Lateral and Longitudinal Coordinated Control of Intelligent Vehicle Based on High-Precision Dynamics Model under High-Speed Limit Condition

This study focuses on improving the trajectory tracking control for intelligent vehicles in high-speed and large curvature limit conditions. To this end, a high-precision five-degree-of-freedom (5-DOF) dynamics model (HPM) that incorporates suspension characteristics is introduced. Furthermore, a coordinated lateral and longitudinal control system is developed. The lateral model predictive control (MPC) involves two crucial stages: initially, a desired trajectory with associated speed data is generated based on path curvature. Subsequently, using the high-precision 5-DOF dynamics model, an objective function is formulated to minimize the difference between the vehicle's current state and the desired state. This process determines the optimal front wheel steering angle, taking into account vehicle positional constraints and steering limitations. Additionally, a double proportional-integral-derivative (PID) controller for longitudinal control adjusts the throttle and brake pressure based on real-time position and speed data, ensuring integrated control over both lateral and longitudinal movements. The effectiveness of this approach is confirmed through real vehicle testing and simulation. Results show that the high-precision 5-DOF dynamics model markedly enhances the accuracy of vehicle response modeling, and the coordinated control system successfully executes precise trajectory tracking. In extreme scenarios of high-speed and large curvature, the enhanced model substantially improves trajectory accuracy and driving stability, thus promoting safe vehicle operation.