Researches On Driver Unified Decision Model For Vehicle Assistant Control

Vehicle safety has been improved by both passive safety and active safety along with the development of vehicle itself. The traffic accident and wounded are both reduced. But it can not make a real safety vehicle only through these measures. The reason is that people do not get deep understand of the reason for accident. Research tell us: ninety percent of accident are caused by driver, that's means whatever we do to perfect the performance of vehicle and the road will not work for the reduce of accident. That's why the driver assistant system which may used to make up driver's bug both for driver's organ limitation and its behavior has been the focus these years.Both passive safety and active safety are used to reduce traffic accident and protect driver and passengers. As a man driver itself is not only control vehicle but also get direct information about road circumstance, it is the only input for driver vehicle circumstance closed loop system. That's the reason why driver's behavior is the key to the vehicle handling and stability, it is also decided how to improve vehicle safety form the point of driver.This paper is based on the analysis of driver's behavior and the deeper understand of vehicle dynamics. Algorithm for vehicle course prediction through the decoupling of vehicle longitudinal and lateral dynamics was established. Driver behavior model was constructed based on steady state preview and dynamic state correction, preview follower theory and multi object decision theory. Then analysis parameter in this model in order to describe the driver's behavior by establish of evaluation index for model. In the end Adaptive Cruise Control System and Lane Departure Warning System were got depend on this model. There are also a lot of simulations cover all circumstances and part experiment to verify the performance of these systems. The main context of this paper is:(1)Figure out the main reason for traffic accident after analysis of driver's behavior and vehicle dynamics. The reason for why that's so important to research driver's behavior has been given based of the analysis of traffic accident. At last the reason for driver assistant's study was given and the context of this paper was confirmed. (2)Driver's behavior is not only the foundation of vehicle assistant but also the key of the research for vehicle closed loop handling and stability. Factors such as vehicle performance, driver's characters, road rules and circumstance have been analyzed based on the analysis of driver's sense feeling and handling. The process of driver's behavior has been divided into three basic parts, that's information apperceive, course decision and correction. Based on things above and hypothesis of steady state preview and dynamic state correction, key problems were given in the following sections. Vehicle course prediction algorithm depend on body dynamics was established and the evaluation algorithm for optimal point in the set was given. Integrated algorithm was established at last through multi object decision method. Index for evaluation of driver model was get from the method of vehicle closed loop evaluation, parameters about the most common driver was got from plenty of simulations. Simulation about different kind of circumstance proved the rationality for the description of driver behavior.(3) The nonlinear characteristic of vehicle dynamics is the main reason for the slow development of it's control. There is not an only method now for the description of its nonlinear characteristic. New method about its description by nonlinear theory of it's linear method in small area was given based on the research of vehicle dynamics. The concept of vehicle steady motion was put forward. Identification about the longitudinal and lateral dynamics was finished based on the decoupling of it. The sheet was got which can be used to finish the algorithm for vehicle control with internal model control theory. In order to get deeper verification field operation test was carried out and good result produced to verify the performance of this algorithm.(4) Vehicle Adaptive Cruise Control System is one of the typical system used to reduced driver's burden, improve safety, saving petrol and reform surroundings. Integrated decision model become not only a method to describe driver's behavior but also the foundation of vehicle assistant system. Adaptive Cruise Control system was established based on integrated decision model, in which evaluation and decision part depend on decision model and correction part depend on calibrated method for nonlinear dynamics system and internal model method. All kinds of circumstance simulation proved the rational and efficiency of the model.(5) Establish of Lane Departure Warning System. Lane Departure Warning is one of the main reasons for traffic accident. Basic theory for this system was put forward and evaluation algorithm was also established. Two kinds of simulation proved its usefulness and natural performance.The creative point of this paper is that establish of integrated decision model, establish of evaluation algorithm of the model, description of driver's behavior, calibrated field operation test method of vehicle dynamics character and its steady state, perfect control method and finally adaptive cruise control system and lane departure warning system. Simulation for all kinds of circumstance proved its usefulness and correctness.