A framework for the implementation of self-tuning/adaptive control at potable water treatment works

This paper concerns the development of an interactive control scheme that applies self-tuning/adaptive control of simple PI and predictive PI controllers. There has been extensive interest in feedback control systems that automatically adjust their controller settings to compensate for changes in the process or the environment. Such systems are referred to as adaptive. The scheme described satisfies this basic definition but adaptation is not continuous. The algorithm consists of two basic operations. The first is based on continuous monitoring of the process performance and can be programmed to initiate a re-tune when the performance degrades to some pre-specified condition. The self-tuning strategy used, which incorporates a facility for time-delay compensation, will be outlined. The paper concludes with an example common to water treatment, namely the adjustment of the pH of the treated water.