Self-Tuning pH Control in Dyeing

Abstract

pH control has received considerable attention in dyeing processes because of its critical role in quality assurance. In dyeing, pH exhibits strong nonlinearity and time- varying behavior, thus increasing the difficulties of control by conventional means. This necessitates the creation of a controller that adapts itself to changing system parameters, and a new approach involving a self-tuning proportional-integral-derivative (PID) control ler is proposed. The gains of the PID controller are automatically tuned by an estimated parameterized model, which is updated by input and output sequences. The simulation results illustrate that the controller can bring the pH from any initial value to any other value for a simplified dyeing process. The approach is expected to achieve the same results in practical dyeing due to its features of self-tuning and robustness. Hence an operator can manipulate pH control even without knowing the design philosophy.