An approach for semi-autonomous recovery of unknown objects in underwater environments

Autonomous grasping of unknown objects by a robot is a highly challenging skill that is receiving increasing attention in the last years. This problem becomes still more challenging (and less explored) in underwater environments, with highly unstructured scenarios, limited availability of sensors and, in general, adverse conditions that affect in different degree the robot perception and control systems. This paper describes an approach for semi-autonomous grasping and recovery on underwater unknown objects. A laser stripe emitter is attached to a robot forearm that performs a scan of a target of interest. This scan is captured by a camera and the partial 3D structure of the scene is recovered. A user then indicates the part where to grab the object, and the final grasp is automatically planned on that area. The methods herein presented are tested and validated in real conditions in a water tank.