FPSO内转塔浮子穴结构建造工艺

FPSO是依靠特殊的系泊系统永久系泊在海上。该文重点介绍了内转塔式单点系泊FPSO关键的特殊结构(浮子穴)、建造精度并剖析了浮子穴与周围结构的建造方法,进而指出了浮子穴建造中应注意的问题。     

Analysis of the pencil of conics with double complex contact and its application to camera calibration

In this paper,we introduce a novel class of coplanar conies,the pencil of which can doubly contact to calibrate camera and estimate pose.We first analyze the properties of con-axes and con-eccentricity ellipses, which consist of a natural extending pattern of concentric circles.Then the general case that two ellipses have two repeated complex intersection points is presented.This degenerate configuration results in a one-parameter family of homographies which map the planar pattern to its image.Although it is unable to compute the complete homography,an indirect 3-degree polynomial or 5-degree polynomial constraint on intrinsic parameters from one image can also be used for camera calibration and pose estimation under the minimal conditions.Furthermore, this nonlinear problem can be treated as a polynomial optimization problem(POP) and the global optimization solution can be also obtained by using SparsePOP(a sparse semidefinite programming relaxation of POPs). Finally,the experiments with simulated data and real images are shown to verify the correctness and robustness of the proposed technique.