Hardware Implementation of a Crowd Evacuation Model Based on Cellular Automata

Summary Cellular Automata (CA) can sufficiently represent phenomena of arbitrary complexity and at the same time they can be precisely simulated by digital computers, because of their intrinsic discreteness. A two-dimensional (2-D) CA dynamic system has been proposed to efficiently model crowd behaviour inside bounded areas to contribute to the upgrade of public facilities. This paper examines the on-chip realisation of the proposed model. The hardware implementation of the CA model is based on FPGA logic. CA cells obtain discrete values, thus indicating their status; either free or occupied. Significant parameters of the local CA rule, such as the number and the allocation of the exits or the obstacles are inputs of the dedicated processor. Initial data is loaded to the dedicated processor in a semi-parallel way, i.e. all rows of the CA grid are loaded simultaneously while data propagates in a serial way from one cell of column j to the other cell of its successive column, j+1. The automatic response of the processor provides the signals that guide the crowd in correspondence to its density around exits. In collaboration with smart cameras, the proposed FPGA processor could be incorporated in an efficient, real-time, decision-support system that would be able to guide the crowd in cases of emergency, using sound and optical signals.