Imagine That! Leveraging Emergent Affordances for Tool Synthesis in Reaching Tasks

Yizhe Wu, Sudhanshu Kasewa, Oliver Groth, Sasha Salter, Li Sun, Oiwi Parker Jones, Ingmar Posner

TL;DR: We demonstrate that a task-driven traversal of a structured latent space leads to object affordances emerging naturally as directions in this space accessible via optimisation.

Abstract: In this paper we investigate an artificial agent's ability to perform task-focused tool synthesis via imagination. Our motivation is to explore the richness of information captured by the latent space of an object-centric generative model - and how to exploit it. In particular, our approach employs activation maximisation of a task-based performance predictor to optimise the latent variable of a structured latent-space model in order to generate tool geometries appropriate for the task at hand. We evaluate our model using a novel dataset of synthetic reaching tasks inspired by the cognitive sciences and behavioural ecology. In doing so we examine the model's ability to imagine tools for increasingly complex scenario types, beyond those seen during training. Our experiments demonstrate that the synthesis process modifies emergent, task-relevant object affordances in a targeted and deliberate way: the agents often specifically modify aspects of the tools which relate to meaningful (yet implicitly learned) concepts such as a tool's length, width and configuration. Our results therefore suggest, that task relevant object affordances are implicitly encoded as directions in a structured latent space shaped by experience.

Keywords: Affordance Learning, Imagination, Generative Models, Activation Maximisation