A/D Converter Switching Circuit for Sensor Anomaly Detection
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Solution Overview
Problem
Existing A/D conversion devices face challenges in efficiently converting a large number of analog signals to digital signals without increasing the number of A/D converters and in providing a failure diagnosis function without additional circuits, while also being unable to detect anomalies in the A/D converters and connected devices.
Innovation Solution
An A/D conversion device that includes an A/D converter, switching circuits, and a control section which generates multiple output modes to independently manage analog signals, allowing for anomaly detection of the A/D converter and connected devices without increasing the number of A/D converters or adding additional circuits, by using switching circuits to output signals in different configurations and detecting anomalies based on voltage and resistance values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple A/D converters are used to convert multiple analog signals, then the number of analog signals that can be converted increases, but the device complexity and cost increase
Solution Approach 1:
The patent segments the conversion process into two distinct stages: first, multiple analog signals are converted to digital signals by individual A/D converters; second, the digital signals are multiplexed by a selection unit to output sequentially. This segmentation allows multiple signals to be processed with fewer A/D converters, resolving the contradiction between conversion capacity and device complexity
Solution Approach 2:
The patent implements periodic action through the selection unit that sequentially outputs digital signals from different A/D converters in a time-multiplexed manner. Each A/D converter converts analog signals continuously, but the output is periodic and sequential rather than simultaneous, allowing multiple signals to be handled with fewer converters while maintaining signal integrity
2Device complexity
If switching circuits are added to selectively switch multiple items of information to one A/D converter, then the number of A/D converters can be reduced, but the reliability decreases due to potential switch failures
Solution Approach 1:
The patent segments the signal path into dedicated conversion channels where each A/D converter operates independently without sharing switching components. This eliminates the single point of failure in the switch, improving reliability while the sequential output mechanism keeps the number of A/D converters manageable
Solution Approach 2:
The patent introduces a digital selection unit as an intermediary between multiple A/D converters and the output interface. This digital selector operates in the digital domain rather than analog switching, providing more reliable signal routing without the vulnerability of analog switch failures, thus resolving the reliability concern while maintaining device efficiency
3Reliability
If additional circuits are added to provide a failure diagnosis function, then the reliability can be improved, but the device complexity increases
Solution Approach 1:
The patent implements self-service diagnostics where the system automatically detects and reports failures of A/D converters and connected devices without requiring external diagnostic equipment. The control unit monitors the operational status of each component and generates failure information, enabling the system to diagnose itself and improving reliability without adding complex external diagnostic circuits
Solution Approach 2:
The patent establishes feedback loops where the control unit continuously monitors the output and operational status of A/D converters and connected devices. When anomalies are detected, the system provides feedback about the failure condition, enabling real-time diagnosis and improving reliability while using the existing control infrastructure rather than adding separate diagnostic circuits
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
Enables the conversion of multiple analog signals to digital signals without increasing A/D converter count and adds a failure diagnosis function with a simple additional circuit, while effectively detecting anomalies in the A/D converter and connected devices, improving signal conversion reliability.
Implementation Method 1
an A/D converter which converts analog electricity quantities of objects to be detected to digital quantities
Implementation Method 2
cause the output to the A/D converter to be pulled down by a resistor
Data Source
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AI summary
A mode in which a first switching element (42) and a second switching element (43) are turned off, and a first sensor (40) and a second sensor (41) are not connected, and in which a path of a second resistor (10) is placed in an on-state, and an anomaly of one of the resistors (8,10) connected to the A/D port (6a) is detected based on A/D conversion values.