Optical Tracking Calibration via Inertial Sensor Feedback

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Solution Overview

Problem

Conventional gaming systems require a controlled and precise calibration process to accurately track object movements, which is time-consuming and inconvenient for users.

Innovation Solution

A method and apparatus for calibrating a tracking system that allows users to simply point a game controller at an optical sensor and press a button, using positional data from the optical sensor and inertial data to compute the pitch and yaw of the optical sensor, enabling automatic calibration without the need for precise setup.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional calibration process is used, then measurement precision is improved, but ease of operation deteriorates

Engineering Contradiction:
Improvetracking accuracyVSAvoidcalibration complexity
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The system uses the game controller's own inertial sensors to provide calibration data, eliminating the need for external calibration tools or controlled environments. The controller self-calibrates the tracking system by pointing it at the sensor and using its built-in accelerometers and gyroscopes to determine orientation and position.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The game controller serves multiple functions: it is both the object to be tracked and the calibration tool. The inertial sensors in the controller are used for both game input and calibration purposes, eliminating the need for separate calibration equipment.

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

2Measurement precision

If conventional calibration process is used, then measurement precision is improved, but loss of time increases

Engineering Contradiction:
Improvetracking accuracyVSAvoidcalibration time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system performs calibration automatically as part of the game startup process or when conditions indicate calibration is needed, rather than requiring users to perform manual calibration steps. The computing device initiates and guides the calibration process automatically.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The calibration process is automated and performed by the system itself based on data from the controller's inertial sensors, eliminating the time-consuming manual measurement steps required by conventional systems.

Inventive Principle:
Principle #25Self-service

3Ease of operation

If automatic calibration is implemented, then ease of operation is improved, but measurement precision deteriorates

Engineering Contradiction:
Improvecalibration simplicityVSAvoidtracking accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The system uses feedback from the controller's inertial sensors (accelerometers and gyroscopes) to continuously monitor and adjust the calibration parameters. The computing device processes this feedback data to determine the controller's orientation and position, maintaining accuracy while simplifying operation.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system changes the parameters used for calibration from manual measurements of camera tilt and distance to automatic detection of inertial sensor data, including acceleration vectors and angular velocity, which are then used to compute pitch, yaw, and roll angles.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2435784B1Tracking system calibration using object position and orientation
Publication Date: 2016.10.05 SONY INTERACTIVE ENTERTAINMENT LLC
  • EP2435784B1 patent drawingFigure 1
  • EP2435784B1 patent drawingFigure 2~3
  • EP2435784B1 patent drawingFigure 4A

AI summary

To calibrate a tracking system, a computing device receives positional data of a tracked object from an optical sensor as the object is pointed approximately toward the optical sensor. The computing device computes a first angle of the object with respect to an optical axis of the optical sensor using the received positional data. The computing device receives inertial data corresponding to the object, wherein a second angle of the object with respect to a plane normal to gravity can be computed from the inertial data. The computing device determines a pitch of the optical sensor using the first angle and the second angle.