TOF Distance Measurement Delay Correction for Accurate Ranging
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Solution Overview
Problem
The TOF method for distance measurement is inaccurate due to delays in light emission and reception instructions and processing, leading to errors in object distance calculation.
Innovation Solution
A distance measuring apparatus with a light emitter and receiver, corrected by processors to account for delays in light emission and reception, and optical corrections to improve accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the TOF method is used to measure distance based on light flight time, then distance measurement capability is achieved, but measurement precision deteriorates due to delays in light emission and reception timing
Solution Approach 1:
The patent applies preliminary action by measuring and storing delay times before they affect the distance measurement. Specifically, the system pre-measures the delay time between when the light emitter is instructed to emit light and when the light receiver starts measuring, and stores this correction value for later use in distance calculations. This allows the system to compensate for timing delays without adding real-time measurement complexity.
Solution Approach 2:
The patent implements feedback by using the measured delay time to correct the distance measurement results. The system continuously monitors the actual light emission timing and reception timing, calculates the discrepancy, and feeds this correction back into the distance calculation process. This closed-loop approach ensures that timing delays are systematically compensated, improving measurement precision.
2Measurement precision
If multiple correction parameters are applied to improve distance measurement accuracy, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the correction process into distinct, manageable components. Each light emitting element's delay time is measured and stored separately, and corrections are applied individually to each element's distance measurements. This modular approach allows the system to handle multiple correction parameters without creating a monolithic complex processing system, as each correction can be independently calculated and applied.
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
Enhances the accuracy of distance measurements by correcting for delays and optical path differences, resulting in precise distance data.
Implementation Method 1
a light emitter configured to emit light to be irradiated onto an object... measure a time of flight of the light from the light emitter
Implementation Method 2
a light receiver configured to detect light reflected by the object among the light from the light emitter, measure a time of flight of the light from the light emitter
Data Source
AI summary
A distance measuring apparatus includes a light emitter configured to emit light onto an object and including a plurality of light emitting elements, and a drive unit configured to output a drive voltage for causing each light emitting element to emit the light, a light receiver configured to detect light reflected by the object among the light from the light emitter, measure a time of flight of the light from the light emitter, and generate distance data based on the time of flight, and one or more processors that operate to correct the distance data based on predetermined delay times.