Fractional Order Adaptive Fast Super-Twisting Sliding Mode Control for Steer-by-Wire Vehicles with Time-Delay Estimation

It is difficult to model and determine the parameters of steer-by-wire (SBW) system accurately, perturbation variable with complex changeable tire–road conditions. In order improve control performance vehicle SBW system, an adaptive fast super-twisting sliding mode (AFST-SMC) scheme time-delay estimation (TDE) proposed. The proposed uses TDE acquire lumped dynamics in a simple way establishes practical model-free structure. Then, fractional (FO) surface structure were designed on basic ensure convergence high accuracy. Since uncertain boundary information actual unknown, novel algorithm regulate gain based errors. Theoretical analysis concerning stability given Lyapunov theory. Finally, effectiveness method verified through comparative experiments. results show that TDE-AFST-FOSMC has advantages model-free, response