Model Reference Adaptive Control with inverse compensation applied to a pH plant

In this paper, the Model Reference Adaptive Control (MRAC) with dead-zone compensation is proposed to improve two MRAC variations: MRAC with fixed adaptive gain (γ) and MRAC with variable γ based on η-adaptive optimization algorithm. The proposed MRAC is often used to compensate the dead-zone effect on valve that is not taken into consideration in the usual MRAC. It was also implemented a compensation in inverse dynamic on dead-zone. The nonlinearity inverse model is estimated by method of Recursive Least Squares (RLS). All comparisons and validations were made based on results collected from a simulation and developed in accordance with two models: a simplified Hammerstein model and a phenomenological model of Wiener. To verify the proposed controllers with inverse compensation performance we applied to a pH neutralization process. Simulations have been presented to confirm the effectiveness of the technique.