Design And Implementation Of Platoon Stability Test System Based On Bench Test

Vehicle platooning technology enables vehicles to sense or communicate with each other by installing sensors,radars,and on-board communication units on vehicles,and then multiple vehicles can be lined up to maintain a certain safety distance by applying of specific control strategy.This technology enables multiple vehicles to drive safely at a relatively high average speed and a short following distance,which improves traffic safety and efficiency.Aiming at the problems of the current simulation conditions are too ideal,the cost of large-scale actual vehicle testing is too high and there are hidden safety hazards.A bench-based vehicle platoon stability test system is proposed and application software for test and analysis are developed based on the analysis of vehicle hardware-in-the-loop,bench testing and vehicle platoon stability research at home and aboard.The main research works of this paper are as follows:The basic theories involved in vehicle platoon stability are analyzed,and a vehicle platoon stability analysis method based on system transfer function is proposed.On this basis,a benchbased vehicle platoon stability test system is constructed.Firstly,the equipment are selected based on the existing equipment in the laboratory.Secondly,the host computer program of the vehicle under test is mainly developed to ensure that the selected equipment can communicate with each other and then the overall framework of the system is designed.Finally,the corresponding detailed workflow is well designed and the debugging of the system is carried out to ensure that the system is in a good state.A numerical analysis method is proposed to analyze and determine the communication delay boundary under the condition of vehicle platoon stability.Firstly,the principle of vehicle longitudinal dynamics is described,and the criterion of vehicle platoon stability is given in combination with the analysis of linear CACC control strategy,which is that the modulus value of the speed error transfer function is less than 1.Secondly,a detailed study of the CTG strategy is made.By adding the communication delay to the acceleration information item of the preceding vehicle,the specific speed error transfer function of the CTG strategy considering the communication delay is obtained.Furthermore,the stability area of the CTG control strategy’s parameters is analyzed,and it is concluded that the communication delay boundary under the condition of ensuring the vehicle platoon stability is 0.5s.Finally,other parameters that affect the vehicle platoon stability are analyzed.The proposed communication delay boundary was tested and verified in the simulation environment and the bench-based vehicle platoon stability test system.Firstly,a series of test and evaluation indicators for analyzing the platoon status are proposed,including speed,speed error,distance error,and real-time headway.Secondly,the platoon stability test and analysis under two scenarios of “acceleration-cruise-braking” and “sinusoidal oscillation” are performed on the Plexe simulation platform,validating that the communication delay boundary obtained by the previous numerical analysis method is correct for 0.5s.Finally,tests are performed on the bench-based vehicle platoon stability test system,including the adjustment of vehicle platoon stability and the test under “sinusoidal oscillation” scenario.The result also validating the communication delay boundary theory.By comparing the bench test result with the simulation results,the differences are analyzed and reasonable explanations are given.