A method, a system and a harvester (100) are arranged to detect a steady operating state of the harvester (100). A crop sensor (178b, 178c, 178e, 178f, 178g) senses a crop parameter. A processing result sensor (172a, 172b, 174, 178a, 178d) senses at least one processing result parameter. The crop parameter, the processing result parameter and time derivatives of the crop parameter and the processing result parameter are submitted as input signals to a fuzzy logic circuit (222). The fuzzy logic circuit (222) is configured to generate a binary steady state signal value indicating a steady state of the crop processing in the harvesting machine based upon the input signals.
