| With the increasing shortage of land resources and the implementation of the marine power strategy,China pays particular attention to the development of marine technology and the development of deep-sea resources.As an important carrier for the development of marine resources,the related research of dynamic positioning vessels(DPVs)has attracted extensive attention,and has become an important part of national development.Trajectory tracking task is one of the task objectives of the dynamic positioning vessel(DPV),and the tracking performance in the process of trajectory tracking is particularly key as the measurement index of control completion.However,in addition to the constraints of tracking performance,there are many practical factors that will further increase the design difficulty of trajectory tracking controller of the DPV,including time-varying wind and wave disturbances in deep-sea working environment,uncertainty of system parameters of the DPV,propeller failure,kinematic constraints and other practical engineering problems.Therefore,the research on the prescribed performance control(PPC)of the trajectory tracking task of the DPV in the deep sea environment has important theoretical and application value.Taking the trajectory tracking task of the DPV as the background,this paper makes an in-depth research on the PPC under multiple constraints.The main research contents are as follows:(1)A mathematical model of the horizontal plane motion was established for the target ship "Offshore Oil 201",which provides a model basis for the design of the tracking control design of the dynamic positioning ship’s preset performance;Meanwhile,it simulated the marine environment of the South China Sea deep sea area where the target ship was performing pipe-laying operations in the "Lingshui 17-2 Gas Field" at a depth of 1542 meters,and the simulation verified the motion characteristics of the "Offshore Oil 201”ship under the environmental disturbances of the deep sea area;In addition,the theoretical basis of stability is given as the theoretical basis for the stability proof of subsequent control system design.(2)Aiming at the problems of time-varying disturbance and system uncertainty in the control system of the DPV,a finite time prescribed performance control method based on fuzzy adaptive is proposed to improve the robust adaptive ability of the system.Firstly,the time-varying environmental disturbances and the unknown parameters of the system are regarded as a unified uncertainty term,and then the uncertainty term is estimated according to the principle of fuzzy logic system;Then,a high gain observer is designed to estimate the unknown state(speed)variables of the system;Subsequently,according to the performance index requirements in the trajectory tracking process,a novel appointed-time prescribed performance function is designed to restrict the transient steady-state error of the system tracking performance;On this basis,a prescribed performance function controller based on the specified time is proposed to realize the accurate control of the tracking process,and it is proved that the system error is uniformly ultimately bounded by using Lyapunov stability;Finally,the effectiveness of the proposed algorithm for trajectory tracking control of the DPV is verified by simulation and comparative experiments.(3)Aiming at the trajectory tracking control problem of the DPV with actuator failure,an adaptive passive fault-tolerant control method based on second-order fast nonsingular terminal sliding mode is proposed to improve the fault-tolerant ability of the control system.Firstly,the time-varying environmental disturbance and the unknown parameters of the system are regarded as a unified uncertainty term,and then the uncertainty term is estimated according to the principle of adaptive neural network;Then,the second-order fast nonsingular terminal sliding mode surface is designed,including proportional integral sliding mode surface and fast nonsingular terminal sliding mode surface;Subsequently,according to the performance index requirements in the trajectory tracking process,a new finite time prescribed performance function is designed to restrict the transient steady-state error of the system tracking performance;On this basis,an adaptive high-order sliding mode passive fault-tolerant controller with finite time prescribed performance is proposed to realize the fault-tolerant control of trajectory tracking process,and it is proved that the system error is asymptotically globally convergent by Lyapunov stability;Finally,simulations and comparative experiments verify the effectiveness of the proposed algorithm in solving actuator failures in the process of the DPV trajectory tracking.(4)Aiming at the problem of coupling constraint control between kinematic model and dynamic model of the DPV,considering the actual task requirements of tracking performance and the uncertainty of system parameters,a dynamic decoupling cascade adaptive prescribed performance control method is proposed.Firstly,according to the cascade lemma,the properties of trigonometric function and the simplified mathematical motion model of the DPV,the decoupling model of cascade system is designed and its rationality is verified;Then,the time-varying environmental disturbances and the unknown parameters of the system are regarded as a unified uncertainty term,and then the uncertainty term is estimated according to the principle of adaptive neural network;Subsequently,according to the performance index requirements in the trajectory tracking process,a novel time-varying piecewise finite time prescribed performance function is designed to restrict the transient steady-state error of the system tracking performance;On this basis,a cascade adaptive prescribed performance controller with dynamic decoupling is proposed,which simplifies the design process of the controller and realizes the accurate control of the tracking process.It is proved that the system error is uniformly ultimately bounded by using Lyapunov stability;Finally,the effectiveness of the proposed algorithm for trajectory tracking control of the DPV is verified by simulation and comparative experiments.(5)Aiming at the frequent triggering of actuators in the control system of the DPV,comprehensively considering the communication bandwidth of the control system and external time-varying disturbances,a dynamic event-triggered prescribed performance control method is proposed.Firstly,the traditional DPV motion mathematical model is improved by designing the decoupled sliding surface,and its accuracy is verified;Then,an integral disturbance observer is designed to estimate the time-varying wind wave disturbance accurately;Subsequently,according to the performance index requirements in the trajectory tracking process,a novel second-order prescribed performance function is designed to restrict the transient steady-state error of the system tracking performance;On this basis,a full state dynamic event-triggered controller is proposed to realize the efficient control of the tracking process,and the tracking error is proved to be uniformly ultimately bounded by using Lyapunov stability;Finally,simulation and comparative experiments verify the effectiveness of the proposed dynamic event-triggered control algorithm for trajectory tracking control of the DPV and the efficiency of reducing trigger frequency. |
PDF Full Text Request