Research On Distributed Hybrid Control Method For Multi-Vehicle Cooperative Driving

The cooperative driving system can make full use of the road conditions and realize the cooperative control and driving among individual vehicles,on the premise of meeting the requirements of road traffic safety and efficiency,which not only has the platoon characteristics of fast speed and small spacing,but also can achieve the lane changing,merging and splitting and other different cooperative behavior according the corresponding road conditions,and improve the safety and flexibility of the traffic.Vehicle cooperative driving is essentially a hybrid control system which is the combination of discrete event system and continuous dynamic system,including the transition between the discrete cooperative strategies and the execution of continuous control process.However,the definition of discrete and continuous cooperative behavior is not clear,and the description and modeling methods of interaction process are lacking.In particular,how to make use of the advantages of vehicle-to-vehicle communication and information sharing to construct a hierarchical and distributed cooperative driving system,and model the cooperative state transition rules to realize continuous control process under state transition,meet the real-time changing characteristics of the road environment to enhance multi-vehicle driving safety and road capacity,remains to be resolved.Around these issues,this paper carried out the following research:1)Multi-vehicle cooperative driving system includes both the discrete cooperative state switching and the vehicle continuous motion control,which belongs to the typical hybrid system.At the same time,the distributed and hierarchical control structure is adopted,and the cooperative layer is responsible for the discrete state switching.The control layer is responsible for continuous motion control,and finally established the distributed hybrid control architecture of multi-vehicle cooperative driving;2)Multi-vehicle cooperative driving is a control process with multi-input and multi-constraint,which includes both single vehicle intelligent cruise control under vehicle-vehicle communication and multiple vehicles platoon cruise control.In this paper,a control algorithm is proposed,which combines the artificial potential field with Model Predictive Control(MPC),uses MPC to replace the gradient method in traditional artificial potential field,which can take in to account the vehicle kinematics characteristic during the process of vehicle path planning based on artificial potential field,realizes the vehicle path planning and tracking control synchronously.While the generated predictive control path can also be shared with other vehicles to achieve the effect of cooperative control;3)Based on the hybrid state automata,a multi-vehicle cooperative state switching model is established for two kinds of discrete states in cooperative driving: single vehicle intelligent cruise control and multiple vehicles platoon cruise control.By defining different environmental events related to discrete states and formulating the state switching rules,a hybrid automaton model for multi-vehicle cooperative state switching is established,which can effectively guarantee the correct switching of different discrete states in multi-vehicle cooperative driving process;4)After the functional verification of the distributed hybrid control system of multi-vehicle coordinated driving,this paper designs a series of typical traffic scenes which are closer to the real environment.By using the mixed scene of single vehicle intelligent cruise control and multiple vehicles platoon cruise control,the performance and effectiveness of multi-vehicle cooperative driving control under multiple experimental conditions are compared and analyzed through software simulation,and the results of this paper are further verified.Based on the existing research on vehicles' active safety control,this paper proposes a distributed hybrid control architecture based on the hybrid dynamic characteristics of multi-vehicle cooperative driving.A multi-vehicle cooperative control system based on artificial potential field,model predictive control and hybrid automata is designed.The result of this research will be extremely important for advancing and promoting the intelligent connected vehicle,which is supposed to increase road safety and ease traffic jam.