METHOD AND ARRANGEMENT FOR MONITORING THE WORKING MOVEMENT OF A DEVICE OPERATED BY A HYDRAULIC CYLINDER

摘要

The invention relates to a method and system for following accurately the working motion of an apparatus powered by a hydraulic cylinder such as the working motion of the cutting saw of a harvester as well as predicitng accurately and reliably the ending time of the working motion. The invention may be applied e.g. for timing the colour marking of cut logs as well as halting the saw at the end point of the working motion. It is characteristic that the oil withdrawing from the hydraulic cylinder during the working motion is conducted into a hydraulic motor (30). The rotations or partial rotations of the hydraulic motor (30) are registered as electric pulses with an inductive transducer (24) or the like device.