MEMS Optical Scanner for High-Precision 3D Tracking
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Solution Overview
Problem
Current technologies for real-time 3D tracking of moving objects lack a simple and cost-effective solution with sufficient precision and flexibility, particularly when objects are close to the tracking system, and existing imaging systems using CCD arrays or barcode scanning are limited by their two-dimensional nature and high costs.
Innovation Solution
A system utilizing MEMS optical scanners with two-dimensional actuators and controllers to determine the three-dimensional position of objects, enabling alignment of optical paths and precise tracking with high-resolution angle determination and wide-angle lenses for distant tracking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If MEMS mirrors with small aperture are used for scanning, then device size is reduced and scanning speed is increased, but the amount of reflected light received is insufficient
Solution Approach 1:
The system separates the scanning function (performed by small MEMS mirrors) from the light collection function (performed by large stationary photodetectors). This segmentation allows each component to be optimized independently - the MEMS mirrors remain small for fast scanning while the photodetectors are large for sufficient light collection.
Solution Approach 2:
The patent decouples the spatial dimensions of the scanning aperture and the receiving aperture. The small MEMS mirror operates in one dimensional space while the large photodetector operates in another, allowing the system to achieve both fast scanning and sufficient light collection simultaneously.
2Measurement precision
If CCD arrays are used for imaging, then position information can be obtained, but the field of view is limited and the cost increases significantly
Solution Approach 1:
The system uses a single photodetector that can detect light from any direction within a wide field of view by receiving reflected light from the scanning MEMS mirrors. This single detector performs the function that would otherwise require an entire CCD array, achieving both wide field of view and position measurement capability.
Solution Approach 2:
Instead of using a CCD array to directly capture images, the system uses MEMS mirrors to scan and copy the light path to a single photodetector. The scanning mirrors create multiple optical paths that all converge on one detector, effectively replicating the functionality of a multi-pixel array with a single pixel.
3Productivity
If scanning speed is increased for real-time tracking, then tracking performance is improved, but resolution is lost when objects are close
Solution Approach 1:
The system uses feedback from the position of the MEMS mirrors to determine object location. By precisely controlling and measuring the mirror angles, the system can calculate object position with high resolution regardless of distance, maintaining precision even at high scanning speeds for real-time tracking.
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 provides high-precision, low-cost, and versatile 3D tracking with the ability to measure object positions at a bandwidth of 10 kilohertz or more, achieving greater than 10-bit resolution and enabling tracking of moving objects with precision up to 20 μm on the X and Y axes and 1.5 mm on the Z-axis at distances of up to 5 meters.
Implementation Method 1
a reflector mounted to a two-dimensional actuator configured to control a tilt of the reflector
Implementation Method 2
The one or more optical detectors are responsive to radiation from one or more optical sources
Data Source
AI summary
An optical tracking system can include at least one scanning detector having a scanning mirror and one or more fixed photo-detectors located near the scanning mirror. The scanning mirror can be configured to deflect a light beam from a source towards a retroreflective target and the photodetectors are configured to collect a portion of the light beam that is retroreflected from the target. A scanning optical detector apparatus may optionally comprise a substrate, a scanning mirror having at least one portion monolithically integrated into the substrate, and one or more photodetectors monolithically incorporated into the substrate. It is emphasized that this abstract is provided to comply with rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the claims' scope or meaning.