Research On Rebalancing Optimization Problem Of Urban Bicycle Sharing Systems

With the traffic congestion,environmental pollution and energy consumption caused by urban traffic problems have become increasingly prominent,bicycle sharing system is considered to be an important means to alleviate the urban traffic pressure and promote the development of green transportation,which is a kind of environmental friendly,economic and healthy trip mode.However,due to the site layout planning is not perfect and the residents travel is dynamic,and daily rebalancing based on human experience,which lack of scientific and reasonable rebalancing method,it is difficult to rent or return a bike has seriously affected the operational efficiency and user satisfaction of bicycle sharing system.Based on the relevant research results,this paper considering the site importance of bicycle rebalancing problem in order to improve system efficiency and customer satisfaction,to reduce operation costs,which has a certain theoretical significance and practical value.Firstly,this paper introduces the bicycle rebalancing problem,analyzes the reasons of the rebalancing problem,the main methods and the characteristics of the BRP,and discusses the rebalancing strategy.Secondly,based on the traditional model of 1-PDTSP,a single and a multiple depot route optimization model of bicycle rebalancing vehicle considering the importance of station is established,which objectives are minimize rebalancing transportation costs and maximize customer satisfaction.The more importance of station,the more penalty cost if the vehicle did not satisfy the best time window.In order to reduce the complexity of problem,the multi-objective problem is transformed into single objective problem which minimize the rebalancing cost which include transportation cost and penalty cost.To verify the accuracy and practical of the model,a small scale instance is solved,and analyze the results of different parameters.Finally,in order to solve the large scale instance,a hybrid algorithm combined with the simulated annealing algorithm and genetic algorithm is designed,using a actual instance of city bicycle sharing system,which demonstrate the effectiveness and robustness of the algorithm..It is proved that the multi depot model considering the importance of the site is of great significance to improve the overall rebalancing efficiency,to improve the customer satisfaction and to reduce the operation cost.