Dynamic Current Threshold for Spacecraft SEL Protection
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Solution Overview
Problem
Existing methods for protecting electronic devices in spacecraft from Single Event Latch-Up (SEL) are inadequate due to weight and cost constraints of passive shielding, and existing current threshold detection methods interfere with normal operation by requiring a static threshold that is too high to avoid false shutdowns.
Innovation Solution
A method and system that dynamically adapts the current threshold based on the operation state, pre-recorded values, and calibration factors to detect SEL, allowing for real-time adjustment and minimizing interference with normal operation, using integrated modules within the electronic device to sense and compare input currents without external assistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a static current threshold is used for SEL detection, then the electronic device can be protected from SEL damage, but normal operation is interfered with due to false shutdowns when the threshold is set too high
Solution Approach 1:
The patent applies dynamics by transitioning from a static current threshold to a dynamic current threshold that adapts in real-time based on the electronic device's operational state. The threshold is continuously adjusted according to factors such as operating mode, temperature, and workload, allowing it to distinguish between normal high-current operations and actual SEL events, thereby preventing false shutdowns while maintaining reliable SEL protection
Solution Approach 2:
The patent implements parameter changes by modifying the current threshold parameter dynamically rather than keeping it fixed. The threshold value is changed based on multiple parameters including operational mode (idle, active, sleep), temperature conditions, and device characteristics, enabling the system to maintain optimal protection levels across different operating conditions without interfering with normal functionality
2Reliability
If passive shielding is used to protect electronic devices from cosmic rays, then SEL damage is prevented, but weight and cost increase significantly
Solution Approach 1:
The patent replaces the mechanical/physical shielding approach with an electronic/detection-based system. Instead of using physical barriers (shielding materials) to block cosmic rays, the system uses current monitoring and dynamic threshold comparison to detect SEL events electronically, thereby eliminating the need for heavy passive shielding while maintaining protection capability
Solution Approach 2:
The patent implements self-service by enabling the electronic device to monitor its own current consumption and autonomously detect SEL events without external intervention. The device compares its actual current draw against dynamically calculated thresholds and automatically responds to SEL conditions, eliminating the need for external protection systems or heavy shielding
3Ease of operation
If a static current threshold is set above maximum normal input current, then false shutdowns are avoided, but SEL events with current below maximum cannot be detected
Solution Approach 1:
The patent resolves this contradiction by making the current threshold dynamic rather than static. The threshold adapts to the device's operational state, being lower during idle periods (enabling SEL detection) and higher during high-performance modes (avoiding false shutdowns). This dynamic adjustment allows the system to detect SEL events across the full range of operational currents without compromising normal operation
Solution Approach 2:
The patent changes the threshold parameter based on operational context. By adjusting the threshold value according to factors like operating mode, temperature, and device characteristics, the system can set appropriate thresholds for different scenarios - lower thresholds when the device is idle (improving SEL detection) and higher thresholds when the device is under heavy load (preventing false shutdowns)
Data Source
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AI summary
This application relates to a method for protecting an electronic device (10) from damage due to a Single Event Latch-Up, SEL. The method comprises a determination (S101) of an operation state of the electronic device. Further, an input current to the electronic device is sensed (S102) and a current threshold is set (S103) based on the determined operation state of the electronic device (10). The current threshold is a threshold for detecting the SEL in the electronic device. Further, the sensed input current is compared (S104) to the current threshold, for determining whether to interrupt (S105) current supply to the electronic device.