Individual Behavior And Target Driven Combined For The Study Of Multi-UUV Formation Method

The application of unmanned underwater vehicle (UUV) for underwater target tracking operation is an important representation of autonomy and intelligence in UUV. As an important branch of UUV development, Multi-UUV formation technology is playing an significant role in the marine engineering applications increasingly. The content of this paper is on the premise of UUV individuals behavior combined with target driven to achieve Multi-UUV formation control. The target driven condition can be considered that when UUV search and detect target in the sea, the Multi-UUV formation structure with moving target in the geometric center to track target collaboratively based target motion estimation, and then gathering target informations from multi-angle or multi-dimension in the sea. The main contents of the paper are described as following.1. A decentralized control system frame for target driven based on individual tiered frame is proposed. The function of it making the tracking control and Multi-UUV formation control interact and influence each other, and to achieve collaborative moving target tracking mission ultimately.2. The target motion estimation method is an important prerequisite for tracking control mission. In this paper, the target motion estimation method is based on variable dimension Kalman filter. In consideration of the maximum speed of UUV and the minimum distance to the moving target, an optimization algorithm about the location of UUV is proposed, which can depress the covariance matrix of target position estimation, and then achieve the goal of target motion estimation optimization.3. A control model about the goal of mission is established for the special application about collaborative target tracking. On the basis of UUV plane mathematical model and control goal model, the formation controller is design and improved using backstepping from the study of kinematics and dynamics. The controller can avoid collision between UUVs,UUV and obstacle, UUV and moving target, and then keep tracking the moving target with a stable fonnation structure. The target tracking controller is divided into two basic control problems: speed control and heading control, which is embedded in each UUV individuals.4. The self-control strategy for collaborative tracking moving target mission is clarified by defining four kinds of formation behavior (target searching, target confirming, target re-searching, target surrounding and tracking) and three kinds of individual behavior (target detecting, leader role switching, target surrounding and tracking ). The leader of formation is generated randomly when Multi-UUV is searching target. When the target that is searching and tracking can be confirmed to the target that is required in the mission, the UUV that detects the target firstly will convert to the leader. The aim of this strategy based on leader switching is to reduce numbers of the excited time that reacquire the target behavior, and Multi-UUV formation has a higher ability to keep up with the target to track moving target.Some typical cases are designed in the simulation to illustrate the combination of collaborative target tracking strategy, target motion estimation and optimization, embedded target tracking controller and coordinated formation controller can solve the particular target driven application.