SMART-Merge Planner: A Safe Merging and Real-Time Motion Planner for Autonomous Highway On-Ramp Merging

TL;DR

The paper presents SMART-Merge, a lattice-based motion planner for autonomous highway on-ramp merging that ensures safe, efficient, and comfortable merges with a 100% success rate in high-fidelity simulations.

Contribution

It introduces a novel cost-adaptive lattice-based planner with a speed heuristic specifically designed for safe and efficient highway merging tasks.

Findings

Achieves 100% success rate in simulated highway merges.

Completes merges faster than baseline methods.

Demonstrates robustness across hundreds of scenarios.

Abstract

Merging onto a highway is a complex driving task that requires identifying a safe gap, adjusting speed, often interactions to create a merging gap, and completing the merge maneuver within a limited time window while maintaining safety and driving comfort. In this paper, we introduce a Safe Merging and Real-Time Merge (SMART-Merge) planner, a lattice-based motion planner designed to facilitate safe and comfortable forced merging. By deliberately adapting cost terms to the unique challenges of forced merging and introducing a desired speed heuristic, SMART-Merge planner enables the ego vehicle to merge successfully while minimizing the merge time. We verify the efficiency and effectiveness of the proposed merge planner through high-fidelity CarMaker simulations on hundreds of highway merge scenarios. Our proposed planner achieves the success rate of 100% as well as completes the merge maneuver in the shortest amount of time compared with the baselines, demonstrating our planner's capability to handle complex forced merge tasks and provide a reliable and robust solution for autonomous highway merge. The simulation result videos are available at https://sites.google.com/view/smart-merge-planner/home.