Multi-IMU Handshake Guidance for GPS-Denied High-G Flight
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing precision guided munitions (PGMs) face challenges in GPS-denied or degraded environments due to high cost, large size, and vulnerability to jamming, with tactical grade IMUs failing under high g-shock and spin conditions, limiting their effectiveness in gun launch environments.
Innovation Solution
A miniature multi-IMU package using low-cost IMUs in combination with sensor fusion algorithms to create a single high-performance IMU, capable of surviving high g and spin conditions, providing accurate location and guidance by integrating multiple low-accuracy IMUs within a small form factor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If tactical grade IMUs are used to provide robust navigation in GPS-denied environments, then navigation reliability is improved, but device size, cost, and dynamic range capability worsen
Solution Approach 1:
The system divides the IMU functionality into multiple low-cost, miniaturized sensor modules distributed throughout the projectile. Each module contains accelerometers and gyroscopes that individually provide limited measurement capability but collectively deliver tactical-grade navigation performance through sensor fusion algorithms.
Solution Approach 2:
Multiple low-accuracy IMU modules are combined and integrated through sensor fusion processing to achieve high-accuracy navigation. The individual sensor outputs are merged and processed to compensate for individual sensor limitations, producing navigation accuracy comparable to single tactical-grade IMUs while reducing size and cost.
2Reliability
If tactical grade IMUs are used to provide robust navigation in GPS-denied environments, then navigation reliability is improved, but cost worsens
Solution Approach 1:
The navigation system is segmented into multiple independent low-cost sensor modules rather than relying on a single expensive tactical-grade IMU. This segmentation allows the use of affordable commercial-off-the-shelf sensors while achieving comparable system-level performance through their combined output.
Solution Approach 2:
The system employs multiple inexpensive, disposable sensor modules that can be manufactured at low cost. These modules are designed for single-use in munitions applications, replacing the need for expensive, reusable tactical-grade IMUs while providing sufficient navigation reliability for the mission duration.
3Measurement precision
If tactical grade IMUs are used to provide robust navigation, then measurement precision is improved, but adaptability to high g-shock and spin conditions worsens
Solution Approach 1:
The system dynamically switches between different sensor modules based on operational conditions. During high-g launch phases, accelerometers are prioritized for measurement, while during spin-stabilized flight phases, gyroscopes are emphasized. This dynamic adaptation allows the system to maintain measurement precision across varying extreme conditions that would overwhelm a static tactical-grade IMU configuration.
Solution Approach 2:
The sensor fusion algorithm dynamically adjusts measurement parameters and sensor weighting based on detected operational conditions such as g-shock levels and spin rates. This parameter adaptation enables the system to optimize measurement precision for each phase of flight, from launch through terminal phase, despite the extreme and varying environmental conditions.
4Measurement precision
If multiple low-accuracy IMUs are combined to achieve high-accuracy navigation, then measurement precision is improved, but device complexity is improved (in a way that increases size)
Solution Approach 1:
Multiple IMU modules are nested within the compact projectile body, with each module containing integrated sensors and processing electronics. The modules are arranged in a space-efficient configuration that minimizes overall device size while maintaining the redundancy and measurement precision benefits of multiple sensors.
Data Source
AI summary
Presented herein are systems and methods using inertial measurement units (IMUs) for providing location and guidance, and more particularly for providing location and guidance in environments where global position systems (GPS) are unavailable or unreliable (GPS denied and/or degraded environments), and for such location and guidance being provided to projectiles, munitions, or rounds that are released, fired, or deployed from vehicles or weapons systems. More particularly, this disclosure relates to the use of a series of low-accuracy or low-resolution IMUs, in combination, to provide high-accuracy or high-resolution location and guidance results. This further relates to an electronics-control system for handing off control of the measurement and guidance of a body in flight between groups or subgroups of IMUs to alternate between high dynamic range/lower resolution and lower dynamic range/higher resolution measurement and guidance as the environment dictates.