多次部分充电策略下双车型车辆配送路径研究

针对物流配送过程中燃油车和电动车并存的实际情况,综合考虑多次部分充电策略下双车型、充电设施、碳排放等因素,构建了以车辆使用成本、运输成本(含充电成本)、燃油车碳排放成本之和最小为目标的混合整数线性规划模型。选择某市配送中心为算例进行研究,采用CPLEX求解算例。结果表明:采用多次部分充电策略能进一步缓解“里程焦虑”,提高电动车装载率。之后进行单因素灵敏性分析,分析电动车的续航里程、额定载重量、充电站位置与数量对双车型路径优化结果的影响。

双积分政策下考虑双车型联合生产的研发投资策略

实施双积分政策是引导传统车企加大节能减排研发投入的重要途径。本文基于双积分政策构建垄断汽车制造商和竞争经销商组成的二级供应链,研究汽车制造商同时生产燃油车和新能源车的研发投资策略,探讨双积分政策和研发投资策略的交互影响。研究表明,在双车型生产模式下,双积分政策对燃油车燃油能耗的核算直接影响制造商研发投资策略,只有实际能耗和标准能耗适中时,汽车制造商才会同时对两类车型进行研发投资;提高研发投资水平总能增加新能源积分,但只有在其得分效率较高时才能增加燃油消耗积分;双积分政策对燃油车节能减排标准越严格,燃油车产销量越少,但并不一定能激励节能降耗的研发投资,车型能耗水平并不一定改善。

第三类摩托车——横V双缸跑车型太子车

作者尝试设计出一款新型的摩托车并已申请了外观设计专利,它具有跑车的外观造型,又保持了太子车(哈利车)特有的轻松驾姿。本文仅提出初步构想,不进行尺寸设定和理论推导。

双后桥平衡悬架骑马螺栓的布置分析

分析了双后桥车型底盘平衡悬架板簧连接骑马螺栓竖直布置与内八斜拉布置2种布置形式对平衡悬架系统的性能的影响,并通过CAE软件完成了相应骑马螺栓的受力及变形分析。通过分析可知,骑马螺栓内八字斜拉布置应力分布优于竖直布置结构,该布置可增加板簧的有效作用长度。

Bi-level model for shared parking decision-making based on parking lot assignment simulation

In order to carry out comprehensive decision-making of multi-class shared parking measures within a region, a bilevel model assisting decision-making is proposed. The upper level selects parkers＇ average satisfaction and the violation rate during peak hours as indices in object function, and sets probability distribution models describing dynamic parking demand of each site, the feasibility of shared parking scenarios and occupancy requirements during peak hours of each parking lot as restrictions. The simulation model in the lower level sets up rules to assign each parker in the random parking demand series to the proper parking lot. An iterative method is proposed to confirm the state of each parking lot at the start of formal simulations. Besides, two patterns linking initialization and formal simulation are presented to acquire multiple solutions. The results of the numerical examples indicate the effectiveness of the model and solution methods.

Bi-level programming model and algorithm for optimizing headway of public transit line

Due to the fact that headway is a key factor to be considered in bus scheduling, this paper proposes a bi-level programming model for optimizing bus headway in public transit lines. In this model, with the interests of bus companies and passengers in mind, the upper-level model＇s objective is to minimize the total cost, which is affected by frequency settings, both in time and economy in the transit system. The lower-level model is a transit assignment model used to describe the assignment of passengers＇ trips to the network based on the optimal bus headway. In order to solve the proposed model, a hybrid genetic algorithm, namely the genetic algorithm and the simulated annealing algorithm （GA-SA）, is designed. Finally, the model and the algorithm are tested against the transit data, by taking some of the bus lines of Changzhou city as an example. Results indicate that the proposed model allows supply and demand to be linked, which is reasonable, and the solving algorithm is effective.

Control Strategies for PM Synchronous Machine Controlled Rectifier Intended for Heavy-Duty Vehicle

In order to charge batteries and supply all the electrical devices like wheel-motors used in a heavy-duty hybrid electric vehicle, a solution consists in using an assembly permanent magnet generator driven by a diesel engine and a three-phase insulated gate bipolar transistor/diodes bridge controlled rectifier connected to the battery. In this work, hysteresis current control strategies combined with a judicious current sensing mode for the assembly permanent magnet synchronous machine-controlled rectifier are investigated. Main issues first concern the different kinds of transistors switching modes allowed by the proposed current sensing mode when the machine operates either as a generator or as a motor. Second, the modulated hysteresis method is presented, which merges the performances of robustness and dynamic of the classical hysteresis method and imposes the switching frequency alike pulsewidth modulation techniques. A test bench at reduced power permits to test the switching modes as well as classical and modulated hysteresis methods for both motor and generator operating modes and to validate the simulation predictions. The digital signal processor algorithm elaborated for the control strategy is flexible and adaptable to all kinds of transistor switchings and machine operating modes.

A New Lattice Model of Two-Lane Trafc Flow with the Consideration of the Honk Efect

In this paper, a new lattice model of two-lane traffic flow with the honk effect term is proposed to study the influence of the honk effect on wide moving jams under lane changing. The linear stability condition on two-lane highway is obtained by applying the linear stability theory. The modified Korteweg-de Vries （KdV） equation near the critical point is derived and the coexisting curves resulted from the modified KdV equation can be described, which shows that the critical point, the coexisting curve and the neutral stability line decrease with increasing the honk effect coe^cient. A wide moving jam can be conceivably described approximately in the unstable region. Numerical simulation is performed to verify the analytic results. The results show that the honk effect could suppress effectively the congested traffic patterns about wide moving jam propagation in lattice model of two-lane traffic flow.

A new cellular automaton model for traffic flow considering realistic turn signal effect

In real traffic,any vehicle must give lane-changing signal(i.e.the turn signal) before changing lanes;at this time,the vehicles behind the lane-changing vehicle will be hindered and may form "plugs" due to the turn signal effect.However,few studies focus on exploring the effect.In this paper,the turn signal effect was taken into account by proposing a new symmetric two-lane cellular automaton(T-STCA) model,and the new model was set to compare with the STCA,H-STCA and A-STCA models.Numerical results show that using the T-STCA model to describe lane-changing or overtaking,the process appeared in several consecutive time steps;while using the other three models,the process appeared only in one time step.In addition,the T-STCA model could describe the mixed traffic flow more realistically and the turn signal effect could help the plugs to dissolve more quickly.

Incident-based traffic congestion control strategy

Traffic incident happens frequently in urban traffic network and it affects normal operation of traffic system seriously so that study on incident-based congestion control strategies is very important. This study addresses the problem of the temporary vehicle movement bans design under incident-based traffic congestion situation. A bi-level programming model is proposed to formulate this problem. The upper level problem is to minimize the total travel cost in the view of traffic management agencies, and the lower level problem is to present travelers’ dynamic route choice behavior under temporary vehicle movement bans using the simulation of cell transmission model, then a genetic algorithm is employed to solve the proposed bi-level programming model. Computational results show that the temporary vehicle movement bans measure is able to alleviate the traffic network incident-based congestion effectively and improve system performance of traffic network.