Reset Control of an Industrial In-Line pH Process

This work presents a reset/hybrid control application of an in-line pH process. The nonlinear process dynamic is linearized around different operating points, and as a result a second-order plus dead time plant with uncertain gain and delay is obtained for control purposes. A standard PI compensator and reset compensator are designed and tuned. The main aim of this work was to compare the performance of both compensators by practical experimentation. The results show the reset compensator is able to overcome fundamental limitations of linear and time invariant control with a faster tracking response and overall improvement in disturbance rejection.