Angular Position Measurement via Refractive Beam Offset
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Solution Overview
Problem
Conventional methods for measuring the angular position of a rotating body are limited by speed and accuracy, particularly in applications requiring high-precision measurements at fast rotation rates, such as in medical imaging and gimbal systems.
Innovation Solution
A system utilizing refractive elements, like glass blocks, around a rotating body to measure angular position through the lateral offset of light beams as they pass through these elements, with multiple emitter-detector pairs providing continuous and precise angular position data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional interferometric techniques are used to measure angular position, then measurement precision is maintained, but the system cannot operate at high rotational speeds
Solution Approach 1:
The patent replaces conventional mechanical interferometric measurement systems with an optical refraction-based system. Light beams pass through refractive elements (glass blocks) mounted on the rotating body, and the lateral displacement of these beams due to refraction is measured by stationary detectors. This substitution eliminates the mechanical limitations of interferometers, enabling operation at high rotational speeds while maintaining measurement precision through optical means.
Solution Approach 2:
The patent introduces refractive elements (glass blocks) as intermediary components between the rotating body and the measurement system. These elements modulate light beams in a manner that encodes angular position information, allowing the measurement to be performed by stationary detectors rather than requiring the entire measurement system to rotate or operate at high speeds like conventional interferometers.
2Productivity
If the rotational speed increases, then productivity is improved, but measurement precision deteriorates due to limitations of conventional interferometric techniques
Solution Approach 1:
The system replaces speed-limited mechanical interferometry with an optical refraction method that has no inherent speed limitations. The refractive elements and stationary detectors can accurately measure angular position even when the rotating body moves at high speeds, thereby improving productivity without sacrificing measurement precision.
Solution Approach 2:
The patent creates a dynamic measurement system where the refractive elements rotate with the body while the detectors remain stationary. This dynamic configuration allows continuous measurement at high rotational speeds, transforming the measurement process from a static interferometric approach to a dynamic optical sampling approach that maintains precision across varying speeds.
3Ease of operation
If conventional interferometers are used, then angular position can be measured, but the device complexity increases and operation becomes difficult at high speeds
Solution Approach 1:
The patent extracts the measurement function from the rotating body, placing detectors in stationary positions while only the refractive elements rotate with the body. This extraction simplifies operation by eliminating the need for complex high-speed interferometric equipment, making the system easier to operate at high rotational speeds.
Solution Approach 2:
By replacing the complex mechanical interferometer system with a simpler optical refraction system using glass blocks and stationary detectors, the patent improves ease of operation. The simplified system has no moving measurement components, reducing operational complexity while enabling high-speed operation.
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
Enables high-accuracy measurement of angular position at high rotational speeds, suitable for a wide range of applications, including medical imaging and high-speed gimbals, with continuous resolution and no moving parts other than the rotating body.
Implementation Method 1
at least some of the refractive elements are arranged to pass through and laterally shift the first light beam upon rotation of the rotatable body
Data Source
AI summary
An apparatus for measuring the angular position of a rotatable body comprises: refractive elements extending radially outward from a peripheral surface of the rotatable body at respective angular locations; first and second emitters that respectively emit first and second light beams along first and second path extending through respectively first and second regions within an annual vicinity around the rotatable body, wherein the refractive elements are arranged to pass through and laterally shift the light beams upon rotation of the rotatable body; first and second detectors arranged to respectively receive the first and second light beams and to determine respective first and second lateral offsets of the light beams caused by the time-varying angular orientation of refractive elements within the light beams; and a processor that determines an angular position of the rotatable body based on the first and second lateral offsets.