Using Unwrapped Full Color Space Palette Recording to Measure Exposedness of a Vehicle Exterior Parts for External Human Machine Interfaces

2026-04-13

AI Summary

Autonomous vehicles often struggle to clearly communicate their driving intentions to pedestrians, posing significant safety risks. This study addresses this challenge by evaluating the externally visible regions of a 2015 Ford F-150 at intersections, using mesh unwrapping shaders, a full-color spatial palette logging technique, and visual exposure analysis implemented in Unity. The findings indicate that while the bumper, grille, and hood exhibit high visibility, they are frequently occluded by vehicles in the same lane. To overcome this limitation of conventional front-fascia external human–machine interfaces (eHMIs), the work proposes a distributed eHMI layout that integrates the windshield and front fenders. This strategy effectively mitigates occlusion issues and substantially enhances pedestrians’ reliability in perceiving vehicle intent.

Technology Category

• Computer Vision: Interpretability, Explainability, and Transparency
• Application Domains: Transportation
• Intelligent Robots: Multimodal Perception & Sensor Fusion

Application Category

• Responsible Web: Machine-in-the-loop, human agency and autonomy
• User Modeling, Personalization and Recommendation: Accountability, Transparency, and Ethics for personalization
• Economics, Online Markets and Human Computation: The sharing economy

Abstract

One of the concerns with autonomous vehicles is their ability to communicate their intent to other road users, specially pedestrians, in order to prevent accidents. External Human-Machine Interfaces (eHMIs) are the proposed solution to this issue, through the introduction of electronic devices on the exterior of a vehicle that communicate when the vehicle is planning on slowing down or yielding. This paper uses the technique of unwrapping the faces of a mesh onto a texture where every pixel is a unique color, as well as a series of animated simulations made and ran in the Unity game engine, to measure how many times is each point on a 2015 Ford F-150 King Ranch is unobstructed to a pedestrian attempting to cross the road at a four-way intersection. By cross-referencing the results with a color-coded map of the labeled parts on the exterior of the vehicle, it was concluded that while the bumper, grill, and hood were the parts of the vehicle visible to the crossing pedestrian most often, the existence of other vehicles on the same lane that might obstruct the view of these makes them insufficient. The study recommends instead a distributive approach to eHMIs by using both the windshield and frontal fenders as simultaneous placements for these devices.

Problem

• autonomous vehicles
• external human-machine interfaces
• visibility
• pedestrian communication
• vehicle exterior parts

Innovation

• unwrapped full color space palette
• external Human-Machine Interface (eHMI)
• visibility exposure mapping
• Unity-based simulation
• distributed eHMI placement