Triangulation Position Sensor Occlusion Control
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Solution Overview
Problem
Non-contact position measuring devices using triangulation methods face accuracy issues due to occlusion and excessive light intensity, leading to decreased measurement precision when adjusting laser light intensity based on received light levels.
Innovation Solution
A position measuring device with a light emitter, image capturer, first and second beam splitters, light receivers, and a controller that detects and controls laser light intensity based on signals from both the light emitter and image capturer sides, preventing excessive light capture by determining occlusion states and adjusting intensity accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If feedback control is performed to increase laser light intensity in response to decreased light received due to occlusion, then the amount of light received is compensated, but when occlusion is resolved, excessive diffused light is generated and measurement accuracy decreases
Solution Approach 1:
The system performs preliminary detection of occlusion states using the first light receiver before feedback control is applied. By detecting occlusion in advance and setting a flag, the system prevents excessive light intensity from being generated when occlusion is resolved, thereby avoiding measurement errors caused by light overflow.
Solution Approach 2:
The system uses feedback control to adjust laser light intensity based on light received levels, but incorporates an occlusion detection mechanism that overrides the feedback control when occlusion is detected. This prevents the feedback loop from increasing light intensity during occlusion, which would cause excessive light when occlusion is resolved.
2Illumination intensity
If laser light intensity is increased to compensate for decreased light received during occlusion, then light reception is improved, but measurement precision decreases due to light overflow when occlusion is resolved
Solution Approach 1:
The system detects occlusion in advance using the first light receiver and sets an occlusion flag before feedback control increases light intensity. This preliminary detection prevents the system from increasing light intensity during occlusion, thereby preventing light overflow and maintaining measurement precision when occlusion is resolved.
Solution Approach 2:
The first light receiver acts as an intermediary detection device that monitors occlusion states independently from the main imaging path. By using this separate detection channel, the system can identify occlusion conditions and prevent excessive light intensity without interfering with the normal measurement process.
3Stability of the object's composition
If feedback control adjusts laser light intensity based on light received levels, then measurement consistency is improved, but measurement accuracy decreases when occlusion occurs and light intensity is inappropriately increased
Solution Approach 1:
The system performs preliminary occlusion detection using the first light receiver before feedback control adjusts light intensity. By detecting occlusion in advance and setting a flag, the system prevents inappropriate light intensity adjustments during occlusion, thereby maintaining measurement accuracy while still achieving light received consistency under normal conditions.
Solution Approach 2:
The system dynamically switches between feedback control mode and occlusion prevention mode based on real-time occlusion detection. When occlusion is detected, the system overrides feedback control to maintain appropriate light intensity, thereby preserving measurement accuracy while maintaining stability under normal operating conditions.
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 configuration ensures highly accurate position measurement by preventing excessive light capture and maintaining optimal laser light intensity, thereby enhancing measurement precision and reducing errors caused by occlusion and light overflow.
Implementation Method 1
The first light receiver receives light propagating along the first optical axis toward the light emitter and reflected by the first beam splitter
Implementation Method 2
a light emitter that emits laser light along a first optical axis for measuring a position of an object to be measured
Implementation Method 3
an image capturer that is provided on a second optical axis which is non-parallel to the first optical axis
Data Source
AI summary
A position measuring device includes a light emitter, an image capturer, a first beam splitter, a first light receiver, a second light receiver, a calculator, and a controller. The first light receiver receives light that propagates along a first optical axis toward the light emitter and is reflected by the first beam splitter, and outputs a first signal. The second light receiver outputs a second signal corresponding to an intensity of light propagating along a second optical axis toward the image capturer. The controller controls the intensity of the laser light based on the second signal when a difference between the first signal and the second signal is smaller than a predetermined threshold, and performs control so that the laser light has a predetermined intensity when the difference between the first signal and the second signal is equal to or greater than the threshold.