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Meta-frequency modulation in LQR vibration control with chirp excitation
Simone Mesbahi1, Nicola Roveri2, Silvia Milana1
1Department of Mechanical and Aerospace Engineering, La Sapienza University, Via Eudossiana 18, 00184, Rome, Italy.
Scientific Reports
|April 16, 2025
Summary
This study demonstrates indirect control of inertial properties using tunable dampers. Semi-active control manipulates damping to prevent resonance and introduces a novel meta-frequency modulation phenomenon.
Area of Science:
- Mechanical Engineering
- Control Systems Engineering
- Vibration Analysis
Background:
- Traditional vibration control often relies on passive elements.
- Semi-active control offers adaptable damping characteristics.
- Understanding the dynamic response of complex systems is crucial for effective control.
Purpose of the Study:
- To investigate the indirect control of inertial properties in a rigid body system.
- To analyze the impact of semi-actively modified damper viscosity on system response.
- To introduce and define a novel phenomenon termed meta-frequency modulation.
Main Methods:
- Utilizing Linear Quadratic Regulator (LQR) optimal control logic.
- Employing Hilbert-Huang Transform (HHT) for system response analysis.
- Implementing an iterative LQR scheme with chirp excitations on a 2-degree-of-freedom (2-d.o.f.) Toy Model.
Main Results:
- Demonstrated manipulation of equivalent mass and natural frequency by adjusting damping coefficients.
- Successfully prevented resonance through optimal damping control.
- Identified and characterized meta-frequency modulation, a new phenomenon in controlled systems.
Conclusions:
- Semi-active control of damper viscosity provides a viable method for indirect inertial property manipulation.
- The Hilbert-Huang Transform is effective in elucidating the cause-and-effect relationship in complex control scenarios.
- Meta-frequency modulation represents a significant nonlinear distortion in optimally controlled systems, distinct from passive optimization.
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