Robust PID-like controllers -: Design and tuning

The contribution presents a new method for design and robust tuning of continuous-time controllers for SISO systems without and with time delays. Controllers are obtained via general solutions of Diophantine equations in the ring of proper and stable rational functions. A class of PI and PID controllers is generated by the proposed method for first and second order transfer functions. The methodology covers both stable and unstable systems. Uncertainty is studied through the infinity norm H-infinity. A scalar parameter was proposed as a tuning knob for influencing of stability, minimization of the sensitivity function and uncertainty evaluation. A Matlab-Simulink package was developed for automatic design and simulation of proposed algorithms. Copyright (C) 2000 IFAC.