CAN Node Impedance Testing for Predictive Fault Location
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Solution Overview
Problem
Existing CAN bus systems struggle to detect and locate errors in message transmission, which often occur sporadically under specific environmental or interference conditions, leading to costly and unnecessary component replacements.
Innovation Solution
A CAN node with a CAN module that adjusts output impedance to simulate errors, allowing for the detection and prediction of potential transmission faults by sending test messages under reduced impedance and analyzing response signals to identify faulty branches.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional CAN bus error detection methods are used, then errors can be detected when they occur, but errors cannot be predicted before they occur and fault location cannot be determined
Solution Approach 1:
The system performs preliminary actions by reducing output impedance below normal operating levels to create stress conditions that reveal potential faults before they occur in normal operation. Test messages are sent under these reduced impedance conditions to proactively identify branches that will fail under normal or elevated load conditions, enabling predictive maintenance rather than reactive repair.
Solution Approach 2:
The system applies preliminary anti-action by intentionally creating adverse test conditions (reduced output impedance) that simulate worst-case scenarios. This allows the system to preemptively counteract potential transmission errors by identifying and flagging faulty branches before actual operational errors occur during normal vehicle operation.
2Reliability
If components are replaced to prevent sporadic errors, then system reliability may improve, but costs increase and unnecessary replacements occur
Solution Approach 1:
The system performs self-service by automatically identifying and locating faulty branches through impedance reduction testing and response message analysis. This eliminates the need for manual troubleshooting and component replacement, allowing the system to service itself by pinpointing exactly which branch requires attention, thereby avoiding unnecessary component replacements and reducing maintenance costs.
Solution Approach 2:
The system replaces mechanical troubleshooting and component replacement with an electrical diagnostic method. Instead of physically testing or replacing components, the system uses electrical impedance manipulation and message transmission analysis to identify faults, substituting a sophisticated electrical diagnostic approach for traditional mechanical maintenance practices.
3Measurement precision
If output impedance is reduced to test for errors, then potential faults can be revealed, but normal message transmission may be affected
Solution Approach 1:
The system applies dynamics by temporarily changing output impedance for diagnostic purposes and then restoring it to normal operating levels. The impedance is dynamically adjusted below normal levels during testing to reveal faults, then returned to standard levels for normal operation, allowing the system to adapt its electrical characteristics based on operational requirements rather than being fixed.
Solution Approach 2:
The system implements periodic action by conducting impedance reduction tests at scheduled intervals or under specific conditions rather than continuously. This allows normal message transmission to proceed undisturbed during most operation, with diagnostic testing performed periodically to identify potential faults without continuously affecting transmission reliability.
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 prediction of future transmission errors, reducing the need for unnecessary component replacements by identifying imminent faults before they occur, thus minimizing downtime and costs.
Implementation Method 1
the output impedance is reduced by the CAN module such that the output impedance corresponds to a test impedance
Data Source
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AI summary
The present invention relates to a CAN node being configured to predict, based on the at least one response message and a reference response, a fault of the CAN network and to determine a fault location of the predicted fault of the CAN network. The present disclosure also relates to a CAN system and a method for the CAN node.