Study On The Discrimination Of The Key Targets In Front Of The Cruise Vehicle Based On The Radar Information

When adaptive cruise control work, the vehicle follows the target vehicle is known as a key target, specifically a longitudinal distance from the vehicle in the lane nearest the target vehicle in front or adjacent lane to cut into the lane of the vehicle. Furthermore, information will be sent to key objectives to the adaptive cruise control system controls the vehicle longitudinal velocity, so that the vehicle and the vehicle in front to maintain appropriate safety distances. Therefore, fast and accurate determination of the key objectives of the car in front of the cruise for adaptive cruise control system of the vehicle is important.On the basis of the radar information, the thesis researches a judgment method on the key objectives in front of the cruise vehicle for adaptive cruise control system by using theoretical analyses and simulation. Thesis consists of five parts. The first part introduces the research background, significance, research status and main contents of the paper. The main aim of the second part is to estimate the running state of the cruise vehicle based on Extended Kalman Filter theory. A two-freedom model on the Yaw rate and sideslip angle of maneuvering stability was established for designing an estimator on the cruise state. In the third part, different methods have been applied to discriminate a key objective in front of the multi-target vehicle for the straight and curved road driving conditions. By estimating the state of the cruise vehicle, a real-time online road curvature is obtained under the condition of curved road driving. On the basis of the curvature estimation, a key objective discriminant model is set up to calculate the distance from the target vehicle to the vehicle running track centerline of the cruise vehicle using a geometric relationship for determining whether the target vehicle is to be within the in-lane. For the straight driving conditions, in addition to considering the in-lane goal, it is need to consider the goal in the adjacent lane to cut the in-lane possibility. Therefore, the thesis uses fuzzy control theory to study the key objective discrimination strategy under the condition of the straight running with changing behavior. A fuzzy controller, which includes two input variables, the lateral relative distance and relative speed, and an output variable, the possibility of changing in-lane, is designed to determine the straight key objective. The fourth part pay close attention to validate the control performances on the proposed control strategy using CarSim and Matlab/Simulink simulation aiming at various cases, the straight road driving, straight road cut-in and the curve road with the preceding vehicle, and so on. Simulation results show that the key objectives discrimination methods proposed can identify accurately the key objectives in front of the cruise vehicle for adaptive cruise control system. The fifth part is the conclusion, which summarizes the thesisresearch results and the issue needed to further discuss.The research result has important reference value for improving the control function of the adaptive cruise control system and improvement and developing the system’s product.