Research On Adaptive Cruise Control Algorithm And Strategy

With the development of the automotive industry,the safety of automobiles has received more and more attention,and adaptive cruise systems are an important part of active safety systems.The system can effectively alleviate the driver's fatigue during the driving process,and improve the intelligent level of the vehicle under the premise of ensuring safe driving,and ensure the driver's comfort.China's technology in this field is not yet mature.Therefore,the adaptive cruise algorithm studied in this paper is of great significance for China to improve its independent research and development capabilities.This article has conducted in-depth research through the following work.(1)Different working modes and switching strategies of the adaptive cruise system are formulated to ensure that the car has different execution operations under different working conditions.In this paper,the safety distance algorithm of the adaptive cruise control system increases the driving characteristics of different drivers based on the variable safety time interval to perform the safety distance control at different levels.The overall control algorithm of the system adopts hierarchical control,which avoids the disadvantages of unmatched system mismatch caused by integrated control,and is divided into upper layer control and lower layer control.(2)The upper control algorithm is divided into a cruise mode algorithm and a car mode algorithm.The cruise mode algorithm adopts the traditional PID control and the optimal PID parameter is adjusted by experimental simulation;The model predictive control(MPC)algorithm is used to solve the multi-objective optimization problem effectively,and the constraints such as fuel economy,human comfort,and driving safety are considered under the normal operating state of the system.Considering the complex working conditions and the influence of driving behavior,the MPC calculation of the expected amount of control sometimes presents non-feasible solutions.In this paper,a method of softening hard constraints is designed to solve the problem of no feasible solutions in emergency situations.(3)The lower controller sets up the braking model and the driving model,sets up the driving braking switching logic,simulates the rationality of the braking driving switching curve,and optimizes the switching logic.This paper will adopt appropriate amplification compensation strategies to ensure the smooth switching of vehicles,The problem of body jitter is effectively solved when driving brake switch in adaptive cruise system.(4)Carsim and Simulink are used to test the performance of the system.The simulation results show that the algorithm strategy of the system can meet the cruise function under different conditions.