Comparison of Various Methods for the Calculation of the Distance Potential Field

TL;DR

This paper reviews and compares various methods for calculating distance potential fields in pedestrian dynamics, focusing on their accuracy and computational efficiency, especially when the environment changes during simulation.

Contribution

It provides an overview of existing and new methods for potential field calculation, analyzing their accuracy and speed, and discusses their advantages and drawbacks.

Findings

Exact methods vary in computational speed.

Approximate methods offer faster calculations with some accuracy trade-offs.

Environmental changes during simulation impact method choice.

Abstract

The distance from a given position toward one or more destinations, exits, and way points is a more or less important input variable in most models of pedestrian dynamics. Except for the special case when there are no obstacles in a concave scenario -- i.e. each position is visible from any other -- the calculation of these distances is a non-trivial task. This isn't that big a problem, as long as the model only demands the distances to be stored in a Static Floor Field also called Potential Field, which never changes throughout the whole simulation. In this case a pre-calculation once before the simulation starts is sufficient. But if one wants to allow changes of the geometry during a simulation run -- imagine doors or the blocking of a corridor due to some hazard -- in the Distance Potential Field, calculation time matters strongly. This contribution gives an overview over existing and new exact and approximate methods to calculate a potential field, analytical investigations for their exactness, and tests of their computation speed. The advantages and drawbacks of the methods are discussed.