Research On The Optimization And Decision Support About Loading And Reinforcement Of Railway Exceptional Dimension Freight

Goods loading reinforcement plays an important role in guaranteeing the safety of railway transportation and is an important part of transportation organization. It ensures the safety of the goods, locomotives and transportation operation. Recently, with the rapid development of railway logistics and the appearance of personalized customer requirements, it has become an urgent problem how to better utilize the carrying capacity and volume of railway freight cars to provide safe, reasonable, economical and convenient loading reinforcement plans quickly.Nowadays, the competition between railway transportation and road transportation is becoming increasingly fierce. Recently, road transportation vehicles have been developing rapidly, and its transport technology has been improving unprecedentedly. Also, road transportation has more advantages than railway transportation, like its flexibility and convenience. Thus, railway transportation is facing a huge challenge. The monopoly situation for the railway as the first choice for transportation has been greatly changed; thus, the competitiveness in exceptional dimension freight transportation of the railway has to be improved comprehensively, so that exceptional dimension freight transportation of the railway can achieve better development.Exceptional dimension freight requires a high standard for railway transportation. At the same time, the development of high speed trains imposes a new requirement for the safety of railway freight cars. In order to avoid accidents caused by the problems of goods loading reinforcement, specific goods loading reinforcement plans has to be made according to the goods to guarantee the safety of the goods as well as railway operation. There are a large number of factors to consider and a lot of computation required when determining the plans for good loading reinforcement. Thus, making the plans manually not only takes a long time, but also tend to cause mistakes. Also, since there are a number of feasible plans for the same goods, it causes extra work to select the optimal plan from the available ones. Because of the above mentioned reasons, traditional ways to determine goods loading reinforcement plans cannot meet the needs of the development of railway transportation. With the development of railway information technology, the research and development of goods loading reinforcement information systems for exceptional dimension freight has been paid increasing attention, so that goods loading reinforcement plans can be determined fast and accurately using computer-aided methods. It can also facilitate railway workers to determine the optimal or conditionally optimal plan fast and scientifically, guaranteeing transportation safety, improving transportation efficiency, lowering transportation cost, improving customer satisfaction and catering the needs of the development of railway logistics, thus it is very theoretically meaningful and practically useful to carry out research on optimizing exceptional dimension freight loading reinforcement and facilitating loading reinforcement plan-making.Exceptional dimension freight loading reinforcement plan-making is very complex and computational, and it has to strictly follow relevant railway regulations and technical requirements of the locomotives. The optimal or conditionally optimal plans for exceptional dimension freight loading reinforcement should be the most economically reasonable plan among all feasible plans; it has to meet the requirements of the Regulations for Railway Freight Loading Reinforcement and guarantee the safety of railway transportation; it also has to be optimal economically, fully making use of the carrying capability both in weight and volume of relevant locomotives, reaching the lowest off-gauge grade after the freight is loaded, reducing the number of carriages needed, being easy to apply on the reinforcement and lowering the cost for the reinforcement materials and so on. At the same time, the personalized requirements of the customers have to be considered so that the service quality can be improved.Determining the loading reinforcement plan for exceptional dimension freight in railway transportation is a typical semi-structural problem. In practical processes, there are a lot of factors that influence the determining of the loading reinforcement plan, and it requires heavy efforts of relevant personnel. In this thesis, an aiding system for plan-making is proposed. It first analyzes the technical concepts of exceptional dimension freight loading reinforcement, and then establishes a computer-aided judging method for freight off-gauge grade based on the frame of the freight using geometric theories. After that, the influence of locomotive speed on the lateral acceleration of the freight is analyzed and the basis for the freight loading reinforcement research after the improvement of train speed is provided. The customer satisfaction is also included in the optimal algorithm of selecting the exceptional dimension freight loading reinforcement first time, so that the loading reinforcement plan can be optimized and support can be provided for transportation companies and other users when determining the plan. At last, a system for selecting exceptional dimension freight loading reinforcement plans in railway transportation is developed. The thesis establishes a mathematical model using the shape of the freight and other parameters and designs a computer-aided judging method for freight off-gauge grade, analyzes the influence