Research On The Data Acquisition And Simulation System Of The FlexRay Network

With the continuous development and advancement of automotive electronic technology,the electronicization and intelligence protortion of automobiles is increasing.The number of electronic control units of automobiles is constantly increasing,therefore the requirement for the vehicle network is also increasing.In this background,the FlexRay network stands out as a new generation of automotive network with its unique real-time and efficient transmission characteristic.In the process of motor controller or active suspension controller development,more complete datas of sensors are needed.The traditional data acquisition system based on CAN network can't send the target data completely even if it transmits the target data at the maximum baud rate of 1M,which leads to the loss of relevant data..This hardly meet the requirements in the development process.This study proposes a data acquisition system based on FlexRay,used to acquire more data than traditional acquisition system by CAN.In this study,the latest version of the FlexRay protocol is analyzed.The bus timing and coding characteristics are analyzed by specific experiment.Combined with the actual requirements of data transmission,the communication parameters of the FlexRay network are designed.Because the FlexRay network will generate lots of data,this study proposes to use large-capacity SDRAM as the external cache area to save data temporarily,and then send data to PC through high-speed USB to ensure the real-time and integrity of the acquired data.At the same time,this system integraes the function of acquiring data on the CAN,also can supply vehicle acceleration signals,yaw rate,pitch angle and roll angle signals.In this thesis,according to the specific requirements of the system function,hadware system and software system including the upper computer are designed.Finally,the acquisition function of this system is proved to reach the purpose.This system can accurately acquire data from CAN network.Importantly,compared with the amount of data sent by CAN network at the maximum baud rate,the system can realize the function of sending more data in the same time by FlexRay network.So the system can meet the data acquisition requirements in the process of motor controllers or active suspension controllers development.