Research On Cooperative Adaptive Cruise Control Orientated To Internet Of Vehicles

Adaptive Cruise Control System(ACC)can effectively improve the problems of traffic safety,driving comfort,traffic congestion and other problems caused by the rapid growth of car ownership,but due to the bottleneck in the application of transducer technology,the data of traffic state it obtained is limited,and the driving stability and comfort is in bad condition in the course of driving in low speed,bend and lane changing.With the development of car networking technology,Cooperative Adaptive Cruise Control(CACC),based on Adaptive Cruise Control Technology and through the Dedicated Short-range Communication Technology(DSRC),accesses to the date between the front car and the driving car quickly and accurately,so as to realize the communication between the two cars,to make up for the shortcomings of Adaptive Cruise Control System,and to enhance the driving experience and safety.In this thesis,some key technologies of CACC system are studied by theoretical analysis and simulation,in order to improve the application ability of the system.Firstly,based on the theory of vehicle dynamics and through structural transformation and parameters in CarSim,this thesis builds a complete vehicle model,including the characteristics of seven subsystems: body,tire,suspension,steering system,braking system,transmission system and air dynamics,and mainly focuses on the analysis of the first four subsystems.Secondly,based on the analysis and study of the common workshop time distance strategy: Constant Time Headway(CTH)and Variable Time Headway(VTH),through the concept of time distance,this thesis constructs the equipotential line based on the Psychological Field Theory and designs the optimization strategy of headway based on the drivers' Psychological Field Theory and uses this strategy to verify the digital simulation based on the CarSim and Simulink.The result shows that considering the drivers' psychological field effect,the vehicle has better anti-jamming ability and its speed,acceleration and distance changes more smoothly.Thirdly,based on the main function of CACC control layer,this thesis analyzes PID control algorithm,sliding mode variable structure control algorithm,fuzzy control algorithm,and proposes a double control with CACC controller to deal with the problem that CACC system will delay and pocket loss through the running data obtained by DRSC.When the data reception is good,it designs the fuzzy PID controller and when the situation is unstable,it designs fuzzy controller to take full use of the advantages of different algorithms,the stability and robustness of vehicle control.Finally,in order to test the control effect of the headway strategy and fuzzy PID controller and fuzzy synovium controller based on Psychological Field Theory,this thesis joints simulation using Matlab/Simulink and CarSim,constructs the off-line simulation platform of CACC system,has the software off-line simulation by selecting five kinds of typical driving conditions,and verifies the developed strategy and the accuracy and rationality of the control algorithm based on the simulation results data.