A Causal Approach to Tool Affordance Learning

While abstract knowledge like cause-and-effect relations enables robots to problem-solve in new environments, acquiring such knowledge remains out of reach for many traditional machine learning techniques. In this work, we introduce a method for a robot to learn an explicit model of cause-and-effect by constructing a structural causal model through a mix of observation and self-supervised experimentation, allowing a robot to reason from causes to effects and from effects to causes. We demonstrate our method on tool affordance learning tasks, where a humanoid robot must leverage its prior learning to utilize novel tools effectively. Our results suggest that after minimal training examples, our system can preferentially choose new tools based on the context, and can use these tools for goal-directed object manipulation.