Abstract: In order to quantify influence of walking height on motion features of evacuees, VR technology was adopted to construct evacuation scenarios of different heights. Then, experiment data were collected with laser radar, and fear of height was classified by using acrophobia questionnaire (AQ) and K-means clustering algorithm. Finally, influence of different levels of acrophobia and gender on evacuees' speed, stride and step frequency were investigated at controlled height. The results show that evacuation speed, stride and step frequency of pedestrians decrease along with the increase of height, which is more obvious as it is between 0 m and 50 m. When at the same height, those whose acrophobia is more severe will have lower speed, smaller stride, faster step frequency and are more sensitive to height changes. It is also found that female's walking speed and stride decrease more observably than those of males while the latter's walking speed and stride are larger than females at the same height.

Key words: virtual reality (VR) technology, working height, cvacuation, degree of acrophobia, motion features