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[Objectives]In recent years, ships are becoming larger, faster and more intelligent, so the ship dynamic positioning technology is particularly important. In order to establish a kinematic mathematical model in the dynamic positioning system,we need to determine the values of the parameters in the model.[Methods]Firstly,a dredger is used as the research object to establish the mathematical model of the ship movement,and the surge motion model and the sway and yaw motion model are extracted. The unknown parameters in the model are identified based on the system identification theory and the Feedback Particle Filter(FPF)algorithm,including the thrust coefficients of two main thrusters and one side thruster. Then,the parameters to be identified are obtained by the simulation experiment.[Results] Finally,by comparing with the Extended Kalman Filter(EKF)algorithm,it is shown that the FPF algorithm is better at identifying the parameters and the reliability of FPF algorithm is verified.[Conclusions]This method has good application prospect in ship dynamic positioning system.

Aiming at the problem in which a vessel's dynamic positioning system can control it at an expected position,a novel linear active disturbance rejection controller is designed to solve the problem of poor dynamic performance due to the omission of a tracking differentiator. Based on the advantages of linear and nonlinear tracking differentiators,an improved tracking differentiator is designed which can track the differential signal and degrade the effects of noise; it constitutes a novel Linear Active Disturbance Rejection Controller(LADRC). The simulation results show that the novel LADRC based on the improved tracking differentiator has strong robustness,high control accuracy and good dynamic performance compared with the traditional LADRC.

Affected by complex fault blocks, sedimentary environment and reservoir physical properties, Jidong Oilfield generally develops small-scale sand bodies, accounting for 24.2% of the produced reserves of medium and low permeability reservoirs. Such sand bodies rely on elastic energy to develop and are difficult to use effectively. In this paper, through the three-dimensional hydraulic physical model experiment and the analysis of the oil layer-dry layer-mudstone mixed sand body, the reasons that affect the model parameters are obtained. The results show that: the length of the high-permeability reservoir area, the length of the intermediate-permeability dry layer area, the rate of change of permeability parameters, the viscosity of the construction fluid, and the construction displacement have an impact on the effect of fracturing enhanced injection energy storage.

Networked Control System of Controllable Pitch Propeller (CPP) is the subsystem of ship’s propulsion system. It influences mostly ship motion, so it’s important to study pitch’s modeling and controlling in order to improve ship’s seaworthiness. Along with the better requests of response speed and maneuverability in ship’s propulsion system, it has been developed from traditional control system to distributed networked control system, while the way of networked control has inevitably caused indefinite network delay. The networked controller has been designed based on the combination of Support Vector Machine, Generalized Predictive Control and Queuing Strategy. It is shown by the study case that the algorithm could effectively compensate the influence of network delay and the networked control system posses of better performances of stability and robustness.