Olivier, Laurentz EugeneCraig, Ian KeithChen, Y.Q.2011-12-122011-12-122012L.E. Olivier, et al., Fractional order and BICO disturbance observers for a run-of-mine ore milling circuit, J. Process Control (2011), doi:10.1016/j.jprocont.2011.11.0010959-1524 (print)1873-2771 (online)10.1016/j.jprocont.2011.11.001http://hdl.handle.net/2263/17707Grinding mill circuits are hard to control due to poor plant models, large external disturbances, uncertainties from internal couplings, and process variables that are difficult to measure. This paper proposes a novel fractional order disturbance observer (FO-DOB) for a run-of-mine (ROM) ore milling circuit. A fractional order low pass filter (Q-filer) is used in the DOB to offer an additional degree of freedom in tuning for set-point tracking performance and disturbance rejection performance. Another disturbance observer is introduced in which a Bode ideal cut-off (BICO) filter is used for the Q-filter. A full non-linear plant model is used for evaluation of the performance gained over the ubiquitous PI controller. The simulation results show that the FO-DOB and BICO-DOB schemes are useful additional tools for ROM ore milling circuit control implementations.en© 2011 Elsevier Ltd. All rights reserved.Bode ideal cut-offDisturbance observerFractional orderMillingRun-of-mine oreMilling machineryMilling-machinesProcess controlPreprint Article