Rotating Component Diagnosis Using Low-Current Signal Windows
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing diagnostic systems for rotating components in electric vehicles face challenges in accurately detecting mechanical failures due to electromagnetic interference, which distorts sensor data, leading to operational disruptions and safety concerns.
Innovation Solution
A diagnostic system that records sensor data only when the electric current between the inverter and motor is minimal, eliminating interference, and compares the data with reference signals to detect deviations exceeding predetermined thresholds, thereby accurately identifying mechanical abnormalities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If sensor data is continuously recorded during motor operation, then monitoring coverage is improved, but measurement precision deteriorates due to electromagnetic interference from inverter switching
Solution Approach 1:
The diagnostic system implements periodic monitoring by alternating between measurement phases (when motor current is below threshold and electromagnetic interference is minimal) and non-measurement phases (when motor current exceeds threshold and interference is present). This periodic action allows the system to capture vibration signals only during low-interference intervals, maintaining measurement precision while achieving comprehensive monitoring coverage over time.
Solution Approach 2:
The system performs preliminary assessment of motor current magnitude before initiating vibration signal recording. By checking whether the absolute value of motor current is below the predetermined threshold, the system proactively determines suitable measurement windows in advance, preventing recording during high-interference periods and thus preserving signal quality.
2Productivity
If vibration signals are recorded during high current operation, then productivity is improved, but reliability deteriorates due to electromagnetic interference causing false diagnoses
Solution Approach 1:
The system dynamically changes the operational parameter of signal recording based on the motor current magnitude. When the absolute value of motor current exceeds the predetermined threshold, the system suspends vibration signal recording to avoid capturing interference-corrupted data. When current drops below the threshold, recording resumes. This parameter-based control ensures high diagnosis accuracy by exclusively recording signals during low-interference conditions.
3Ease of operation
If frequency filters are used to remove interference, then ease of operation is improved, but measurement precision deteriorates because interference frequencies are too close to signal frequencies
Solution Approach 1:
Instead of attempting to filter out interference frequencies from the mixed signal, the system extracts only the pure vibration signals by recording exclusively during periods when electromagnetic interference is absent (when motor current is below threshold). This extraction approach avoids the precision loss inherent in frequency filtering methods, as no signal processing is needed to separate overlapping frequencies.
Data Source
Figure 1
Figure 2a~2d
Figure 3
AI summary
The herein described subject matter relates to a method and a diagnostic system 10 for precisely and reliably diagnose mechanical failures of rotating components in a rotation machine for electric vehicles. For this purpose, a measuring signal of at least one sensor 4, 4a, 4b, 4c mounted on a rotating component is recorded by the diagnostic system 10 if the absolute value of a electric current between the at least one inverter and at least one electric motor 1 is equal to or below a predetermined current value.