Modeling And Optimization Of Railway Turnout Maintenance Scheduling Problem

In accordance with the 2008 revisions of the long-term railway network plan,railway mileage in China will be more than 120,000 kilometers by 2020.By the end of 2014,railway mileage has been more than 110,000 kilometers.Railway passenger and cargo traffic have been growing year by year and the traffic volume of the railway station will increase.The area of turnouts gathering known as the bottlenecks is very complex where many frequent technical and shunting operations are performed over a long time.The turnout is not only the key links of railway infrastructure construction,but also one of the three major weaknesses.Because the price of railway transportation is fixed and lower,the overall profitability of the railway sector is poor.In order to guarantee the normal operation of the railway infrastructure,the railway sector spends a lot of money on maintenance and it is a major expenditure.Therefore,the research of turnout maintenance scheduling to reduce the total cost could save a certain amount of money and ensure the normal use of procession of railway turnouts so as to improve the security of the whole railway network.The area of turnouts gathering is the region where the trains must pass through.To avoid conflict of turnout maintenance time and arrival time it needs to optimize the train path sending enough teams to select the gap of the train time for maintenance.In this study,the total cost of maintaining includes turnout maintenance cost,fixed cost of maintenance team and traveling cost between the turnouts.The research of this thesis is as follows:(1)The railway turnout maintenance scheduling problem is summarized.This thesis introduces the research status of train route optimization,turnout maintenance scheduling problem,and the relevant solving algorithms.(2)For the goal of the total maintenance cost,the research firstly considers the arrival time of trains,the distribution of the maintenance team and so on.The start time for maintenance chooses from the time window and a 0-1 linear programming model is established.(3)In the previous question on the basis of considering the travel time between maintenance team on the turnouts,turnouts to maintain order,will start to choose the maintenance time from the scope of the integer variables and a pure integer linear programming model is established.(4)According to the actual situation of Shenyang north station,based on satellite map to establish the bottlenecks network structure,download a table of the train time in the network and then established the practical examples of Shenyang north railway station turnout maintenance scheduling.Taking the instance of Shenyang North Railway Station,the relevant data are acquired through certain rules,and the case is generated.Then,using optimization software CPLEX to verify and analyze the model of a basic mathematical model and a scheduling model will gain the start time of turnout maintenance,the train's route(route means through the turnout in the sequence)and the maintenance order.Based on the analysis of the results,some preliminary conclusions and management implications are obtained.