Proximity Sensor Fault Diagnosis Using Cross-Sensor Electromagnetic Coupling
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Solution Overview
Problem
Existing fault diagnostic methods for proximity sensors, such as those using capacitive sensors on steering wheels, require additional estimation means, leading to increased processing loads and costs.
Innovation Solution
A proximity sensor system with multiple sensors and a fault diagnostic device that diagnoses sensor faults by setting at least two sensors as oscillating and diagnostic targets, measuring electrical characteristics, and comparing voltage frequencies and levels to diagnose faults using electromagnetic waves.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If additional estimation means are used to diagnose proximity sensor faults, then diagnostic accuracy is improved, but device complexity and processing load increase
Solution Approach 1:
The proximity sensor system performs self-diagnosis by using its own sensors to detect electromagnetic waves generated by other sensors in the system. Each sensor can serve both as a diagnostic tool and as a sensor under test, eliminating the need for external estimation means while maintaining diagnostic accuracy
Solution Approach 2:
The proximity sensors are designed to perform multiple functions: they can detect proximity of objects during normal operation and simultaneously serve as electromagnetic wave sources and detectors for fault diagnosis. This multi-functionality allows the system to diagnose faults without adding separate estimation means
2Reliability
If multiple proximity sensors are used for simultaneous proximity detection and fault diagnosis, then diagnostic capability is improved, but processing load increases
Solution Approach 1:
The system periodically switches between normal proximity detection mode and fault diagnosis mode. During diagnosis, sensors are sequentially activated to generate electromagnetic waves for testing other sensors, rather than continuously operating all sensors in both modes simultaneously. This periodic switching reduces the overall processing load while maintaining diagnostic capability
Solution Approach 2:
The fault diagnosis process is merged with the normal operation of proximity sensors. The same hardware components and processing units are used for both proximity detection and fault diagnosis, eliminating the need for separate processing paths and reducing overall processing load
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
Facilitates accurate and efficient fault diagnosis in proximity sensors with a simple configuration, enabling simultaneous detection of proximity and fault identification, contributing to sustainable transportation systems.
Implementation Method 1
a power circuit that applies voltage at an oscillation frequency to the electrode
Implementation Method 2
a measuring circuit that measures electrical characteristics of the electrode... acquires a result of measuring the electrical characteristics with the measuring circuit of the diagnostic target, while the power circuit of the oscillating target is generating electromagnetic waves
Data Source
AI summary
A proximity sensor system includes: a plurality of proximity sensors 4 to 7; and a fault diagnostic device 8 that diagnoses the presence or absence of faults in the proximity sensors 4 to 7. Each of the proximity sensors 4 to 7 includes: an electrode 40 to 70; a power circuit 45 that applies voltage at an oscillation frequency to the electrodes; and a measuring circuit 46 that measures electrical characteristics of the electrodes. The fault diagnostic device 8 sets at least two of the proximity sensors as an oscillating target and a diagnostic target, acquires a result of measuring the electrical characteristics with the measuring circuit of the diagnostic target, while the power circuit of the oscillating target is generating electromagnetic waves at the oscillation frequency. The fault diagnostic device 8 diagnoses the presence or absence of faults in the diagnostic target, based on the result of measurement.