Projectile Roll Posture Detection Using Thermopile Sensors
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Solution Overview
Problem
Existing methods for determining the roll posture of spin-stabilized projectiles face challenges, particularly in complex flight motions, where inertial navigation systems are difficult to use and GPS-based systems are cumbersome and prone to jamming, especially for small munitions.
Innovation Solution
An apparatus comprising thermopile sensors to sense temperature differences between the ground and sky sides of a projectile, combined with a signal processor to determine roll posture, spin direction, and gyro sensors to measure roll angular velocity, allowing for accurate estimation of roll angle and spin number.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If an inertial navigation system is used to measure roll posture, then measurement precision is improved, but device complexity increases and reliability decreases due to difficulty in use during complex flight motions
Solution Approach 1:
The patent replaces the mechanical/inertial navigation system with a thermal sensing system. Thermopile sensors detect temperature differences between the ground side and sky side of the projectile, converting thermal energy into electrical signals to determine roll posture. This substitution eliminates the complexity of inertial measurement units while maintaining measurement capability during complex flight motions.
2Measurement precision
If a GPS-based system is used to estimate roll posture, then measurement precision is improved, but reliability decreases due to jamming susceptibility and device complexity increases
Solution Approach 1:
The patent substitutes the electromagnetic GPS system with a thermal sensing system. By using thermopile sensors to detect temperature gradients between ground and sky, the system eliminates dependence on external electromagnetic signals that can be jammed. This provides reliable roll posture estimation independent of GPS signal availability.
3Device complexity
If a geomagnetic field-based method is used to detect ground side, then device complexity is reduced, but measurement precision decreases due to geomagnetic field variations at different launch positions
Solution Approach 1:
The patent changes the detection parameter from geomagnetic field strength to temperature difference. Thermopile sensors measure the temperature difference between the ground side and sky side, which provides a consistent reference frame independent of launch position. This parameter change eliminates the variability issue of geomagnetic fields while maintaining suitability for small munitions.
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 provides a robust and accurate method for determining roll posture with improved signal-to-noise ratio, resistant to jamming and computational complexity, suitable for small munitions and complex flight dynamics.
Implementation Method 1
at least one thermopile sensor sensing a temperature of a side of the projectile
Implementation Method 2
sense temperature differences between the ground and sky sides of a projectile
Data Source
AI summary
An apparatus for determining a roll posture of a projectile includes: at least one thermopile sensor sensing a temperature of a side of the projectile; and a signal processor determining a roll posture of the projectile by using an output signal output as a result of the sensing by the at least one thermopile sensor.