A hierarchical fault tolerant architecture for component-based service robots

Due to the benefits of reusability and productivity, component-based approach has become the primary technology in service robot system development. However, because component developer cannot foresee the integration and operating condition of the components, they cannot provide appropriate fault tolerance function, which is crucial for commercial success of service robots. The recently proposed robot software frames such as MSRDS (Microsoft Robotics Developer Studio), RTC (Robot Technology Component), and OPRoS (Open Platform for Robotic Services) are very limited in fault tolerance support. In this paper, we present a hierarchically-structured fault tolerant architecture for component-based robot systems. The framework integrates widely-used, representative fault tolerance measures for fault detection, isolation, and recovery. The system integrators can construct fault tolerance applications from non-fault-aware components, by declaring fault handling rules in configuration descriptors or/and adding simple helper components, considering the constraints of components and the operating environment. To demonstrate the feasibility and benefits, a fault tolerant framework engine and test robot systems are implemented for OPRoS. The experiment results with various simulated fault scenarios validate the feasibility, effectiveness and real-time performance of the proposed approach.