Applied Mechanics and Materials Vols. 409-410

Abstract: The driver characteristic is an important factor that affects driver behaviors, however, the existing driver behavior models little consider the influence of driver own characteristic differences on the driver behaviors. As the driver mental and physical behaviors in the process of driving are uncertainty and ambiguity, the mainline vehicles at expressway-ramp merging area are selected as research object, and the fuzzy clustering theory is introduced. In order to describe the mainline drivers characteristics accurately, the mainline vehicle acceleration, the relative speed of the current mainline vehicle to the all mainline vehicles and the lag gap of the mainline vehicle are selected to cluster by the fuzzy clustering method, and the driver type distribution model is built by K-S test method. Then, the driver type distribution data as a key parameter is incorporated into the expressway merging model, in order to represent the effect of driver characteristic on drive behavior. Finally, the microscopic traffic simulation system MTSS is taken as the simulation plat to build simulation model and validate the built mainline driver type model, the output results from the simulation system are compared with the field data, the satisfactory results indicate that the built driver type model can be used to describe the impact of driver type on driving behavior.

Abstract: The objective of this study is to develop a dynamic algorithm for traffic control subarea partition. Influencing factors are classified into static factors and dynamic factors. We mainly focus on the three dynamic factors which are cycle length, platoon length and traffic flow continuation. An integrated correlation model is established to quantify the correlation degree of adjacent intersections and then a dynamic partition algorithm is developed based on the model. Both this algorithm and Changs algorithm, which is a representative achievement in subarea partition cited by Traffic control systems Handbook, are applied to a network including 20 signalized intersections in VISSIM to compare their benefits. Statistical results show that: (a) adjacent intersections with high correlation degree can be partitioned into one subarea to execute signal coordination according to our algorithm; (b) implementing our algorithm can save average vehicle delay by 8.9% and average vehicle stops by 7.8% than implementing Changs algorithm.

Abstract: To develop a quick offset optimization mehtod for traffic signal coordination scheme, the calculating methods for common cycle length and green split are brought forward firstly. Based on the vehicle delay model under isolated traffic control mode, the progression factor is introduced to improve the model. Then the relationship between progression factor and offset is derived. Minimizing average vehicle delay is selected as the optimization objective, the function with simple structure between the objective and offset is developed. At last, take two adjacent signalized intersections as example, the optimizaiton method is validated and the results show that the method is effective.

Abstract: As the complex urban transportation network node,passenger transfer hub is the area of vary transport mode transforming and vary direction passenger flow assembling.Improve the service level and the transfer efficiency will increase the convenience, comfort and safety of the passenger transfer hub.Firstly,pedestrian traffic characteristics were analyzed in the hub based on the field experimental data.Secondly,pedestrian parameter relation models and relation curves of horizontal channel and stairs were established,and space parameter added at the same time.Finally,Applying Commuter software to simulate on Hohhot railway station for example and obtain some basic data related to pedestrian and vehicle equipment in order to provide certain support for evaluating the transfer efficiency-service level-operational management of the hub.

Abstract: In reality transportation network is dynamic and stochastic. Studies on the dynamic stochastic shortest path problem are of great research and application value. This paper introduces basic genetic algorithm into it. Then an improved self-adaptive genetic algorithm is proposed by improving population initialization, selection strategy, crossover strategy and mutation strategy. In addition, the improved genetic algorithm adjusts the crossover and mutation factors adaptively. The results of simulation experiment show that the improved genetic algorithm proposed by this paper has much higher capacity of global optimization than Dijkstra and A* algorithm in the dynamic stochastic shortest path problem.

Abstract: Taking the fact that the fire explosion is the major danger during the transportation of flammable solid into account, the paper proposes a Fault Tree (FT) model about fire explosions affected greatly by packing, loading and unloading, vehicles, management and other factors, and converts the FT model into Bayesian Network (BN) one for quantitative analysis. Finally, the paper uses the data based on the BN model to prove that the model and algorithm are feasible.

Abstract: Extracting vehicles track at roundabout is the basis research for motion characteristics of vehicles. At present, most of the vehicle trajectory was obtained by using single data source. However, the precision of the method needs to be improved. In this paper, two cameras are set at two different directions shooting the same scene image to obtain image data. And then a new method to extracted vehicles track more accurately by integrate the dual data source organically was proposed. In the case analysis, through the contrastive analysis of 4 different curves, the result shows that the error of dual data detection is decreased by 2.7% than single data detection. The method to extract vehicles track by dual data source can provide the theoretical support for the analysis of traffic conditions at roundabout.

Abstract: Port inventory is a very important part in iron ore supply chain. Through the inventory management, we can get the best inventory strategy to minimize the total inventory cost. The inventory management of the port iron ore can get a reasonable and feasible inventory management strategy through the dynamic planning model.

Abstract: One new structure of Semi-step Walking Wheel Modeled on Impeller is constructed based on Vehicle-Terramechanics. Based on Passive earth pressure of soil mechanics put forward by C.A.Coulomb, the front force formula of the vane of Semi-step Walking Wheel modeled on Impeller is reduced and the wheel traction force when a set of vanes insert the earth is derived. Some Kinematics Simulations are conducted for installing Lunar rover model with ADAMS software. The simulation results show that the wheel can travel smoothly on straight road, climb over bump obstacles. Also, the ability of the lunar rover one-side surmounting obstacle is better than the ability of two-sides. The walking wheel inherits high ride comfort of traditional wheel and excellent cross obstacle ability of walking wheel.

Abstract: With the building and analysis of 2 DOFs linear model of vehicle ,the keeping at zero of body sideslip angle is regarded as the control target of four-wheel-steering(4WS) to conduct the simulation and analysis of its handling stability in Simulink. There are many methods and parameters to evaluate handling stability. In this paper,one kind of double-move-line performance is used to do the evaluation.In order to make the result more intuitive,virtual reality toolbox in MATLAB are used to link the data in Simulink and the virtual world built by V-Realm Builder,which display the transient response of 4WS in high speed when it is in the emergency of obstacle avoidance .For the purpose of evaluation of handling stability,a front-wheel-steering(2WS) model is built to present a comparison to 4WS.