CONTROL FOR AUTOMATIC TRANSMISSION

A fuzzy-logic controlled automatic transmission of a motor vehicle comprises a series of detectors for detecting parameters indicative of running conditions which the motor vehicle is involved in and generating a series of detector signals indicative of the parameters detected, a fuzzy-logic controller which contains a series of rules of thumb, each being expressed by a series of membership functions of the detector signals and recommending an action which the automatic transmission should take. In the fuzzy-logic controller, the series of rules of thumb are tested one after another based on the detector signals to determine the degrees to which the series of rules of thumb are satisfied, and a position which the automatic transmission should take is determined in response to the degrees determined. An output signal is generated by the fuzzy-logic controller which is indicative of the position determined. A modifier is provided which changes or modifies at least one of the series of membership functions of at least one of the series of rules of thumb when the history of at least one of the series of detector signals shows a predetermined state.