Research On Key Problems Of Ship Block Outdoor Logistics In The Shipyard

The current 13 th Five-Year Plan is a critical period for Chinese shipbuilding industry from the stage of large to become strong.It is an effective way to enhance the core competitiveness of Chinese shipbuilding enterprises through improving the quality and efficiency of ship construction,reducing the cost and energy consumption.In modern shipbuilding mode,ship block is the most important intermediate product in the shipbuilding process,and ship block outdoor logistics is an important intermediate link in the whole shipbuilding process.Optimizing scheduling of the key resources in block outdoor logistics,establishing reasonable block logistics planning and scientific management of block logistics process will help improve ship production management,which is effective in reducing the cost and improving the efficiency.In order to make it possible to use the key resources in the process of ship block logistics efficiently and balanced,minimize the block logistics delay and the cost of block logistics transportation,intensive researches on several key problems about ship block outdoor logistics have been made.With respect to the above analysis,the main contents of this dissertation are outline as follows:(1)In this paper,the simulation platform was selected that is applicable to the shipbuilding production through the literature research and analysis,based on the actual demand which for reducing the logistics cost through the local re-layout of the shipyard.Aiming at the disadvantage that be difficult to build the PPR information model of automobile and aviation in the field of manufacturing simulation now.The standard simulation model of ship block outdoor logistics was established by using the theory of 6-Factor information of shipbuilding.This paper provided a decision reference for shipyard manangement layer based on simulation and analysis of different layout schemes which based on the secondary development of the simulation platform that constructed a 3D virtual shipyard model.The simulation experiment showed the effectiveness of the establishment of standard block logistics simulation data model which used 6-Factor information theory,and verified the effectiveness of the analysis block outdoor logistics field layout in the shipyard based on the method of discrete event system simulation.(2)Aiming at the problems of block stockyard scheduling operation in the process of ship block outdoor logistics,a stockyard model was established,which was divided by row with the non-width,to overcome the disadvantages that the actual characteristics of block transportation requiring trestles to support may not have been taken into account in the previous research.The space utilization of stockyard can be improved and the operation of transporters can be simplified inside the stockyard by using this model.According to the actual characteristics of the target shipyard,the dynamic optimization models were established respectively for one-way stockyard and two-way stockyard based on dynamic equation theory.In order to minimize the interference movement of blocks,greedy algorithm was designed.According to the simulation results by using the greedy algorithm,compared with the results of Monte Carlo simulation,it was shown that greedy algorithm is a good solution for this problem.What's more,the problem of selecting the optimal intermediate stockyard for blocks which the capacity constraints of the stockyard must be satisfied.And then the model of block stockyard scheduling operation was put forward with consideration of the assignment of blocks.According to calculate the optimal solution the sum of the block transportation time and the interference time in the stockyard,the optimal plan for block stockyard scheduling operation was established based on genetic algorithm.The effectiveness of the model and algorithm was verified by simulation experiments.It has been proved that this solution will make a great progress on block stockyard scheduling operation to overcome the disadvantages of low efficiency to establish the block stockyard scheduling operation plans just based on the artificial scheduling model of expert experience.(3)Considering the characters of block transportation scheduling problem,it belongs to multi vehicle scheduling problem with time constraints.In order to minimize the penalty time,which is the sum of empty transporter travel time,delay time and tardy time,an optimization model was proposed with consideration the constraints of loading capacity for different types of transporters and the time constraints of block logistics transportation tasks.Due to the result of the proposed solution based on genetic algorithm is not good and it is apt to appear premature convergence,an approximate model was developed based on bounded estimation theory.By this method,then the complex multiple traveling salesman problem was transformed into assignment problem and asymmetric traveling salesman problem.Based on this,hybrid greedy algorithm was proposed to solve this mathematical model.The numerical simulation confirmed the effectivity and precision of the hybrid greedy algorithm based on assignment problem model and asymmetric traveling salesman problem model.It was pretty obvious that the efficiency and results are much better than those of genetic algorithm.(4)According to the extensive research of the shipyard,this paper systematically analyzes the problems and the necessity of the research on the real-time monitoring of ship block outdoor logistics in the shipyard.In order to solve the fixation management of the ship block outdoor logistics and visual tracking problem,the system scheme of the comprehensive real-time monitoring of the shipyard ship block outdoor logistics was put forward.And a shipyard outdoor field digital map based on address encoding system of shipyard outdoor area and geographic information system technology was constructed.An measurement scheme for the size and position blocks was presented based on buried the RFID tags underground in the outer field of shipyard and the handheld terminal system technology.Aiming at the problem of inaccurate positioning of transporters in the complex metal environment in the shipyard,this paper proposed a solution based on transporters which the technology of combination of GPS and RFID was adopt.In order to reduce the energy consumption of the transporters,a real-time optimal logistics path model of block transportation was established,taking account of the optimal driving path and the number of turns,and the Dijkstra algorithm was used to solve the model.The simulation results validated the validity of the model and algorithm,the model and algorithm can completely satisfied the requirements of real-time optimal energy consumption path planning in the block logistics process.(5)Combined with the actual situation of the block outdoor logistics in a shipyard,the ship block outdoor logistics operation system was constructed.Taking the block stockyard operational plan,the block transportation scheduling plan and the block visual tracking of the block outdoor logistics in the shipyard as an example,the established mathematical model,the corresponding algorithm and the related proposal of this study were verified.