Trajectory Planning And Tracking Control Of UUV For Underwater Recovery

As a reusable marine vehicle, unmanned underwater vehicle (Unmanned Underwater Vehicle, UUV) must be recovered after executing the mission. Although, there are a variety of UUV recovery modes in the domestic and overseas, the only target of every UUV workers is to realize the underwater autonomous recovery of the UUV. In addition, the UUV which has the ability of autonomous underwater recovery can also experience its' intelligence level and its' flexibility. In this paper, I carry out my research work based on the research background that is the mother submarine autonomously recovering UUV, at the same time, my research is focus on the space trajectory planning?space trajectory tracking control and tracking mother submarine method in the recovery of UUV. Through the research, my purpose is to provide theoretical and technical references for the realization of underwater autonomous recovery of UUV.Through the analysis of the process that the movement submarine autonomously recovers the UUV is divided into the typical three stages: rendezvous, homing and docking. The content of this thesis is aimed at the first two stages. Firstly, the UUV can reach the recovery collection point by the space trajectory planning and trajectory tracking control. Then, UUV tracks the movements of mother submarine and back to the near of the docking mechanism.Lastly, UUV waits for the next docking stage.The space trajectory planning can solute the problem of that UUV can track what kind of the trajectory to the rendezvous under the constraint conditions. The constraints include the time reaching the rendezvous? attitude constraints and kinematics constraints of UUV, at the same time the environment of space is three-dimensional with unknown obstacles. In this paper, I use the polynomial with parametric to describe space trajectory, and adjust the coefficient of the polynomial to obtain a collision free, optimal and satisfying the above constraints trajectory. The processes of saluting the problem have characteristics of online execution, so UUV can online replace the trajectory when it detects the obstacles. The simulations of typical cases can verity the feasibility of the method.Next, according to the planned trajectory that is decrypted by parametric, I carry out the research about the trajectory tracking control of UUV, so that UUV cans track the trajectory to the collection point. In the tracking process, in order to satisfy the time and attitudes constraints, UUV must track the velocity state and position state of the space trajectory.Therefore, I built the partially linearzed kinematic errors model and dynamic errors model of UUV in tracking processes. Aiming at underactuated error system, the space trajectory tracking controller is designed by using the backstepping method and Lyapunov function. The simulations of tracking the planned space trajectory can verith the feasibility of the controller.Finally, paper carried out the research of the homing stage which UUV tracked the movement of mother submarine. At the same time in order to avoiding collision with mother submarine, UUV must avoid the hull prohibited areas which move with the mother ship. The model of UUV tracking submarine problem is builded. Based on the expansion of the traditional potential field method, the position information of UUV, the mother submarine and prohibited areas are regard as the planning elements, joining their velocity information. Lastly,the UUV motion planning can be realized in the case of no influence of prohibited area, and in the cases of there are influences of prohibited area or many prohibited areas.