• CN: 11-2187/TH
  • ISSN: 0577-6686

Journal of Mechanical Engineering ›› 2025, Vol. 61 ›› Issue (10): 335-348.doi: 10.3901/JME.2025.10.335

Previous Articles    

Hierarchical Iterative Search-based Trajectory Planning Method for Self-driving Heavy-duty Semi-trailer Tractors

He Yi1,2,3, DU Yuhao1,2,3, Wu Kang4, Qiu Zhijun1,2,3   

  1. 1. Intelligent Transportation Systems Research Center, Wuhan University of Technology, Wuhan 430063;
    2. Engineering Research Center for Traffic Information and Safety, Ministry of Education, Wuhan 430063;
    3. National Key Laboratory of Vehicle Road Integrated Intelligent Transportation, Beijing 100088;
    4. Sunward Intelligent Equipment Co., Ltd., Changsha 410100
  • Received:2024-05-22 Revised:2024-12-02 Published:2025-07-12

Abstract: A hierarchical iterative search trajectory planning method is proposed to address the slow efficiency of dynamic trajectory solving caused by the highly nonlinear kinematic model and safety constraints of semi-trailer tractors. Firstly, based on the Frenet coordinate system, the lateral and longitudinal motion of the semi-trailer tractor is decoupled, and a polynomial trajectory sampling solution method based on the kinematics of the semi-trailer tractor is designed to obtain the motion trajectories of the tractor and trailer separately. Secondly, to simplify the search process and improve trajectory solving speed, a prior loss estimation model is constructed and a hierarchical iterative search framework is used to obtain the optimal candidate trajectory. Finally, the optimal feasible motion trajectory is selected through curvature, acceleration, and multi circle envelope collision checks. Simulation results show that the proposed algorithm can generate smooth and collision free motion trajectories for semi-trailer tractors, and complete obstacle avoidance tasks under complex working conditions. Compared with the two existing algorithms, the solving efficiency is improved by 85% and 58% respectively, which can better balance the relationship between trajectory quality and solving efficiency and meet the needs of real-time obstacle avoidance path solving.

Key words: automotive engineering, semi trailer tractor, hierarchical iterative search, trajectory planning, autonomous driving

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