6-DoF Stylus Pose Estimation With Camera-IMU Neural Tracking

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Solution Overview

Problem

Existing 3D display systems lack accurate six-degree of freedom (6-DoF) pose estimation for styluses, particularly in interactive augmented reality (AR) and virtual reality (VR) experiences, which hinders precise interaction with virtual objects.

Innovation Solution

Implementing a neural network model and/or a dataset-based model for 6-DoF pose estimation of a stylus, combined with an Inertial Measurement Unit (IMU) and integrated cameras, to determine the stylus's position and orientation in 3D space.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional 3D display systems are used without advanced pose estimation models, then the system complexity remains low, but the measurement precision of stylus pose is insufficient

Engineering Contradiction:
Improvestylus pose estimation accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The pose estimation system is divided into multiple independent modules: IMU module for motion sensing, camera module for visual tracking, and separate neural network/dataset-based models for processing. This segmentation allows each module to be optimized independently while maintaining overall system accuracy.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces intermediary processing layers including neural network models and dataset-based estimation models that act as mediators between raw sensor data and final pose estimation. These intermediaries enhance measurement precision by processing and filtering data before final interpretation.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If multiple sensing technologies (IMU, cameras, neural networks) are integrated for pose estimation, then the measurement precision improves, but the device complexity increases

Engineering Contradiction:
Improve6-DoF pose estimation accuracyVSAvoidsensing system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent merges multiple sensing technologies (IMU, cameras) and processing approaches (neural network models, dataset-based models) into a unified pose estimation system. This combination allows the system to leverage the strengths of each component while achieving accurate 6-DoF pose estimation through data fusion.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The integrated system serves multiple functions: motion tracking via IMU, visual recognition via cameras, and pose estimation through multiple algorithmic approaches. This multi-functionality allows a single system to handle various sensing and processing tasks, reducing the need for separate dedicated systems.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Measurement precision

If advanced models (neural network, dataset-based) are implemented for pose estimation, then the interaction precision with virtual objects improves, but the computational energy consumption increases

Engineering Contradiction:
Improvevirtual object interaction accuracyVSAvoidcomputational energy consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The system implements multiple estimation models (neural network, dataset-based) that can be selectively applied based on computational resources available. Not all models need to run simultaneously or at full capacity, allowing the system to achieve sufficient precision while managing energy consumption through selective activation of processing components.

Inventive Principle:
Principle #16Partial or excessive action

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

Enables precise and accurate interaction with virtual objects by estimating the stylus's 6-DoF pose, enhancing the user's experience in AR and VR environments.

Implementation Method 1

The user input device may determine, via an inertial measurement unit (IMU), motion of the user input device in three-dimensional (3D) space

Methodology Applied
Scientific EffectInertial measurement: Accelerometer

Implementation Method 2

a user input device may capture, e.g., via at least one camera of the user input device, images in a direction that the user input device is directed

Methodology Applied
Scientific EffectLight detection: Photoelectric Effect

Data Source

PatentUS12474791B2Six-degree of freedom pose estimation of a stylus
Publication Date: 2025.11.18 ZSPACE INC
  • US12474791B2 patent drawing
  • US12474791B2 patent drawing
  • US12474791B2 patent drawing

AI summary

Systems and methods for six-degree of freedom (6-DoF) pose estimation of a user input device, e.g., in a three-dimensional (3D) system rendering interactive augmented reality (AR) and/or virtual reality (VR) experiences include the user input device capturing, via a camera disposed at a forward-facing tip of the user input device, images in a direction the user input device is directed and providing the images to a computer system. The user input device provides inertial measurement unit (IMU) data to the computer system as well. The computer system may then determine pose information associated with the user input device based on the images and IMU data of the user input device. The determination of the pose information may be via usage of at least one of a neural network model, estimation model trained on a set of unique and identifiable patterns, and/or an estimation model trained on a dataset of images.