Self-tuning of Multivariable Plant

In order to improve and maintain the waste water quality where removal of nitrate and ammonium are stressed then some control techniques have been used. In this paper, a decentralized PI controller which is self-tuned is adaptable to change the controlled variable of the process for a multivariable system. This controller has been proposed with an adaptive interaction algorithm. The wastewater treatment plant is commonly known as complex and have large number of parameters and states. Also, some interaction methods named as Relative Gain Array (RGA) and Niederlinski Index (NI) have been used. These methods help to choose proper pairing so that not all output got effected. The aim of this paper is to tune the PI system parameters for controlling the concentration of the dissolve oxygen and nitrate with respect to a constant value.