Adaptive Suppression of High-Frequency Wide-Spectrum Vibrations With Application to Disk Drive Systems

2014 ◽  
Author(s):  
Liting Sun ◽  
Xu Chen ◽  
Masayoshi Tomizuka
Keyword(s):  
High Frequency ◽  
Vibration Suppression ◽  
Wide Spectrum ◽  
Disk Drive ◽  
Parameter Adaptation ◽  
Spectral Peaks ◽  
Drive Systems ◽  
Vibration Compensation ◽  
Very High Frequencies ◽  
Peak Widths

In the big-data era, requirements for storage capacity and access speed in modern Hard Disk Drive (HDD) systems are becoming more and more stringent. As the track density of HDDs increases, vibration suppression of the recording arm in HDDs is becoming more challenging. Vibrations in modern HDDs are environment/product-dependent with different frequency characteristics. Furthermore, they can occur at very high frequencies with wide spectral peaks. This paper presents an adaptive algorithm to identify and suppress these high-frequency wide-spectrum vibrations. We design a vibration-compensation controller based on an adaptive disturbance observer (DOB), and devise parameter adaptation algorithms not only for the vibration frequencies but also for the spectral peak widths of the vibration. The peak-width parameters are adaptively tuned online to maximally attenuate the vibration with minimal error amplifications at other frequencies. The proposed algorithm is verified by simulations of HDDs for the problem of suppressing high-frequency wide-spectrum vibrations.

scholarly journals Strain Sensing With Piezoelectric Zinc Oxide Thin Films for Vibration Suppression in Hard Disk Drives

2008 ◽  
Author(s):  
Sarah Felix ◽  
Stanley Kon ◽  
Jianbin Nie ◽  
Roberto Horowitz
Keyword(s):  
Vibration Suppression ◽  
Transfer Functions ◽  
Hard Disk Drives ◽  
Hard Disk ◽  
Disk Drive ◽  
Strain Sensing ◽  
Linear Quadratic ◽  
H2 Control ◽  
Hard Drives ◽  
Optimization Methodology

This paper describes the integration of thin film ZnO strain sensors onto hard disk drive suspensions for improved vibration suppression for tracking control. Sensor location was designed using an efficient optimization methodology based on linear quadratic gaussian (LQG) control. Sensors were fabricated directly onto steel wafers that were subsequently made into instrumented suspensions. Prototype instrumented suspensions were installed into commercial hard drives and tested. For the first time, a sensing signal was successfully obtained while the suspension was flying on a disk as in normal drive operation. Preliminary models were identified from experimental transfer functions. Nominal H2 control simulations demonstrated improved vibration suppression as a result of both the better resolution and higher sensing rate provided by the sensors.

Vibration suppression and energy transfer by parametric excitation in drive systems

2012 ◽  
Vol 226 (8) ◽  
pp. 2000-2014 ◽  
Author(s):  
Horst Ecker ◽  
Thomas Pumhössel
Keyword(s):  
Energy Transfer ◽  
Parametric Excitation ◽  
Vibration Suppression ◽  
Negative Impact ◽  
Energy Transfer Mechanism ◽  
Engineering Systems ◽  
Excitation Mechanism ◽  
Electrical Drive ◽  
Excitation Mechanisms ◽  
Drive Systems

Drive systems may experience torsional vibrations due to various kinds of excitation mechanisms. In many engineering systems, however, such vibrations may have a negative impact on the performance and must be avoided or reduced to an acceptable level by all means. Self-excited vibrations are especially unwanted, since they may grow rapidly and not only degrade the performance but even damage machinery. In this contribution it is suggested to employ parametric stiffness excitation to suppress self-excited vibrations. In the first part of the article we study the basic energy transfer mechanism that is initiated by parametric excitation, and some general conclusions are drawn. In the second part, a hypothetic drivetrain, consisting of an electrical motor, a drive shaft and working rolls is investigated. A self-excitation mechanism is assumed to destabilize the drive system. Parametric excitation is introduced via the speed control of the electrical drive, and the capability of stabilizing the system by this measure is investigated. It is shown that the damping available in the system can be used much more effectively if parametric stiffness excitation is employed.

