SD-TCSs Control Deriving from Fractional-order Sliding Mode and Fuzzy-compensator

Uncertainty and disturbance (UAD) always exist and influence negatively on technical systems. Focusing on improving the effectiveness of smart dampers (SDs)-based semi-active train-car suspensions (SD-TCSs), we present the fuzzy-compensator-enhanced fractional-derivative (FD) order sliding control of a class of SD-TCSs subjected to UAD, in which the disturbance time-varying rate (DTVR) may be high but bounded. To reduce uncertainty related to the mathematical model error, we propose a fractional derivative (FD)-based sliding mode controller (FDSMC) for specifying the main control signal. Whereas, to estimate the compensation for external disturbance, first, we utilize the well-known DO to build an initial framework of the compensator. To avoid conflict between the update-laws of the DO and FDSMC, as well as to make the system dynamic response converge stably to the desired state even if the DTVR increasing but bounded, constraints along with a fuzzy-based adjusting mechanism are then discovered. Thus, we obtain an improved DO (imDO), update-laws of the imDO and FDSMC, and their combination model (imDO-FDSMC) of the proposed controller. The survey results reflect the positive capability of the method.