Cooperative Location Of Unmanned Surface Vessels Based On UKF Algorithm

With the development of science and technology, development and utilization of marine resources has become the focus of national attention, most of the Earth's surface is covered by oceans, because of the large deep draft ships can not sail smoothly in some coastal waters,For these cases developed a small,low-cost and unmanned surface vessel capable of navigating in a variety of harsh conditions has become a top priority national research efforts..Unmanned surface vessel is essentially an offshore platform,a number of complex marine operations task can not rely on one platform to complete, must use multiple platforms to collaborate together to complete. This paper focuses on unmanned surface vessel cooperative navigation and location technology research, while the initial alignment problem of unmanned surface vessels equipped with its own inertial navigation equipment for a certain amount of research.In this thesis, the application of unmanned surface vessels in the background, first briefly introduces the basic characteristics of unmanned surface vessels and the development and application of unmanned surface vessel in various countries; then the strapdown inertial navigation technology that has been widely applied and two assisted navigation devices were described. For traditional linearization approach to nonlinear problems, given UKF filtering algorithm which can be used directly in a nonlinear system model, then for the case additive noise given a simplified UKF algorithm, in order to further enhance the system's real-time, at the same time get a better real-time estimation accuracy, given the UKF algorithm based on proportion of SSUT sampling .For the problem of coarse alignment of unmanned surface vessels equipped with micro-inertial navigation equipment, Gives the micro inertial systems and electronic compass alignment method; Considering the interference factors of the actual application, such as ships and other marine carrier will have a greater impact by waves interference acceleration,platform error angle remains large angle after coarse alignment, established the nonlinear error equation and appropriate system model, and finally through simulation verify the correctness of the system model created by the text, compare the estimation accuracy of EKF algorithm, UKF algorithm and the UKF algorithm based on the proportion of SSUT sampling,to verify the effectiveness of the UKF algorithm based on the proportion of SSUT sampling,to improve the real-time and accuracy of the estimation accuracy.Cooperative navigation and location technology of unmanned surface vessel is described in detail, then described the cooperative location principle of unmanned surface vessel and the implementation process of cooperative location. For unmanned surface vessels without outside assistance information as a reference,can only use their own low-precision equipment for dead reckoning navigation case, establish the corresponding dead reckoning model, when unmanned surface vessel received the outside auxiliary information, it can make use of high-precision location information to cooperative location, this paper gives the system model of single leader and multi-leaders cooperative location and observability analysis of each cooperative mode, and further analysis of the impact of various factors on the results of the cooperative location. Through simulation design different motion paths to verify the superiority of cooperative navigation algorithms and correctness of the observability analysis results,and different filtering methods were compared to verify the effectiveness of UKF algorithm based on the proportion of SSUT sampling to improve system estimate accuracy and reduce calculated amount; Finally, through cooperative experiments to further prove the superiority of navigation and location technology.