前向树状紧急疏散网络的自适应性控制策略分析

Adaptive strategy for managing forward tree-shaped evacuation networks

针对前向树状的紧急疏散网络,提出了一种不需要进行需求预测且具有适应性和强鲁棒性的分散式控制疏散策略。通过分析如何确定典型匝道与快速路交汇点处的最优疏散路线,明确了构建可控疏散网络的基本原则。定义了前向树状紧急疏散网络,并对所构建网络的适用范围和具体风险水平标定处理作了明确说明。针对前向树状网络的典型子结构,给出了可以始终充分利用下游通行能力,且充分考虑上游来流具有较高风险水平特点的具体疏散路线选择及放流策略。在上述典型子结构分析基础上,给出了包括如何逆流向确定路段限制性通行能力、顺流向确定路段最大可行流量以及实时动态调整疏散策略等基本步骤的网络疏散策略。最后,通过一个数值算例,比较了新策略与纯粹上游优先策略、纯粹下游优先策略的运行效率,证明了新的适应控制策略的可行性与有效性。

To evacuate the forward tree-shaped network, this paper proposed a decentralized, adaptive and robust control evacua- tion strategy that does not require demand estimate. Through analyzing how to determine the optimal routes at a typical ramp-to- freeway merge, it presented the basic principle to construct a controlled evacuation network. It defined the conception of forward tree-shaped emergency evacuation network and the made feasible application range and the specific risk level marking clear. For the typical substructure of forward tree-shaped network, it provided the evacuation routing and discharging strategy that make full use of the downstream capacity and take into account the higher risk level of the upstream incoming flow. Based on above analy- ses, it gave the basic steps of network evacuation strategy that include determining the limited capacity for every link in the up- stream direction, determining the maximum feasible flow in the downstream direction, and adjusting the strategy dynamically. At last, it used a numerical example to compare the performance among the pure upstream priority strategy, the pure downstream pri- ority strategy and the strategy proposed, the feasibility and effectiveness of the new proposed strategy are demonstrated.