Flywheel proof mass actuator for active vibration control

This paper presents the experimental results of a new proof mass actuator for the implementation of velocity feedback control loops to reduce the flexural vibration of a thin plate structure. Classical proof mass actuators are formed by coil–magnet linear motors. These actuators can generate constant force at frequencies above the fundamental resonance frequency of the spring–magnet system, which can be used to efficiently implement point velocity feedback control loops. However, the dynamics of the spring–magnet system limit the stability and control performance of the loops when the actuators are exposed to shocks. The proof mass actuator investigated in this paper includes an additional flywheel element that improves the stability of the velocity feedback loop both by increasing the feedback gain margin and by reducing the fundamental resonance frequency of the actuator. This paper is focused on the stability and control performance of decentralized velocity feedback control loops

Velocity feedback control with a flywheel proof mass actuator

This paper presents four new proof mass actuators to be used in velocity feedback control systems for the control of vibrations of machines and flexible structures. A classical proof mass actuator is formed by a coil\u2013magnet linear motor, with either the magnet or the armature-coil proof mass suspended on soft springs. This arrangement produces a net force effect at frequencies above the fundamental resonance frequency of the springs\u2013proof mass system. Thus, it can be used to implement point velocity feedback loops, although the dynamic response and static deflection of the springs\u2013proof mass system poses some stability and control performance limitations. The four proof mass actuators presented in this study include a flywheel element, which is used to augment the inertia effect of the suspended proof mass. The paper shows that the flywheel element modifies both the dynamic response and static deflection of the springs\u2013proof mass system in such a way as the stability and control performance of velocity feedback loops using these actuators are significantly improved

Flywheel proof mass transducer for energy harvesting applications

This paper introduces a new flywheel coil\u2013magnet proof mass transducer for vibration energy harvesting. The seismic transducer presented in this paper includes an additional flywheel element that produces three effects on the elastically suspended proof mass: firstly, it lowers the fundamental resonance frequency, secondly it lowers the static displacement and thirdly it lowers the mechanical damping effect. The combination of all three effects is beneficial for vibration energy harvesting applications. In fact, having a low resonance frequency transducer facilitates the tuning of the harvester to a low frequency band where ambient vibration energy is normally higher. Also, having a low static displacement of the proof mass element allows the construction of a device robust to shocks and fast movements despite it has a low fundamental resonance frequency. Finally, having a low internal mechanical damping leaves more energy for the conversion to electrical energy. The paper presents both simulations and experimental results that contrast the principal electro-mechanical properties and the energy harvesting effects of classical and proposed flywheel coil\u2013magnet proof mass transducers connected to a purely resistive load