Extended range tactility in material handling

Abstract

Optical fibres sensitized to their geometric curvature are arranged in loops around an autonomous guided vehicle (AGV) in order to extend the vehicle's tactile sensing range and allow larger speeds that require larger stopping distances. When the AGV approaches other objects (obstacles) within this range, fibre optic loops deform and sense the gradual change in their curvature. No intermediate mechanical elements are used to either transfer the impact loads onto the sensitive element or to provide compliance to it. Optical fibres themselves achieve these two functions simultaneously. As a result, tactility is achieved within a comparatively large position range extending over 15 cm. Throughout this range, virtually no reaction forces are generated with the impacting body. The range mentioned is on top of the one provided by the more traditional elastic bumper on which the optical fibres are mounted. Obstacle avoidance and wall-following AGV guidance can readily be achieved with such loops of optical fibre. A high degree of reactive capability and safety is hence provided in the system. With similar advantages, the method can likewise be applied to fixed or mobile material-handling robots.