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

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 nontrivial 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 [1, 2, 3, 4, 5, 6, 7, 8], 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.