Forward Looking Turret Gimbal Mechanism Avoiding Gimbal Lock
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing airborne optical turrets face gimbal lock singularities when the line of sight is parallel to the azimuth axis, leading to instability in servo control and limited aperture size, which restricts the collection of optical energy and imaging.
Innovation Solution
A gimbal mechanism with a sphere and disk configuration, where the disk rotates within the sphere about a second axis perpendicular to the first axis, allowing for near-hemispherical field coverage without gimbal lock singularities, and a support member with opposing yoke arms that extend from the pod to minimize drag and maximize aperture size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the azimuth axis is oriented perpendicular to the aircraft flight direction to avoid gimbal lock, then gimbal lock singularity is avoided, but the achievable aperture size as a percentage of the host pod diameter is severely limited
Solution Approach 1:
The patent introduces a third rotational degree of freedom (the cone angle about the flight path axis) in addition to the traditional two-axis gimbal system. This dimensional addition allows the aperture to achieve near-hemispherical field coverage (±60 degrees azimuth, ±30 degrees elevation) without requiring the azimuth axis to be perpendicular to the flight direction, thereby resolving the contradiction between avoiding gimbal lock and maximizing aperture size
Solution Approach 2:
The patent employs a dynamic three-axis gimbal system where the aperture can independently rotate about the flight path axis (cone angle) while maintaining its orientation relative to the aircraft. This dynamic capability allows the system to avoid gimbal lock conditions while preserving large aperture dimensions, as the aperture can reorient itself in three-dimensional space rather than being constrained to a fixed two-axis configuration
2Quantity of substance
If the aperture size is maximized to enhance optical energy collection, then detection capability is improved, but the pod diameter must be increased which increases drag
Solution Approach 1:
By adding the third rotational axis (cone angle about flight path), the patent enables the aperture to achieve near-hemispherical coverage without increasing pod diameter. The aperture can sweep through a wider field of view by rotating about the flight path axis rather than requiring a larger physical structure, thereby maintaining compact pod dimensions and minimizing drag while maximizing optical energy collection capability
3Adaptability or versatility
If the field coverage is expanded to near-hemispherical, then detection coverage is improved, but the gimbal mechanism complexity increases
Solution Approach 1:
The patent implements a dynamic three-axis gimbal system where each axis can rotate independently about its own bearing assembly. The aperture rotates about the flight path axis (cone angle) while maintaining its orientation, and the gimbal mechanism dynamically adjusts to avoid gimbal lock conditions. This dynamic design achieves near-hemispherical field coverage with a manageable level of complexity by distributing the rotational freedom across three independent axes rather than requiring an overly complex mechanism
Data Source
AI summary
A gimbal mechanism for a turret includes a support member and a pair of opposing yoke arms extending from the support member. The pair of opposing yoke arms define a first axis. A sphere is rotatably mounted between the opposing yoke arms for rotation about the first axis. A disk is rotatably mounted within the sphere for rotation about a second axis perpendicular to the first axis. The disk is sized for rotation within the sphere. The second axis may be offset from the first axis. An aperture is provided in the disk. The sphere includes a slot within which the aperture is moveable in response to rotation of the disk about the second axis. The aperture is movable to define a field of coverage in response to rotation of the sphere about the first axis and the disk about the second axis.