Automatic Feed Rate Control with Feed-forward for Crushing and Screening Processes

Crushing and screening processes for aggregates are purpose-designed processes for producing aggregate fractions with pre-specified quality specifications. An aggregate production plant, crushing station, basically involves crushers in series for crushing rocks and screens for classifying and separating fractions measured in size. The specifications on the end-products affect the plant layout including a number of the required crushing stages. However, one thing being in common with all plants is that the first stage of the process is human-based excavator or dumper feeding. A load of rocks are fed onto a primary feeder on an irregular basis. Then, the feeder carries the rocks to the primary crusher determining the maximum achievable production rate. The automatic control of the primary feeder is in the scope of this paper. A new feed-forward control -based approach is presented for allowing a non-interruptible and a more productive aggregate production.