SkillBlender: Towards Versatile Humanoid Whole-Body Loco-Manipulation via Skill Blending

TL;DR

SkillBlender is a hierarchical reinforcement learning framework that enables humanoid robots to perform diverse loco-manipulation tasks by blending pre-trained primitive skills, reducing the need for task-specific tuning and improving versatility.

Contribution

It introduces a novel skill blending approach with pre-trained primitive skills and a new benchmark for evaluating humanoid loco-manipulation.

Findings

Outperforms baseline methods in simulated experiments

Achieves more accurate and feasible movements across tasks

Regularizes behaviors to prevent reward hacking

Abstract

Humanoid robots hold significant potential in accomplishing daily tasks across diverse environments thanks to their flexibility and human-like morphology. Recent works have made significant progress in humanoid whole-body control and loco-manipulation leveraging optimal control or reinforcement learning. However, these methods require tedious task-specific tuning for each task to achieve satisfactory behaviors, limiting their versatility and scalability to diverse tasks in daily scenarios. To that end, we introduce SkillBlender, a novel hierarchical reinforcement learning framework for versatile humanoid loco-manipulation. SkillBlender first pretrains goal-conditioned task-agnostic primitive skills, and then dynamically blends these skills to accomplish complex loco-manipulation tasks with minimal task-specific reward engineering. We also introduce SkillBench, a parallel, cross-embodiment, and diverse simulated benchmark containing three embodiments, four primitive skills, and eight challenging loco-manipulation tasks, accompanied by a set of scientific evaluation metrics balancing accuracy and feasibility. Extensive simulated experiments show that our method significantly outperforms all baselines, while naturally regularizing behaviors to avoid reward hacking, resulting in more accurate and feasible movements for diverse loco-manipulation tasks in our daily scenarios. Our code and benchmark will be open-sourced to the community to facilitate future research. Project page: https://usc-gvl.github.io/SkillBlender-web/.