AD Converter Current-Sum Fault Detection for Motor Signal Processing
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Solution Overview
Problem
Existing signal processing devices for AD converters require a large number of channels to detect failures, leading to increased parts and wiring complexity, especially when dealing with multiple current paths in motor systems.
Innovation Solution
A signal processing device with two to N independently provided AD converters calculates a current sum value from the converted signals, determining an abnormality when the absolute value exceeds a threshold, reducing the total number of channels needed to N to (2N−1) and allowing for efficient abnormality determination using fewer channels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If redundant input of same analog signal to two independent AD converters is used for failure detection, then reliability of failure detection is improved, but device complexity and wiring complexity increase
Solution Approach 1:
The patent uses digital copying of sensor signals between AD converters instead of physical analog signal copying. The signal processing device generates a copy of the digital output from a first AD converter and compares it with the output from a second AD converter, eliminating the need for redundant analog wiring while maintaining failure detection reliability
Solution Approach 2:
The patent replaces the mechanical/analog signal path with a digital signal processing approach. Instead of physically routing analog signals through multiple converters, the system uses digital signal copying and processing to achieve the same failure detection function, reducing wiring complexity
2Measurement precision
If multiple AD converters with multiple channels are used to monitor all current paths, then measurement completeness is improved, but device complexity and parts quantity increase
Solution Approach 1:
The patent makes the AD converter system multi-functional by enabling a single converter to serve multiple purposes through digital signal copying. The first AD converter's output is copied and used for both normal processing and failure detection comparison, allowing the system to monitor all current paths effectively without requiring additional dedicated converters for each path
Solution Approach 2:
The patent merges the failure detection function with the normal signal processing function. By copying digital signals within the same processing device and using comparison logic, the system combines monitoring and processing functions, reducing the total number of separate parts needed while maintaining complete current path monitoring
3Measurement precision
If N AD converters each with N channels are used to convert N sensor signals, then conversion completeness is improved, but device complexity increases
Solution Approach 1:
The patent applies partial action by using only N channels instead of the full N×N channels that would be required for complete redundant conversion. The system converts N sensor signals using N channels of AD converters, which is sufficient for the application, and uses digital signal copying rather than full physical redundancy, thereby reducing device complexity while maintaining conversion completeness
Data Source
AI summary
A signal processing device includes two to N pieces of AD converters provided independently of one another and each having at least one channel to which the sensor signal is input. The signal processing device is configured to calculate a current sum value as a sum of the N pieces of the converted signals corresponding to currents flowing in and out of the connection point with respect to the converted signals output from the AD converters and, when an absolute value of the current sum value is greater than a determination threshold, determine that any of channels of any of the AD converters is abnormal.