1. A feedback controller for controlling a process having a process input and process output, the feedback controller receiving a reference input related to a desired process output and producing a process input, the feedback controller comprising: a comparator for comparing the reference input to the process output to produce an error signal; a differentiator for differentiating a function of the process output to create feedback difference signal; fuzzy logic applying a set of fuzzy rules to the error signal and the feedback difference signal to produce a proportional action signal and a differential action signal both being fuzzy functions of both the error signal and the feedback difference signal; an integrator receiving the differential action signal to produce an integrated action signal; and a summing junction for summing the integrated action signal and the proportional action signal to produce the process input.