|A Modified FOPID Versus H∞ and m Synthesis Controllers: Robustness Study
International Journal of Control, Automation, and Systems, vol. 17, no. 3, pp.639-646, 2019
Abstract : "The H∞, m synthesis and fractional order (FPM) controllers are types of robust designs that use the
linearized model of the system and provide a linear controller. The m synthesis approach directly considers the
uncertainty, but H∞ and FOPID run for the worst uncertainty scenario. mFPM is the modified version of FOPID
design where 1) it takes into account the given uncertainty by a graphical Phase Margin Distribution Map (PMDP),
and 2) reduces the controller design calculations by working on the samples of the system frequency response
instead of its analytical equation. The design strategy can perfectly force the desired flatness in the phase margin
band and maintain the system performance robustness. For evaluation, the algorithms are applied to a second-order
uncertain system and a perturbed UAV roll control. In both cases, the lowest output response variance and the best
performance robustness is gained from the mFPM design. This is verified through numerous simulations."
Fractional order controller, H∞, m-synthesis, robust control, uncertainty.