Photosensor-Based Latency Measurement System for Head-Mounted Displays.

Area of Science:

• Human-Computer Interaction
• Virtual Reality Technology
• Biomedical Engineering

Background:

• Motion-to-photon latency in head-mounted displays (HMDs) is a primary cause of user-induced motion sickness and dizziness.
• Existing latency measurement systems lack accuracy and do not adequately account for real human physical head movements.
• Reducing latency is crucial for improving the user experience and comfort in immersive virtual reality environments.

Purpose of the Study:

• To propose and validate a novel photosensor-based system for precise measurement of motion-to-photon latency in HMDs.
• To address the limitations of current measurement techniques by incorporating physical head movement simulation.
• To provide an accurate tool for analyzing and mitigating latency-related issues in HMD systems.

Main Methods:

• Development of a measurement system integrating a head position model-based rotary platform, a pixel luminance change detector, and signal analysis modules.
• Quantification of latency as the precise time difference between user's physical head movement and the corresponding output image luminance change.
• Experimental validation using a commercial HMD under varying rendering workloads.

Main Results:

• The proposed system accurately measures motion-to-photon latency, achieving high precision.
• Latency measurements in a commercial HMD reached up to 47.05 ms under normal conditions.
• Increased rendering workload significantly elevated measured latency, reaching up to 381.17 ms.

Conclusions:

• The developed photosensor-based system offers a highly accurate method for measuring HMD motion-to-photon latency.
• The system's ability to model physical head movement provides a significant advantage over existing methods.
• Latency increases substantially with rendering workload, highlighting a critical factor for HMD performance optimization and user comfort.