Entity

Time filter

Source Type

Minami-rinkan, Japan

Prefectural University of Hiroshima is a public university in Hiroshima Prefecture, Japan, established in 2005.It has three campuses, located in these cities: Hiroshima Shōbara Mihara Wikipedia.


Wu H.,Prefectural University of Hiroshima
IET Control Theory and Applications | Year: 2010

The problem of adaptive robust stabilisation is considered for a class of dynamical systems with multiple time-varying delayed state perturbations, time-varying uncertain parameters, and external disturbances. It is assumed that the upper bounds of the delayed state perturbations, uncertainties and external disturbances are unknown, and that the time-varying delays are any non-negative continuous and bounded functions. In particular, it is not required that the derivatives of time-varying delays have to be less than one. For such a class of uncertain time-delay systems, a new method is presented whereby a class of memoryless continuous adaptive robust state feedback controllers is proposed. By employing a quasi-Lyapunov function, it is shown that the solutions of uncertain time-delay systems can be guaranteed to be uniformly exponentially convergent towards a ball which can be as small as desired. In addition, since the proposed adaptive robust state feedback controllers are completely independent of time delays, the results obtained in the study may be also applicable to a class of dynamical systems with uncertain time delays. Finally, a numerical example is given to demonstrate the validity of the results. © 2010 The Institution of Engineering and Technology. Source


Wu H.,Prefectural University of Hiroshima
International Journal of Systems Science | Year: 2012

The problem of decentralised adaptive robust stabilisation is considered for a class of uncertain large-scale time-delay interconnected dynamical systems. It is assumed that the upper bounds of the uncertainties, interconnection terms and external disturbances are unknown, and that the time-varying delays are any nonnegative continuous and bounded functions, and do not require that their derivatives have to be less than one. For such a class of uncertain large-scale time-delay interconnected systems, a new method is presented whereby a class of continuous memoryless decentralised local adaptive robust state feedback controllers is proposed. It is also shown that the solutions of uncertain large-scale time-delay interconnected systems can be guaranteed to be uniformly exponentially convergent towards a ball which can be as small as desired. In addition, since the proposed decentralised local adaptive robust state feedback controllers are completely independent of time delays, the results obtained in this article may also be applicable to a class of large-scale interconnected dynamical systems with uncertain time delays. Finally, a numerical example is given to demonstrate the validity of the results. © 2012 Copyright Taylor and Francis Group, LLC. Source


Xiao Y.,Prefectural University of Hiroshima
IEEE Transactions on Audio, Speech and Language Processing | Year: 2011

A new narrowband ANC system structure is proposed which requires only two reference signal filtering (x-filtering) blocks regardless of the number of targeted frequencies. The reference cosine or sine waves are combined, respectively, to form an input to an x-filtering block. The output of each x-filtering block is decomposed into filtered-x cosine or sine waves by a special bandpass filter bank. In this way, the computational cost of the system may be significantly reduced. Analysis of the new system is then provided and discussed in some detail. Analytical results reveal that the proposed system performs quite the same as its counterpart does while requiring considerably fewer multiplications. Modification to the proposed structure is also made to cope with the frequency mismatch (FM) in real-life applications. Extensive simulations are conducted to demonstrate the effectiveness of the proposed system and its modified version, and as well as to confirm the validity of analysis. © 2010 IEEE. Source


Wu H.,Prefectural University of Hiroshima
IET Control Theory and Applications | Year: 2013

The problem of adaptive robust state observer design is considered for a class of uncertain non-linear dynamical systems with multiple time-varying delays. It is assumed that the upper bounds of the non-linear delayed state perturbations are unknown and that the time-varying delays are any non-negative continuous and bounded functions, which do not require that their derivatives have to be less than one. In particular, it is only required that the non-linear uncertainties, which can also include time-varying delays, are bounded in any non-negative non-linear functions, which are not required to be known for the system designer. For such a class of uncertain non-linear time-delay systems, a new method is presented whereby a class of memoryless adaptive robust state observers with a rather simpler structure is proposed. It is also shown that by employing the proposed adaptive robust state observer, the observation error between the observer state estimate and the true state can be guaranteed to be uniformly exponentially convergent towards a ball, which can be as small as desired, in the presence of significant uncertainties and time delays. Finally, a numerical example is given to demonstrate the validity of the results. © The Institution of Engineering and Technology 2013. Source


Xiao Y.,Prefectural University of Hiroshima | Wang J.,Beihang University
IEEE Signal Processing Letters | Year: 2011

Performance of the conventional broadband active noise control (ANC) system may degrade severely if its primary and reference noise signals contain both wideband and narrowband components simultaneously. In this letter, we propose a new feedforward hybrid ANC system capable of reducing such primary noise signals. First, typical simulation results are provided to show the performance deterioration of the conventional system in the presence of mixture of wideband and narrowband components. Next, a new hybrid ANC system is proposed to tackle the problem. The new system consists of three subsystems, i.e., a sinusoidal noise canceller, a broadband and a narrowband ANC subsystem, which work in harmony. Extensive simulations are conducted to demonstrate the effectiveness of the proposed system. © 2011 IEEE. Source

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