Automatic Feed-Rate Control of Combines

by Friesen, Orlando H.

This thesis describes the development of an automatic control system which controls the forward speed of a self propelled combine in relation to the load on the cylinder. The purpose of the system is to keep the feed rate of the combine constant in order to increase the machine's efficiency. The system can be adjusted according to the crops and fieled conditions encountered.

Field tests were carried out in wheat, oats, and barley at several moisture and yield levels. Tests indicated that the system was able to control the feed rate at a preset level, within the range of the system dead zone. On the basis of these tests and previous grain loss vs feed rate tests, it is concluded that the control system is able to keep the grain losses from the combine at a preset level, within a range determined by the system characteristics.

The system is low in cost, simple to operate, and does not interfere with the control or operation of any other combine mechanisms.