Multi-stage safe ship control with neural state constraints

The paper describes an application of the dynamic programming method to determine own ship´s safe trajectory during the passing of other ships encountered. A dynamic model of the process with kinematic constraints of state determined by a three-layer artificial neural network has been used for the synthesis of control. Non-linear activation functions in the first and second layers may be characterised by a tangent curve while the output layer is of a sigmoidal nature. Neural Network Toolbox from the Matlab package has been used to model the network. The learning process used an algorithm of a backward propagation of the error with adaptively selected learning step. The considerations have been illustrated with example of computer simulation the algorithm of determination the safe ship´s trajectory in situation of passing 18 ships encountered, recorded on the ship´s screen radar in real navigational situation in Skagerrak Strait.