Reliability and integrated capabilities of locomotion and manipulation for autonomous robot assembly

Autonomous assembly with a mobile robot is a demanding task. On the other hand, high sophisticated capabilities such as assembly are a qualification for future service robots. Autonomous behaviour of a robot is always based on the extent of individual capabilities, the integration of individual capabilities to obtain new ones, and the reliability of the various capabilities. The Karlsruhe Autonomous Mobile Robot KAMRO, a mobile two-arm robot, is able to perform assembly tasks without human intervention in a limited scope. It is able to move collision free between several workstations in an industrial environment, to locate assembly parts at a workstation and to put them together. During the past three years the robot has become more powerful and reliable by different improvements. The extensions are: reactive mobility, simultaneous use of both manipulators, independent or in a kinematic chain, active vision with hand-eye cameras, and mobile manipulation. The reliability has been increased by strategies for error avoidance on planning and execution level and error recovery. The improvements are basic steps towards reliable robots for large scale applications. They have increased the success rate of the KAMRO robot by almost two magnitudes.