Orientation Calculation Using Gyro, Acceleration, and Image Sensors

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Solution Overview

Problem

Existing orientation calculation methods using gyro sensors for input devices suffer from errors due to limitations in detecting angular rates, especially during slow movements or rapid changes, leading to inaccurate orientation calculations.

Innovation Solution

An orientation calculation apparatus that combines data from gyro sensors, acceleration sensors, and image pickup means to correct orientation calculations. The apparatus includes first and second correction means, where the first correction adjusts based on acceleration data and assumes a vertically downward direction, and the second correction adjusts based on images of a predetermined subject, ensuring accurate orientation calculation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If gyro sensor is used to calculate orientation, then orientation calculation is possible, but error occurs between calculated orientation and actual orientation

Engineering Contradiction:
Improveorientation calculation accuracyVSAvoiddetection reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent combines data from multiple sensors (acceleration sensor and gyro sensor) to calculate orientation. The acceleration sensor detects gravitational acceleration to determine vertical direction, while the gyro sensor detects angular velocity for orientation changes. By merging these complementary data sources, the system achieves more reliable and accurate orientation calculation than using either sensor alone.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The system continuously compares the orientation calculated from acceleration sensor data with the orientation calculated from gyro sensor data, and uses this feedback to correct cumulative errors. The acceleration sensor provides a reference frame that resets the accumulated gyro errors, ensuring long-term accuracy.

Inventive Principle:
Principle #23Feedback

2Speed

If gyro sensor detects angular rate during slow movement, then orientation can be calculated, but detection error occurs

Engineering Contradiction:
Improvemovement speedVSAvoidangular rate detection accuracy
Core Design Contradiction:
SpeedVSMeasurement precision

Solution Approach 1:

The acceleration sensor acts as an intermediary reference that provides a stable vertical direction based on gravitational acceleration. This reference is used to correct the gyro sensor's orientation calculations, particularly when angular velocity is low and gyro detection becomes inaccurate. The acceleration data serves as a mediator that anchors the orientation calculation to a known reference frame.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Speed

If gyro sensor detects abrupt angular rate changes, then fast movement orientation can be captured, but detection error occurs when change is too rapid

Engineering Contradiction:
Improveangular rate change speedVSAvoidangular rate detection accuracy
Core Design Contradiction:
SpeedVSMeasurement precision

Solution Approach 1:

The system continuously monitors acceleration data to detect abrupt changes in movement. When rapid angular changes are detected, the system prepares correction algorithms that use the acceleration sensor's vertical reference to reset and realign the gyro-based orientation calculation, preventing cumulative errors from developing during fast movements.

Inventive Principle:
Principle #10Preliminary action

4Device complexity

If only gyro sensor is used for orientation calculation, then device complexity is low, but orientation accuracy deteriorates over time

Engineering Contradiction:
Improvesensor system complexityVSAvoidorientation accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent merges the simple gyro sensor (which integrates easily into input devices) with the acceleration sensor that provides vertical reference. This combination maintains relatively low device complexity while dramatically improving orientation accuracy by correcting the gyro's cumulative errors using the acceleration-based vertical frame.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The acceleration sensor serves multiple functions: it provides the vertical reference frame for orientation calculation, detects device movement states (static vs. dynamic), and triggers appropriate correction algorithms. This multi-functionality justifies the added complexity by providing multiple benefits from a single sensor addition.

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

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

The combined approach significantly reduces errors in orientation calculation, providing accurate and stable orientation data for input devices by leveraging multiple data sources, enhancing the accuracy and usability of input devices in applications like game controllers.

Implementation Method 1

correction means configured to correct the first orientation data based on acceleration data detected by an acceleration sensor, wherein the correction is performed under an assumption that a direction of acceleration represented by the acceleration data is a vertically downward direction

Methodology Applied
Scientific EffectGravitation: Gravitation

Implementation Method 2

an input device comprising at least a gyro sensor, an acceleration sensor, and an image pickup means

Methodology Applied
Scientific EffectGyroscope: Gyroscope

Data Source

PatentEP2140918B1Orientation calculation apparatus, storage medium having orientation calculation program stored therein, game apparatus, and storage medium having game program stored therein
Publication Date: 2020.09.30 NINTENDO CO LTD
  • EP2140918B1 patent drawingFigure 1
  • EP2140918B1 patent drawingFigure 2
  • EP2140918B1 patent drawingFigure 3

AI summary

An orientation calculation apparatus obtains data from an input device comprising at least a gyro sensor, an acceleration sensor, and an image pickup means, so as to calculate an orientation of the input device. Firstly, the orientation calculation apparatus calculates an orientation of the input device in accordance with an angular rate detected by the gyro sensor. Secondly, the orientation is corrected in accordance with acceleration data detected by the acceleration sensor. Further, the orientation is corrected in accordance with an image of a predetermined subject to be taken by the image pickup means.