New Method of Ship Rolling Real Time Forecast

The ship rolling real time forecast is carried out using the diagonal recurrent neural network, the traing training of which uses the BPTD algorithm proposed in this paper. The time delay (TD) algorithm based on the basic principle of reinforcement learning (BL) is presented. Then, an algorithm named BPTD based on the time delay algorithm in reinforcement learning and the error back propagation algorithm for the train of multi layer feed forward neural networks are proposed to train the diagonal recurrent neural networks. The diagonal recurrent neural network using the BPTD algorithm is applied to the real time forecast of ship rolling. Experiments based on the measured data of full scale ship roll motion indicated the results of 1 step, 2 steps, 3 steps and 4 steps forecast have the very good precision, but the results of real time forecast after 5 steps begin to deteriorate. These results demonstrate the effectiveness and, efficiency of the methods proposed in this paper.