On the PID control of systems with large delays

摘要

This paper deals with the control of systems with pure delays. Linear first order systems with pure delays are considered. Proportional-Integral-Derivative (PID) controllers were determined by the minimisation of the settling time. The optimisation procedure used genetic algorithms. Empiric expressions of the PID parameters has been found. These expressions depend on the static gain, the time constant of the first order model and its pure delay. The obtained PID parameters give good and satisfactory performances. A discussion with respect to the model parameter was also presented. As an illustration, the PID control of a high order system was considered.