Systematic methods of regulation of PI and PID-plus-filter controllers for stable or unstable processes or those with integration

This article aims to develop systematic regulation methods for such controllers applicable to most of the processes encountered in industry and responding specifically to the demands of this medium. The typical needs of industry with regard to tracking and regulation performances as well as the noise immunity, stability and robustness of the system to parameter variations are considered first. With the aid or the concepts of phase and gain margin, overvoltage factor and optimal control, these demands are then translated into specifications of the open-loop frequency response of the system. Methods of regulation leading to an operational system in the industrial medium are finally developed for the different types of processes