Image Capturing Apparatus Orientation Correction via Motion Vector Feedback

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Solution Overview

Problem

Existing image capturing apparatuses struggle to accurately estimate orientation when geomagnetism sensor outputs are unreliable, such as near metal objects or in areas with weak geomagnetism, due to integration errors from angular velocity sensors.

Innovation Solution

Incorporating a motion vector detection unit to correct angular velocity sensor outputs and calculate orientation angles using data from angular velocity, acceleration, and motion vector sensors, even in situations where geomagnetism sensor values are unavailable.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If output values from angular velocity sensor are continuously integrated to calculate orientation, then relative orientation changes can be calculated, but the calculated orientation gradually deviates from the true value due to error accumulation

Engineering Contradiction:

Improveorientation calculation accuracyVSAvoidorientation estimation reliability

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent uses motion vector detection from captured images as feedback to correct the accumulated orientation errors. The motion vector detection unit detects actual image plane motion, and this information is fed back to correct the orientation calculation, preventing drift from the true value.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent replaces reliance on geomagnetism sensor data with a vision-based motion vector detection system. Instead of using magnetic field information, the system uses image processing to detect motion vectors and substitute this optical information for the mechanical/sensor-based geomagnetism correction method.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If geomagnetism sensor output is used to correct angular velocity sensor values, then orientation estimation accuracy is improved, but the system fails when geomagnetism sensor cannot obtain accurate output values

Engineering Contradiction:

Improveorientation estimation accuracyVSAvoidsystem adaptability to different environments

Core Design Contradiction:

Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent introduces motion vector detection as an intermediary between the angular velocity sensor and the final orientation calculation. Instead of directly using geomagnetism sensor data, the system uses motion vectors from image processing as an intermediate correction mechanism that works in environments where geomagnetism data is unavailable.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the correction parameter from geomagnetism sensor values to motion vector values. By switching the basis of correction from magnetic field parameters to optical flow parameters, the system becomes adaptable to environments where geomagnetism data is unreliable or unavailable.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If motion vector detection unit is added to correct angular velocity sensor outputs, then orientation accuracy is maintained without geomagnetism sensor, but device complexity increases

Engineering Contradiction:

Improveorientation calculation reliabilityVSAvoidsystem structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent makes the image capturing apparatus perform multiple functions: it not only captures images for primary purposes but also uses the captured images for motion vector detection and orientation correction. This multi-functionality reduces the need for dedicated sensors and reduces overall system complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system uses its own captured images to generate motion vectors that correct its orientation calculation. The image capturing apparatus serves itself by using its primary output (captured images) to improve its orientation accuracy, eliminating the need for external geomagnetism sensors.

Inventive Principle:

Principle #25Self-service

Data Source

PatentUS11361465B2Image capturing apparatus and control method thereof, and orientation angle calculation apparatus for estimating orientation of image capturing apparatus

Publication Date: 2022.06.14 CANON KK

AI summary

An image capturing apparatus comprises an angular velocity detection sensor that detects an angular velocity, an acceleration detection sensor that detects an acceleration, a motion vector detection unit that detects a motion vector on the basis of an image captured by the image capturing apparatus; and a calculation unit that calculates an orientation angle of the image capturing apparatus on the basis of a detection value from the angular velocity detection sensor, a detection value from the acceleration detection sensor, and a detection value from the motion vector detection unit, wherein the calculation unit corrects an output of the angular velocity detection sensor using the detection value obtained by the motion vector detection unit, and calculates an orientation angle of the image capturing apparatus on the basis of the corrected value.