3D Laser Scanner Stray Light Compensation Method
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Solution Overview
Problem
3D laser scanners face challenges in accurately determining and compensating stray light, which can lead to falsified distance and intensity values due to external influences like soiling of protective glass, especially when measuring distant or dark objects, resulting in cyclic phase and amplitude errors that degrade the quality of the acquired data.
Innovation Solution
A method involving two step sequences for determining and compensating stray light parameters, where the first sequence determines parameters independently of the 3D point cloud and can be applied proactively, and the second sequence uses analysis of the 3D point cloud to correct stray light effects, allowing flexible adaptation to field conditions for improved data quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If stray light compensation is performed using traditional methods, then distance and intensity values can be obtained, but the measurement precision deteriorates due to无法 differentiate plural targets and mixed pixels at edges
Solution Approach 1:
The patent segments the measurement process into multiple independent steps: first determining stray light parameters using a first step sequence (emitting beam toward sky or reflective surface), then using a second step sequence to determine object parameters. This segmentation allows separate optimization of stray light compensation from object measurement, resolving the contradiction between obtaining measurements and avoiding stray light interference.
Solution Approach 2:
The patent applies preliminary action by determining stray light parameters before measuring the object. The first step sequence is executed prior to or during the detection process, establishing stray light compensation values in advance. This ensures that when the second step sequence measures the object, the stray light effects are already accounted for, improving measurement precision while maintaining accuracy.
2Measurement precision
If both step sequences are applied for stray light determination, then measurement precision improves, but device complexity increases
Solution Approach 1:
The patent implements dynamics by making the selection between first and second step sequences flexible and adaptive. The control unit dynamically decides which sequence to apply based on environmental conditions, object characteristics, and measurement requirements. This dynamic approach allows the system to optimize between measurement precision and process complexity for each specific scenario rather than always using the most complex method.
Solution Approach 2:
The patent applies parameter changes by adjusting the measurement parameters and processing methods based on the selected step sequence. When the first sequence is used, parameters are determined independently of the 3D point cloud; when the second sequence is used, parameters are determined from the generated 3D point cloud. This parameter adaptation allows the system to achieve high precision when needed while simplifying the process when standard conditions apply.
3Measurement precision
If stray light parameters are determined independently of the 3D point cloud, then measurement precision for stray light compensation improves, but the time required for measurement increases
Solution Approach 1:
The patent applies preliminary action by determining stray light parameters before the main object measurement process. The first step sequence is executed in advance to establish accurate stray light compensation values, which are then stored and applied during subsequent object measurements. This timing strategy ensures high precision compensation while distributing the time cost across multiple measurement cycles rather than adding it as a separate bottleneck.
Solution Approach 2:
The patent maintains continuity of useful action by integrating stray light parameter determination into the ongoing measurement process. The control unit continuously monitors and updates stray light parameters using the first step sequence while simultaneously processing object data from the second step sequence. This continuous operation ensures that both precision and time efficiency are maintained through overlapping computations rather than sequential processing.
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 method effectively compensates stray light, even in high-intensity scenarios, ensuring accurate distance and intensity values by averaging stray light parameters and identifying wave patterns in the 3D point cloud, thereby enhancing the quality of the data acquired by the 3D laser scanner.
Implementation Method 1
the phase-based method cannot differentiate plural targets located in the spot of a measuring beam, but forms a mean value from the distances and intensities of the targets hit by the spot
Implementation Method 2
the proportion of the measuring beam reflected by the object to the emitted measuring beam
Implementation Method 3
a receiver such as a photodiode, without having been incident on the object to be detected before
Data Source
AI summary
A method is disclosed for determining and compensating a proportion of stray light of a measuring beam of a 3D laser scanner by which a 3D point cloud of an object to be detected can be generated via phase-based distance measurement including a first sequence by which first parameters of a proportion of stray light can be determined independently of the 3D point cloud and/or a second sequence by which second parameters of the proportion of stray light dependent on the generated 3D point cloud and a step can be determined. The proportion of stray light can be compensated as a function of the first parameters and/or the second parameters.