3D stereo imaging enables accurate non-contact vibration measurement of hovering multicopters

Gilching, Germany, October 7, 2025 – Multicopter drones are unmanned aerial vehicles that use multiple rotors for lift and propulsion, rather than a single large rotor like traditional helicopters. Multicopters are highly agile, allowing aggressive maneuvering, hovering, and rapid direction changes by varying the speed of the individual rotors. Their agile maneuverability made multicopters popular for aerial photography, infrastructure inspection, surveying, agriculture, search and rescue operations, and more.


Multicopters, like other drones, vibrate during flight. Excessive vibration can reduce the stability of the multicopter, resulting in reduced flight time, premature component deterioration, and other negative effects.


To better understand vibration distribution during flight, engineers from Hiroshima University (Hiroshima Prefecture) proposed a model-tracking 3D-DIC vibration measurement method that uses two Mikrotron EoSens 2.0CXP 2 cameras to visualize a hovering multicopter from the ground. By applying digital image correlation (DIC) to the camera’s 500 frames per second stereo 1920 x 1080 pixel images, engineers achieved accurate 3D vibration analysis based on thousands of tracked measurement points. Identifying areas of severe vibration during multicopter flight can detect potential structural anomalies that require maintenance or repair.

Experimental setup

For testing, Hiroshima University engineers used a DJI Mini 4 Pro quadcopter. Its surface has a random pattern drawn on it, and 12 black and white markers are affixed to the body to allow you to track the model frame by frame.


During the test, the researchers hovered the quadcopter two meters above the lab floor, spinning its rotors at about 100 revolutions per second. Two Mikrotron EoSens 2.0CXP2 cameras equipped with 50mm lenses were placed on the ground surrounded by LED lights. A 1920 x 1080 pixel stereo 8-bit RGB image was captured for 10 seconds at 500 fps with an exposure time of 1.0 ms. Images were transmitted from the Mikrotron camera to the PC via a CXP-12 quad frame grabber. The processing PC was equipped with an Intel Core i9-13900K 3.00GHz CPU, NVIDIA GeForce RTX 2080 Ti, and Windows 11 Professional 64-bit as the OS.


A highly detailed 3D point cloud that digitally represents the quadcopter’s surface was generated using a ZEISS 3D scanner measuring 953,038 points. We then resampled each cloud to reduce the number of measurement points for the 3D software sensor to 3518 points. This step enabled visualization of frequency domain 3D images up to 250 Hz.


Color mapping of the 3D image clearly identified the local region of the vibrating quadcopter and the frequency intensity of that region. Frequency (Hz) refers to vibration cycles per second, or the rate at which vibrations occur. Intensity, on the other hand, refers to the amplitude, or strength, of vibration.

conclusion

Using a hovering multicopter and two Microtron cameras, Hiroshima University engineers were able to validate a 3D-DIC vibration measurement method that isolates local vibration frequencies and intensities critical to flight stability, safety, and reliability. Unlike accelerometers and strain gauges, the 3D-IDC method is not limited by mounting location restrictions. Also, since it is non-contact, it does not affect flight performance.


Going forward, engineers plan to enhance the system to gain deeper insight into flight dynamics and structural behavior.

About Mikrotron, a brand of SVS-Vistek GmbH

SVS-Vistek GmbH has acquired 100% of the shares of Mikrotron GmbH with retroactive effect from January 1, 2022. Through the merger of the two companies under the TKH Vision umbrella, both companies will combine their respective strengths and capabilities and position camera expertise with a strong entrepreneurial spirit.

Mikrotron, now branded SVS-Vistek, is internationally renowned as a compact and particularly robust high-speed camera for the industrial imaging market. Digital high-speed cameras have excellent technical performance characteristics and are widely used not only in industrial and scientific applications, but also in the fields of sports, advertising and nature filmmakers.

SVS-Vistek GmbH is a TKH technology company. TKH Group NV (TKH) is a leading technology company focused on advanced innovative technology systems in high-growth markets. Its mission is to create best-in-class technology in the areas of smart vision systems, smart manufacturing systems, and smart connectivity systems. TKH employs more than 6,000 FTE employees and operates around the world, with growth concentrated in Europe, North America, and Asia. TKH is listed on Euronext Amsterdam under the ticker symbol TWEKA. TKH reports on three segments: Smart Vision Systems, Smart Manufacturing Systems, and Smart Connectivity Systems.