Sliding Mode Control of Magnetorheological Fluid Damper to Mitigate Impact Loads in Semi Active Isolation Systems

This paper presents a robust sliding mode control (SMC) strategy for regulating a magnetorheological fluid damper (MRFD) in a semi-active impact isolation system subjected to high-intensity transient loads. Conventional passive and proportional–integral–derivative (PID)based damping systems often exhibit limited adaptability and reduced robustness under rapidly varying nonlinear impact conditions. To address these limitations, a singledegree-of-freedom (SDOF) recoil-type impact isolation model integrated with an Adaptive Neuro-Fuzzy Inference System (ANFIS) based MRFD model is developed. Experimental data obtained under varying impact energies and input currents are utilised to characterise the nonlinear and field-dependent behaviour of the MRFD. The proposed SMC algorithm regulates the input current supplied to the damper in real-time to enhance dynamic response suppression and improve system robustness against uncertainties. Numerical simulations are conducted under low-, medium-, and high-impact energy conditions, and the proposed controller is compared with passive and PID controlled systems. The performance evaluation is based on jerk, acceleration, and transmitted force using root mean square (RMS) analysis. The results demonstrate that the SMC-controlled MRFD consistently outperforms the passive and PID controllers, achieving average reductions of approximately 42%, 41%, and 42% in jerk, acceleration, and transmitted force, respectively. The proposed approach exhibits superior effectiveness under high-impact energy conditions while maintaining a simple control structure and low computational complexity. These findings highlight the strong potential of the proposed SMC strategy for real-time impact mitigation applications, particularly in military recoil systems and industrial shock isolation environments.