HMD Viewpoint Latency Measurement Using Accelerometer and Light Sensing

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing flight simulator technologies using head-mounted displays (HMDs) face challenges in accurately determining and quantifying viewpoint transition delays, leading to potential motion sickness and inaccuracies in simulated environments.

Innovation Solution

A method and apparatus are developed to measure viewpoint fidelity in HMDs by generating a virtual environment with shifting viewpoints, using a data acquisition system to receive signals from accelerometers and light sensors, and encoding data to assess latency and delay in head movements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If head-mounted display (HMD) is used in flight simulator, then immersive training environment is created, but viewpoint transition delay causes motion sickness and simulation inaccuracy

Engineering Contradiction:

Improveimmersive training environmentVSAvoidviewpoint transition accuracy

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent replaces complex mechanical tracking systems with optical sensing (cameras and light sensors) to detect head movements. This substitution reduces mechanical latency and improves the accuracy of viewpoint transition timing, thereby reducing motion sickness while maintaining immersive training capabilities

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system implements real-time feedback by continuously monitoring head position and orientation through optical sensors and immediately updating the virtual environment accordingly. This closed-loop feedback mechanism minimizes viewpoint transition delay and ensures synchronous visual feedback, improving reliability of the simulation

Inventive Principle:

Principle #23Feedback

2Measurement precision

If sophisticated motion tracking technologies are combined, then realistic output is provided, but measurement of viewpoint transition delay becomes challenging

Engineering Contradiction:

Improvehead position and orientation dataVSAvoidviewpoint transition delay

Core Design Contradiction:

Measurement precisionVSDifficulty of detecting and measuring

Solution Approach 1:

The patent introduces a dedicated timing and synchronization system that acts as an intermediary between the motion tracking sensors and the virtual environment rendering. This intermediary component precisely timestamps each viewpoint transition event, enabling accurate measurement of delay without compromising the precision of head position and orientation data

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The system segments the viewpoint transition measurement into distinct measurable components: head movement detection time, data processing time, and rendering update time. By breaking down the overall delay into separable segments, the system can precisely measure and optimize each component independently

Inventive Principle:

Principle #1Segmentation

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach allows for precise measurement and quantification of viewpoint latency, ensuring accurate and immersive simulations by reducing mismatch between physical and virtual movements, thereby minimizing motion sickness and enhancing training effectiveness.

Implementation Method 1

receiving, by a data acquisition system (DAQ), from an accelerometer mounted on the model head, changed signaling indicating the movement of the model head

Methodology Applied

Scientific EffectAccelerometer: Accelerometer

Implementation Method 2

receiving, by the DAQ, from a light sensor mounted on the model head, changed signaling based on displaying the updated virtual viewpoint in the HMD

Methodology Applied

Scientific EffectLight sensor: Photoelectric Effect

Data Source

PatentEP4712062A1Systems and methods for measuring delay in representing head motion in a virtual environment

Publication Date: 2026.03.18 TRU SIMULATION TRAINING

Figure 1
Figure 2
Figure 3A

AI summary

A method, apparatus, system and medium are provided. The method includes generating a virtual environment of a test scenario for a head mounted display (HMD) mounted to a model head on a test stand, where the virtual environment includes at least a first shape and a second shape, moving (720) the model head on the test stand, receiving (730), by a data acquisition system (DAQ), from an accelerometer mounted on the model head, changed signaling indicating the movement of the model head, updating (755) the virtual viewpoint of the HMD based on the movement of the model head, displaying (760) the updated virtual viewpoint in the HMD, receiving (770), by the DAQ, from a light sensor mounted on the model head, changed signaling based on displaying the updated virtual viewpoint in the HMD, and generating (790), by the DAQ, a data file encoding the signaling from the accelerometer and the light sensor.