Ground-Truth Depth in Vision Language Models: Spatial Context Understanding in Conversational AI for XR-Robotic Support in Emergency First Response
Rodrigo Gutierrez Maquilon, Marita Hueber, Georg Regal, Manfred Tscheligi
TL;DR
This study addresses the challenge of spatial reasoning in emergency first response (EFR) by integrating ground-truth depth from robot-mounted sensors with a vision-language model (VLM) to produce metrically grounded distance descriptions of objects in mixed reality. The authors implement a hybrid pipeline combining YOLO-based detection and depth measurements within a VLM loop, and evaluate it in a mixed-reality toxic-smoke scenario against three conditions: video-only, depth-agnostic VLM, and depth-augmented VLM. Results show that depth augmentation improves distance-estimation accuracy and reduces variance without increasing workload, while also elevating situational awareness and perceived usefulness. These findings demonstrate that metrically grounded, object-centric verbal information can enhance spatial reasoning and decision-making under time pressure in XR-robotic EFR, offering a concrete path toward more trustworthy human–AI collaboration in hazardous environments.
Abstract
Large language models (LLMs) are increasingly used in emergency first response (EFR) applications to support situational awareness (SA) and decision-making, yet most operate on text or 2D imagery and offer little support for core EFR SA competencies like spatial reasoning. We address this gap by evaluating a prototype that fuses robot-mounted depth sensing and YOLO detection with a vision language model (VLM) capable of verbalizing metrically-grounded distances of detected objects (e.g., the chair is 3.02 meters away). In a mixed-reality toxic-smoke scenario, participants estimated distances to a victim and an exit window under three conditions: video-only, depth-agnostic VLM, and depth-augmented VLM. Depth-augmentation improved objective accuracy and stability, e.g., the victim and window distance estimation error dropped, while raising situational awareness without increasing workload. Conversely, depth- agnostic assistance increased workload and slightly worsened accuracy. We contribute to human SA augmentation by demonstrating that metrically grounded, object-centric verbal information supports spatial reasoning in EFR and improves decision-relevant judgments under time pressure.
