Target tracking for a mobile robot with a stereo camera considering illumination changes

Tracking a specific person in dynamic environments is a fundamental task of mobile service robots. Image information is essential to identify a target person, however, the information is not reliable under varying illumination. In this paper, we propose a target-tracking system using a stereo camera. Color and location information is used for the target´s feature, which is useful to distinguish a target from the other people. An evaluation value to identify a target is defined as weighted sum of the color and location features. The weight to the features is derived from a parameter of illumination changes. The parameter of illumination changes provides the system with capability of robust tracking even under varying illumination. We confirmed robustness of the proposed system through target-tracking experiments in outdoor environment where the lighting condition changes extremely.