Design And Realization Of Real-time Monitoring System For SCR Running State Of Diesel Vehicle

With the strengthening of environmental protection,environmental laws and policies have been issued by various departments.The draft of Naitonal VI emission standard has passed the review,vehicle "remote emission management" will be included in the regulation.In addition,with the development of automotive networking has become a major trend,the aftertreatment of engine tail gas should also make a difference in these frontiers.A real-time monitoring system for running state is designed based on the diesel engine SCR system in this paper.The SCR system of heavy diesel vehicle which meets Naitonal V emission standard is taken as the monitoring object,and the signal collection and fault diagnosis are carried out according to the requirements of HJ437-2008.Using GPRS to transmit SCR status information to WAN server.At the same time,computer monitoring platform and mobile phone APP have been developed based on E4 A and Qt.Using Socket programmed technology to obtain SCR status information from Server,and displayed to the owners,manufacturers and government departments,implement the real-time interaction between the SCR system of heavy diesel vehicle and the above three categories of users.The design of this paper can be summarized as the following steps: firstly,clear the detection target through the analysis of the SCR system and the HJ437-2008 regulation.Secondly,MC9S12XS128 is chosen as the main control chip,realize the signal acquisition based on CAN communication and A/D conversion,at the same time,the control strategy of fault diagnosis is designed and using C language to complete embedded development.Again,the monitoring data are transmitted to the Internet server based on GPRS wireless communication and serial communication.Then,the mobile phone APP and computer terminal software are developed based on E4 A and QT to display the running status of the SCR system.Finally,the function of developed system is tested.Through the complete development process mentioned above,the primary physical development of the project is completed.The experimental results show that the SCR real-time monitoring scheme designed in this paper is technically feasible,and has advantages in cost and implementation,and it can also be extended to other exhaust post-processing systems.