Multipath Light Test Device for TOF Depth Error Analysis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing TOF module technologies face challenges in accurately determining the impact of multipath light on depth value measurements due to uncontrollable multipath light interference, leading to subjective and qualitative assessment methods that fail to objectively quantify the error in depth values.
Innovation Solution
A multipath light test device for a TOF module is designed, comprising a light-splitting plate, first and second reflector plates arranged at specific angles, which split and redirect light to simulate multipath light paths, allowing for the determination of depth value errors by comparing theoretical and measured depth values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multipath light is simulated using a controllable test device, then measurement precision and objectivity are improved, but device complexity increases
Solution Approach 1:
The optical path is segmented into multiple independent components: a light-splitting plate that divides light into direct and indirect paths, reflector plates that create controlled reflection paths, and a diffuser plate that simulates target surfaces. This segmentation allows each component to be independently optimized and adjusted, achieving precise multipath light simulation while maintaining manageable device complexity.
Solution Approach 2:
A diffuser plate is introduced as an intermediary element between the reflector plates and the TOF module. This diffuser plate uniformly distributes the reflected light to simulate realistic target surfaces, enabling accurate depth value measurement under multipath light conditions without requiring complex direct illumination arrangements.
2Loss of information
If multiple optical paths are created to simulate multipath light, then the ability to quantify depth error is improved, but the difficulty of detecting and measuring increases
Solution Approach 1:
The direct light path and indirect multipath light are extracted and separated through the light-splitting plate. The direct path light travels straight to the target and back, while the indirect path light reflects off the reflector plates before reaching the target. This extraction allows independent control and measurement of each light path's contribution to depth error.
Solution Approach 2:
Different wavelengths or characteristics of light could be used to label and distinguish between direct and indirect light paths, although the patent primarily uses spatial separation. The diffuser plate creates uniform light distribution that mimics natural target reflection, making the multipath light indistinguishable from actual target light to the TOF module.
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 solution enables the qualitative and quantitative assessment of depth value errors caused by multipath light, providing an objective and accurate method to determine the impact of multipath light on TOF module measurements.
Implementation Method 1
a light-splitting plate configured to split light emitted from the TOF module; one part of light in the emitted light from the TOF module is returned to the TOF module along a first optical path after being reflected by the light-splitting plate
Implementation Method 2
the other part of the emitted light from the TOF module is transmitted through the light-splitting plate, incident to the first reflector plate
Implementation Method 3
a first reflector plate connected to the light-splitting plate and forming a first angle with the light-splitting plate; and a second reflector plate disposed on one side opposite to the first reflector plate, forming a second angle with the first reflector plate; the other part of the emitted light from the TOF module is transmitted through the light-splitting plate, incident to the first reflector plate and further to the second reflector plate, and then returned to the TOF module along a second optical path
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The present invention relates to a multipath light test device for a time of flight (TOF) module (40) and a depth error measuring method and a depth error measuring system. The test device comprises: a light-splitting plate (10) configured to split light emitted from the TOF module (40); a first reflector plate (20) connected to the light-splitting plate (10) and forming a first angle with the light-splitting plate (10); and a second reflector plate (30) disposed on one side opposite to the first reflector plate (20) and forming a second angle with the first reflector plate (20); one part of the emitted light from the TOF module (40) is returned to the TOF module (40) along a first optical path (200) after being reflected by the light-splitting plate (10) with a first reflectivity; and the other part of the emitted light from the TOF module (40) is transmitted through the light-splitting plate (10) and incident to the first reflector plate (20) and then returned to the TOF module (40) along a second optical path. The present invention can qualitatively and quantitatively determine the error of the depth value acquired by the TOF module (40) resulted from the multipath light. In application, for analyzing the error the depth value acquired and outputted by the TOF module 40 due to the mixed light of some specific long and short paths, the multipath light test device 100 for the TOF module may be adopted to test the mixed light of these specific long and short paths.