The video shows the result of an experiment on the creation of a control system that reduces the amplitude of forced bending vibrations of a metal beam.
An aluminium beam 3 mm thick and 70 cm long is disposed vertically and fixed at one point near to the lower end.As a result of an external harmonic loading at the fixation point, the beam starts to vibrate.The largest vibration amplitude is observed at the upper end of the beam when excited at the frequency of the first resonance (about 7 Hz).
The control system includes piezoelectric sensors and actuators, which have the form of rectangular plates.In total, two sensor-actuator pairs are used, attached to both sides of the beam in two locations.The objective of the control system is to suppress beam vibrations at the two lowest resonance frequencies as much as possible.The purpose of the experiment is to compare local and modal approaches to active vibration control, and the result shows that modal control system works more efficiently.The video shows the result of turning on the modal control system when the beam vibrates at the first resonance: it can be seen that the vibration amplitude decreases by about 5 times.
The given references are devoted to the experimental and numerical comparison of various approaches to active control on the example of suppression of forced beam vibrations using piezoelectric sensors and actuators.

References:

1. Belyaev A.K., Fedotov A.V., Irschik H., Nader M., Polyanskiy V.A., Smirnova N.A. Experimental study of local and modal approaches to active vibration control of elastic systems // Structural Control and Health Monitoring. 2018. Vol. 25. No. 8. e2105.
2. A.K. Belyaev, V.A. Polyanskiy, N.A. Smirnova, A.V. Fedotov, Identification procedure in the modal control of a distributed elastic system, St. Petersburg Polytechnical State University Journal. Physics and Mathematics. 2017. Vol. 10. No. 2. Pp. 69-81.
3. A.V. Fedotov. The damping of the distributed system vibrations using piezoelectric transducers: simulation, St. Petersburg Polytechnical State University Journal. Physics and Mathematics. 2019. Vol. 12. No. 1. Pp. 142-155.
4. Fedotov A.V. Active vibration suppression of Bernoulli-Euler beam: experiment and numerical simulation // Cybernetics and Physics. 2019. V. 8. № 4. P. 228-234.
5. Fedotov А.V. Applicability of simplified models of piezoelectric elements in the problem of active vibration damping. Journal of Instrument Engineering. 2020. Vol. 63, N 2. P. 126-132 (in Russian).
6. Fedotov A.V. Shape Control and Modal Control Strategies for Active Vibration Suppression of a Cantilever Beam. In: Indeitsev D.A., Krivtsov A.M. (eds) Advanced Problem in Mechanics II. APM 2020. Lecture Notes in Mechanical Engineering. (2022) P. 234-244. Springer, Cham.
7. Fedotov A.V., Belyaev A.K., Polyanskiy V.A., Smirnova N.A. (2022). Local, Modal and Shape Control Strategies for Active Vibration Suppression of Elastic Systems: Experiment and Numerical Simulation. In: Polyanskiy, V.A., Belyaev, A.K. (eds) Mechanics and Control of Solids and Structures. Advanced Structured Materials, vol. 164. P. 151-169. Springer, Cham.