Comments, with reply, on ´Fuzzy logic for control of roll and moment for a flexible wing aircraft´ by S. Chiu et al

In a paper by S. Chiu et al. (see ibid., vol.11 no.4, p.42-8, 1991) the use of fuzzy logic in certain control problems is explored as an alternative to conventional control methodologies. An attempt is made to demonstrate the usefulness of the fuzzy design by example. There are two notable features about the article that deserve a closer look. It is shown that it is a simple matter to design a linear controller that appears to outperform the fuzzy logic controller presented in the paper, and that the claims made about the capabilities of fuzzy logic are vague and unsubstantiated.<>