Research On Ship Type Selection And Allocation Scheme Optimization For Repair Equipment Of Large Repair And Support Ships On A Deep Sea

To meet the huge challenges of the repair and support on a deep sea from ships and offshore platforms,and promote the development and improvement of the repair and support system construction on a deep sea in our country,the research of large repair and support ships is gradually deepened and refined from three aspects:quantitative analysis of market requirement,economic analysis and parameter optimization of ship type,and optimization of repair equipment allocation according to the characteristics of repair and support requirements on a deep sea.The main research works and progresses are as follows.(1)The multi-requirements of repair and support on a deep sea are analysed and their characteristics are summarized with comprehensive repair technology,long offshore distance and heavy weight of repair objects.Based on this,the design requirements and functional positioning of large repair and support ships on a deep sea are analysed,and a qualitatively analysis is made to explore the competition between large repair and support ships and shipyards in repairing damaged ships and offshore platforms from the aspects of time,space and cost.It lays a foundation for the applicability of multi-requirements in the next research on the large repair and support ships.(2)Considering that there will be a competition with the shipyard mode when the repair and support ship mode enters the repair market of ships and offshore platforms,the market requirement analysis model of large repair and support ships based on competition is established,and an algorithm is designed to solve this model combining with the first-order partial derivative condition.Taking the repair and support ship mode and shipyard mode repairing an offshore platform with faults as examples,the market requirements of the two repair modes are calculated,which verifies the rationality and effectiveness of the model and solution method.At the same time,the influences of offshore distance,damage degree,maritime repair difficulty and choice preference on the market requirement of repair and support ship mode are discussed.Finally,the countermeasures and suggestions are put forward to expand the market requirement of repair and support ship mode.(3)To evaluate the economy of ship type scheme,an economic analysis model of large repair and support ship is established.On this basis,in order to further optimize the ship parameters,a multi-objective optimization model for the ship parameter design of the large repair and support ship is established.The solution methods based on the weighted ideal point method and the non-dominated sorting genetic algorithm are adopted to solve this model.The optimized ship type schemes of large repair and support ships are obtained through empirical analysis and the rationality and effectiveness of the model and two solution methods are verified.This method provides theoretical and technical support to optimize the ship type of large repair and support ships,and enhances the repair and support applicability of large repair and support ships on a deep sea.(4)To meet the multi-requirements of repair and support on a deep sea,and improve this capacity,the repair equipment allocation problem for a large repair and support ship on a deep sea is researched for the first time.To address this hybrid problem which is composed of an extended multi-dimensional and multi-choice knapsack problem and a multi-criteria decision making problem with quantitative and qualitative information,a hybrid multi-criteria decision making and optimization approach is designed.The evidence reasoning approach is used to aggregate the evaluation information of quantitative and qualitative criteria.Then,a mathematical repair equipment allocation model of a large repair and support ship is formulated,which is a mixed-integer nonlinear model.A removal strategy based on a greedy algorithm that modifies infeasible solutions is designed to facilitate the use of a genetic algorithm with an elite strategy to address the model above.The rationality and effectiveness of the model and solution method are verified by a random test instances.This method provides a novel idea for the repair equipment allocation problem,and provides a theoretical basis for further enhancing the repair and support capability of large repair and support ships on a deep sea.Theoretical discussion and method research are made on ship type selection and allocation scheme optimization for repair equipment of large repair and support ships on a deep sea.The research results are of great significance and promotion to enhance the repair and support force,and develop and improve the construction of repair and support system on a deep sea in our country.At the same time,it also has important theoretical significance in the quantitative analysis of market requirement,parameter design optimization,equipment allocation optimization.