Fixed-time sliding mode control and dynamics modeling of an Electric Anti-Roll Bar for vehicle rollover mitigation

Electric Anti-Roll Bars (EARBs) are increasingly used in premium vehicles to enhance stability during high-speed cornering. However, many existing studies simplify both the EARB actuator and vehicle dynamics, which leads to noticeable differences from real driving behavior. Conventional control strategies also tend to show reduced performance, overshoot, phase delay, and chattering under demanding conditions. This work addresses these limitations in two main ways. First, we develop a spatial vehicle dynamic model that captures the complete steering response, including the inertia, elasticity, and damping of both the anti-roll bar and its actuator. Second, we propose a Fixed-Time Sliding Mode Control (FxTSMC) scheme that improves motor current tracking and strengthens the overall EARB performance. Unlike standard SMC designs, the proposed controller uses smooth nonlinear functions to enhance transient behavior and effectively suppress chattering. The dynamic model and control scheme are validated through numerical simulations with a sine-wave steering input. Results show that the peak roll angle decreases from 7.787° to 5.852°, while the minimum vertical tire force increases markedly from 270.832 N to 2807.514 N. The proposed method also eliminates phase lag and chattering, resulting in a notable reduction in energy consumption compared with benchmark controllers. These improvements underscore the potential of the approach for practical applications that aim to enhance vehicle stability and safety during severe steering maneuvers.