Study Of Driving Fatigue Based On Typical Parameters Of Physiological And Operating Behavioral Characteristics

Large amounts of domestic and international data shows that fatigue is one of the main causes of freeway traffic accident. Compared to the plain freeway, the driver needs to be more concentrated while driving on the mountain freeway with complicated linearity, thus it needs more driving intension, and more likely to cause fatigue and the bigger severity of fatigue accident. So it is important to study the fatigue accident of the mountain freeway which can improve road safety service level. There are many reasons will cause fatigue accidents, in addition to the duration of driving and road traffic environment, circadian rhythms will also affect fatigue driving. Affected by the circadian rhythms, the human body shows different levels of arousal under different times, which leads to the driver lethargy at certain times. However, the current research on fatigue mainly focused on the duration of driving, only a few of scholars had analyzed the effect of afternoon or at night on fatigue. Therefore this article, explored the ECG characteristics and speed and acceleration characteristics under different time embarked from the circadian rhythms, and selected appropriate indicators to evaluate fatigue of different types of driver under different times. The main contents of this article are as follows:First of all, based on the summary of domestic and foreign literature on the periods of fatigue and analysis of accident statistics, the times which was chosen to study was determined. At the same time, based on purpose of research, the ECG characteristics and speed and acceleration characteristics were chosen to study. The real vehicle experiment was designed to gather the electricity, speed and acceleration, subjective fatigue evaluation data of different types of drivers under different times.Secondly, the changing rule of ECG characteristics and speed and acceleration characteristics of different type of driver under different times was studied using statistical methods. And the ECG characteristics focused on the average of heart rate and the ratio of low frequency and high frequency. Speed and acceleration characteristics focused on the standard deviation of speed, the absolute mean of acceleration, the standard deviation of acceleration. Then appropriate test method was used to texted the difference of various characteristic parameters of different types of drivers under different times.Then, based on the correlation between characteristic parameters, this article used the principal component analysis to analyze three indicators with substantial correlation which were the standard deviation of speed, the absolute mean of acceleration, the standard deviation of acceleration. Thus the comprehensive indicator of typical parameter of operation behavior was obtained. And the average of heart rate, the ratio of low frequency and high frequency and the comprehensive indicator were used to evaluate the degree of driver fatigue. The k-means clustering analysis was used to analysis the relationship between the three indicators and the degree of driver fatigue. The threshold of three indicators were determined of different types of driver under different levels of fatigue. After that, the degree of fatigue of different types of driver under different times was evaluated based on the fuzzy synthetically evaluation method. And comparing the evaluation results and subjective fatigue evaluation data, it proved that both had good consistency.Finally, based on the conclusion of this article, considering the intelligent monitoring and warning of fatigue, drive travel time, the science formulation of continuous driving times and so on, probable applications and suggestions were put forward to guarantee driving safety of the mountain freeway.