Determination of time to contact and application to timing control of mobile robot

Usually, robots have some sensors that measure the distance between the robots and any obstacles, for example, ultrasonic sensors, infrared distance sensors, and etc. On the other hand, although animals and insects do not have distance sensors, they can behave adaptively in unknown environments. The mechanism of adaptive behavior has been studied in ecological psychology, and it is assumed that animals and insects employ time-to-contact information instead of distance information. This time-to-contact is called the “tau-margin,” and animals and insects obtain this information from the apparent size of objects and the temporal changes in the size. In this paper, we propose a visual system to determinate the tau-margin, and we apply the tau-margin for controlling a mobile robot. Experiments using the real robot have been conducted and effective behaviors have been realized.