NSP: A Neuro-Symbolic Natural Language Navigational Planner

TL;DR

This paper introduces NSP, a neuro-symbolic framework that combines neural language understanding with symbolic path planning to interpret natural language instructions for robotics, achieving high validity and shorter paths.

Contribution

The paper presents a novel neuro-symbolic approach that integrates LLMs with symbolic planning, improving natural language path planning accuracy and efficiency.

Findings

Achieves 90.1% valid path generation.

Paths are 19-77% shorter than neural-only methods.

Effective self-correction via feedback loop.

Abstract

Path planners that can interpret free-form natural language instructions hold promise to automate a wide range of robotics applications. These planners simplify user interactions and enable intuitive control over complex semi-autonomous systems. While existing symbolic approaches offer guarantees on the correctness and efficiency, they struggle to parse free-form natural language inputs. Conversely, neural approaches based on pre-trained Large Language Models (LLMs) can manage natural language inputs but lack performance guarantees. In this paper, we propose a neuro-symbolic framework for path planning from natural language inputs called NSP. The framework leverages the neural reasoning abilities of LLMs to i) craft symbolic representations of the environment and ii) a symbolic path planning algorithm. Next, a solution to the path planning problem is obtained by executing the algorithm on the environment representation. The framework uses a feedback loop from the symbolic execution environment to the neural generation process to self-correct syntax errors and satisfy execution time constraints. We evaluate our neuro-symbolic approach using a benchmark suite with 1500 path-planning problems. The experimental evaluation shows that our neuro-symbolic approach produces 90.1% valid paths that are on average 19-77% shorter than state-of-the-art neural approaches.