Intelligent Control And Simulation Of Automobile Active Cruise System

With the rapid development of the social economy and the improvement of human living standards,people's requirement for the automobile active safety and the riding comfort is getting higher.Automobile active cruise system can automatically adjust its longitudinal acceleration to realize the intelligent tracking of the set speed or the speed of preceding car by automatically controlling the throttle opening and the brake pressure.The system is able to reduce the driver's workload and improve the automobile's active safety to some extent.However,the traditional automobile cruise system usually neglects the driver's driving habits and adopts different control algorithms for different working conditions,which greatly increases the cost and time of the product research and development and cannot ensure the systematic performance and stability when switching system function.For the shortcomings of automobile active cruise system,the paper focuses on the integration control functions and the systematic stability of automobile active cruise system considering the driver's driving habits based on fuzzy control theory.The main contents of the dissertation are as shown below:(1)The overall design of automobile active cruise system.According to the active cruise system's control function to want to achieve,the overall design scheme is proposed and the hierarchical control structure of automobile active cruise system is analyzed.(2)Constructing the dynamic model of automobile active cruise system.Based on the automobile dynamics knowledge and actual data,the automobile cruise system dynamics models that can reflect the system's dynamic characteristics and accomplish complex driving conditions are built as well as considering the accuracy and conciseness in the process of constructing model.At last,each simulation module on dynamics model built above is designed using Matlab/Simulink.(3)The controller design of automobile active cruise system.On the basis of the overall design of automobile active cruise system,a control function definition layer is designed in order to realize the control mode switch,and the mathematical model of safety distance and actual relative distance is established.Based on the fuzzy control theory,an upper fuzzy controller is designed to obtain the expected acceleration of host car to take into full account the driver's driving habits.Furthermore,a model matching lower controller is built by using the model matching method in order to accomplish the expected acceleration matching more accurately and quickly.(4)The simulation and evaluation of automobile active cruise system.First of all,the sub-modules designed above are connected to build a completed automobile active cruise system module.The integration control functions of the active cruise system are validated for the various actual conditions in the car's driving process,such as collision avoidance,stop&go,intelligent follow,cruise control,switch between the cruise control and intelligent follow mode using Matlab/Simulink.The simulation results indicate that the active cruise system established in this paper can realize the integration control for the various actual driving conditions and ensure the stability of switching system function under the satisfied driving habits.It is of great significance to improve the automobile's active safety and riding comfort,and the road utilization rate.The conclusions and achievements of the dissertation can not only provide theoretical reference for researchers to carry out scientific research on automobile's active safety control,but also provide the necessary technical support for the technicians engaged in the product development of automobile cruise system.