Research On Lane Departure And Lane-changing Model For Highway Driving Safety Warning

With the rapid development of economy, vehicle registrations are growing fast. Thus theurban traffic problem are aggravating, mainly for growing number of road traffic accidents,more serious traffic congestion and associated with environmental pollution, etc. Especiallywith the constant improvement of highway construction level, vehicle speed are increasing,the number of traffic accidents and casualties are increasing year by year. Traffic safety hastaken more and more attention, become a major problem which the whole world faces.Therefore, research of vehicle safety assistant driving technology has important theoreticalsignificance and practical application value for realizing the auto safety driving andimproving road traffic safety.On the basis of review and analysis of development and research status of the vehiclesafety assistant driving technology, this dissertation selects horizontal driving behavior’ssecurity on the motorway to be the research object of which main research content includesthe vehicle lane departure warning systems and vehicle safety lane changing model, studiesand discusses the key theory and technology. The main research work and research results inthis dissertation are summarized as follows:1. The estimation model of vehicle Time to Lane Crossing (TLC) is established.According to whether the vehicle’s steering wheel angle is zero or not when moving, themovement track of vehicle is divided into two kinds: straight trajectory and curve trajectory.At the same time, on the basis of vehicle kinematics theory, geometry knowledge andtrigonometric function knowledge, the calculation method of TLC is studied when vehiclesare driving in a straight line and curve sections respectively, then the estimation models ofTLC are established in the cases of vehicle departure to left and right. Finally, the simulationanalysis with effect of vehicle lateral distance, relative yaw angle and curve radius of road onthe TLC is carried out, the corresponding simulation results are obtained, which have animportant guiding role for driver’s safe driving and road alignment design. The experimentresults show that TLC value that is obtained from established model of this dissertation ismore approximate to true value, and the error is less than that of other methods.2. The fuzzy decision system of driver classification based on the transverse drivingbehavior is proposed. Through the analysis of driver’s driving history data, this dissertationselects the lateral velocity and lateral position as the main factors of evaluating driving lateraldriving styles by combining with the characteristics of vehicle departure. Then, the driver’sdriving styles classified system is obtained based on the Mamdami inference reasoning method, which lays the foundation to establish adaptive characteristics of lane departurewarning model.3. The lane departure warning model of variable virtual lane boundary based on drivertype and real-time driving situation is established. Combining with driver’s driving style,real-time horizontal displacement and lateral velocity, this dissertation gives the adjustmentscheme of variable virtual lane boundary by using Mamdami inference reasoning method,which can adapt to different kinds of drivers and real-time change of driving conditions. Then,both false alarm rate and warning time are choose as the evaluation index of variable virtuallane boundary departure warning model, after comprehensive analysis of characteristics oflane departure warning system and warning performance index being used in existingresearches. In the end, this dissertation sets up a virtual experiment simulation due to thelimited experimental equipment and simulation conditions, and detailed introduce theexperiment setting, experiment evaluation method and comparison results manifestation withother methods.4. The vehicle lane changing models based on the minimum safe distance are established.First of all, this dissertation details the vehicle lane changing process, gives three stages oflane changing and collision classification from the vehicle lane-changing behaviorcharacteristic and the kinematics characteristics of perspective. At the same time, the vehiclelane changing environment, kinematics parameters and time parameters are defined. Then, onthe basis of the goal of avoiding collisions, the kinematics relation between lane-changingvehicle M and its surrounding adjacent vehicle (vehicle Mol, Mdl, Mdf) in the process of lanechanging is analyzed from the view of the vehicle lane changing kinematics, then theminimum initial safety lane changing distance model between lane-changing vehicle M andassociated adjacent vehicles is set up.5. The simulation analysis is performed about the vehicle M changes lane according tochanging strategies of constant speed and accelerating. On the basis of the minimum initialsafety lane changing distance model, this dissertation sets up two different lane changingstrategies of vehicle M respectively, as follows: one way is that the vehicle M changes lane ata constant speed, the other way is that vehicle M changes lane at the condition of acceleration.Then, the simulation analysis of two different lane changing situation is carried out by usingthe Matlab simulation software. The relational graphs of safety region and non-safety regionare given between vehicle M and adjacent vehicles (vehicle Mol, Mdl, Mdf) in the process oflane changing. After analysising the simulation results, this dissertation gets relevant factorsthat affect vehicles’ safety lane-changing. At the same time, after contrasting of safety region between vehicle M and adjacent vehicles in the cases of lane changing at the constant speedand acceleration changing strategies, the analysis results show that the security region will bebroaden when vehicle M taking acceleration lane changing strategy, and there will be morereliable safety and security for lane-changing.