METHOD AND APPARATUS FOR DIAGNOSIS OF SENSORS FAULTS USING ADAPTIVE FUZZY LOGIC

A method for monitoring the sensors in a vehicle control system. The method includes identifying a plurality of potential faults, identifying a plurality of measured values, and identifying a plurality of estimated values based on models in the control system. The method further includes identifying a plurality of residual error values as the difference between the estimated values and the measured values. The method also defines a plurality of fuzzy logic membership functions for each residual error value. The fuzzy logic membership functions are adaptive in that they change depending on the vehicle operating region, i.e., the non-linearity level of the vehicle, and the vehicle operating conditions, i.e., steady state verses transients. A degree of membership value is determined for each residual error value based on the membership functions. The degree of membership values are then analyzed in a fuzzy logic reasoning system to determine whether a potential fault exists.