Applied Mechanics and Materials Vols. 97-98

Abstract: Travel time reliability, as a measure of performance, is attracting more and more attention because unreliable transportation information hinders travelers’ decision making and creates difficulties for authorities to manage network operations. Since travel time reliability is closely related to the stochastic properties of the day-to-day travel time distribution, several statistical measures have been proposed, including standard deviation, coefficient of variation, buffer index, misery index and so on. Each of these measures is derived from travel time distribution but captures only one or two characteristics of travel time. In this paper, an effort is made to evaluate travel time reliability incorporating as many characteristics of travel time as possible based on fuzzy logic. The basic rules are: (1) the larger the variance is, the more unreliable the travel time is; (2) the larger the travel times of unlucky travelers are, the more unreliable the travel time is; (3) the larger the distribution skews to the left, the more unreliable the travel time is. The proposed methodology has been tested and analyzed with field data.

Abstract: A dynamic parameters model is presented based on cellular automata for pedestrian evacuation in this paper. The dynamic parameters: Direction-parameter, Empty-parameter and Cognition-parameter are formulated to simplify tactically the decision-making process of pedestrians, which can reflect the pedestrian judgment on the surrounding conditions and decide the pedestrian’s choice of action. Pedestrian moving rules were established, according to two-dimensional cellular automaton. The simulation results of the model are analyzed. It is observed that there is a linear relationship between evacuation time and pedestrian density, however, there is a negative exponential relationship between evacuation time and exit width. The simulation results correspond with the actual, it is instructional significant for pedestrian evacuation.

Abstract: In order to evaluate waterway navigation environment more systemically, the Set Pair Analysis Evaluation Model for the environment was established according to basic principle of SPA, on basis of safety affection factors being analyzed. In accordance with risk degree of each factor, the expression of Connection Degree can be obtained, proceeding with estimating the safety of a channel. This model used, the waterway navigation safety level can be evaluated more objectively, comprehensively and systemically, and criticalities of affect or indeterminate factors gained in a quantitative way. Targeting measures could be implemented to improve navigation conditions to ensure navigation safety with the assessment conclusion being based on.

Abstract: In the actual process of navigation, signal interference and inaccurate tracking model can cause inaccurate positioning of navigation. Various filtering algorithms are needed to filter out the interference and improve precision.First of all, this paper elaborates and compares Kalman filtering algorithms and H∞ filtering algorithm, which are both applied in filtering GNSS navigation data. After that, some datas are selected from the vehicle navigation data as the source datas. In the meantime, depend on the ideal model, factors are added into it in consideration of practical application. As a result, the mathematical models for Kalman and H∞ are established. According to the filter algorithm and the mathematic model, simulation programs and their flow charts of Kalman filtering algorithm and H∞ filtering algorithm are all accomplished. Finally, it shows the results of simulation and analyses the problems appeared.

Abstract: The Car networking based on WiMax and Zigbee technology is mainly adopting WiMax network and Zigbee technology to build traffic information transmission system, using sensor carrying on the real-time data acquisition including the vehicle running and road condition data, with the chip storing date of vehicles or road, thus realizing the information communication between vehicles and vehicles, vehicle and roads, security control of vehicles. Test results show that the system can realize remote communication between vehicles and roads, traffic signs automatic identification, measuring the distance between vehicles and the safety control of vehicles in cases of emergency brake. Compared with traditional network, this network has its advantage with lower cost, easier to deploy and operating. This system is feasible in technique and reasonable in economy, suitable for security applications, such as collision warning, efficiency application, such as road tolling, commercial applications and information entertainment applications, has quite strong practicability.

Abstract: This paper bases on LabVIEW, combines corresponding NI industrial computer and DAQ card, completes stress strain signal data acquisition and processing automatically. It had real time storage, data processing and other functions. It had the advantages of flexibility using, portability and costly effective. It shows that using the NI computer testing replaces traditional strain measuring instrument, which has an important signification for stress and strain signal data acquisition and processing.

Abstract: The Macro-road traffic accident prediction is an important branch of ITS, which could not only make improving direction, but also improve the traffic operation. The paper based on the analyzing the existing macro prediction model, aiming at the existing shortcomings of prediction models with low accuracy and slow convergence speed, introducing the Radial Basis Function, establishing the accident prediction model between Population, Economic situation, cars, road mileage and the index of accident Statistics, and apply Matlab to Simulation to prove the Feasibility and Practicality of the model.

Abstract: The position of Container Terminal as a transit of a complete logistics system is very prominent. With the rapid development of modern port, the rapid increase in container traffic takes tremendous pressure to terminals. The impact of the restowing problem to the operational efficiency is increasingly prominent. The research on addressing model of the container is important to cut down the restowing rate and improve the operational efficiency. A study is conducted on this in this paper.

Abstract: Hierarchy control strategy and ant colony optimization are proposed for coordinated ramp control. The macroscopic model to describe the evolution of freeway traffic flow is firstly established. Then the coordinated ramp control system is designed. There are two layers in this coordinated control system: the coordination control layer to select traffic models, to adjust the model parameters, and to determine the desired traffic density in each freeway section according to the current traffic status; and the direct control layer to keep the actual values of state variables in the vicinity of the desired state points via PI controllers. Ant colony algorithm is used to find the optimal PI control parameters. Simulation results show that the control system is of good performance. It can eliminate traffic jams, maintain traffic flow stability, and make vehicles travel more efficiently and safely.

Abstract: Train operation safety is the most important and the most basic requirement. Locomotive traction motor is the train operation of traction power equipment, whose reliability relates directly to the train operation safety. And locomotive traction motor fault diagnosis is to ensure the reliability of the traction motor scooter important technique means. Through the locomotive pulling motor failure diagnosis method's research, the traction motor typical fault type has been summarized, the main intelligent diagnosis method principle has been narrated, the main principles of the intelligent diagnosis, diagnostic procedures, and their advantages and disadvantages are described in detail, the existing problems in the field and future trends are pointed out finally.