Learning physical intuition for robotic manipulation

Thesis

When we compare object manipulation capabilities in humans and contemporary robots, we observe an intriguing dichotomy: On one hand, robots have access to advanced compute capacity and precise models of physics, yet their object manipulation skills are comparatively narrow and brittle. On the other hand, the human understanding of physics is allegedly acquired from experience and exhibits many predictive shortcomings, yet their manipulation skills far exceed any contemporary robot’s. Motivated by this observation, this thesis studies the question how much robotic manipulation can benefit from embracing data-driven, approximate models of physics and poses the hypothesis that a tight integration of intuition and control can unlock sophisticated manipulation behaviour.

In particular, three aspects of physical intuition are investigated: (i) high-level intuitions for visual task assessment and their application in object stacking and tool use, (ii) low-level intuitions for rigid-body motions and their application in rearrangement planning and visuomotor control, (iii) the integration of dynamics approximation into control policy learning and its application in structured exploration of an environment.

In the first part, we demonstrate the effectiveness of a visual stability classifier in planning and constructing stable stacks of objects with varying geometries. We also employ a similar task classification technique in a goal-reaching task and show that the associated variational latent space induces an affordance manifold which can be traversed to synthesise suitable tools for a given task. In the second part, we demonstrate that the introduction of dynamics modelling into an object-centric latent space facilitates object disentanglement from raw visual training data and allows to generate physically plausible scenes and videos from scratch. Visual dynamics approximation is also used in our novel, goal-conditioned, visuomotor control architecture where it enables zero-shot transfer to unseen object rearrangement tasks. Finally, we integrate dynamics forecasting and control policy learning in the third part of this thesis and optimise both components using a curiosity objective. This setup leads to the unsupervised emergence of complex, human interpretable manipulation and locomotion behaviour and highlights the crucial importance of physical intuition in the learning process of sophisticated, embodied behaviour.

Authors: Groth, OM

• Type of award: DPhil
• Level of award: Doctoral
• Awarding institution: University of Oxford
• Language: English
• Keywords: artificial curiosity; visuomotor control; structured latent space; physical intuition
• Subjects: Machine learning; Robotics