PLUNDER: Probabilistic Program Synthesis for Learning from Unlabeled and Noisy Demonstrations

Learning from demonstration (LfD) is a widely researched paradigm for teaching robots to perform novel tasks. LfD works particularly well with program synthesis since the resulting programmatic policy is data efficient, interpretable, and amenable to formal verification. However, existing synthesis approaches to LfD rely on precise and labeled demonstrations and are incapable of reasoning about the uncertainty inherent in human decision-making. In this paper, we propose PLUNDER, a new LfD approach that integrates a probabilistic program synthesizer in an expectation-maximization (EM) loop to overcome these limitations. PLUNDER only requires unlabeled low-level demonstrations of the intended task (e.g., remote-controlled motion trajectories), which liberates end-users from providing explicit labels and facilitates a more intuitive LfD experience. PLUNDER also generates a probabilistic policy that captures actuation errors and the uncertainties inherent in human decision making. Our experiments compare PLUNDER with state-of the-art LfD techniques and demonstrate its advantages across different robotic tasks.