Patent US 5,287,432

Fuzzy control is disclosed in the environment of tracking control for a playback head relative to a medium from which signals are played back. Tracking control data is generated as a function of the detected signal level of the played back signal by using fuzzy inference to obtain direction and magnitude values of the control data which then is used to adjust the tracking of the head. Membership functions for tracking control signals are represented as a set of equivalent triangles and are provided as identifying data characterizing the shape of a membership function and position data locating the respective position of each membership function along the abscissa.