Research On The Aerodynamic Characteristics And Longitudinal Control Of Electric Truck Platoon

Electric trucks have emerged as a typical green and low-carbon logistics transportation solution,garnering increasing attention in recent years.When electric trucks travel in a convoy,they can achieve a mode of logistics transportation that is characterized by low energy consumption,low pollution,and high safety and efficiency.In this study,a specific electric truck was selected as the research subject,and an investigation was conducted on the aerodynamic characteristics and longitudinal control of a vehicle convoy consisting of three trucks.The primary research objectives of this paper are to achieve stable control of the electric truck convoy and evaluate its energy consumption.(1)Aerodynamic characteristics of electric truck platoon was studied.Based on the analysis of the aerodynamic resistance of electric truck and the characteristics of the flow field,a finite element model was constructed for the aerodynamic analysis of a single electric truck,and the aerodynamic characteristics of single electric truck operation were studied.A three-vehicle platoon composed of electric truck was established,and a finite element model was developed for the aerodynamic analysis of the platoon based on the aerodynamic characteristics of the threevehicle platoon.The influence of the following distance of electric truck on the aerodynamic characteristics of the platoon was investigated.The aerodynamic resistance coefficients of the three vehicles were fitted according to the impact law of the following distance on the aerodynamic resistance coefficient.The research showed that the aerodynamic resistance coefficient of each electric truck in the platoon was lower than that of a single vehicle,and the aerodynamic resistance coefficient of each electric truck decreased as the following distance decreased.The fitted aerodynamic resistance coefficients of the platoon vehicles are reliable and can be used for subsequent analysis of longitudinal dynamics and power consumption evaluation of power batteries.(2)Relevant models for electric truck platoon was researched.Based on the structural analysis of electric trucks,a dynamic battery and motor model was developed,with the fitted aerodynamic resistance coefficient introduced.A longitudinal dynamics model was established for electric trucks based on force relationships,and the accuracy of the model was validated with experimental data.Various platoon driving strategies were analyzed,and a constant headway distance was chosen as the strategy for this paper.The communication topology structure for electric truck platoon driving was studied,and a state feedback control rule for platoon communication was designed.Through multidimensional numerical simulation analysis of three communication topology structures,the leader-follower communication topology was selected as the communication topology structure for the electric truck platoon in this paper.(3)Longitudinal control of electric truck platoon was researched.This study analyzed a model-predictive distributed control scheme for electric truck platoon,developed a vehiclefollowing model for platoon driving,and designed a model-predictive controller and an expected acceleration analytic controller for the platoon.The effectiveness of the designed controllers was verified through simulation experiments,and the energy consumption of the platoon was evaluated through cyclic driving experiments.The results showed that regardless of the driving conditions,the model-predictive controller designed in this study could quickly stabilize the platoon.Compared to the traditional model-predictive controller,the model-predictive controller designed based on linear time-varying Kalman filtering could significantly reduce the spacing error between vehicles and suppress the longitudinal acceleration fluctuation of the platoon,resulting in better stability and comfort during platoon following.The cyclic driving experiment results demonstrated that platooning of electric trucks was significantly more energy-efficient than individual driving,with a maximum energy-saving rate of 6.6% per cycle.Moreover,compared to urban dynamometer driving schedule(UDDS),the energy-saving advantage of electric truck platooning was more pronounced during highway fuel economy test(HFET).