Active vibration control

About: Active vibration control is a research topic. Over the lifetime, 6770 publications have been published within this topic receiving 76599 citations. The topic is also known as: active vibration damping.

Quantitative measurements of vibration amplitude using a contact-mode freestanding triboelectric nanogenerator.

Abstract: A vibration sensor is usually designed to measure the vibration frequency but disregard the vibration amplitude, which is rather challenging to be quantified due to the requirement of linear response. Here, we show the application of triboelectric nanogenerator (TENG) as a self-powered tool for quantitative measurement of vibration amplitude based on an operation mode, the contact-mode freestanding triboelectric nanogenerator (CF-TENG). In this mode, the triboelectrically charged resonator can be agitated to vibrate between two stacked stationary electrodes. Under the working principle with a constant capacitance between two electrodes, the amplitudes of the electric signals are proportional to the vibration amplitude of the resonator (provided that the resonator plate is charged to saturation), which has been illuminated both theoretically and experimentally. Together with its capability in monitoring the vibration frequency, the CF-TENG appears as the triboelectrification-based active sensor that can gi...

Bearing induced vibration in precision high speed routing spindles

Abstract: This paper presents a detailed model of bearing vibration, including the effect of contact spring non-linearity in balls-to-raceways' contacts. The model incorporates the effect of surface waviness of rolling elements and off-sized balls upon the dynamic internal radial clearance of the bearing. The vibration forces and moments generated are formulated and the significant principal and secondary side-band contributions are highlighted. This model is employed successfully in the recognition of complex real-time vibration spectra of a precision routing spindle, obtained by accurate non-contact sensors.

Six degree-of-freedom active vibration control using the Stewart platforms

Abstract: Multiple degree-of-freedom (DOF) vibration control systems are essential for precision control of a wide range of Space-borne structures as well as earth-based systems. This paper studies the design and control problems of a class of multiple DOF vibration isolation systems using the concept of a Stewart truss and Stewart platform mechanism. A novel geometric arrangement of a Stewart platform, called the "cubic configuration" is developed and used. A new design and analysis of actuators employing magnetostrictive material Terfenol-D is presented. Robust adaptive filter algorithms for active vibration control are formulated. Prototype hardware for a six degree-of-freedom active vibration isolation system with the "cubic configuration" of the Stewart platform has been implemented and tested. About 30 dB of vibration attenuation is achieved in real-time experiments. >

Active vibration control of beams with optimal placement of piezoelectric sensor/actuator pairs

Abstract: This paper considers the optimal placement of collocated piezoelectric actuator?sensor pairs on flexible beams using a model-based linear quadratic regulator (LQR) controller. A finite element method based on Euler?Bernoulli beam theory is used. The contributions of piezoelectric sensor and actuator patches to the mass and stiffness of the beam are considered. The LQR performance is taken as the objective for finding the optimal location of sensor?actuator pairs. The problem is formulated as a multi-input multi-output (MIMO) model control. The discrete optimal sensor and actuator location problem is formulated in the framework of a zero?one optimization problem which is solved using genetic algorithms (GAs). Classical control strategies like direct proportional feedback, constant gain negative velocity feedback and the LQR optimal control scheme are applied to study the control effectiveness. The study of the optimal location of actuators and sensors is carried out for different boundary conditions of beams like cantilever, simply supported and clamped boundary conditions.

Inverse feedforward controller for complex hysteretic nonlinearities in smart-material systems

Abstract: Undesired complex hysteretic nonlinearities are present to a varying degree in virtually all smart-material-based sensors and actuators provided they are driven with sufficiently high amplitudes. In motion and active vibration control applications, for example, these nonlinearities can excite unwanted dynamics, which leads in the best case to reduced system performance and in the worst case to unstable system operation. This necessitates the development of purely phenomenological models that characterize these nonlinearities in a way that is sufficiently accurate, amenable to a compensator design for actuator linearization, and efficient enough for use in real-time applications. To fulfil these demanding requirements, this article describes a new compensator design method for invertible complex hysteretic nonlinearities that is based on the so-called Prandtl-Ishlinskii hysteresis operator. The parameter identification of this model can be formulated as a quadratic optimization problem, which produces the best L 2 2 -norm approximation for the measured output-input data of the real hysteretic nonlinearity. Special linear inequality constraints for the parameters guarantee the unique solvability of the identification problem and the invertability of the identified model. This leads to a robustness of the identification procedure against unknown measurement errors, unknown model errors, and unknown model orders. The corresponding compensator can be directly calculated and thus efficiently implemented from the model by analytical transformation laws. Finally, the compensator design method is used to generate an inverse feedforward controller for the linearization of a magnetostrictive actuator. In comparision to the conventionally controlled magnetostrictive actuator, the nonlinearity error of the inverse controlled magnetostrictive actuator is lowered from about 30% to about 3%.