Embodiments of the invention relate to compounds and methods for controlling algal growth, for example, in bodies of water or surfaces exposed to algae. In a method for detecting a change in a field of view from a first point in time to a second point in time, a current three-dimensional dataset of the field of view is generated from a point of reference based on data received in real-time. The type of vehicle that moves on top of the guideway includes auxiliary wheels which cooperate with auxiliary tracks in Y junctions to insure reliable support.