A method for dismantling a stack of flat objects piece by piece, in which the top object of the stack is moved in its plane, gripped at its freed edge and removed from the stack. The control unit detects a line segment along a lane in which the vehicle is traveling, detects a vector indicative of the direction on a road-fixed coordinate system of the obtained line segment, and controls correction of horizontal and vertical directions of the center axis of the sensor so as to coincide with the direction of the detected vector. The memory control device and the slave device each include read and write aligners. Functions can include, feeding documents into the apparatus, singulating documents, transporting documents through at least a portion of the apparatus, scanning documents, printing on documents and sorting documents according to scanned information. Finally, the tentative model is updated with the data values from the spectral simulations.