PERFORMANCE ASSESSMENT OF PID CONTROLLERS.

Criteria based on disturbance rejection and system robustness are proposed to assess the performance of PID controllers. The robustness is measured by a two-block structured singular value, and the disturbance rejection is measured by the minimum singular value of the integral gain matrix. Examples show that the criteria can be applied to a variety of processes, whether they are stable, integrating, or unstable and single-loop or multi-loop. [ABSTRACT FROM AUTHOR]