Design and Implementation of Novel Fractional-Order Controllers for Stabilized Platforms

Comments and Corrections to “Design and Implementation of Novel Fractional-Order Controllers for Stabilized Platforms”

“…In addition, the equation for definition of the integer-order controller (Eq. (5) in [1]) is incorrect too. There is…”

“…In the above article [1], the author found some mistakes in equations as well as proposed algorithm.…”

“…In the article [1], an incorrect Grünwald-Letnikov definition (GLD) of fractional derivative was given as a D α t f (t) = lim f (t − kh), (1) where n r = Γ(α + k) Γ(k + 1) .…”

“…Both equation (1) and equation (2) of the paper [1] are incorrect. Even the symbols in (2) do not correspondence on the left and right side of the equation, nevertheless such expression of the binomial coefficients (2) is not used in (1).…”

“…In the article [1], the authors mentioned that fractional calculus operators have some interesting properties, but they did not specify them, except one of them, that is, it can reduce the number of calculation data sets by reducing the memory duration. This is not the property of fractional calculus but of the method called "short memory principle" proposed by Podlubny for numerical calculation of the fractional derivatives and integrals [4].…”