IDIL: Imitation Learning of Intent-Driven Expert Behavior
Sangwon Seo, Vaibhav Unhelkar
TL;DR
IDIL tackles imitation learning when experts act under time-varying intents by modeling behavior with an Agent Markov Model and learning an intent-aware policy and intent dynamics. It introduces an EM-like, non-adversarial algorithm that factorizes the occupancy-measure objective into two tractable subproblems solved with IQ-Learn, enabling stable learning in high-dimensional or continuous domains. Theoretical results provide convergence under reasonable approximations, and experiments across MG-n, OneMover, Movers, and Mujoco show IDIL outperforming baselines in intent-driven tasks and delivering interpretable, diverse behaviors along with accurate intent inference. The method offers practical benefits for human-agent collaboration and scalable modeling of heterogeneous expert behavior, with clear directions for extension to larger intent sets and multi-agent scenarios.
Abstract
When faced with accomplishing a task, human experts exhibit intentional behavior. Their unique intents shape their plans and decisions, resulting in experts demonstrating diverse behaviors to accomplish the same task. Due to the uncertainties encountered in the real world and their bounded rationality, experts sometimes adjust their intents, which in turn influences their behaviors during task execution. This paper introduces IDIL, a novel imitation learning algorithm to mimic these diverse intent-driven behaviors of experts. Iteratively, our approach estimates expert intent from heterogeneous demonstrations and then uses it to learn an intent-aware model of their behavior. Unlike contemporary approaches, IDIL is capable of addressing sequential tasks with high-dimensional state representations, while sidestepping the complexities and drawbacks associated with adversarial training (a mainstay of related techniques). Our empirical results suggest that the models generated by IDIL either match or surpass those produced by recent imitation learning benchmarks in metrics of task performance. Moreover, as it creates a generative model, IDIL demonstrates superior performance in intent inference metrics, crucial for human-agent interactions, and aptly captures a broad spectrum of expert behaviors.
