Low-frequency Magnetic Field Measurement And Supporting Software Development Of Vehicle Passenger Compartment

The magnetic field environment of the passenger compartment of contemporary automobiles is becoming more and more complex,and the health of the occupants is threatened.The national standards require the measurement of the magnetic field of the passenger compartment and limit the intensity.Based on this,this paper develops a LF magnetic field measurement system,so that the LF magnetic field compliance assessment of the passenger compartment can be carried out efficiently.The measurement system is composed of two parts: data acquisition and data processing.This article introduces the acquisition of LF magnetic field data and the development of data processing software in turn.Finally,the accuracy of the measurement system is verified by the LF magnetic field immunity test.Based on the analysis of the frequency range(10Hz-400 k Hz)and public magnetic field exposure limits specified in GB/T 37130 and GB 8702-2014,the data collection plan was selected,including equipment selection,frequency band division and collection process.Considering that the current data processing methods are too inefficient,it is clear that the development of supporting data processing tool software is necessary,and then based on the MATLAB development platform,developed a log-in management,data input and output,data processing and result evaluation functions.Data processing software,the processing efficiency of test data has been significantly improved.Finally,the accuracy of the measurement system developed in this paper is verified based on the standard magnetic field of 15Hz-150 k Hz.The generation and calibration process of the standard magnetic field conforms to the ISO 11452-8 test standard.The calibration result before the test shows that the power amplifier needs to increase the output of about 3.50% on the expected value of the theoretical field strength to generate a standard magnetic field of the target strength in a given area.The results of the formal verification test show that the average absolute percentage error of the measured value is 4.77%,and the error expressed in decibels is-0.42 d B,which can better meet the accuracy requirements of engineering use.