Faceted Retro-Mirror for Jitter Sensing in Gimbaled Systems
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional jitter sensing mechanisms in gimbaled optical sensor systems are limited in accurately sensing line-of-sight jitter over a wide field of regard, particularly in multi-axis systems, where the angular movement of steering mirrors can cause the jitter sensing beam to fall outside the detector's field of view, compromising accuracy.
Innovation Solution
A faceted retro-mirror is used to allow a double-pass line-of-sight monitoring beam to sense jitter, with facets tilted relative to each other to compensate for the angular movement of the 2:1 gain mirror, ensuring the beam remains within the detector's field of view and accurately reflects the jitter information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional single mirror is used for jitter sensing, then the system structure is simple, but the beam falls outside the detector's field of view during large angular movements
Solution Approach 1:
The retro-mirror is divided into multiple facets (e.g., 7 facets) arranged in a specific geometric pattern. Each facet is tilted at a specific angle relative to the others, allowing the beam to be reflected to different positions on the detector depending on the mirror's angular orientation. This segmentation enables the system to maintain beam detection across a wide field of regard while preserving jitter measurement precision.
Solution Approach 2:
The retro-mirror facets are arranged in a two-dimensional geometric pattern rather than a simple linear arrangement. This spatial configuration in multiple dimensions allows the beam to be redirected to appropriate detector regions based on the combination of azimuth and elevation angles, expanding the effective field of regard without compromising measurement accuracy.
2Adaptability or versatility
If the retro-mirror has multiple tilted facets, then the beam remains within the detector's field of view over a wide angular range, but the device complexity increases
Solution Approach 1:
The faceted retro-mirror structure serves multiple functions simultaneously: it acts as a beam reflector, an angular-to-positional converter, and a field-of-view expander. By integrating these functions into a single component, the system avoids the need for additional separate devices, thereby reducing overall system complexity despite the intricate facet geometry.
Solution Approach 2:
The patent combines the retro-reflection function with the beam steering function into a single faceted mirror structure. Instead of using separate components for retro-reflection and angular compensation, the faceted design merges these functions, simplifying the optical path while maintaining wide field of regard capability.
3Reliability
If a stabilized source with multiple actuators is used, then line-of-sight stabilization is achieved, but the system complexity and cost increase
Solution Approach 1:
The faceted retro-mirror is rigidly mounted on the gimbal structure, meaning it moves passively with the gimbal's angular movements without requiring its own actuators or control systems. The mirror's facet geometry automatically compensates for angular changes, eliminating the need for additional active stabilization components and reducing system complexity.
Solution Approach 2:
The faceted retro-mirror acts as an intermediary between the gimbal's mechanical movements and the beam detection system. It translates mechanical angular displacements into corresponding beam position changes on the detector, enabling jitter measurement without requiring active control mechanisms.
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 solution enables precise line-of-sight jitter sensing and control, maintaining accuracy even with large angular movements, thereby improving the stability of optical functions in gimbaled optical sensor systems.
Implementation Method 1
a flat mirror mounted on an inner-most gimbal axis of the multi-axis gimbal and configured to reflect the jitter sensing beam
Implementation Method 2
the faceted retro-mirror configured to reflect the jitter sensing beam from at least one facet of the faceted retro-mirror via the flat mirror to a field of view of the jitter sensing beam detector
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A jitter sensing mechanism for a gimbaled optical sensor system. In one example, the jitter sensing mechanism includes a faceted retro-mirror (410) configured to allow a double-pass line-of-sight monitoring beam (320) to sense line-of-sight jitter in a multi-axis gimbaled optical sensor system where the inner-most gimbal axis (150) includes a 2:1 gain mirror (160).