Physical Quantity Detection Circuit With Resonance-Masked Failure Diagnosis
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Solution Overview
Problem
Existing physical quantity detection devices are prone to erroneous failure diagnosis due to resonance caused by mechanical impacts or vibrations, leading to incorrect detection of failures even when the device is functioning correctly.
Innovation Solution
A physical quantity detection circuit and device that includes an amplifier circuit, failure diagnosis signal output circuit, mask signal output circuit, and disabling determination circuit to accurately diagnose failures by comparing signal levels with set detection levels and disabling false failure flags.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If failure diagnosis is performed based on signal levels from amplifiers, then reliability of failure detection is improved, but false diagnoses occur due to resonance from mechanical impacts or vibrations
Solution Approach 1:
The patent changes the parameter of signal level thresholds by introducing multiple detection levels (first detection level and second detection level) instead of a single threshold. This allows the system to adapt to different signal conditions and distinguish between normal resonance and actual failures, thereby improving measurement precision without sacrificing reliability
Solution Approach 2:
The patent introduces a mask signal as an intermediary element that mediates between the failure diagnosis result and the final failure flag output. The mask signal temporarily suppresses false failure flags during resonance conditions, allowing the system to maintain reliable failure detection while avoiding false positives caused by mechanical impacts or vibrations
2Measurement precision
If detection sensitivity is increased to detect actual failures, then failure detection capability is improved, but false failure flags are generated during normal operation with resonance
Solution Approach 1:
The patent performs preliminary action by generating a mask signal in advance based on comparison with the first detection level before the failure diagnosis result is finalized. This preliminary mask signal generation prevents false failure flags from being generated in the first place during resonance conditions, rather than correcting them after generation
Solution Approach 2:
The patent uses two different detection levels (first detection level for mask signal generation, second detection level for failure diagnosis) to create a hysteresis effect. This parameter differentiation allows the system to be sensitive enough to detect actual failures while maintaining reliability by requiring a higher threshold for confirming failure conditions
Data Source
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AI summary
A physical quantity detection circuit includes: a physical quantity detection signal output circuit that includes an amplifier circuit that amplifies a signal output from a physical quantity detection element, and outputs a physical quantity detection signal corresponding to a physical quantity; a failure diagnosis signal output circuit that outputs a failure diagnosis signal based on a signal output from at least one of a plurality of amplifiers included in the amplifier circuit; a failure diagnosis circuit that performs failure diagnosis based on the failure diagnosis signal and outputs a failure flag indicating a result of the failure diagnosis; a mask signal output circuit that compares a level of a signal output from each of the plurality of amplifiers with each of a plurality of set detection levels and outputs a mask signal based on a result of the comparison; and a disabling determination circuit that disables the failure flag based on the mask signal.