Distance Measurement Error Correction via Defocus and Optical Flow
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing imaging devices with distance measurement functions face errors due to shifts in the relative positional relationship between the optical system and imaging sensor caused by thermal expansion and contraction, leading to inaccurate distance measurements, especially when temperature variations are not uniformly detected.
Innovation Solution
A device with a processor and memory that acquires and corrects distance measurement errors by using a combination of first and second information, where the second information has lesser errors, to calculate and apply a correction value, thereby reducing the influence of time-based errors in distance measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a temperature sensor is used to detect temperature for correcting distance measurement errors, then temperature-based correction can be applied, but the temperature sensor only detects temperature at its specific location and cannot accurately detect temperature distribution across the sensor surface or lens, leading to insufficient correction accuracy
Solution Approach 1:
The patent uses image data as an intermediary to indirectly detect temperature distribution. Instead of directly measuring temperature across the sensor surface, the system captures images at different focus positions and uses the defocus amounts (which are influenced by temperature-induced lens expansion/contraction) to infer the temperature distribution and calculate correction values.
Solution Approach 2:
The patent replaces the mechanical/physical temperature sensor system with an optical-based measurement system. Instead of using temperature sensors to directly measure temperature, the system uses the optical system itself (lens and sensor) to capture image data, and then processes this data computationally to derive temperature-induced errors and correction values.
2Measurement precision
If the optical system and imaging sensor are used for distance measurement, then distance information can be acquired, but thermal expansion and contraction of the lens or lens barrel cause shifts in the relative positional relationship between the optical system and imaging sensor, leading to distance measurement errors
Solution Approach 1:
The patent implements a feedback mechanism where the system continuously monitors defocus amounts from image data, compares them against reference values, and automatically calculates and applies correction values to compensate for temperature-induced positional shifts. This closed-loop feedback ensures that distance measurement accuracy is maintained despite thermal expansion and contraction of the optical components.
Solution Approach 2:
The patent changes the approach from trying to physically stabilize the optical system against thermal changes to instead changing the measurement parameters (using defocus amounts from multiple focus positions) and computational parameters (calculating correction values based on observed defocus changes). This allows the system to adapt to thermal changes through software rather than requiring physical stabilization.
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
This approach effectively reduces measurement errors by converting parallax amounts into defocus amounts and using optical flow methods to generate correction values, resulting in more accurate distance measurements despite changes in the imaging device's optical characteristics over time.
Implementation Method 1
acquire first information including an error via an optical system
Data Source
AI summary
In order to realize a device that can reduce the influence of errors, the device includes a first acquisition unit configured to acquire first information including an error via an image formation optical system, a second acquisition unit configured to acquire second information of which the error is less than that of the first information, a correction information generation unit configured to calculate a correction value for correcting the error of the first information on the basis of the second information, and a correction unit configured to correct the first information by using the correction value.