Research On Multi-vehicle Cooperation And Control In An Intersection Without Traffic Light

The technology of unmanned vehicle has been to a certain level, but it still has a longdistance to be completely applied to our real life. Especially in the mixed traffic scenario, itreserves to be a serious problem that how to cooperate between the multi-unmanned vehiclesor between the unmanned vehicle and the manned vehicle. In this thesis, the multi-vehiclecollaborative control was carried out under an intersection environment without traffic lights.The proposed framework forces on cooperation and control among the multi-unmannedvehicles, as well as the unmanned vehicle and the manned vehicle, during which vehicledynamics are considered.The unmanned vehicle interacting with the manned vehicle through cooperation in anintersection was firstly studied. In this situation, the unmanned vehicle obtained the statusinformation of the manned vehicle via wireless communication and then the finite statemachine (FSM) model was established to predict the behaviors of manned vehicles in theintersection. Then the ego-unmanned vehicle states were taken into considerationcomprehensively, the hybrid state system (HSS) for an unmanned vehicle was built and theFSM model was used to analyze the district states combined with the safety rules ofunmanned vehicle and to control the vehicle under the safety condition. Then the co-simulation with Simulink/Stateflow and PreScan were built to verify the algorithm. The resultof the simulation showed that it was able to help the unmanned vehicle to interact with themanned vehicle safely in the intersection without traffic light.In the scenario of multiple unmanned vehicles driving through the intersection, theintersection control system was set up based on the idea of hierarchical control. The proposedsystem can be divided into macroscopic intersection controller (MIC), top level controller(TLC) and the low level controller (LLC). Among them, MIC obtained the states informationof the unmanned vehicles approaching intersection through wireless, calculated theunmanned vehicles’ safety speed via the collaboration algorithm, and transmitted the safetyspeed to the unmanned vehicle respectively in the real-time. The TLC and LLC helpedvehicle to track the target velocity. The simulation experiments were built with PreScan and Matlab/Simulink. The experiments result showed that the collaboration algorithm based oncollision prediction and avoidance improves the efficiency of the road traffic safety whileguarantees the vehicles’ safety.In order to verify the multi-vehicle collaboration algorithm under the real condition (thereal unmanned vehicle in the real circumstance), the longitudinal control system of unmannedvehicle was designed based on the platform of Dong Feng Motors (DFM). The proposedframework to realize the longitudinal control of the unmanned vehicle includes the electroniccontrol brake system, electronic control throttle system, the acquisition of velocity and aimvelocity control. The experiment platform for research combines two vehicles--the unmannedvehicle and a manned vehicle. GPS and Inertial Navigation System (INS) were used to getthe vehicles’ position and heading information in the platform, and ZigBee modules wereused to communicate between the vehicles. The experiments results showed that thecollaborative algorithm was able to be used in the real intersection without traffic lights, andimproved the driving safety of the unmanned vehicle.