Discrete-Time H-Infinity Synthesis of Frequency-Shaped Sliding Mode Control for Suppression of Vibration With Multiple Peak Frequencies

2016 ◽  
Author(s):  
Minghui Zheng ◽  
Masayoshi Tomizuka
Keyword(s):  
High Frequency ◽  
Sliding Mode ◽  
Disk Drive ◽  
Sliding Surface ◽  
Surface Dynamics ◽  
H Infinity ◽  
High Frequencies ◽  
Multiple Peak ◽  
Significant Performance ◽  
The Stability

Vibration with multiple large peaks at high frequencies may cause significant performance degradation and have become a major concern in modern high precision control systems. To deal with such high-frequency peaks, it is proposed to design a frequency-shaped sliding mode controller based on H∞ synthesis. It obtains an ‘optimal’ filter to shape the sliding surface, and thus provides frequency-dependent control allocation. The proposed frequency-shaping method assures the stability in the presence of multiple-peak vibration sources, and minimizes the weighted H∞ norm of the sliding surface dynamics. The evaluation is performed on a simulated hard disk drive with actual vibration sources from experiments, and the effectiveness of large vibration peak suppression is demonstrated.

scholarly journals Observation and a numerical study of gravity waves during tropical cyclone Ivan~(2008)

2013 ◽  
Vol 13 (4) ◽  
pp. 10757-10807 ◽  
Author(s):  
F. Chane Ming ◽  
C. Ibrahim ◽  
S. Jolivet ◽  
P. Keckhut ◽  
Y.-A. Liou ◽  
...  
Keyword(s):  
Tropical Cyclone ◽  
Gravity Waves ◽  
High Frequency ◽  
Lower Stratosphere ◽  
Numerical Study ◽  
Wide Spectrum ◽  
Spectral Characteristics ◽  
Background Wind ◽  
Quasi Biennial Oscillation ◽  
North East

Abstract. Activity and spectral characteristics of gravity-waves (GWs) are analyzed during tropical cyclone (TC) Ivan (2008) in the troposphere and lower stratosphere using radiosonde and GPS radio occultation data, ECMWF outputs and simulations of French numerical model Meso-NH with vertical resolution varying between 150 m near the surface and 500 m in the lower stratosphere. Conventional methods for GW analysis and signal and image processing tools provide information on a wide spectrum of GWs with horizontal wavelengths of 40–1800 km and short vertical wavelengths of 0.6–10 km respectively and periods of 20 min–2 days. MesoNH model, initialized with Aladin-Réunion analyses, produces realistic and detailed description of TC dynamics, GWs, variability of the tropospheric and stratospheric background wind and TC rainband characteristics at different stages of TC Ivan. In particular a dominant eastward propagating TC-related quasi-inertia GW is present during intensification of TC Ivan with horizontal and vertical wavelengths of 400–600 km and 1.5–3.5 km respectively during intensification. A wavenumber-1 vortex Rossby wave is identified as a source of this medium-scale mode while short-scale modes located at north-east and south-east of the TC could be attributed to strong localized convection in spiral bands resulting from wavenumber-2 vortex Rossby waves. Meso-NH simulations also reveal high-frequency GWs with horizontal wavelengths of 20–80 km near the TC eye and high-frequency GWs-related clouds behind TC Ivan. In addition, GWs produced during landfall are likely to strongly contribute to background wind in the middle and upper troposphere as well as the stratospheric quasi-biennial oscillation.

scholarly journals Supernarrow spectral peaks and high-frequency stochastic resonance in systems with coexisting periodic attractors

1994 ◽  
Vol 49 (2) ◽  
pp. 1198-1215 ◽  
Author(s):  
M. I. Dykman ◽  
D. G. Luchinsky ◽  
R. Mannella ◽  
P. V. E. McClintock ◽  
N. D. Stein ◽  
...  
Keyword(s):  
Stochastic Resonance ◽  
High Frequency ◽  
Spectral Peaks ◽  
Periodic Attractors

Vibration Suppression in a Tension-Aligned Structure Through Sequential Application and Removal of Constraints

2012 ◽  
Author(s):  
Tingli Cai ◽  
Ranjan Mukherjee ◽  
Alejandro R. Diaz
Keyword(s):  
Vibration Control ◽  
High Frequency ◽  
Vibration Suppression ◽  
Primary Role ◽  
Accurate Knowledge ◽  
Array Structure ◽  
System States ◽  
Aligned Array ◽  
Control Methodology

We present an efficient method for vibration suppression in a tension-aligned array structure using constraint actuators. The primary role of constraint actuators is to cyclically apply and remove constraints such that vibration energy is efficiently funneled into high-frequency modes of the structure, where it can be dissipated quickly and naturally due to high rates of damping. A cycle of constraint application and removal can never add energy and hence the method can potentially achieve vibration control without accurate knowledge of the system states. The vibration control methodology is applied to a tension-aligned array structure supported by a structure in compression. Our approach for vibration suppression has the potential to positively influence the development of tension-aligned architectures which are contemplated for large precision apertures in space.

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