HFR-Video-Based Chatter Monitoring Synchronized With Tool Rotation

This study presents a high-frame-rate (HFR) video-based chatter monitoring approach for high-speed rotating tools, utilizing the digital image correlation (DIC) method with sub-pixel-accurate vibration monitoring through synchronized HFR imaging to ensure consistent tool appearance. By using an HFR camera as virtual vibration sensors, it addresses the limitations of conventional accelerometer-based monitoring, enabling vibration distribution analysis without physical attachment to the tool. To verify this approach, chatter vibrations in the kHz range were recorded during cutting using an end mill operating at 6720 rotation per minute, with a length of 80 mm and a diameter of 16 mm, and 1024×1024 images at 4480 fps, synchronization with 40 times the tool’s rotational speed, which enabled visualization of vibration distributions across 23 measurement points, from the root to the top of the rotating tool. The experimental results demonstrate that the rotation-synchronized HFR vision-based method accurately measures chatter vibrations in the kHz range, particularly 1620–1660 Hz, with sensitivity equal to or greater than that of accelerometers. This approach eliminates variations in appearance and vibrations caused by rotation, enabling precise visualization of chatter intensity and the progression of vibration distribution, amplitude, and frequency as the axial depth increases on a workpiece.