Research And Design Of S32K144 Even Data Recorder

In recent years,a large number of traffic accidents have occurred in the world every year,and the number of people who die in traffic accidents each year remains high,and the identification of responsibility after a traffic accident and the cause of the accident are mostly analyzed and obtained by the traffic police department according to the speed of the vehicle,the event data recorder,the camera,and the work experience of the analyst,however,the lack of direct data support,resulting in low efficiency,the analysis of the accident is too one-sided,the analysis results are not accurate,resulting in the responsibility of the accident can not be clearly identified,the cause of the accident can not be accurately inferred.Based on the principle of airplane "black box",the researchers have studied the EDR(Event Data Recorder)of the vehicle accident Data Recorder.In the past,most of the Data records recorded the Data of the airbag control module,the information is single,and the manufacturers keep it secret,the format of the data record varies,and the data is used only for airbag improvements.For the sake of scientific analysis and evidence collection of the cause of the accident collision and the study of accident reconstruction,it is required that the data recorded by the EDR accident data can reflect the running state of the vehicle in an all-round and accurate way when the accident occurs,standardization of data recorded by EDR.The data recorder designed in this paper is mainly used in motor vehicles to record the driving parameters of the vehicle before and after the accident and the specific operation taken by the driver,EDR Data include vehicle speed,engine speed,seat belt usage,brake pedal status,date and so on.The analysis of EDR data can objectively analyze the operation parameters of the vehicle when the vehicle has a collision accident,which not only provides powerful data support for the judicial organs to enforce the law fairly and efficiently,it also provides technical support for the research of road accident reconstruction.In view of the shortcomings of the one-sided data recorded by the recorder in the pastand the inaccurate analysis results,the data recorder designed in this paper is based on the mandatory standard GB 7258-2017 "technical requirements for motor vehicle operation safety" drafted in 2017,the functional requirement of data recorder is analyzed,and a data recording system using CAN bus as communication medium is proposed.In this design,S32K144 of NXP is selected as the main control chip,and two CAN interfaces are drawn out by using the CAN controller and TJA1042 T high-speed CAN transceiver to form CAN bus communication module,and the peripheral sensor module is responsible for detecting collision threshold,once the trigger threshold is reached,the collision data is collected by CAN bus communication module and stored in Flash memory.The data recorder designed in this paper is mainly composed of hardware and software.In the hardware part,CAN bus communication module,sensor module,power module and SWD module are designed.In the software part,Standard C language is used to design and program the receiving and sending module of CAN bus,sensor module and Flash storage and erase module,and the driver CAN control the work of hardware circuit directly.Finally,the hardware and software are combined to test the system’s CAN communication module and Flash memory.The test shows that the data recording system can run stably and record the target data completely,which provides strong data support for the judicial appraisal of the accident.