Guidance And Control Method Study On Dynamic Traffic Assignment

With the economy growth and the rapid increase of automobile, traffic jam is becoming more and more severe, and it is an imperative problem what kinds of traffic control and guidance methods can be applied to lighten it and effectively improve traffic systems' efficiency. Dynamic traffic assignment is the key to this problem, and it plays an important role in the traffic control and guidance. Dynamic traffic assignment is based on equilibrium assignment, so that we can duly apply appropriate control or guidance methods to improve traffic assignment of time and space, and make systems run fluently.According to different traffic types and conditions, we employ different guidance policies. For comparatively simple freeways or long sections of highways, it is apt to apply outer-vehicle colony guidance. While for comparatively complex urban roads, it is apt to inner-vehicle unit guidance. This paper mainly focus on the following two aspects:Firstly, for a simple sample freeway with one origin and one destination, this paper applies outer-vehicle colony guidance method. Comparing with some previous researches, the paper considers the norm-bounded exogenous disturbance in the traffic model. By applying the MINIMAX control approach, it is shown that the resulting control law is of the bang-bang type. The simulation result shows that the MINIMAX control approach is preponderant.Secondly, this paper applies inner-vehicle unit guidance method to complexurban traffic networks with multi-origin and multi-destination, and it deals with the dynamic routing problem of traffic networks by employing nonlinear H control design methodology so that provides robustness against bounded disturbance. This paper solves the optimal dynamic routing problem by only performing simple algebraic operations in real-time, unlike existing techniques which rely on lengthy off-line/ on-line mathematical operations.