Coordinated Control of Longitudinal/Lateral/Vertical for Vehicular Body

This paper investigates a combined sliding mode-fuzzy coordinated control strategy for the lateral, longitudinal, and vertical directions of a vehicle. A fourteen-degree-of-freedom vehicle model incorporating the steering system and semi-Active suspension system was constructed. A four-wheel random road excitation model was established using the filtered white noise method. A semi-Active suspension sliding mode control system was designed with ideal canopy damping as the reference. The optimal damping coefficient was selected through specific operating condition traversal, and anti-shake parameters were determined in coordination with MATLAB/Simulink. Innovatively, a sliding mode-fuzzy coordinated controller was established. By incorporating fuzzy control theory, a fuzzy controller was designed with vehicle vertical acceleration and pitch acceleration as inputs and suspension damping force fine-Tuning as outputs. This fine-Tunes the damping force output from the sliding mode control, achieving coordinated control across the vehicle's lateral, longitudinal, and vertical axes. Simulation validation was conducted under both random and deterministic road surface conditions. Results demonstrate that compared to passive suspension, the sliding mode-fuzzy coordinated control achieves:-28.2% optimization in body vertical acceleration-24.7% optimization in pitch acceleration-19.4% optimization in longitudinal slip rate-23.5% optimization in lateral velocity.