The Testing Platform Of FlexRay Bus And The Optimization Research On FlexRay Bus Communication

With the development of the automotive electronic, vehicle electronic equipment has the increasing demand of bandwidth and real-time requirements in the vehicle communication network. Because of high bandwidth, dual-channel redundancy and certainty time of message transmission, FlexRay as a next-generation vehicle network has been widely used. This thesis focuses on two issues to research. (1) In the FlexRay bus communication network design and debugging process, the test platform which can record the detailed data of network is needed in order to obtain the operating state of each node and analyze the network performance. (2) In FlexRay communication network, the current general approach is assigning a static segment FlexRay slots for each message, but this has led to the static segment FlexRay slot utilization is low, which causes a waste of bandwidth.In this thesis, for the first question The FlexRay network test platform, composed of data acquisition device and the program page for PC monitoring is designed, using FPGA as the core device. The FPGA has an IP core with CPU, SPI interface, memory controller and others.The SPI protocol is designed for FPGA communicating with FlexRay network nodes. The USB communication protocol used for FPGA and PC communication, and MySQL database management software are designed, so that data can be collected into the MySQL database and can be displayed in real time for the user for further analysising.For the second question, based on the study of FlexRay network communication mechanism, the thesis proposed quadratic integer programming model, which can optimize allocation of slots for node sending messages and to improve bandwidth utilization. By circulating solving constraint, the quadratic integer programming solving problem is converted into an integer programming problem, and then the CPLEX software is used to get the optimal solution and FlexRay network schedule table. The random message generator for generating messages and optimization results display page for showing the results of the optimization solution are designed for model test, According to FlexRay communication scheduling table, the buffer configuration code generator based on MC9S12XF512 microprocessor is designed. Finally, according to the configuration code the FlexRay communication program is transplanted to test the FlexRay communication on this network test platform, and ultimately the feasibility of the model is verified in the actual network.