Adaptive Cruise Control Algorithm Based On Driving Behavior Analysis

As an automatic car-following technology,the adaptive cruise control system(ACC)has been widely used on the road.For the design of ACC system,the control ability of vehicle spacing,the increase of traffic flow,the improvement of fuel economy and acceptance of drivers have become extremely essential and urgent.From the current research status of the ACC system,we can see that in order to improve the utilization of the system,the comfort of the system is one of the most unneglected aspects,that is to say,the control behavior of the ACC system to the vehicle should be consistent with the manipulating characteristics of the skilled driver.Therefore,in order to imitate the operating behavior of a skilled driver,more consideration should be given to the driver's operation behavior characteristics in the design of control algorithm of ACC,which can realize the humanization of the system and improve the utilization and acceptance.This paper is supported by the national key research project ‘Electric vehicle intelligent auxiliary driving technology research and development and industrialization'.In this paper,the adaptive cruise control algorithm based on driving behavior analysis is studied,we mainly research on the following several aspects:(1)On the basis of the analysis of the dynamic characteristics of the electric vehicle during the longitudinal driving process,the longitudinal dynamic model of electric vehicle is established for the purpose of this study considering the dynamic characteristics of the tire and the slope of the road,which provides the basis for the subsequent control strategy design.(2)A cruise control strategy of electric automobile was investigated by means of hierarchical control architecture in this paper,which can comprehensively address issues of tracking capability and driver longitudinal ride comfort.As an actor of driver,the upper controller gives optimal acceleration depending on the actual speed received and the desired value preset by driver.Lower controller compensates for nonlinear vehicle dynamics and enables tracking of desired acceleration given by upper controller.Active disturbance rejection controller(ADRC)was used to design the lower controller for its good performance to suppress the influence of parameter uncertainty and unknown disturbance on cruise control.Results indicate that the ADRC not only assures the stability of closed-loop systems while the load is changing but also can overcome the effect of road slope.On this basis,a saturated function was used to design upper controller in order to imitate the driver's behavior.Finally,corresponding simulations are performed in SIMULINK of MATLAB,and the performance of cruise control system under different conditions is also analyzed.(3)A new safe distance model which can comprehensively address issue of driving safety,tracking performance,and confirms to driver's driving characteristics is proposed in this paper according to the analysis of real-world driving test data and safe distance based on molecular dynamics,besides,a driving type factor and the adhesive coefficient between the tire and the road are also considered.Finally,the superiority of the model is illustrated by numerical validations with the traditional models,and the security of the model is verified on the basis of the optimal control algorithm.(4)In order to achieve naturalistic behavior of the vehicle that can comprehensively address issue of driving safety,tracking performance,fuel economy and ride comfort,the control objectives above are transformed into corresponding performance indicators and system constraints,and finally transformed into a quadratic programming(QP)problem under the framework of model predictive control theory.Due to the high complexity of MPC computing,Hildreth's quadratic programming procedure was used for its fast calculating speed.Finally,the simulation results show that the control strategy proposed in this paper can provide natural following performance that not only can satisfy driving safety,tracking performance but also can achieve fuel economy and ride comfort.