This research aims to propose an efficient and economic operation mode for bus scheduling optimization by combining with the skip-stop buses and all-stop buses.The skip-stop tactics in bus operation provide service of...This research aims to propose an efficient and economic operation mode for bus scheduling optimization by combining with the skip-stop buses and all-stop buses.The skip-stop tactics in bus operation provide service of high efficiency,good punctuality and high speed for long distance commuters,which attracts wide scholarly attention.This paper establishes a model to quantitatively evaluate the relevance between stops,and then develops a new optimization method of skip-stop tactics using the data sets of IC card and bus GPS trajectory.A collaborating scheduling optimization model considering the support and confidence among the stops is proposed to precisely suit passengers’demands and improve bus service.The optimization objective is to reduce the passengers’total travel time,the number of vehicles in use,and operation energy for both the user’s and the operator’s benefits.This methodology is developed for a single-directional route using a multi-decision choice model with genetic algorithm applied to attain efficient solutions.A case study of Qingdao,which is assessed in this new model,shows a reduction of 18.31%in total passenger travel time and 17.65%in the operational inputs as compared with solutions that do not consider the skip-stop tactics.展开更多
By thorough research on the prominent periodic and aperiodic scheduling algorithms,anon-line hard real-time scheduler is presented,which is applicable to the scheduling of packets over a link.This scheduler,based on b...By thorough research on the prominent periodic and aperiodic scheduling algorithms,anon-line hard real-time scheduler is presented,which is applicable to the scheduling of packets over a link.This scheduler,based on both Rate Monotonic,pinwheel scheduling algorithm Sr and Polling Serverscheduling algorithms,can rapidly judge the schedulability and then automatically generate a bus tablefor the scheduling algorithm to schedule the packets as the periodic packets.The implementation of thescheduler is simple and easy to use,and it is effective for the utilization of bus link.The orderly executionof the bus table can not only guarantee the performance of the hard real time but also avoid the blockageand interruption of the message transmission.So the scheduler perfectly meets the demand of hard real-time communication system on the field bus domain.展开更多
It is becoming increasingly difficult for Chinese citizens to access traditional public transport because of overcrowded community structures. Therefore, novel ideas are required to improve the transport system. In th...It is becoming increasingly difficult for Chinese citizens to access traditional public transport because of overcrowded community structures. Therefore, novel ideas are required to improve the transport system. In this respect, this study considers the design of a public transport scheduling model for a micro system. The model aims to minimize passenger waiting time and maximize number of passengers one bus carries, by simultaneously optimizing departure intervals and use of traditional and rapid buses. The model is superior to traditional models, as it analyzes the phenomena of vehicle overtaking, vehicle capacity limit, and passenger determination uncertainty. In addition, the model is a sophisticated nonlinear multi-objective optimization problem and contains more than one type of decision variable, therefore two composite algorithms, HPSO and GAPSO, are proposed, which are improvements of the Genetic Algorithm (GA) and Particle Swarm Optimization (PSO). These two algorithms are compared to the classical GA with respect to stability and effect, and the results show them to be strong in both respects. In addition, the simultaneous optimization method has evident advantages compared to single-method optimizations.展开更多
The purpose of this paper is to develop an implementable strategy of brake energy recovery for a parallel hydraulic hybrid bus. Based on brake process analysis, a dynamic programming algorithm of brake energy recovery...The purpose of this paper is to develop an implementable strategy of brake energy recovery for a parallel hydraulic hybrid bus. Based on brake process analysis, a dynamic programming algorithm of brake energy recovery is established. And then an implementable strategy of brake energy recovery is proposed by the constraint variable trajectories analysis of the dynamic programming algorithm in the typical urban bus cycle. The simulation results indicate the brake energy recovery efficiency of the accumulator can reach 60% in the dynamic programming algorithm. And the hydraulic hybrid system can output braking torque as much as possible.Moreover, the accumulator has almost equal efficiency of brake energy recovery between the implementable strategy and the dynamic programming algorithm. Therefore, the implementable strategy is very effective in improving the efficiency of brake energy recovery.The road tests show the fuel economy of the hydraulic hybrid bus improves by 22.6% compared with the conventional bus.展开更多
基金the MOE Project of Humanities and Social Sciences(18YJCZH039)General Social Science Projects of Beijing Municipal Education Commission(SM202010005016)。
文摘This research aims to propose an efficient and economic operation mode for bus scheduling optimization by combining with the skip-stop buses and all-stop buses.The skip-stop tactics in bus operation provide service of high efficiency,good punctuality and high speed for long distance commuters,which attracts wide scholarly attention.This paper establishes a model to quantitatively evaluate the relevance between stops,and then develops a new optimization method of skip-stop tactics using the data sets of IC card and bus GPS trajectory.A collaborating scheduling optimization model considering the support and confidence among the stops is proposed to precisely suit passengers’demands and improve bus service.The optimization objective is to reduce the passengers’total travel time,the number of vehicles in use,and operation energy for both the user’s and the operator’s benefits.This methodology is developed for a single-directional route using a multi-decision choice model with genetic algorithm applied to attain efficient solutions.A case study of Qingdao,which is assessed in this new model,shows a reduction of 18.31%in total passenger travel time and 17.65%in the operational inputs as compared with solutions that do not consider the skip-stop tactics.
