Research On Optimization Of Engine Room Data Transmission Based On OBD

With the development of science and technology,OBD(On-Board Diagnostics)systems are now installed in cars,which can monitor the basic parameters of vehicle engines and emission systems and be used for vehicle fault diagnosis,so the research on OBD systems is a hot field.In this paper,the real-time working parameters in the engine compartment are collected by the automobile OBD system,which provides data support for analyzing the sudden failure of the automobile.At the same time,in order to improve the cloud transmission efficiency of multiple vehicle parameters,the unloading model of cloud computing is optimized.The main contents of this paper are as follows:1.Based on the study of the working principle and mode of automotive OBD system and analyzing the ISO15765 protocol of the CAN bus,a system for real-time acquisition of relevant working parameters of engine compartment is developed to collect data such as engine speed,vehicle speed,torque,computer load,throttle opening and coolant temperature.2.Based on STM32 single-chip microcomputer,the hardware circuit of the acquisition system is designed,including power supply circuit,data acquisition circuit,clock circuit,SD card storage circuit,4G communication circuit,and download and debugging circuit.The parsing code,and the file system is compiled to store the data,and the remote cloud transmission function of the data is realized based on the 4G wireless communication module.3.Aiming at the problem that the computing offloading algorithm has a single function in a single MEC(Mobile Edge Computing,MEC)server system,a multi-objective computing offloading algorithm based on the interior point method is studied to optimize the delay and energy consumption during the transmission of the collected data to the cloud,Optimization,effectively reducing the time delay and energy consumption during the transmission process.The algorithm re-establishes the time delay and energy consumption model,uses the cost function to balance local computing and computing offloading,and then uses the interior point method to solve the data offloading probability.4.The ELM327 simulator is used to test the data acquisition system.Through the test of each module of the system,the accuracy and real-time of the collected data are verified.At the same time,by establishing the calculation model of multiple vehicles and a single mobile edge server,it is verified that the optimized calculation unloading algorithm can effectively reduce the delay and energy consumption in the calculation process,and the performance is optimized by 15% compared with a single calculation unloading algorithm.