Abstract
Control of pH is mostly needed in continuous process industries and is difficult and challenging due to its time-varying and nonlinear nature of the chemical or biological process. Conventional controllers do not incorporate nonlinear dynamics of the entire pH range (both acid and alkali) and do not show good performance. Dynamics based on specific process nonlinearity of two different ranges is used to design double-control scheme in a feedback structure to enhance the performance of pH process. The mathematical model of pH for a weak acid-strong base is used to design IMC based PID double-controller scheme which provides outstanding set-point tracking and disturbances rejection simultaneously to control pH processes.
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Shobana, S., Panda, R.C. Control of pH process using double-control scheme. Nonlinear Dyn 67, 2267–2277 (2012). https://doi.org/10.1007/s11071-011-0144-x
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DOI: https://doi.org/10.1007/s11071-011-0144-x