A Study On Automatic Stowage And Trim Adjustment In Loading Computer For Bulk Carrier

Because of fixed route, abundant supply, strong ability of transportation and high loading and unloading efficiency, bulk carrier plays an important role in the carriage of goods by sea. International Maritime Organization requires that bulk carrier whose length is more than 150 meters must be equipped with loading computer. With the application of computer and information technology, the loading computer of bulk carrier is gradually moving towards intelligent direction. In terms of ensuring operating safety and improving loading efficiency, it’s very necessary for loading computer to give stowage plans before loading and trim adjustment recommendations at the end of loading. Under this background, automatic stowage and trim adjustment of bulk carrier were attributed to optimization problems, and a differential evolution algorithm based on self-adaptive penalty function was used to make a study on automatic stowage and trim adjustment in loading computer for bulk carrier.In terms of automatic stowage, firstly, according to the balance equation of ship free floatation, a single-objective optimization model was set up for automatic stowage, differential evolution algorithm based on self-adaptive penalty function was used to solve the model, and stowage plans that meets the requirements of floatation was obtained. Secondly, ship stability and strength of these stowage plans was checked and feasible stowage plans that meets the requirements of criterion was selected. Thirdly, a fast non-dominated sorting approach was used to sort these feasible stowage plans according to ship bending moment and shearing force and the first non-dominated set of stowage plans was selected which namely the set of automatic stowage plans. Besides, in the process of solving the model, the capacity data was used to get the center of gravity of goods, which can improve the calculation accuracy. Finally,38,000 tons bulk carrier "DOLCE VITA" was taken as an example to calculate automatic stowage plans and the result of the calculation shows that this method can achieve automatic stowage plans that make the bulk carrier have a better bending moment and shearing force.In terms of trim adjustment, a trim adjustment method based on differential evolution algorithm was proposed. Compared with the traditional "Trimming Moment Method", this method can improve the calculation accuracy.38,000 tons bulk carrier "DOLCE VITA" was taken as an example to adjust trim and the result proves that our method is not only suitable for using a small quantity of goods to adjust trim, but also is suitable for using a large quantity of goods to adjust trim. Especially, when the quantity of the goods is large, our method can effectively reduce the deviation.