Imitation learning is a popular approach for teaching motor skills to robots. However, most approaches focus on extracting policy parameters from execution traces alone (i.e., motion trajectories and perceptual data). No adequate communication channel exists between the human expert and the robot to describe critical aspects of the task, such as the properties of the target object or the intended shape of the motion. Motivated by insights into the human teaching process, we introduce a method for incorporating unstructured natural language into imitation learning. At training time, the expert can provide demonstrations along with verbal descriptions in order to describe the underlying intent (e.g., "go to the large green bowl"). The training process then interrelates these two modalities to encode the correlations between language, perception, and motion. The resulting language-conditioned visuomotor policies can be conditioned at runtime on new human commands and instructions, which allows for more fine-grained control over the trained policies while also reducing situational ambiguity. We demonstrate in a set of simulation experiments how our approach can learn language-conditioned manipulation policies for a seven-degree-of-freedom robot arm and compare the results to a variety of alternative methods.

这篇研究论文介绍了一种将自然语言引入模仿学习中的方法，可以让专家在提供动作演示的同时，提供自然语言的描述。通过融合语言、知觉和动作的关系，实现了更加精细的控制，降低了场景的模糊度。在七自由度机械臂控制任务上的模拟实验表明，此方法可有效学习自然语言条件下的机器人操作策略，并与其他方法相比做出了明显改进。

语言条件下的机器人操作任务模仿学习