Effects Of Lumbar Support Magnitude On Vibration Characteristics Of Human Body

Prolonged fatigue driving leads to frequent occurrence of various diseases,especially waist,neck,arm and shoulder diseases,and even cause chronic musculoskeletal injuries.Fatigue driving easily lead to accidents and it is important to improve the comfort of driver.Car seat has a significant impact on driver comfort,and in many design variables seat backrest variables have the greatest influence on comfort.The magnitude of lumbar support is an important parameter on backrest variables.To reduce drivers muscle fatigue during vibration,it is important to research the relationship of lumbar support magnitude and human fatigue.By analyzing the relationship between the lumbar support magnitude and the muscle fatigue time,acquire back pain prevention methods,and provide a reference for car seat design and comfortable.This paper includes the following aspects:First of all,introduces the EMG signal generation principle and acquisition process.Designed a thickness adjustable lumbar support mechanism,the adjustment range is 0,10,20,30 and 40mm,analyze its force conditions.The analysis results proved that the lumbar support mechanism could meet the experiment needs.It provides a theoretical basis for vibration fatigue experiment and acceleration experiment.Secondly,the lumbar support mechanism is mounted on the car seat,the seat fixed to the vibration table,to do vibration fatigue experiment.When the thickness of the lumbar support is 0,20 or 40mm,by Delsys software and hardware facilities,collecting the surface EMG signal of erector spinae,neck muscles,trapezius,biceps femoris.The RMS,IEMG and median frequency could be obtained by time and frequency domain analysis.The increasing of IEMG and RMS,and the attenuation of median frequency could explain the local muscle fatigue time and degree.Compared to 0mm or 40mm,20mm of lumbar support magnitude,muscle fatigue is relatively low.20mm of lumbar support magnitude could reduce driver fatigue during long drive,and enhance the comfort of seats.Thirdly,the vibration acceleration experiments in different thickness lumbar support,analyzed the vibration acceleration transfer characteristics on neck,shoulders,chest and waist,in the X-axis and Z-axis direction,given a reasonable magnitude of lumbar support to reducing the transmission of vibration acceleration.