3D Measurement Timing Window for Multiple-Reflection Noise
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Solution Overview
Problem
Existing three-dimensional measurement devices using optical scanning face challenges in accurately measuring distances due to noise caused by multiple-reflected reference light beams, which are not effectively addressed by existing methods.
Innovation Solution
A three-dimensional measurement device that projects reference light while scanning, sets a scanning time extent and a region of interest, and calculates three-dimensional information using triangulation to exclude noise from multiple reflections by limiting data collection within these defined parameters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If event-based image sensor is used to speed up light section method, then measurement speed is improved, but noise from multiple-reflected light cannot be effectively filtered
Solution Approach 1:
The system pre-calculates and stores the expected arrival time range of direct reflected light for each pixel before measurement begins. During actual measurement, this pre-established time reference is used to quickly filter events, enabling fast noise rejection without compromising measurement speed or accuracy
Solution Approach 2:
The patent introduces an intermediary time-extent filtering mechanism that sits between the event-based sensor output and the measurement processing. This intermediary layer uses temporal information to distinguish direct reflected light from multiple-reflected light, solving the noise filtering problem while maintaining the high-speed advantage of event-based sensors
2Quantity of substance
If scanning time extent is extended to capture more light signals, then signal coverage is improved, but noise from multiple reflections is also included
Solution Approach 1:
The system dynamically adjusts the time-extent parameter for each pixel based on its position and the expected light travel time. By changing the temporal parameter rather than spatial or optical parameters, the system captures sufficient direct reflected light signals while automatically excluding multiple-reflected light that arrives outside the expected time window
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
Reduces the influence of noise from multiple-reflected light by ensuring only directly reflected light is captured within the scanning time extent or region of interest, thereby improving measurement accuracy and reducing latency.
Implementation Method 1
a light projection unit (7) that projects reference light onto an object W to be measured; a light reception unit (3) that receives the reference light reflected by the object W
Implementation Method 2
a three-dimensional information calculation unit (9) that calculates three-dimensional information of the object W by triangulation
Data Source
AI summary
This three-dimensional measurement device comprises: a projection unit that projects reference light to an object while performing scanning with the light; a light reception unit that receives the reference light reflected on the object; a time extent setting unit that sets a scanning time extent of the reference light in accordance with a distance-measuring range for each prescribed section of the light reception unit; and a three-dimensional information calculation unit that calculates three-dimensional information about the object W by means of triangulation based on information of the light reception unit within the set scanning time extent.