Research On Eco-driving Strategy Of Plug-In Hybrid Electric Vehicles In Intelligent And Connected Environment

Energy conservation and emission reduction becomes the melody in long-term development of the automotive industry due to the major issue of energy crisis and environmental pollution that restricting the development of human society.Combining the advantages of hybrid electric vehicle(HEV)and pure electric vehicle(EV),Plug-in Hybrid Electric Vehicle(PHEV)has been vigorously promoted in China.With the development of vehicle-to-infrastructure(V2I),vehicle-to-vehicle(V2V)communication technologies and intelligent vehicles,more reasonable vehicle speed trajectories and driving behaviors can be regulated based on the abundant driving environment information obtained,which further improves energy economy.Taking PHEV as the research object,this paper focus on the eco-driving strategy of the PHEV in intelligent and connected environment,considering the goals of vehicle energy consumption economy,riding comfort,safety and traffic efficiency.The main research contents are as follows:A calculation-oriented model of PHEV energy consumption considering road curvature is established.First,the vehicle dynamics model considering the road curvature is established,and the configuration of the PHEV powertrain system is analyzed.Then,the simulation models of powertrain components are built,and the rule-based energy management strategy is formulated.On this basis,the interpolation-based vehicle energy consumption model is established.Finally,the efficiency models of PHEV’s powertrain components and cornering rolling resistance coefficient are fitted by polynomial fitting method,and a fast energy consumption model of vehicle based on polynomial fitting is proposed.A real-time vehicle speed planning method for the whole-trip of PHEV is proposed.First,a hierarchical economic speed planning control framework for PHEVs in intelligent and connected environment is proposed.Then,based on the dynamic programming algorithm,the lower-level vehicle speed planning problem is solved in the space domain,and the economic speed characteristics under different battery SOCs are analyzed.On this basis,a low-level multi-objective speed planning method based on bare-bones multiobjective particle swarm optimization(BBMOPSO)algorithm is proposed.Finally Taking the energy consumption economy and traffic efficiency as the optimization goals,based on the lower-level vehicle speed planning method and the shortest path faster algorithm(SPFA),a dynamic backward hierarchical vehicle speed planning method of whole-trip is proposed.In the simulation scenario,the backward method is compared with the forward hierarchical vehicle speed planning method.A lane-changing decision-making model considering economy is constructed in intelligent and connected environment.First,based on the trajectory planning method of autonomous vehicles and the vehicle energy consumption model of PHEV,the energy consumption of vehicle driving in a straight line is compared with vehicle driving in curved driving conditions.Then,the vehicle speed control method in the following mode is proposed,and the safety of the following distance is verified.Ultimately,considering the speed and confidentiality of information transmission between vehicles in intelligent and connected environment,the content and method of information interaction based on V2 V technology are discussed,and a lane-changing decision-making model considering economics is established,and a simulation is carried out in the expressway scene.The simulation and experiment of PHEV eco-driving strategy in intelligent and connected environment is carried out.First,a complex driving environment simulation scene is built,and the road status information,traffic signal timing information and surrounding vehicle driving status information are set respectively.Then,the influence of the algorithm iteration times of BBMOPSO on the optimization results in the vehicle speed planning method of whole-trip is analyzed.Besides,the simulation comparative analysis of the eco-driving strategy proposed in this paper and the fixed-time eco-driving strategy verifies the effect of the eco-driving strategy proposed in this paper.Finally,The experimental platform based on the NI real-time simulator is built to verify the effectiveness of the proposed real-time vehicle speed planning method of whole-trip.