ABSTRACT
This chapter examines the strategy of time-to-collision (TTC) estimation of nonrigid approaching object, specifically, human walkers. Because there is a correspondence between walking velocity and body movement, body movement can serve as an effective cue for estimating walking velocity. The chapter hypothesizes that the judgment of TTC with human-walker is based on the apparent walking velocity and, at the same time, that the walking velocity is estimated on the basis of the walker’s body movement. It uses stick-figures of a walker as stimuli, which were created from data acquired through Vicon 3D motion-capture system. When a trial began, the stick figure walker traveled toward the goal which was placed on the floor for two steps, and then disappeared.
