High Performance PID Control Design Based on Time-Scale Separation - a Case Study

The paper presents a novel method of PID controller tuning dedicated to regulatory control of second order plants. To this end, a case study of level control is performed for a system of two non-interacting tanks. Disturbance attenuation is analyzed analytically and interpreted using root loci. Closed-form expressions to calculate dynamical parameters of control signal and control error are derived and the influence of measurement noise on control signal is studied. Immunity to the change of working point is treated as one of major factors for performance assessment. Superiority of the presented approach over other contemporary design methods is highlighted. The performance limit is shown to depend on measurement noise characteristics.