基于时频分析的通话驾驶转向特征研究

Research on Turning Characteristics of Talk DrivingBased on Time-Frequency Analysis

对不同驾驶经验下的分心驾驶转向盘转角数据进行Kruskal-Wallis H与Mann-Whitney U检验,应用快速傅里叶变换(FFT)对转向盘转角数据进行频域分析,探究转向盘转角在时域及频域范围内的变化规律.结果表明:在不同分心程度条件下,非熟练驾驶人转向盘转角的绝对均值与其波动值均大于熟练驾驶人;非熟练驾驶人在正常、免提,以及手持通话驾驶下的转向盘转角均存在显著差异(p<0.001),熟练驾驶人在免提与手持通话时转向盘转角无显著差异(p>0.05);在频域范围内,转向盘转角功率谱密度分布与驾驶经验及分心程度具有显著效应(p<0.001).随着分心程度升级,非熟练驾驶人转向盘转角幅值逐渐增大,功率谱峰值不断向高频段偏移,在手持通话时大幅度转动方向频率较高;熟练驾驶人在免提通话时峰值频率最高,较大幅度转动转向盘频率相对较高.

Kruskal-Wallis H and Mann-Whitney U tests were conducted on steering wheel angle data of distracted driving under different driving experiences,and fast Fourier transform(FFT)was used to analyze the steering wheel angle data in frequency domain,so as to explore the changing law of steering wheel angle in time domain and frequency domain.The results show that the absolute mean value and fluctuation value of steering wheel angle of unskilled drivers are greater than those of skilled drivers under different distractions.There are significant differences in steering wheel angles among unskilled drivers under normal,hands-free and hand-held calls(p<0.001),while there is no significant difference between skilled drivers under hands-free and hand-held calls(p>0.05).In frequency domain,the power spectral density distribution of steering wheel angle has a significant effect on driving experience and distraction degree(p<0.001).With the escalation of distraction,the amplitude of steering wheel angle of unskilled drivers gradually increases,and the peak value of power spectrum constantly shifts to high frequency band,and the frequency of turning direction is higher when holding a phone call.Skilled drivers have the highest peak frequency when talking hands-free,and the frequency of turning the steering wheel greatly is relatively high.