Research On Bus Rapid Transit Platoon Control Based On RTK Technology

The continued increase in motor vehicle ownership,leading to frequent traffic accidents and a rise in traffic congestion in several cities.Bus Rapid Transit(BRT)is a kind of efficient bus operation system,which can solve the problem of traffic delay to some extent.Automated bus platooning control technology can reduce traffic accidents caused by factors such as fatigue and environmental complexities,improve efficiency and safety of buses.This thesis considers the speed tracking problem of the leader and the position tracking problem of the follower from the perspective of longitudinal platooning of BRT vehicles,and study of ways to control longitudinal platooning of BRT vehicles.The thesis has completed the following work:(1)The relative distances are obtained by using RTK technology to locate the vehicles in front and behind the BRT fleet.Firstly,The RTK positioning program based on the RTK positioning algorithm of the global satellite navigation system is written to calculate the positioning results under the static mode.Then,analysis of dynamic test data using RTKPLOT.The results show that RTK positioning results in an environment where the satellite signal is not blocked satisfy the BRT platoon.(2)In order to solve the platooning problem of BRT vehicle,an intervehicle distance control is proposed.Firstly,a vehicle speed and position cruise control system based on an internal mode compensator is studied through a vehicle longitudinal dynamics model.Then,the multi-vehicle spacing control system is established based on the multiagent concept,and the bus platooning model is constructed.Finally,by analyzing the influence of internal model control coefficient on the control system to select the appropriate internal model control parameters,and build a Simulink model to verify.The results show that the multi-vehicle spacing control system can realize BRT platooning and ensure the string stability.(3)In order to improve the accuracy of relative distance estimation and leader speed estimation in BRT platooning,a state speed estimator based on fuzzy Kalman filter are designed.Firstly,by establishing the state equation and observation equation of vehicle longitudinal driving,the vehicle state estimator based on Kalman filter is designed.Secondly,the fuzzy controller of vehicle position measurement noise variance adjustment value and the fuzzy controller of velocity measurement noise variance adjustment value are designed by using fuzzy control theory,and then the vehicle state estimator based on fuzzy Kalman filter is established.Then,the vehicle state estimator is applied to a single vehicle cruise control system to obtain the improved vehicle cruise control system,and then the improved multivehicle spacing control system is obtained.Finally,by building a Simulink model of bus rapid transit platoon for simulation,the results show that the above method improves the accuracy of vehicle speed and position estimates,ensures the stable driving of a single vehicle and the stability of the vehicle fleet,which is of great significance to ensure traffic safety.