1. In a control system having redundant sensors providing at least two sensed values of a single parameter being measured, and having means for generating a synthesized value of said parameter; a method of determining a single output value of said parameter for use in the control system, comprising the steps of: determining a first error by comparing said sensed values to one another; determining a second error by comparing said sensed values to said synthesized value; determining a graded membership of said first and second errors from a fuzzy logic look-up table; and calculating a preselected weighted average of said sensed values based on said graded membership, said preselected weighted average being the single output value of said parameter for use in the control system.