Experimental Results of Adaptive Periodic Disturbance Cancellation in a High Performance Magnetic Disk Drive

Author(s):  
Alexei Sacks ◽  
Marc Bodson ◽  
Pradeep Khosla
1996 ◽  
Vol 118 (3) ◽  
pp. 416-424 ◽  
Author(s):  
Alexei Sacks ◽  
Marc Bodson ◽  
Pradeep Khosla

This paper considers the implementation of an adaptive algorithm for periodic disturbance cancellation. It is shown that the maximum rate of adaptation can be calculated precisely based on measurements of the system’s frequency response. The response of the closed-loop system to additional disturbances can also be computed on that basis. The results are verified experimentally on a high track density magnetic disk drive. Excellent matching between the theoretical and experimental results is observed. An improved method is also proposed that leads to faster convergence of the adaptive algorithm and better disturbance rejection capabilities. The results of this paper significantly enhance the ability of the control engineer to design and analyze adaptive feedforward algorithms for a variety of applications where periodic disturbances are encountered.


Author(s):  
Ne´stor O. Pe´rez Arancibia ◽  
Chi-Ying Lin ◽  
Tsu-Chin Tsao ◽  
James S. Gibson

This paper presents a control scheme for rejecting both repeatable and non-repeatable runout components of disturbances occurring in rotational devices. To exemplify this method, implementation and experimental results for track following control of a computer hard disk drive (HDD) read/write heads are presented. Aiming for high performance, the control design involves two steps. The first is the design and tuning of a recursive least-squares (RLS) based scheme intended to achieve minimum variance performance. The second step integrates repetitive and adaptive control schemes in a real-time implementation to compensate for variations and changes in the disturbance dynamics. The repetitive part of this controller targets specific periodic disturbances. The adaptive part compensates for broad bandwidth stochastic disturbances. The key element in this design is the formulation of an appropriate optimization problem, solvable recursively by applying recursive adaptive algorithms. Experimental results obtained from the implementation of this method in a commercial HDD demonstrates the effectiveness of this approach.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Mehdi Srifi ◽  
Ahmed Oussous ◽  
Ayoub Ait Lahcen ◽  
Salma Mouline

AbstractVarious recommender systems (RSs) have been developed over recent years, and many of them have concentrated on English content. Thus, the majority of RSs from the literature were compared on English content. However, the research investigations about RSs when using contents in other languages such as Arabic are minimal. The researchers still neglect the field of Arabic RSs. Therefore, we aim through this study to fill this research gap by leveraging the benefit of recent advances in the English RSs field. Our main goal is to investigate recent RSs in an Arabic context. For that, we firstly selected five state-of-the-art RSs devoted originally to English content, and then we empirically evaluated their performance on Arabic content. As a result of this work, we first build four publicly available large-scale Arabic datasets for recommendation purposes. Second, various text preprocessing techniques have been provided for preparing the constructed datasets. Third, our investigation derived well-argued conclusions about the usage of modern RSs in the Arabic context. The experimental results proved that these systems ensure high performance when applied to Arabic content.


2014 ◽  
Vol 971-973 ◽  
pp. 714-717 ◽  
Author(s):  
Xiang Shi ◽  
Zhe Xu ◽  
Qing Yi He ◽  
Ka Tian

To control wheeled inverted pendulum is a good way to test all kinds of theories of control. The control law is designed, and it based on the collaborative simulation of MATLAB and ADAMS is used to control wheeled inverted pendulum. Then, with own design of hardware and software of control system, sliding mode control is used to wheeled inverted pendulum, and the experimental results of it indicate short adjusting time, the small overshoot and high performance.


2009 ◽  
Vol 156-158 ◽  
pp. 199-204
Author(s):  
Hiroaki Kariyazaki ◽  
Tatsuhiko Aoki ◽  
Kouji Izunome ◽  
Koji Sueoka

Hybrid crystal orientation technology (HOT) substrates comprised of Si (100) and (110) surface orientation paralleling each <110> direction attract considerable attentions as one of the promising technology for high performance bulk CMOS technology. Although HOT substrates are fabricated by wafer bonding of Si (110) and Si (100) surfaces, it is not clear the atomic configuration of interfacial structure. Furthermore, the possibility for the interface to be an effective gettering source of impurity metals was not well studied. In this paper, we studied the interfacial structure and gettering efficiency of the atomic bonded interface by molecular simulations. The results indicate that the simulated atomic configuration and gettering efficiency of the bonded interface agreed well with the experimental results.


2021 ◽  
pp. 1-11
Author(s):  
Oscar Herrera ◽  
Belém Priego

Traditionally, a few activation functions have been considered in neural networks, including bounded functions such as threshold, sigmoidal and hyperbolic-tangent, as well as unbounded ReLU, GELU, and Soft-plus, among other functions for deep learning, but the search for new activation functions still being an open research area. In this paper, wavelets are reconsidered as activation functions in neural networks and the performance of Gaussian family wavelets (first, second and third derivatives) are studied together with other functions available in Keras-Tensorflow. Experimental results show how the combination of these activation functions can improve the performance and supports the idea of extending the list of activation functions to wavelets which can be available in high performance platforms.


2018 ◽  
Vol 16 (1) ◽  
pp. 944-948 ◽  
Author(s):  
Sinan Maraş ◽  
Mustafa Yaman ◽  
Mehmet Fatih Şansveren ◽  
Sina Karimpour Reyhan

AbstractIn recent years, studies on the development of new and advanced composite materials have been increasing. Among these new technological products, Fiber Metal Laminates (FML), and hybrid structures made of aluminium, carbon, glass or aramid fiber, are preferred especially in the aircraft industry due to their high performance. Therefore, free vibration analysis is necessary for the design process of such structures. In this study, the vibration characteristics of FML for clamped-free boundary conditions were investigated experimentally and numerically. Firstly, numerical results were obtained using Finite Element Method (FEM) and then these results were compared with the experimental results. It was seen that the numerical results were in good agreement with the experimental results. As the theoretical model was justified, the effects of various parameters such as number of layers, fiber orientations, and aluminium layer thickness on the in-plane vibration characteristics of the FML straight beam were analysed using FEM. Thus, most important parameters affecting the vibration characteristics of the hybrid structures were determined.


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