Control of a grinding mill circuit using fractional order controllers

- Control of a grinding mill circuit using fractional order SISO controllers is addressed.
- A continuous time dynamic phenomenological non-linear population balance model is used to describe and simulate the circuit.
- Designed controllers can achieve similar or better results to that achieved using linear model predictive control, which is an advanced multivariable control techniques.
- Controllers are tested in the presence of disturbances and process noise.

This paper presents the design and application of fractional single-input-single-output (SISO) controllers to a grinding mill circuit, which is a multiple-input-multiple-output (MIMO) process. Two kinds of controllers are presented: fractional order proportional-integral (FOPI) controllers, and a combination of FOPI and fractional order model reference adaptive controllers (FOMRAC). The parameters of the controller are tuned using off-line particle swarm optimization. In the presence of disturbances and process noise, the SISO fractional controllers achieve similar or better performance compared to linear model predictive control (LMPC).