Experiments with Diversified Models for Fault-Tolerant Planning

B. Lussier, M. Gallien, J. Guiochet, F. Ingrand, M.-O. Killijian, D. Powell



Autonomous robots make extensive use of decisional mechanisms, such as planning. These mechanisms are able to take complex and adaptative decisions, but are notoriously hard to validate. This paper reports an investigation of how redundant, diversi ied models can be used to tolerate residual design faults in such mechanisms. A fault-tolerant temporal planner has been designed and implemented using diversity, and its effectiveness demonstrated experimentally through fault injection. The pa- per describes the implementation of the fault-tolerant planner and discusses the results obtained. The results indicate that diversi ication provides a noticeable improvement in planning reliability with a negligible performance overhead. However, further improvements in reliability will require implementation of a on-line checking mechanism for assessing plan validity before execution.

Keywords: robotics; fault tolerance; dependability; diverse programming; planning