Pedestrian Simulation In Transport Hub Based On Macro And Micro Distribution Model

Because of the continuous expansion of city size and increase of population density, the problem of traffic has become the main bottleneck of Restricting the rapid development of a city. At home and abroad a common method to solve traffic problems is to construct large-scale urban rail transport hub, however, the evaluation of these hubs tend to rely on the judge by experience or Obtained through field investigation and analysis after the completion of construction. But the transport hub is difficult to do large-scale transformation because the construction cost and time-spent are very enormous, which makes the traffic simulation technology came into being.Transportation simulation originated in the sixties of last century, was an important application of multi-agent simulation technology in the field of traffic engineering and along with advances in computer technology to develop. Through simulation and analysis of computer technology, realized the reproduction and prediction of the collection and distribution behavior of large-scale pedestrian flow in transport hub, thus provided the data support for querying the bottleneck of collection and distribution in existing transport hub as well as analyzing and evaluating the design for newly built transport hub.This article take the urban track transport hub as an example in the existing rationale, using the pedestrian OD type and the knowledge of corresponding key activity link node as well as the FSM of pedestrian condition to realizes the production and control of the pedestrian dynamic move plan, and separately from macroscopic, microscopic two aspects discussed the algorithm of Agent's path choice in transport hub as well as the algorithm of collision avoidance and detouring between pedestrians, pedestrians and obstacles.Macro:with the method which based on the view to search all the associated obstacles between adjacent logic facilities in transport hub, and on this basis, using A* algorithm to search the shortest path between adjacent logic facilities. At the same time, combined with their habit of pedestrians walking to amend the shortest path to determine the macro-walking track of pedestrian flow in the transport hub. In the process of using A* algorithm to find the shortest path between adjacent logic facilities, the evaluation function of this algorithm has been discussed in this paper and the concept of the direction angle have been introduced based on the traditional Euclidean distance, making the speed of the shortest path search improved obviously. Micro:separately using the model of social force and the model of blocking angle to solve the phenomenon of Collision and overlapping causing by the difference of pedestrian flow's direction of the movement and speed along the path followed by the macro activities through its own chain of the main facilities of each logical. The model of social force use Newton's second law to change the trajectory of pedestrian entity by stress analysis to pedestrian entity in each simulation step; the model of blocking angle solved the problem of collision avoidance during walking by establishing a blocking angle array with some obstacles or pedestrians around the pedestrian who is being considered and choosing a Local optimum direction from the array as the direction of walking. At the same time the model can solve the problem of being surrounded by obstacles in the algorithm of path finding. Combining the model of blocking angle with the social forces can successful solve the problem of path querying and arriving judgment as well as bypassing between pedestrians in the process of pedestrians walking between the two services. It has provided an economy, repeatable, and controlled simulation-program for the transport hub.