Identification-based PID tuning without external excitation

Identification-based proportional, integral, and derivative (PID) controller tuning is studied in this work. A method of closed-loop PID tuning without using test signals is developed. The basic idea is to shift the PID control parameters properly to achieve persistent excitation condition in closed-loop test. In this way, not only the closed-loop system can be identified accurately without using external exciting signals but also the control performance can be improved during the test. A stochastic model error bound is introduced for model validation. An internal model control design method is applied to tune the PID parameters. The effectiveness of the proposed approach is illustrated by simulations.