Nonlinear Adaptive Control of a pH Neutralization Process

Nonlinear adaptive control strategies for a pH neutralization process are developed and evaluated via simulation. A physically-based nonlinear model is derived using the concept of reaction invariants. The nonlinear controller design is based on a modified input-output linearization approach. In order to account for changes in buffering, nonlinear adaptive controllers are developed using direct and indirect parameter estimation schemes. The nonlinear adaptive controllers are compared for setpoint changes and unmeasured disturbances. The robustness of the controllers to sampling is also investigated.