Research On Green Dynamic Positioning For UUV Based On Predictive Control

The dynamic positioning control of the Unmanned Underwater Vehicle(UUV)refers to the process in which UUV outputs the control in real time through various propeller devices to keep its position in a certain target area under environmental disturbance.In practical engineering applications,UUV’s dynamic positioning control has problems such as excessively frequent propulsion of the propeller,which leads to UUV unable to complete long-term work tasks.Therefore,this paper focuses on the UUV green dynamic positioning control method.This paper includes the following aspects:Firstly,a mathematical model of the research object is established.According to the UUV hydrodynamic characteristics and its own structural characteristics,combined with the actual requirements of the UUV green dynamic positioning control,the simplified model to be available for subsequent research is obtained,and relevant simulation experiments are carried out to verify the reasonableness of the model.Secondly,aiming at the problem of large signal noise in UUV dynamic positioning control,a state estimation filter based on unscented Gaussian particle filter is designed.Aiming at the defects of particle degradation and depletion existing in the traditional Gaussian particle filter,a method of generating the Gaussian distribution and generating the importance function in particle filter by using UKF is proposed,which makes the importance density function closer to the real distribution,it is also effective for the problem of filtering accuracy degradation caused by particle degradation and depletion.The simulation case is designed and verified by the comparison with the unscented Kalman filter.The effectiveness of the filter designed in this paper are verified.Thirdly,the design of the control system is completed from the demand of UUV green dynamic positioning.A discontinuous control strategy based on Green-DP is proposed.Based on the above-mentioned UUV simplified model,the UFL series and the Li derivative are used to solve the optimal control rate in the continuous time by giving the performance index.A dynamic positioning controller based on model prediction is completed,and the stability of the state controller is proved.Finally,combined with engineering application,the specific case was designed and the simulation experiment of UUV fixed-point hovering process is completed.The simulation experiment includes the comparison experiments with the traditional PID controller and the verification experiment of the UUV green dynamic positioning strategy under the constant current flow disturbance.The experimental results show that the controller designed in this paper has more stable control effect than the PID controller,and the proposed UUV green positionign discontinuity control strategy is feasible and effective,that is,the design of this paper can meet the basic needs of UUV green dynamic positioning control.