Plant control system

摘要

A plant control system has a reference value setting unit (7a) for variably setting a reference value for an air-fuel ratio to be given to an exhaust system (E) including a catalytic converter (3), depending on a component based on an adaptive control law of a manipulated variable of the air-fuel ratio generated by a controller according to an adaptive sliding mode control process in order to converge an output of an O2 sensor (6) disposed downstream of the catalytic converter to a target value. The plant control system also has an estimator for estimating the difference between an output of the O2 sensor after the dead time of the exhaust system and a target value therefor, using the difference between the set reference value and a detected value of the air-fuel ratio, and giving the estimated difference to the controller. <IMAGE>