Fault tolerance via component redundancy for a modularized sensitive skin

Abstract

The objective of this work is to develop a fault tolerant system for a sensitive skin-based motion planning system. The purpose of the skin is to provide real-time collision avoidance for a machine (e.g. a mobile robot or an arm manipulator) operating in an uncertain environment with obstacles. The skin is designed to cover virtually any kind of machine; in the version used in this project the skin covers an industrial arm manipulator and contains about 1000 infrared sensors. In order to operate such a complex system in real time, effective fault tolerance is necessary. The latter is achieved in our system via component redundancy: the distance measurements necessary for motion planning are done using a particular scheme for sensor grouping. The system achieves safe motion planning even if some of the sensors are dead or partially inoperative. Based on the fault tolerance model used a fault tolerance algorithm is developed, tested and demonstrated experimentally.