An adaptive and iterative scheme for PID auto-tuning based on design formulae

The first classical design principle for PID regulators was to cancel the two major time constants of a plant and tune the integrating action to the remaining low order time delay process. This paper renew the original approach introducing a stochastic-deterministic iterative or recursive adaptive scheme, estimating the process parameters and the time delay at the same time, and using design formulas for automatic tuning of the regulator parameters.