Optical Position Detector Using Intensity Ratio for Reflectivity Independence
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Solution Overview
Problem
Conventional distance measurement technologies using optical fibers face challenges such as unreliable results due to physical features of multimode fibers, dependency on target reflectivity, and limited flexibility in achieving desired resolution and measurement range.
Innovation Solution
A detector system comprising a transfer device with a focal length, optical receiving fibers with specific core diameters and cladding ratios, and optical sensors to generate and evaluate combined signals for determining object position independently of target reflectivity, enhancing measurement range and resolution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional time of flight measurement is used, then distance measurement is possible, but results are unreliable due to physical features of multimode fibers
Solution Approach 1:
The patent changes the measurement parameter from time of flight to light intensity ratio. Instead of measuring the time photons take to travel, the system measures the ratio of light intensities detected by different sensors, which is affected by the angular distribution of light emerging from the fiber. This parameter change eliminates the reliability issues associated with time of flight measurements in multimode fibers.
Solution Approach 2:
The patent replaces the temporal measurement mechanism (time of flight) with an intensity-based optical measurement mechanism. By using multiple optical sensors to detect light intensity ratios and relating these to angular distributions, the system substitutes a mechanical/temporal measurement approach with an optical field-based approach that is more reliable for fiber optic applications.
2Productivity
If light intensity based distance measurement is used, then measurement is possible, but results depend on target reflectivity
Solution Approach 1:
The patent segments the single intensity measurement into multiple intensity measurements at different angular positions. By using multiple optical sensors arranged to detect light at different angles, the system creates multiple measurement channels. This segmentation allows the calculation of angular distribution characteristics that are independent of the overall light intensity, thereby eliminating dependence on target reflectivity.
Solution Approach 2:
The patent introduces asymmetry in the sensor arrangement relative to the fiber optic cable. The optical sensors are positioned at asymmetric angular positions around the fiber axis, allowing the system to detect the asymmetric angular distribution of light emerging from the fiber. This asymmetric arrangement enables the system to measure angular characteristics that are invariant to the total light intensity, thus independent of target reflectivity.
3Measurement precision
If triangulation is used, then angle of incidence can be identified, but a spatially well resolved array system is required
Solution Approach 1:
The patent makes the fiber optic cable itself serve multiple functions: it acts as both the light delivery medium and the angular distribution sensor. The fiber's physical structure and light propagation characteristics are exploited to encode angular information in the intensity distribution detected by simple sensors. This multi-functionality eliminates the need for complex separate angular sensing systems while maintaining measurement precision.
Solution Approach 2:
The system uses the fiber optic cable's inherent properties to perform the angular measurement function. The angular distribution of light emerging from the fiber is a natural consequence of the fiber's physical characteristics and light propagation modes. By detecting this naturally occurring angular distribution, the system allows the fiber to serve its own measurement function without requiring external complex measurement apparatus.
4Reliability
If DPR technology is used, then measurements independent of target reflectivity are possible, but flexibility in designing systems with given resolution and measurement range is limited
Solution Approach 1:
The patent introduces dynamic configurability through the arrangement and spacing of multiple optical sensors. The system can adapt its measurement characteristics by changing the angular positions, numbers, and types of sensors used. This dynamic arrangement allows the system to be configured for different measurement ranges and resolutions while maintaining reflectivity independence, providing the flexibility that fixed DPR systems lack.
Solution Approach 2:
The patent extends the measurement from simple intensity ratios to three-dimensional angular distribution characterization by arranging sensors in multiple angular positions around the fiber. This dimensional extension from 1D intensity measurement to 3D angular space measurement provides additional degrees of freedom for system design, enabling flexible adjustment of measurement range and resolution while maintaining reflectivity independence.
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 system reliably determines object position with improved measurement range and resolution, independent of target reflectivity, by using a transfer device and optical receiving fibers with specific configurations to process light beams effectively.
Implementation Method 1
a transfer device (1030), in particular a lens, having at least one focal length in response to the at least one incident light beam (1002) propagating from the object to the detector
Implementation Method 2
a transfer device (1030), in particular a lens
Implementation Method 3
at least one optical receiving fiber (1021, 1022), wherein each of the optical receiving fibers comprises at least one cladding (1008) and at least one core (1007)
Data Source
AI summary
Described herein is a detector for determining a position of at least one object. The detector includes:at least one transfer device;at least one illumination source adapted to generate at least one light beam for illuminating the object;at least one first optical receiving fiber and at least one second optical receiving fiber;at least two optical sensors; andat least one evaluation device being configured for determining at least one longitudinal coordinate z of the object by evaluating a combined signal Q from the sensor signals.