In this paper, we discuss a mobile robot (Campro-RIS) that provides visual support for human activities by projecting information onto the surfaces of various objects in living spaces through a structured-environment approach. Campro-RIS employs a parallel two-wheeled vehicle system with a camera and a projector whose angle can be controlled with a pan/tilt actuator. By actively examining visual markers placed in the environment in advance, the robot projects distortion-free image onto surfaces located at arbitrary distances and orientations. To precisely project the image onto the target location while simultaneously avoiding obstacles around the robot and staying within the pan/tilt actuator's movable range, we newly propose a robust projection control method built upon an image-based visual servoing technique based on actuator redundancy. The effectiveness of the proposed method is demonstrated in a three dimensional experimental system.