A new mixed skyhook-backstepping semi-active control approach for high-speed train magnetorheological suspension

To improve the car body lateral vibration of high-speed trains (HSTs), this paper first proposes a backstepping semi-active control (BSSAC) for HST magnetorheological (MR) suspension. Second, a novel mixed semi-active control approach, skyhook (SH)-BSSAC, is further proposed, which can achieve excellent performance within the range 0-10 Hz. First, the nonlinear seven-degrees-of-freedom (DOF) HST model with MR dampers is constructed. Then, single semi-active controllers-including SH, acceleration driven damping (ADD), and BSSAC-were applied in the model for the frequency-domain test. The results show that SH and BSSAC worked optimally in the low-frequency range (LFR) and high-frequency range (HFR), respectively. Based on this result, the mixed SH-BSSAC, which combines the advantages of SH and BSSAC, is proposed to achieve superior performance in the entire frequency range. In simulations and experiments, different random track irregularities were adopted as the excitation, and results of both the time and frequency domains show that SH-BSSAC outperformed all of the other controllers, including SH, BSSAC, and SH-ADD. Overall, this paper provides an additional choice for the lateral vibration semi-active control of HSTs.