Steering Control Design Of Intelligent Horizontal Transport Equipment In Tianjin Port

With the release of carbon peaking and carbon neutrality goals in China,there are extremely severe challenges in the logistics and transportation field.Therefore,technological reforms must be used to seek breakthroughs.Autonomous driving technology can effectively improve transportation efficiency,reduce air pollution,and avoid traffic accidents.China is the largest trade import and export country in the world,so it is necessary to develop the unmanned driving to in the port logistics and transportation.The application of autonomous driving technology in ports can not only effectively improve transportation efficiency and reduce emissions,but also improve the level of intelligent scheduling and reduce transportation costs.This paper studies the application of unmanned containers in the port in combination with the Tianjin Port Intelligent Level Improvement Project.Aiming at the problems of large volume and dense arrangement of containers in the port,frequent vehicle scheduling and small turning space,etc.,we independently developed and designed a four-axle eight-wheel automatic guided vehicle with high degree of freedom to adapt to various working conditions.Different from the single-axle steering of traditional vehicles,the designed guided vehicle can be steered simultaneously on two axes,reducing the turning radius and making it more flexible.Due to the high degree of freedom and complex control of the vehicle,this paper designs a trajectory tracking control algorithm suitable for dual-axis turning,and conducts simulation and real vehicle tests.The main research work is as follows:The steering-by-wire mechanism and control method of the dual-axis steering automatic guided vehicle are proposed.The steering-by-wire mechanism and parameters are designed.A dual-axis steering dynamics model is established,and the communication interaction mode and protocol for the upper-layer trajectory tracking control are designed for the upper controller interface.In view of the dual-axis steering characteristics of automatic guided vehicles,the adaptive analysis of various trajectory control tracking algorithms is carried out.Considering the multi-input and multi-output control requirements,model predictive control is selected as the control method,and combined with the dual-axis steering dynamics model,the design optimization control objectives;A simulation test environment in complex scenarios through Python is built,and model-in-the-loop tests on the trajectory tracking algorithm is designed.The simulation results show that for complex scenarios,the designed dual-axis steering vehicle and trajectory tracking algorithm can effectively meet the requirements of turning characteristics and trajectory tracking in complex scenarios.In the actual site of Tianjin Port,the real vehicle tests are conducted in the established scenarios.The real vehicle test results show that the designed dual-axle guided vehicle has high flexibility and shorten approach time in corners.The trajectory tracking algorithm has strong real-time,high stability and stable vehicle running state,which can effectively meet the actual needs of dispatching in complex scenarios of port automatic guided vehicles.It has significantly improved the efficiency of container dispatching operations,and raised the safety,efficiency and stability of the automated terminal.