Lateral Stability of Electric Vehicles in Car-Following Scenario Using High-Accuracy NMPC

Adaptive Cruise Control (ACC) enhances comfort and safety in platooning systems, but it faces challenges when driving on curved roads, especially at high speeds and on slippery surfaces. Achieving a high-accuracy solution to ensure vehicle lateral stability in these complex scenarios is vital. Distributed Drive Electric Vehicles (DDEVs) are ideal for maintaining stability due to their ability to flexibly distribute torque to each wheel. In this paper, a hierarchical structure is proposed to enhance the lateral stability of DDEVs during the car-following scenario. In this structure, a Nonlinear Model Predictive Control (NMPC) based on orthogonal collocation is applied in the upper layer to achieve the vehicle's longitudinal and lateral objectives. Applying orthogonal collocation method leads to high accuracy when solving this optimal control problem. The upper layer generates optimal slip ratios and desired acceleration. In the lower layer, feedback linearization and a proportional-integral controller are utilized to attain the desired slip ratios if the vehicle is at risk of instability. Otherwise, an equal torque distribution strategy is used to realize the desired acceleration. Finally, the effectiveness of the proposed scheme is investigated in a car-following scenario on a curved road. The results indicate high-accuracy tracking compared to multiple shooting with Euler discretization, making it suitable for complex vehicular scenarios.