ADAPTIVE INPUT–OUTPUT LINEARIZATION OF A pH NEUTRALIZATION PROCESS

Abstract

SUMMARYAdaptive non-linear control strategies for a pH neutralization process are developed and evaluated via simulation. A non-adaptive non-linear controller is designed using a modified input-output linearization technique which accounts for the implicit output equation in the reaction invariant model. For simplicity the reaction invariants are assumed to be available for feedback. Because the model exhibits significant time-varying behaviour, the input-output linearizing controller is combined with non-linear parameter estimators which account for unmeasured buffering changes. Simulation results demonstrate that a novel indirect adaptive strategy is most suitable for experimental implementation where the reaction invariants must be estimated and sampling is required.

Valve friction quantification and nonlinear process model identification

“…The model is based on the reaction invariant theory from which the pH is given by a nonlinear function of W a4 and W b4 . For more details refer to (Henson and Seborg, 1997). The nominal operating conditions are shown in Table A.1.…”

Adaptive Fuzzy Control of a pH Process

“…, u(t − m +1)) (3) whereŷ(t + 1) is the prediction of y(t + 1), f (·) is a Mamdani type fuzzy system with a product inference engine, a singleton fuzzifier, a center-average defuzzifier and triangular membership functions. It is constructed through three steps: [16][17][18][19][20][21]2006 Step 1: Let X = [α 1 , β 1 ] × · · · × [α s , β s ]. For every j (j = 1, 2, .…”

Nonlinear model feedback linearization control strategy of a pH neutralization process

“…This problem resolved in [18] by using an adaptive backstepping state feedback controller. In [19], many adaptive control strategies for pH processes were compared, and they supported the indirect adaptive input-output linearizing control as a high performance pH regulating approach. They rather supposed an unrealistic assumption, that the invariants in the reaction are available for feedback.…”