A COLOR CONSTANCY APPROACH FOR ILLUMINATION INVARIANT COLOR TARGET TRACKING

Abstract

In this work, we present a color target tracking algorithm aimed at robot localization in varying illumination conditions. In our approach a colored target is put on the top of the robot and a fixed camera is used to detect and track the target. The 3D robot position can be estimated knowing the camera parameters after an analysis of the camera image. The general setup of this approach is sketched on Figure 1: Many robotic agents use color vision to retrieve quality information about the environment. In this work, we present a visual servoing technique, where vision is the primary sensing modality and sensing is based upon the analysis of the perceived visual information. We describe how colored targets can be identified and how their position and motion can be estimated quickly and reliably. The visual servoing procedure is essentially a four-stage process, with color target identification, motion parameter estimation, target tracking and target position estimation. These individual parts add up to a global vision system enabling precise positioning for a demining robot. Mob t A fixed camera ile robo Color target Camera optical axis Geometry center of the target