Video Operating Deflection Shape (Video ODS)
Video Operating Deflection Shape (Video ODS) is an advanced vibration analysis technique that uses high-speed or high-resolution video to visualize how equipment moves during operation. Unlike traditional ODS, which relies on multiple sensor measurements, Video ODS captures motion directly and converts it into a measurable, animated deflection shape.
This method allows analysts to see vibration behavior in real time, making it especially useful for identifying structural issues that are difficult to diagnose using conventional vibration data alone.
How Video ODS Works
- A camera records the machine or structure while it is operating
- Software tracks movement of multiple points in the video
- Motion is processed and amplified to reveal small deflections
- The result is an animated visualization of vibration at specific frequencies
No physical sensors are required on the structure, although reference data (such as speed or phase) may be used to enhance accuracy.
What Video ODS Shows
Video ODS provides:
- Full-field visualization of machine motion
- Relative displacement between components
- Structural flexing, twisting, or rocking
- Amplified motion at specific frequencies
This makes it particularly effective for identifying issues that are not obvious from point measurements alone.
Key Advantages
- Non-contact measurement (no sensor mounting required)
- Rapid setup and data collection
- Ability to analyze large or inaccessible structures
- Immediate visual confirmation of vibration behavior
Limitations
- Lower accuracy compared to sensor-based ODS for quantitative measurements
- Requires stable lighting and clear line-of-sight
- Best suited for low to moderate frequency ranges
- May require reference data for precise frequency isolation
Practical Application – Structural Resonance
A pump skid exhibits high vibration levels, but standard spectrum analysis does not clearly indicate the root cause.
Video ODS is performed at running speed:
- The video reveals the base structure flexing significantly at one corner
- Motion is amplified, showing a clear “rocking” mode shape
This confirms a structural resonance / compliant base condition, not a rotor imbalance.
Corrective action (stiffening the base and improving support) reduces vibration to acceptable levels.
When to Use Video ODS
Video ODS is particularly effective when:
- Structural issues are suspected
- Traditional measurements are inconclusive
- Large surfaces or multiple components are involved
- A visual explanation is needed for decision-making
Application
Video ODS supports:
- Visualization of operating deflection shapes without sensors
- Identification of structural weaknesses and resonance
- Rapid troubleshooting of complex vibration problems
- Communication of findings through clear visual evidence
By combining motion visualization with vibration analysis, Video ODS provides a powerful tool for understanding how equipment behaves in real operating conditions.