Task-based dynamic fault tolerance and its safety considerations in humanoid robot applications

Although the performance of humanoid robots is rapidly improving, very few dependability schemes suitable for humanoid robots have been presented thus far. In the future, various tasks ranging from daily chores to safety-related tasks will be carried out by individual humanoid robots. If the characteristics and importance of the tasks are different, the required fault-tolerant capabilities will also vary accordingly. Therefore, for mobile humanoid robots operating under power constraints, it is desirable to develop a dynamic fault tolerance capable of reducing power consumption because fault-tolerant designs involving hardware redundancy are power intensive. This paper proposes a task-based dynamic fault tolerance scheme based on the hardware redundancy of the computer unit, and describes the implementation of the proposed scheme by considering the safety in humanoid robot applications.