Research And Design Of Vehicle Block Box System Based On RH850

Automobile event Data recording system,EDR for short,also known as automobile black box,is composed of one or more on-board electronic modules,which has the function of monitoring,collecting and recording a variety of vehicle information before,during and after collision events.After the accident,data is extracted and converted by professional tools to construct the accident process.Due to the increasingly complex traffic environment,the function of traditional on-board recording equipment lags behind and other reasons,automotive black box has gradually become an important representative of the new generation of accident identification equipment.In 2020,the National Technical Committee for Standardization formulated the document GB39732-2020 Vehicle Event Data Recording System(hereinafter referred to as the national standard document),which pointed out that from January 1,2022,all new types of car application approval will be equipped with the car black box,starting from the first year of compulsory installation of the car black box.This paper designs a car black box system based on the national standard file.The research contents are mainly divided into three aspects: the basic function of the black box,the diagnosis and refresh of the black box,and the backup of abnormal driving data.The basic function of the black box uses RH850 1KMS4 as the main control chip.In terms of software design,the change of vehicle speed is monitored according to a certain sampling period.If the collision threshold is exceeded,the corresponding event processing interruption will be triggered.Finally,it is stored in the non-volatile storage medium.The hardware design mainly involves the design of power switching circuit,electromagnetic detection circuit,communication bus circuit,data storage circuit,etc.The black Box Diagnostics and Upgrades section is based on the ISO 14229 and ISO-15765 series of international standardization documents.CANOE is used to design the upper computer interface and VN1630 A is used as the hardware/software link bridge to research,design and develop several common services and system upgrades.In the design of abnormal driving data backup function,when EDR detects the possibility of vehicle collision,it sends an abnormal driving status notification to the vehicle master ECU,which reminds the car owner and preprocesses the image recorded by the vehicle camera.YOLOv4 model is used to detect and recognize pedestrians and vehicles in the figure.Moreover,the pixel coordinates,current longitude and latitude,time and other information of the target are saved to the non-volatile storage media of the EDR system,which provides effective data support for the reconstruction of the crash scene in the later stage,and solves the problem of image data loss caused by the damage of the onboard video recording equipment caused by vehicle collision.Finally,combined with the software and hardware,the EDR system described in this paper is tested.The test results show that the system can fulfill the requirements of the national standard file for the basic functions of the new generation of car black box,black box diagnosis and upgrade and abnormal driving data backup can also run stably and realize their respective functions.