Reliability aspects of algorithms for industrial self-tuning P+I controllers

Describes the family of self-tuning PI controllers proposed for distribution within the Bristol Babcock range of programmable industrial controllers. The algorithms include a `one-shot´ closed-loop cycling procedure, a pattern recognition adaptive strategy and a recursive least squares based scheme. The paper details those refinements appended to the basic algorithms to ensure reliable operation under adverse conditions such as noise, load disturbances or non-minimum phase behaviour, and those features of the algorithms which ensure that operation always lies within safe plant operating limits, even when used by unskilled or inexperienced personnel