Mobile systems in the area of modern manufacturing become more and more important. In order to handle an object with a manipulator mounted on an autonomous mobile system (AMS), the object's position has to be determined with sufficient accuracy. Especially within a flexible environment its exact 3D pose relative to the manipulator often is not known a priori. The object recognition unit of the presented system robustly accomplishes this 3D pose estimation using a single CCD camera mounted in the gripper exchange system of the mobile robot. The reliability of the results is checked by an independent fault-detection module. A recovery unit handles most of the possible problems autonomously, thus increasing the system's availability.