of locomotive speed on the lateral acceleration of the freight, and establishes a multi-purpose optimal model for selecting exceptional dimension freight loading reinforcement plans based on the analytic hierarchy process. An optimal algorithm for selecting freight loading reinforcement plans is established systematically and an aiding system for exceptional dimension freight loading reinforcement plan-making is proposed. The main contributions of this research are as follows:(1)analysis and summary of the technical factors of exceptional dimension freight loading reinforcement and research results of goods loading reinforcement at home and abroad are provided. The characteristics of exceptional dimension freight are analyzed; technical factors are analyzed from three perspectives, namely the basic parameters of the freight, the loading location of the freight, and the force exertion on the freight; the influences of different technical factors on the plan-making of freight loading reinforcement are summarized.(2)The shape of the freight is quantized and a judging model for out-of-gauge grade is established. A computer judging algorithm for off-gauge rating is built based on the accurate shape of the freight, so that errors caused by manual measurement can be reduced. The shapes of many exceptional dimension freights are complicated and irregular, and this caused a lot of trouble for cross-section and calculating points detection. Inaccuracies in cross-section and calculating points detection can cause mistakes in judging whether a freight is oversize or what the off-gauge rating is. Using accurate quantized shapes of exceptional dimension freights, the cross-section and calculating points can be detected more accurately. Also, since the judgement for railway limits, locomotive limits and off-gauging rating has rules to follow, relevant mathematical models can be established accordingly, so that off-gauge rating can be judged making full use of the advantage of computer software. In this way, judgement error and manual work can be greatly reduced.(3)An optimal algorithm for exceptional dimension freight loading reinforcement is established. The vehicles are automatically sorted according to the parameters of the freight, making it convenient to choose the most suitable and easiest available vehicle when making the loading plan, and then a vehicle is chosen to be loaded or straddled according to the calculation of the freight parameters. Through human-computer interaction, whether or not using special vehicles to load can be decided. When loading the freight, a proper center of gravity of the freight need to be chosen. The number of carriages can be reduced through the vertical shift of the center of gravity, and the off-gauge rating can be lowered through the horizontal shift of the center of gravity. In this way, an optimal freight loading reinforcement plan can be made.(4)An analysis is made on the influence of the operation speed of the locomotive on the horizontal acceleration of the freight. The Simpack software is used to simulate the horizontal acceleration of the freight when the locomotive is moving. The acceleration of the locomotive body and the freight is mainly determined by the structure of the running gear (the spring suspension of the locomotive at first), the quality of the railway and the speed of the locomotive. In the operation of locomotives, the speed imposes a great influence on the inertia force. Through the simulation, the influence of locomotive speed on the horizontal acceleration can be obtained, so that the computational basis for the horizontal inertia force of the freight can be established with the improvement of locomotive operation speed.(5)A multi-purpose optimal model for exceptional dimension freight loading reinforcement plan-making is established using the analytic hierarchy process. With the rapid development of different kinds of methods of transportation, railway transportation is facing increasing competition. Thus, it is an urgent problem for railway companies to improve the service quality of railway transportation comprehensively. In this research, satisfaction of the customers is included in the goals for the plan-optimizing of exceptional dimension freight loading reinforcement for the first time. Under the prerequisite of transportation safety, theoretical support for the customer satisfaction of the exceptional dimension freight loading reinforcement plans is provided and this follows the trend of the development of railway logistics and the improvement of service quality of railway transportation.(6)An aiding system for exceptional dimension freight loading reinforcement plan-making is proposed. The determining of the loading reinforcement plans has to meet some objective limitations, besides the limitations of different parameters of the freight, the technical parameters of the locomotive, the speed of the locomotive and the performance of the reinforcement materials. Examples for these objective limitations include the availability of the locomotives and reinforcement materials. Thus, the loading reinforcement plan in practical application should be the optimal one under certain limitations, not the best one among all possible ones. The plan-making aiding system considers all possible limitations at the place where the freight is loaded and reinforced; a friendly software interface is designed to increase human-computer interaction, and the plan can be adjusted manually through this interface based on certain conditions. In this way, a conditional optimal plan for exceptional dimension freight loading reinforcement can be determined.