π€ AI Summary
In vision-based reinforcement learning, real-world scenarios often lack precise pose feedback, rendering distance-based reward design ineffective. To address this, we propose ReLAMβa novel framework that introduces a keypoint-guided visual imagination model as a planner, implicitly encoding spatial relationships and generating geometrically aligned intermediate sub-goals to construct a structured instructional curriculum. From this curriculum, ReLAM automatically distills dense, continuous rewards with theoretical guarantees of suboptimality. The method requires only action-free demonstration videos and integrates keypoint detection, visual imagination, hierarchical RL, and goal-conditioned policy learning. Evaluated on complex, long-horizon manipulation tasks, ReLAM significantly improves sample efficiency and final performance, surpassing existing state-of-the-art approaches.
π Abstract
Reward design remains a critical bottleneck in visual reinforcement learning (RL) for robotic manipulation. In simulated environments, rewards are conventionally designed based on the distance to a target position. However, such precise positional information is often unavailable in real-world visual settings due to sensory and perceptual limitations. In this study, we propose a method that implicitly infers spatial distances through keypoints extracted from images. Building on this, we introduce Reward Learning with Anticipation Model (ReLAM), a novel framework that automatically generates dense, structured rewards from action-free video demonstrations. ReLAM first learns an anticipation model that serves as a planner and proposes intermediate keypoint-based subgoals on the optimal path to the final goal, creating a structured learning curriculum directly aligned with the task's geometric objectives. Based on the anticipated subgoals, a continuous reward signal is provided to train a low-level, goal-conditioned policy under the hierarchical reinforcement learning (HRL) framework with provable sub-optimality bound. Extensive experiments on complex, long-horizon manipulation tasks show that ReLAM significantly accelerates learning and achieves superior performance compared to state-of-the-art methods.