Fuzzy control of pH using NAL

A fuzzy controller f o r a neutralization process is described. The controller was set up fo r a laboratory pilot plant. The approach is shown to be effective and can be extended to highly nonlinear and nonstationary processes. The "operator" knowledge encoded in the rules was obtained by several experimental runs o f the system using manual control. Rules are composed using the max-min compositional rule o f inference. The use o f metarules, which depends on controller performance and on active disturbances, makes the controller behave like an adaptive controller. The control program is encoded in NAL, a new experimental logic programming language that was first used in this work in a real-time application.