Videometrics Pose Estimation Based On Sequence Images And Application In Hull Deformation Measurement

Modern ships as a surface warfare or measuring platform,are equipped with a large number of different types of equipments and systems(such as radar,electro-optical tracker,artillery,missiles and other offensive or defensive devices).The unified spatial coordinate datum is the basis of the information sharing and the cooperation of various weapon equippments on the ship.However,the inevitable hull deformation will affect the accuracy of coordinate transformation between the tracking equipment and central inertial navigation platform,thereby leading to the measuring error.Along with the development of modern science-technology,ship-borne advanced weapons emerge in endlessly,the measurement and correction of the hull deformation should be more essential.Overcoming the weakness of existing measuring methods,videometrics has the advantages of high accuracy,non-contact,high real-time,low cost and so on which has a broad application prospect in the field of hull deformation measurement.In this paper,we research on the key techniques of “videometrics pose estimation based on sequence images”.In order to meet the demand of high real-time hull deformation measurement,the closed-form solution based on single frame image to pose estimation is refined.Dual quaternion is able to deal with rotation and translation simultaneously instead of the usual expressions,taking advantage of the unit dual quaternion for its notion concision,computational effectiveness and non-singularity.The closed-form mathematical model based on dual quaternion is proposed in detail.Simulation results verify the validity and high computational effectiveness of the proposed solution which therefore has the potential to be applied in practice after more thorough researches and improvements.Aiming at making full use of the time dimension information of sequences image,an iterative extended Kalman filter(IEKF)is designed to estimate the relative pose.Using the optimal state estimation theory,the relative motion state is obtained and the relative pose parameters are selected as the state variable.The state equation and the observation equation are established.The validity and robustness of the proposed algorithm is verified through simulation.To verify the practicality and robustness of the proposed pose estimation method based on sequence images,this paper carries out the semi physical simulation experiment of the hull vertical deformation in the laboratory.The results show that the proposed method is correct and effective.Besides,some of the real measured data of a ship hull deformation is chosen to verify the proposed algorithm effectiveness and robustness.Pose estimation method based on sequence images has crucial theory value and a broad application prospect in the field of ship hull measurement.