Feed control device for a harvesting machine method of controlling

A method of controlling feed of material to be harvested to a harvesting machine, said harvesting machine comprising an attachment for collecting the material to be harvested, a feed device including at least one rotating element for feeding collected material from the attachment, a rotatable cutting drum for the material, an ejection means for conveying the material away from the cutting drum, hydrostatic means for rotatably driving the at least one rotating element of the feed device hydrostatically and drum drive means for rotatably driving the at least one rotating element of the cutting drum, said method comprising the steps of:

• a) measuring respective actual rotation speeds of the at least one rotating element of the feed device and of the cutting drum by associated rotation speed sensors and transmitting signals indicative of measured values of the actual rotation speeds measured by the rotation speed sensors to an electronic analysis unit;
• b) computing an actual rotation speed ratio of said measured values of the respective actual rotation speeds of the feed device and the cutting drum in the electronic analysis unit;
• c) comparing a set rotation speed ratio with the actual rotation speed ratio computed in step b) in the electronic analysis unit;
• d) computing a difference between the set rotation speed ratio and the actual rotation speed ratio in the electronic analysis unit;
• and
• e) generating a control signal for control of the hydrostatic means for driving the feed device in the electronic analysis unit according to said difference, so that said difference can be at least reduced in accordance with the control signal, which thereby provides a substantially constant length cut of the material.