In one embodiment, a method for determining a contour simplification of an object for a simulation is provided. By this means, a pedestrian navigation device is provided which, when navigating a pedestrian route, is able to accurately detect the direction of advance through judgment of stops and suppression of meandering. The image sequence undergoes pixel processing that determines a current background model and provides an initial pixel assignment as either a background or a foreground pixel. In response to a user’s request to formulate a specified amount of the chemical solution, the volume of water provided to the output port is monitored by a flow meter and the weight of the other component provided to the output port is monitored by one or more load cells.