基于有限状态自动机的人眼开度PERCLOS实现算法

针对驾驶员驾驶过程中因疲劳引起的眼睛开度变化问题, 在原有PERCLOS(percentage of eyelid closure over the pupil over time)标准的基础上, 提出了一种基于有限状态自动机的人眼开度PERCLOS计算方法, 并将其应用到疲劳驾驶预警系统中。该系统首先采用红外摄像头实时获取驾驶员的脸部视频图像, 使用ASM(active shape models)算法进行人脸检测, 在定位到的人脸范围内搜索人眼区域并计算人眼开度, 为了避免人与摄像头距离变化影响计算结果, 对人眼开度进行归一化处理; 然后依据建立的有限状态自动机模型计算PERCLOS值; 最后根据制定的预警机制实现基于人眼开度的疲劳预警。实验结果表明本方法能够实时监测驾驶员疲劳状况, 具有对光照变化、脸部配饰不敏感的特点。

PERCLOS implementation computing method ofeye open degree based on finite state machine

As for the drivers' eye open degree changing due to fatigue, this paper proposed a finite state machine based on PERCLOS algorithm and applied to pre-warning system of fatigue driving according to the original PERCLOS standards. Firstly, it used infrared camera to capture drivers' face in real time and detected face by ASM algorithm. To avoid the influence of the distance between man and camera, it normalized eye open degree when it was calculated. Then it obtained PERCLOS value by the proposed finite state machine based method. Finally, the eye open degree based system pre-warns the fatigue according to the established pre-warning mechanism. The experiment results show that this method can monitor drivers' fatigue status in real time and it is insensitive to light and drivers' accessories.