A Collision Risk Assessment-Based Longitudinal Collision Avoidance Control Strategy for Tractor Semi-Trailers with Slip Ratio Control

<div class="section abstract"><div class="htmlview paragraph">With the advancement of intelligent transportation and smart logistics systems, tractor semi-trailers have gradually become one of the primary modes of transport due to their substantial cargo capacity. However, the growing number of tractor semi-trailers has raised significant traffic safety concerns. Due to their significant spring mass and strong body strength, accidents involving tractor semitrailers often result in severe consequences. Active collision avoidance control strategies provide assurance for vehicle safety. However, existing research predominantly focuses on passenger cars and small commercial vehicles. Research specifically addressing tractor semi-trailers, which have longer bodies and more complex dynamic characteristics, is relatively sparse. Therefore, this paper proposes a collision risk assessment-based longitudinal collision avoidance control strategy for tractor semi-trailers with slip ratio control. Firstly, the paper introduces the braking characteristics and time to collision model of tractor semi-trailers. Furthermore, a collision risk assessment strategy based on fuzzy control theory is proposed, categorizing the vehicle collision risk into three levels: safety, level 1, and level 2. Additionally, a braking force distribution strategy is proposed with the control objectives of achieving shorter braking distances and improved stability. Subsequently, under poor road surface adhesion conditions, insufficient lateral force margin of the tires may lead to skidding, folding, and swaying of the vehicle. To enhance the braking stability, a slip ratio control strategy based on sliding mode control theory is introduced. Finally, a co-simulation model based on TruckSim/Simulink is developed for testing. Simulation results demonstrate that the proposed longitudinal collision avoidance control strategy enables safe driving of the vehicle under three different conditions: CCRs, CCRm, and CCRb.</div></div>