Design Of Safety Monitoring System For Jiefang Heavy Truck Based On CAN Bus

In recent years,CAN bus technology in the vehicle above the increasingly widespread application,significantly enhance the reliability of the electrical system and response time line,also makes the vehicle electrical system design flexibility increased significantly.On the other hand,with the development of the national economy and the increasing popularity of vehicles,the driving safety of vehicles has received more and more attention.In this paper,a safety monitoring system based on CAN bus is designed to enable the driver to directly observe the vehicle safety parameters related to driving,and record these parameters.It can also be used as a compensation and responsibility judgment The basis.The system has good openness,versatility and reliability,and it has a good reference value for the secondary performance development based on this system.Under the premise of clear design requirement,this paper,based on the actual situation of the whole vehicle,first carries on the overall planning to the signal acquisition mode,the sensor arrangement and the system module distribution,which makes the design itself feasible.On this basis,the communication protocol of CAN bus is analyzed.Combining the advanced functional requirements of the system and the advanced experience of SAE J1939 protocol,the frame control domain has been redesigned,which not only improves the adaptability of the system,but also increases the security of the system.Based on the criterion of quality control,the algorithm of sampling data and the differentiating conditions are designed to make the collected data real and credible.(Including data storage,CAN bus transmission,RS232 transmission,A/ D conversion and signal acquisition,Bluetooth transmission,etc.),in order to solve the problem of different modes of communication of the function modules,the use of a variety of functions and modules,The design of the interface between the circuit,so that the controller in the operation at the same time,in two kinds of communication protocols to transfer data between.At the same time in order to improve the reliability and maintainability of the monitoring system,the software design,the establishment of the communication protocol conversion and computing module,the system function expansion and program migration line becomes simple and easy.Finally,the actual operation of each function module shows that the designed safety monitoring system can achieve the expected function,make the driving safety parameters visualization,timely alarm output and can be used as an important basis for the determination of liability,for CAN bus products in the vehicle have a good reference.