|Nonlinear pH Control Using a Three Parameter Model
Jietae Lee/Ho-Cheol Park
Transaction on Control Automation, and Systems Engineering, vol. 2, no. 2, pp.130-135, 2000
Abstract : A two parameter model of a single fictitious weak acid with unknown dissociation constant has been successfully applied to design a neutralization system for many multi-component acid streams. But there are some processes for which above two parameter model is not satisfactory due to poor approximation of the nonlinearity of pH process. Here, for better control of wide class of multi-component acid streams, a three parameter model of a strong acid and a weak acid with unknown dissociation constant is proposed. The model approximates effectively three types of largest gain variation nonlinearities. Based on this model, a nonlinear pH control system is designed. Parameters can be easily estimated since their combinations appear linearly in the model equations and nonlinear adaptive control system may also be constructed just as with the two parameter model.
nonlinear pH control, three parameter model