Occluded object search by relational affordances

Searching for objects in occluded spaces is one of the problems robots need to solve when tackling mobile manipulation tasks. Most approaches focus only on searching for a specific object. In this paper, we use the concept of relational affordances to improve occluded object search performance. Affordances define action possibilities on an object in the environment and play a role in basic cognitive capabilities. Relational affordances extend this concept by modelling relations between multiple objects. By learning and using a relational affordance model we can search for any of the multiple objects that afford a given action, each object type having a probability distribution over possible sizes and shapes, and where spatial relations between objects such as co-occurrence and stacking are modelled. The experimental results show the viability of the relational affordance models for occluded object search.