Robust QFT-based PID controller for a feedforward control scheme

Feedforward control schemes to compensate for disturbances are very well known in process control. In those control approaches, PID controllers are usually considered in the feedback loop, where nominal design for both feedback and feedforward controllers are commonly performed. This paper presents a robustness analysis to study how uncertainties can affect the classical feedforward control scheme. Afterwards, a robust PID controller is designed by using Quantitative Feedback Theory to account for these uncertainties and to fulfill robust specificaitons for the regulation control problem. Results based on frequency and time domains are presented.