Zhengjiang Liu

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The path following problem is concerned for conventional surface ships with second order nonholonomic constraints. A nonlinear feedback algorithm is presented using decoupling control method. The cross track error and heading error are stabilized by means of the rudder alone and the thruster is left to adjust the forward speed. The underactuated following(More)
International Maritime Organization (IMO) implements the principles of risk management through a systematic process called Formal Safety Assessment (FSA). FSA is a structured and systematic methodology, aimed at enhancing maritime safety, including protection of life, health, the marine environment and property, by using risk analysis and cost benefit(More)
A novel output feedback strategy is presented for the berthing control of underactuated surface ships with nonintegrable acceleration constraint. Saturations on actuators, systemic uncertainties and drift caused by current or wind are considered. The problems of trajectory planning and tracking are circumvented by means of iterative nonlinear sliding mode(More)
A wavelet neural network approach is proposed for ship control purpose using nonparametric regression estimation method. The proposed wavelet neural network estimator makes use of residual based selection algorithm for hidden units' selection and adjusts the connecting parameters with back propagation method. It is capable of handling nonlinear regressions(More)
—In order to process the uncertainty information in assessing human element, in this paper, a synthetic assessment method is proposed to seafarers' competency based on cloud models, where various uncertainties in the system are well kept and modeled by cloud theory. The presented approach focuses on effectively modeling the quantitative and qualitative(More)
A recurrent wavelet neural network (RWNN) is introduced to realize identification and control of system with time delay. The identification is based on model type of nonlinear auto-regressive with exogenous inputs (NARX). The method incorporates the delayed massage of the system, the resulting model can give predictions to the object system. The(More)
In this paper, we present a novel safety assessment approach to marine traffic based on cloud models, where various uncertainties in the complex system are well investigated and modeled by cloud theory. The proposed method focuses on the effective model of involved qualitative and quantitative elements in marine traffic safety systems. Optimal cloud models(More)