Episodic Transformer for Vision-and-Language Navigation
This addresses the problem of enabling neural agents to navigate dynamic environments based on natural language instructions, representing a strong specific gain in this domain.
The paper tackles the challenges of handling long sequences of subtasks and understanding complex human instructions in vision-and-language navigation by proposing Episodic Transformer (E.T.), which encodes language and full episode history, achieving 38.4% and 8.5% task success rates on seen and unseen test splits of the ALFRED benchmark.
Interaction and navigation defined by natural language instructions in dynamic environments pose significant challenges for neural agents. This paper focuses on addressing two challenges: handling long sequence of subtasks, and understanding complex human instructions. We propose Episodic Transformer (E.T.), a multimodal transformer that encodes language inputs and the full episode history of visual observations and actions. To improve training, we leverage synthetic instructions as an intermediate representation that decouples understanding the visual appearance of an environment from the variations of natural language instructions. We demonstrate that encoding the history with a transformer is critical to solve compositional tasks, and that pretraining and joint training with synthetic instructions further improve the performance. Our approach sets a new state of the art on the challenging ALFRED benchmark, achieving 38.4% and 8.5% task success rates on seen and unseen test splits.