생체역학 관점에서 장시간 운전 시 승용차 운전자석 불편함의 객관적 평가 방법 제시

Abstract

Objective: The aim of this study is to suggest that an objective biomechanical evaluation method of seat discomfort to sedan driver’s seat during long-term driving.<BR>Background: Recent modern car seat has become increasingly complexed and sophisticated with ongoing seat discomfort problems. Consumers’ demands for better seat comfort have also increased but most of them still choose car seats in the wrong way. Previous researches have recommended quantifying overall car seat discomfort based on questionnaire, analysis driving posture, pressure, physiological changes and etc. Although various studies have been presented to objectively evaluate the seat comfort, but the standard for objectively evaluating seat discomfort has not been established.<BR>Method: Ten males were recruited to participate in a laboratory study. All participants performed three trials according to the seat back angle and each trials was conducted on different day. Each trial was consisted of 120 minutes of continuous driving on different day. The method proposed for the seat discomfort evaluation assumes that the driver’s discomfort were related to the load of lumbar region, and that the load was only caused by the upper body of the driver. In order to calculate the load, the driver’s driving posture was captured by using Kinect v2 sensors, and the reaction force was measured by attaching a pressure distribution mat to the seat back and pan. The questionnaire survey was conducted through long-term driving according to the backrest angle. The results were conducted with correlation analysis between results of the questionnaire and estimated lumbar moment calculated by load and reaction force.<BR>Results: The results show that the discomfort of questionnaire rating increased over time at the lumbar region. Also, at 87° and 107°, the overall discomfort rating was higher than it at 97°. In addition, over time, we found an increase both seat pressure and estimated lumbar moment. The correlation analysis results show that the higher correlation between the changes of difference discomfort rating and the calculated lumbar moments, the lower the discomfort.<BR>Conclusion: This study results suggest that an objective evaluation biomechanical method could be served as a standard for evaluating seat discomfort.<BR>Application: The results of this study might help to prolong the ‘good’ driving posture during long term driving that can reduce the driver’s seat discomfort by evaluating biomechanical method and a system that might be helpful to car seat development process through objective evaluation.