Coherent Modeling and Effective Coordination for Building Emergency Evacuation

Building evacuation has long been recognized as an important issue to improve occupant survivability in case of emergencies. This paper presents coherent modeling and effective coordination of egress and HVAC systems for offline evacuation planning, with the goal to evaluate what is the best that can be achieved assuming that occupants follow egress instructions. Key characteristics of the egress and HVAC systems are abstracted to establish two linear state-space models, and their interdependencies are formulated as linear inequality constraints. To solve the problem, each system establishes a local representation of the global problem by combining its own detail model with an aggregate model of the other system. Model aggregation is achieved based on wavelet transformations, and a local representation of the global problem is solved by using dynamic programming within the Lagrangian relaxation and surrogate optimization framework. The novelty of our approach lies in the coherent transformations of states, multipliers, and decisions across different scales for interdependent systems with discrete variables. The method can generate a good solution when time is limited and allow incremental improvement when more time is available. Numerical results demonstrate the effectiveness of our method.