LEARNING AND CONTROL APPARATUS FOR ELECTRONICALLY CONTROLLED INTERNAL COMBUSTION ENGINE

A learning and control apparatus for an electronically controlled internal combustion engine having such an object to be controlled as, for instance a fuel injection valve for controlling the air-fuel ratio in an air-fuel mixture or an idle speed control valve for controlling the idle rotation number of the engine wherein a pulse duty signal corresponding to a basic control value is set according to engine driving states. The basic control value is corrected by adding an appropriate correction value to the basic control value. Feedback control is carried out so that the actual controlled value is made to follow the aimed control value, and a learning correction quantity is computed by learning said feedback control so that the feedback control amount is set as small as possible. Deviation value detecting means detects and operates a mean value of deviations of the feedback correction quantities from a standard value and learning correction quantity renewal means for a new learning correction quantity by adding the mean value of deviations by a selected ratio to a present learning correction quantity. The ratio of mean value of deviations is set in accordance with the number of renewal of learning correction quantity in such a manner as the ratio decreases when the number of renewal increases.