Vehicle Lane Change Trajectory Planning Based On Driving Comfort

With the rapid development of economy and the continuous improvement of the intelligent degree of vehicles,in addition to meeting the basic needs of people to travel,the driving comfort of passengers in the course of vehicle driving has become more and more an important demand.As one of the most common behaviors in vehicle driving,how to improve the driving comfort is an important research content.Taking the driving comfort as an index to evaluate the vehicle changing behavior,the influence factors of driving comfort are analyzed from three aspects: person,car and road.The analysis shows that the vehicle vibration in the process of vehicle changing course belongs to the secondary factor affecting driving comfort,while the force of horizontal or rotation caused by vehicle translation and rotation is the main factor.By establishing a six-degree-of-freedom model for the vehicle(longitudinal,transverse,steering movement and body trim,roll,lateral rotation),the human body is selected to be more sensitive to the lateral displacement as the factor that has a great influence on the driving comfort,and the lateral acceleration is selected as the evaluation index of driving comfort.standard,and the evaluation model of driving comfort is established.Select the NGSIM vehicle trajectory data set initiated by the federal highway administration(FHWA)for vehicle lane change trajectory study.Aiming at the errors existing in the NGSIM vehicle trajectory data set,the vehicle trajectory data are reconstructed to reduce the influence of the error on the vehicle trajectory model.In this paper,we use wavelet analysis and discrete wavelet transform to decompose the vehicle trajectory data,find the outliers existing in the data,and reconstruct the outliers and their nearby values by Lagrange interpolation.the reconstructed trajectory is more in line with the real state of vehicle operation.Based on the reconstructed data of the NGSIM vehicle trajectory,the vehicle track changing model and the vehicle speed model are constructed.Firstly,the vehicle track changing model is classified,according to the four-stage model tomodify the traditional geometric model,the cubic B spline curve based on the traditional geometric model is established to fit the vehicle track changing curve,and the constraint condition of the cubic B spline curve is formed by the vehicle’s own parameter constraint and the driving comfort constraint on the curve.Through the division of the speed stage,the four-stage vehicle speed model is established by using the least square method.Car Sim simulation platform is selected to carry out the simulation experiment,which shows that the vehicle speed,vehicle lateral displacement and lateral acceleration are taken as the output parameters in the simulation environment.Through the analysis of the parameter image,it is verified that the vehicle track and speed model established in this paper meet the requirements of driving comfort.The vehicle track and speed model established in this paper can be applied to the in-depth intelligent vehicle track planning and driving comfort.