The Research Of Calibration Stability Of Safety Airbag ECU

As the sustaining growth of vehicle quantity in China,the number of people who died from traffic accident every year still be a large number.Safety airbag,which is the last buffering protector in traffic accident,draw more attention and trust from Chinese driver.While in some cases,safety airbag cannot protect passengers very well,even hurt passengers in normal driving.Safety airbag complaints cases take a part in the vehicle quality complaints cases every year.In the safety airbag cases,none deployment in crashes and deployment with no crashes,this two situations will do serious harm to human body.Calibration stability makes direct impact on working stability of airbag ECU.So to improve the calibration stability to provide better protection for passengers,is a significant research subject in passive safety domain.From crash test data collecting to calibration finished,each step in the whole process may has influence on calibration stability.After research,some main factors were found in the whole calibration process,have great effect on the calibration stability.The factors are crash test matrix,dynamic stiffness on the install position of accelerometer,type and cut off frequency of digital filters,fire algorithm and calibration strategy.In order to research the specific influence of these factors,based on one type of vehicle,crash matrix was settled according to Chinese regulations and rating requirement.Crash tests and misuse tests were conducted in crash laboratory.Data processing software and calibration software were programmed based on MATLAB.Test data was handled according to the requirement,and then were input into calibration software to calculate power variation ratio and plot them.By adding threshold dots on the calibration window,threshold line was generated,and the line was stored in type of array.Compare the array with power variation ratio,fire flag and actual time to fire can be calculated by calibration software.Safety margin and the deviation between actual time to fire and required time to fire are important parameters to estimate calibration stability.This paper analyzed the calibration result,and verified the result by using validation crash test data.The result shows that almost all of the crash tests meet the calibration stability requirement.The innovation points of this paper are improving fire algorithm and calibration strategy.