Multimodal Large Language Model-Enabled Machine Intelligent Fault Diagnosis Method with Non-Contact Dynamic Vision
Zihan Lu1, Cuiying Sun2, Xiang Li1
1Key Laboratory of Education Ministry for Modern Design and Rotor-Bearing System, Xi'an Jiaotong University, Xi'an 710049, China.
Sensors (Basel, Switzerland)
|September 27, 2025
Summary
This study introduces a novel non-contact method for bearing fault diagnosis using event cameras and AI. It achieves high accuracy in identifying faults, improving equipment reliability in smart manufacturing.
Area of Science:
- Engineering
- Artificial Intelligence
- Sensor Technology
Background:
- Smart manufacturing requires high equipment reliability and availability.
- Traditional fault diagnosis methods using vibration sensors have limitations in adaptability, maintenance, and preprocessing.
- There is a need for advanced, non-contact fault diagnosis techniques.
Purpose of the Study:
- To pioneer the use of event camera data for bearing fault classification.
- To fine-tune a multimodal large model (Qwen2.5-VL-7B) using dynamic visual information for fault diagnosis.
- To establish a novel, end-to-end intelligent analysis paradigm for non-contact fault detection.
Main Methods:
- Utilized high-temporal-resolution dynamic visual information from an event camera.
- Processed sparse pulse events into event frames via time surface processing.
- Reconstructed event frames into high-temporal-resolution video using spatiotemporal denoising and ROI definition.
- Employed two LoRA fine-tuning strategies (Strategy A: OpenCV frame extraction; Strategy B: built-in video pipeline) with Qwen2.5-VL-7B for bearing fault classification.
Main Results:
- Achieved classification accuracies of 0.9247 (Strategy A) and 0.9540 (Strategy B).
- Demonstrated successful bearing fault classification under varying operating conditions and rotational speeds.
- Validated the effectiveness of non-contact sensing and end-to-end intelligent analysis for fault diagnosis.
Conclusions:
- Event camera-based dynamic visual information is effective for bearing fault diagnosis.
- The multimodal large model fine-tuned with event data offers a promising new paradigm for smart manufacturing.
- Non-contact sensing combined with advanced AI enables robust and efficient equipment health monitoring.

