Multi-Task Hierarchical Imitation Learning for Home Automation

Control policies for home automation robots can be learned from human demonstrations, and hierarchical control has the potential to reduce the required number of demonstrations. When learning multiple policies for related tasks, demonstrations can be reused between the tasks to further reduce the number of demonstrations needed to learn each new policy. We present HIL-MT, a framework for Multi-Task Hierarchical Imitation Learning, involving a human teacher, a networked Toyota HSR robot, and a cloud-based server that stores demonstrations and trains models. In our experiments, HIL-MT learns a policy for clearing a table of dishes from 11.2 demonstrations on average. Learning to set the table requires 19 new demonstrations when training separately, but only 11.6 new demonstrations when also reusing demonstrations of clearing the table. HIL-MT learns policies for building 3- and 4-level pyramids of glass cups from 8.2 and 5 demonstrations, respectively, but reusing the 3-level demonstrations for learning a 4-level policy only requires 2.7 new demonstrations. These results suggest that learning hierarchical policies for structured domestic tasks can reuse existing demonstrations of related tasks to reduce the need for new demonstrations.