Impulsive Feedback Control for Dosing Applications

This paper addresses a design procedure of pulse- modulated feedback control solving a dosing problem originally defined for implementation in a manual mode. Discrete dosing, as a control strategy, is characterized by exerting control action on the plant in impulsive manner at certain time instants. Dosing applications appear primarily in chemical industry and medicine where the control signal constitutes a sequence of (chemically or pharmacologically) active substance quantities (doses) administered to achieve a desired result. When the doses and the instants of their administration are adjusted as functions of some measured variable, a feedback control loop exhibiting nonlinear dynamics arises. The impulsive character of the interaction between the controller and the plant makes the resulting closed-loop system non-smooth. Limitations of the control law with respect to control goals are discussed. An application of the approach at hand to neuromuscular blockade in closed-loop anesthesia is considered in a numerical example.