusions,noise,or sparse feature data.This paper presents a unified solution,Efficient and Accurate Pose Estimation from Point and Line Correspondences(EAPnPL),combining point-based and linebased constraints to improve pose estimation accuracy and computational efficiency,particularly in low-altitude UAV navigation and obstacle avoidance.The proposed method utilizes quaternion parameterization of the rotation matrix to overcome singularity issues and address challenges in traditional rotation matrix-based formulations.A hybrid optimization framework is developed to integrate both point and line constraints,providing a more robust and stable solution in complex scenarios.The method is evaluated using synthetic and realworld datasets,demonstrating significant improvements in performance over existing techniques.The results indicate that the EAPnPL method enhances accuracy and reduces computational complexity,making it suitable for real-time applications in autonomous UAV systems.This approach offers a promising solution to the limitations of existing camera pose estimation methods,with potential applications in low-altitude navigation,autonomous robotics,and 3D scene reconstruction.
基金supported by Foundation of Fujian Education Committee(JA08012)
文摘In this paper,a second order linear differential equation is considered,and an accurate estimate method of characteristic exponent for it is presented.Finally,we give some examples to verify the feasibility of our result.
文摘Purpose:During fracture fixation,the size of tibial nail is a vital factor affecting the outcomes and thus preoperative estimation of tibial nail length is very important.This study aims to find out whether"olecranon to 5th metacarpal head"(O-MH)measurement can be used to reliably predict the tibial nail length.Methods:This was a cross sectional study involving 100 volunteers.Measurements were done and recorded by two observers on two separate occasions.Tibial nail length estimation measurement was done from highest point of tibial tuberosity to the tip of the medial malleolus(TT-MM).O-MH measurement was taken from tip of olecranon to the tip of 5th metacarpal head with wrist in neutral position and hand clenched.Statistical analysis was done to find out correlation between two measurements and influence of age,gender and body mass index on them.Results:Paired t-test showed no systematic error between the readings.Intraclass correlation coefficient showed strong agreement in inter and intra observer settings.Strong correlation was found between the TT-MM&O-MH measurements using Pearson's correlation coefficient test(r=0.966).Hierarchical regression analysis showed age,gender and BMI have no statistically significant bearings on these measurements and their correlations.Conclusion:O-MH measurement is a useful and accurate means of estimating tibial nail length preoperatively.