基金Supported by the Emphases Science and Technology Project Foundation of Sichuan Province(NO.02GG006-037)
文摘By thorough research on the prominent periodic and aperiodic scheduling algorithms,anon-line hard real-time scheduler is presented,which is applicable to the scheduling of packets over a link.This scheduler,based on both Rate Monotonic,pinwheel scheduling algorithm Sr and Polling Serverscheduling algorithms,can rapidly judge the schedulability and then automatically generate a bus tablefor the scheduling algorithm to schedule the packets as the periodic packets.The implementation of thescheduler is simple and easy to use,and it is effective for the utilization of bus link.The orderly executionof the bus table can not only guarantee the performance of the hard real time but also avoid the blockageand interruption of the message transmission.So the scheduler perfectly meets the demand of hard real-time communication system on the field bus domain.
基金supported by the National Key Basic Research and Development Program in China(No.2016YFB0100906)the National Key Technology Research and Development Program(No.2014BAG03B01)+1 种基金the National Natural Science Foundation of China(Nos.61273238 and 61673232)Beijing Manicipal Science and Technology Program(No.D15110900280000)
文摘It is becoming increasingly difficult for Chinese citizens to access traditional public transport because of overcrowded community structures. Therefore, novel ideas are required to improve the transport system. In this respect, this study considers the design of a public transport scheduling model for a micro system. The model aims to minimize passenger waiting time and maximize number of passengers one bus carries, by simultaneously optimizing departure intervals and use of traditional and rapid buses. The model is superior to traditional models, as it analyzes the phenomena of vehicle overtaking, vehicle capacity limit, and passenger determination uncertainty. In addition, the model is a sophisticated nonlinear multi-objective optimization problem and contains more than one type of decision variable, therefore two composite algorithms, HPSO and GAPSO, are proposed, which are improvements of the Genetic Algorithm (GA) and Particle Swarm Optimization (PSO). These two algorithms are compared to the classical GA with respect to stability and effect, and the results show them to be strong in both respects. In addition, the simultaneous optimization method has evident advantages compared to single-method optimizations.
基金supported by Shanghai Science and Technology Committee(No.0904H155100)
文摘The purpose of this paper is to develop an implementable strategy of brake energy recovery for a parallel hydraulic hybrid bus. Based on brake process analysis, a dynamic programming algorithm of brake energy recovery is established. And then an implementable strategy of brake energy recovery is proposed by the constraint variable trajectories analysis of the dynamic programming algorithm in the typical urban bus cycle. The simulation results indicate the brake energy recovery efficiency of the accumulator can reach 60% in the dynamic programming algorithm. And the hydraulic hybrid system can output braking torque as much as possible.Moreover, the accumulator has almost equal efficiency of brake energy recovery between the implementable strategy and the dynamic programming algorithm. Therefore, the implementable strategy is very effective in improving the efficiency of brake energy recovery.The road tests show the fuel economy of the hydraulic hybrid bus improves by 22.6% compared with the conventional bus.