Active steering control of vehicle by sliding mode control - switching function design using SDRE -

This paper proposes an active steering method using adaptive sliding mode control to estimate the upper bounds of time-derived hyperplane and uncertainties of lateral forces. This is achieved by utilizing a state-dependent switching function based on state-dependent Riccati equation (SDRE) for the four-wheel-steering vehicle; it takes lateral force saturation characteristics into account. Our proposed method maintains vehicle motion stability even when the lateral force is in the saturation region; this is because the slope of the switching function varies according to the changes in the state variable. The effectiveness of our proposed method was validated through numerical simulation.