Magnetic Sensor Signal-Path Self-Testing Through Cyclic Evaluation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing magnetic field sensors face challenges in detecting single point failures in signal channels due to combined signal paths, and providing full redundancy is expensive, while constant self-testing is nearly as costly, especially for products requiring high Automotive Safety Integrity Level (ASIL) ratings.
Innovation Solution
Incorporating an additional signal channel with a test signal generator and evaluator in parallel with existing signal paths, allowing for cyclic self-testing of each path by temporarily isolating it for thorough assessment before returning to service, ensuring fault detection within a fixed duration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If full redundancy is provided in signal channels, then reliability is improved, but device complexity and cost increase significantly
Solution Approach 1:
The patent implements cyclic self-testing where the sensor alternates between normal operation mode and test mode. During each cycle, a signal path is temporarily isolated for testing while others remain operational. This periodic testing approach ensures fault detection capability without requiring all paths to be simultaneously redundant, thus maintaining reliability while reducing device complexity and size.
Solution Approach 2:
The sensor performs self-diagnosis by using its own internal resources (test signal generator, path couplers, evaluator) to test its signal paths without external intervention. This self-service capability allows the sensor to autonomously detect faults in its signal channels, improving reliability monitoring without adding external redundant systems that would increase complexity.
2Reliability
If constant self-testing is performed on all signal paths, then reliability is improved, but cost and energy consumption increase
Solution Approach 1:
Instead of continuous testing of all signal paths, the patent implements periodic cyclic testing where each path is tested in turn during dedicated time intervals. The sensor alternates between operational phases and test phases, reducing energy consumption compared to constant simultaneous testing of all paths while still maintaining reliable fault detection through regular periodic assessment.
Solution Approach 2:
The patent tests signal paths partially and sequentially rather than all at once. During any given test cycle, only one or a subset of signal paths is isolated and tested while others remain in service. This partial testing approach reduces the energy and resource requirements compared to exhaustive simultaneous testing of all paths, while still providing comprehensive fault detection over time.
3Measurement precision
If signal paths are isolated for thorough testing, then measurement precision is improved, but productivity decreases due to temporary service interruption
Solution Approach 1:
The patent implements periodic cyclic testing where signal paths are isolated for thorough assessment during dedicated test intervals, then returned to service. This periodic approach allows comprehensive testing that improves measurement precision while limiting service interruption to specific time windows rather than continuous downtime, thus balancing assessment accuracy with operational productivity.
Solution Approach 2:
The sensor performs preliminary testing and validation of signal paths during cyclic intervals before they are fully deployed into service. By conducting thorough assessments in advance during the isolation phase, the system ensures signal path reliability is verified beforehand, improving measurement precision while minimizing the impact on ongoing productivity since paths are validated before critical use.
Data Source
AI summary
A system and method are disclosed to test signal paths within sensor signal channels by providing an additional signal channel having testing means. The additional signal channel has a test signal generator, a test signal evaluator, and a signal path that is provided in parallel to existing signal paths within the sensor. Signal paths between each sensing element and each output are manipulated by input and output path couplers so that sense signals always reach the correct outputs but the intermediary signal path(s) may be changed according to a self-test protocol. In particular, the signal path(s) may be selected for cyclical testing. The signal path under test is subjected to test signals from the test signal generator which are then evaluated by the test signal evaluator for correctness, and faults signaled. The test signals may be selected to test each signal processing function in the signal path.