Management of Uncertainty by Statistical Process Control and a Genetic Tuned Fuzzy System

Figure 6

Online control charts for control error (a) and its derivative (b). The solid bold lines (-) are the statistical values of the upper control limit, mean, and lower control limit. The dotted (⋯) curve is the trajectory that belongs to the nontuned fuzzy controller. The arrows mark where it leaves the statistical corridor. The residual lines (— · —) stay clearly within the control limits and show the error trajectories resulting from the genetic tuned fuzzy controller. Graph (c) shows the output of the nontuned fuzzy controller (⋯) in comparison to the output of the genetic tuned controller (- - -).

(a)

(b)

(c)