IMU Strain Relief and Recalibration for High G Shock
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing inertial measurement units (IMUs) face challenges in providing accurate measurements in high g shock, vibration, and rotation environments, leading to sensor error, offset, or bias shift, which affects the precision of gun-fired projectiles and navigation systems.
Innovation Solution
The development of an Enhanced Performance IMU (EP-IMU) or multi-IMU (MIMU) system that incorporates multiple miniature IMUs in a single package, employing novel packaging strategies for strain relief and a recalibration module to address sensor errors, allowing for continuous accurate measurement before, during, and after high g events.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional IMUs are used in high g shock environments, then the device structure is simple, but sensor error, offset, or bias shift occurs leading to measurement inaccuracy
Solution Approach 1:
The system divides the IMU into multiple independent sensor packages (e.g., three separate packages with accelerometers and gyroscopes), where each package can be individually calibrated and compensated. This segmentation allows error correction without requiring complete system redesign, maintaining measurement accuracy while managing complexity through modular architecture.
Solution Approach 2:
The system dynamically adjusts measurement parameters and calibration values based on detected g-force levels and environmental conditions. By changing operational parameters such as sampling rates, integration methods, and compensation coefficients in response to high g shock events, the system maintains accuracy without permanently increasing structural complexity.
2Measurement precision
If multiple miniature IMUs are packaged together in a single system, then measurement accuracy is improved through error correction, but device complexity increases
Solution Approach 1:
Multiple miniature IMU packages are merged into a single integrated system with unified calibration and error compensation algorithms. The packages work together as a coordinated unit, sharing computational resources and calibration data, which improves measurement accuracy through redundancy while managing complexity through integration rather than independent operation.
Solution Approach 2:
The multi-IMU system performs self-calibration and self-correction by comparing measurements across multiple packages and automatically adjusting for systematic errors. This self-service capability reduces the need for external calibration equipment and complex manual adjustment mechanisms, improving accuracy while keeping the system architecture manageable.
3Measurement precision
If recalibration module is added to correct sensor errors, then measurement accuracy is maintained after high g events, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The recalibration module performs preliminary calibration adjustments before high g shock events occur and continues calibration during and after events. By proactively adjusting bias values and compensation parameters in advance and in real-time, the system maintains accuracy without requiring complex post-manufacturing calibration procedures, easing manufacturing while ensuring performance.
Solution Approach 2:
The system continuously monitors sensor outputs and feeds this information back to the recalibration module, which automatically adjusts calibration parameters based on detected drift or bias shifts. This closed-loop feedback mechanism maintains measurement precision through automatic correction rather than complex manual recalibration procedures, simplifying manufacturing while ensuring ongoing accuracy.
Data Source
AI summary
Inertial measurement units (IMUs) and methods with adaptations to eliminate or minimize sensor error, offset, or bias shift are presented. More particularly, the IMUs and methods for gun-fired projectiles herein are particularly adapted to accurately measure forces and to prevent or minimize the error, offset, or bias shift associated with events exhibiting high g shock, and/or high levels of vibration, and/or rotation. Even more particularly, the IMUs and methods herein utilize novel IMU packaging adapted to prevent or minimize sensor error, offset, or bias shift, and recalibration adaptations and methods adapted to correct or reset the error, offset, or bias shift from such an event. The IMUs are adapted to provide accurate measurements prior to, during and after such event, and to provide continuous accurate measurements during flight of gun-fired projectiles.