Hybrid skyhook mass damper

Abstract

The objective of this study is to increase the efficiency of an initial passive Tuned Mass Damper (TMD) by adding an active control unit. A critical issue in many engineering domains is the design of fail-safe active systems. The proposed hybrid system aims to address this issue and realizes the said objective. It emulates the behavior of a skyhook damper parallel to a passive TMD. Skyhook dampers acts like viscous dampers connected to the ground, reducing the vibration amplitudes without any overshoot. It can be difficult to design a specific control law to obtain a desired dynamical behavior. The paper presents two ways to understand and design the hyperstable control law for Hybrid Mass Damper (HMD) (also called Active TMD), using the power flow formulation or the mechanical impedance analysis. These approaches are illustrated through the synthesis of this hybrid device and the emulation of the Skyhook damper. It is shown that a well-designed control law for this kind of system may result in high damping performance, ensuring stability and a fail-safe behavior. In addition, the amplitude of the primary system’s response is reduced over the entire frequency range which is not the case for the usual active or hybrid systems. Robustness is analyzed and compared to that of the classical active mass damper, and an experimental set up validates the proposed hybrid system.

Torsional active-passive dampers on rotational machinery

“…The emulation of such a damper is accomplished by matching the desired damper behavior to the equation of motion of the actuator. The process is fully described in (Chesné, 2022), and gives the following filter equation: The result is very close to the previous equation ( 4), when (𝑠 + 𝛼) 2 is expended, and the parameter 𝛼 set to its optimal value 2𝜋𝑓 𝑐 . The second "damping" term is on the contrary quite different.…”

“…The emulation of such a damper is accomplished by matching the desired damper behavior to the equation of motion of the actuator. The process is fully described in (Chesné, 2022) and gives the following filter equation:…”

“…Hyperstable control laws, presenting infinite gain margin, are therefore very useful on such hybrid devices but it is not always easy to adapt them to the real systems. Recent research has proved two of them to be both efficient and easy to implement (pole placement α-HMD strategy (Chesné and Collette, 2018) and Skyhook damper emulation (Chesné, 2022)), even though the theoretical hyperstability has been lost during the experiment (despite very high remaining stability margins). However, experiments on these two control laws have been conducted only on bending vibrations.…”

Active Tuned Mass Damper: Sky-hook synthesis

“…Contrary to many hybrid controllers, no response amplifications are observed. More details are given in [10].…”

Nonlinear vibration of a sliding-mode-controlled structure: Simulation and experiment

“…There is also a hybrid approach that combines both active and passive techniques. The hybrid approach ensures a "fail-safe" characteristic, whereby the passive component continues to dampen vibrations if the energy supply to the active component is disrupted [9,10]. For the purpose of this paper, we focus on the active method.…”