Pupil-Division Ranging Camera Defocus Correction for Temporal Errors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing ranging cameras based on the pupil division imaging plane phase difference method are susceptible to temporal ranging errors due to changes in ambient environment and shock, which cannot be corrected using conventional methods designed for stereo cameras with a defined physical baseline length.
Innovation Solution
An information processing apparatus that acquires first and second distance information using a stereo ranging calculation device and a feature point ranging calculation device, respectively, and generates a correction value to correct defocus amounts based on the ratio of image-side defocus amounts, using a correction value calculation device to reduce temporal ranging errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a ranging camera based on the pupil division imaging plane phase difference method is used to acquire distance information, then the device can obtain distance measurements without requiring a physical baseline length, but the system becomes susceptible to temporal ranging errors caused by environmental changes and shock
Solution Approach 1:
The patent implements a feedback mechanism by acquiring both first distance information (with error) and second distance information (with less error), then using the second information to generate correction values that adjust the first information. This closed-loop feedback system continuously compensates for temporal ranging errors caused by environmental changes and shock, thereby improving measurement reliability while maintaining the flexibility of the pupil division method
Solution Approach 2:
The patent changes the parameter used for baseline definition from a fixed physical spatial distance (as in stereo cameras) to an interval between pupil regions in the optical system. This parameter change allows the system to adapt to environmental variations by using optical path differences rather than rigid mechanical baselines, reducing susceptibility to thermal expansion and mechanical shock while maintaining ranging capability
2Measurement precision
If correction methods for stereo cameras using physical baseline length are applied, then the baseline length can be compensated for thermal expansion, but the correction is inapplicable to ranging cameras based on the pupil division imaging plane phase difference method
Solution Approach 1:
The patent creates a universal correction approach that works for both stereo cameras with physical baselines and ranging cameras with pupil region intervals. By defining baseline in terms of optical path interval rather than purely mechanical distance, the correction methodology becomes applicable to both camera types, allowing the same correction logic to handle thermal expansion and environmental variations across different ranging architectures
3Ease of operation
If the baseline length is defined by the interval between pupil regions instead of physical spatial distance, then the ranging camera can operate without mechanical baseline constraints, but conventional correction techniques become inapplicable
Solution Approach 1:
The patent introduces an intermediary correction value generation process that bridges the gap between the simplified pupil region interval definition and the need for accurate correction. Instead of directly applying conventional correction techniques or requiring complex new methods, the system uses the second distance information as an intermediary reference to generate correction values, simplifying the overall system while maintaining correction capability
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 apparatus effectively reduces ranging errors caused by environmental changes and shock by correcting defocus amounts, ensuring accurate distance measurements.
Implementation Method 1
a first distance information acquisition unit that acquires first distance information including an error about a distance between an imaging unit and an object via an optical system
Implementation Method 2
a ranging camera including a single camera using a pupil division imaging plane phase difference method in which a parallax image is acquired by receiving light fluxes
Data Source
AI summary
First distance information including an error about a distance between an imaging unit and an object via an optical system is acquired, second distance information including an error that is less than the error included in the first distance information is acquired, based on a ratio between a first defocus amount corresponding to deviation along an optical axis between a sensor plane and an image plane, the first defocus amount having been used for acquisition of the first distance information, and a second defocus amount used for acquisition of the second distance information, a first correction value is generated to correct the first defocus amount and the distance between the imaging unit and the object is calculated by using the first defocus amount corrected with the first correction value.