Adaptive Cruise Control Strategy Considering The Intention Of Other Vehicles

Adaptive Cruise Control(ACC)has received widespread attention in recent years.Its main function is to automatically adjust the velocity of the vehicle based on sensor such as radar and camera,maintaining a safe distance from the preceding vehicle,reducing the driver’s driving burden.Quickly and accurately determine the following target is the key to the ACC system,however,when the other vehicle is cutting in or host vehicle is running in a curve,the existing ACC system will have the problem of not being able to update the following target in a timely and accurate manner,causing ACC to produce false acceleration or false braking,affecting the safety of the vehicle and the experience of drivers and passengers.In order to avoid false acceleration or false braking caused by ACC,this article starts from considering the driving intention of the other vehicles,makes full use of the motion parameter information of the other vehicles,establishes an identification model to determine the driving intention of the other vehicles,and design the following target update rule based on the intention of other vehicles,to solve the problem that ACC cannot update the following target in a timely and accurate manner.This paper proposes an adaptive cruise control strategy that considers the driving intention of the other vehicles.The main research content and research conclusions are as follows:1.Vehicle motion parameter estimation for the ACC system: estimate the motion parameter information of the host vehicle and the other vehicles,eliminate the influence of the state of host vehicles in the motion parameters of the other vehicle,and obtain the real-time motion parameters of the other vehicle in the world coordinate system.The specific research content is: establish the Extended Kalman Filter estimator of the longitudinal speed,yaw rate and side slip angle of the host vehicle,obtain the abovementioned motion parameter information through the three-degree-of-freedom vehicle dynamics model of the host vehicle;establish the Constant Turn Rate and Velocity kinematic model of the other vehicles,combined with coordinate transformation to eliminate the influence from the state of host vehicle in the other vehicle state ρ,the relative distance φ,relative azimuth ,and relative speed (?) of the host vehicle and the other vehicle obtained by the radar are used as observation values.Get the position,speed,movement direction and other motion parameters of the other vehicle in the world coordinate system.Finally,in the simulation experiment,the root mean square error statistics of the various motion parameters of the other vehicle are all less than 0.4.This method can obtain accurate real-time motion parameter information of the other vehicles and provide a data basis for the identification of the driving intention of the other vehicles.2.Establish the identification model of the other vehicles driving intention: use NGSIM data to train the other vehicle driving intention identification model established by the hidden Markov model method,and use the other vehicle motion parameters to determine the real-time driving intention of the other vehicle.The specific research content is: analyze the relationship between the hidden Markov random process characteristics and the lane-changing characteristics of other vehicles in the ACC scene,and determine to establish three types of driving intention recognition models: left lane change,right lane change,and lane keeping;The driving data is extracted to train the corresponding type of driving intention recognition model;the length of the recognition time is set to comprehensively ensure the real-time and accuracy of the driving intention recognition process.Finally,a test data set is established to test the driving intention recognition model.The results show that when the length of the recognition time is 2s,the recognition accuracy of each driving intention recognition model is above 90%,which can identify other vehicles quickly and accurately,providing the real-time driving intention of other vehicle for the process of following the target determination.3.ACC upper controller using variable headway spacing strategy and MPC control method: using correction item to determine the headway spacing strategy,combined with MPC control method to output ACC expected acceleration.The specific research content is: use the relative speed and the acceleration of the preceding vehicle to correct the fixed headway to obtain a more efficient vehicle-following variable headway spacing strategy,verifying the stability of the following distance of the variable headway spacing strategy when the current vehicle speed tends to be stable;comprehensively considering the design goals of safety,following efficiency,comfort,etc.,using the MPC control method to achieve the desired acceleration of the ACC considering the above multiple design goals.Finally,a simulation scenario is designed for typical ACC working conditions.The simulation results show that the variable headway spacing strategy can better follow the movement of the preceding vehicle under the premise of ensuring the safety of ACC,and effectively improve the traffic efficiency.The ACC upper controller,which considers multiple design goals such as safety,following efficiency,and comfort,can provide guarantee for safe and stable vehicle following.4.Simulation verification of the adaptive cruise control strategy considering the intention of the other vehicles: the adaptive cruise control strategy of the side-frame vehicle steering is established,and the effectiveness of the control strategy is verified.The specific research content is: use vehicle characteristics and road environment influencing factors to divide the potential front target screening area,determine the potential preceding target of the vehicle,identify its driving intention,and determine the vehicle that will affect the future driving trajectory of the host vehicle.Develop an absolute forward target determination method as the safety boundary of the driving intention identification model.Update the following target in time to ensure the safety of the ACC in this article.According to the relative position change rule of the host vehicle and the other vehicle,design the ACC following target update rule,and determine the new following target based on the driving intention of the other vehicles.Clarify the logical relationship between the research contents of each part,and clarify the control strategy of this article on the basis of the ACC upper controller and the process of determining the following target in this article.Finally,a simulation scenario is designed for typical operating conditions to simulate and verify the adaptive cruise control strategy proposed in this paper that considers the driving intention of the other vehicles.The simulation results show that the ACC control strategy proposed in this paper can quickly,accurately and efficiently determine the new target vehicle,and ensure the smooth transition of the vehicle’s speed when the ACC following target changes.