Can we enable humanoid robots to generate rich, diverse, and expressive motions in the real world? We propose to learn a whole-body control policy on a human-sized robot to mimic human motions as realistic as possible. To train such a policy, we leverage the large-scale human motion capture data from the graphics community in a Reinforcement Learning framework. However, directly performing imitation learning with the motion capture dataset would not work on the real humanoid robot, given the large gap in degrees of freedom and physical capabilities. Our method Expressive Whole-Body Control (Exbody) tackles this problem by encouraging the upper humanoid body to imitate a reference motion, while relaxing the imitation constraint on its two legs and only requiring them to follow a given velocity robustly. With training in simulation and Sim2Real transfer, our policy can control a humanoid robot to walk in different styles, shake hands with humans, and even dance with a human in the real world. We conduct extensive studies and comparisons on diverse motions in both simulation and the real world to show the effectiveness of our approach.

我们提出了一种能够在真实世界中让机器人产生丰富、多样和表现力强的动作的方法，通过在一个人型机器人上学习一个整体控制策略，尽可能地模仿人类的真实动作。通过在强化学习框架中利用图形社区的大规模人体动作捕捉数据来训练这种策略，但是直接使用动作捕捉数据集进行模仿学习可能无法适用于真实的人形机器人，因为在自由度和物理能力方面存在巨大差距。我们的方法（Exbody）通过鼓励上半身模仿参考动作，而放松对其两条腿的模仿约束，只要求它们能够稳定地跟随给定速度来解决这个问题。通过在模拟和实际场景中进行训练和仿真转移，我们的策略可以控制一个人形机器人以不同的风格行走，与人类握手，甚至与人类共舞。我们进行了广泛的研究和比较，展示了我们方法的有效性。

人形机器人的表达性全身控制