著者

Kazuaki ANDO

出版者

The Society of Instrument and Control Engineers

雑誌

Transactions of the Society of Instrument and Control Engineers (ISSN:04534654)

巻号頁・発行日

vol.21, no.11, pp.1171-1176, 1985-11-30 (Released:2009-03-27)

参考文献数

7

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Padé approximants of exp(-sT) have been widely used to realize dead-time elements. The companion form realization, however, is numerically ill behaved, if we use a high order approximant, because coefficients of lower order terms of the monic denominator polynomial become very large. In this paper, the realization based on Cauer type continued fraction expansion is shown to be well behaved. A simple method of getting coefficients of the expansion of the Padé approximant, using the continued fraction expansion of the exponential function, is proposed. By simulation, it is shown that the ballancing of the overshoot and the undershoot is attained if we choose the degree L of the mumerator smaller 2 to 5 than the degree M of the denominator, and that the rise time is inversely proportional to L+M.

著者

Hiroshi OKAJIMA Kenji SAWADA Joe KAIBE Nobutomo MATSUNAGA

出版者

The Society of Instrument and Control Engineers

雑誌

Transactions of the Society of Instrument and Control Engineers (ISSN:04534654)

巻号頁・発行日

vol.48, no.6, pp.359-361, 2012 (Released:2012-06-30)

参考文献数

6

被引用文献数

2

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This paper aims at design of network control system for the remote control of robot. As the system includes a communication channel, quantization is required to satisfy communication capacity limitation. Dynamic quantizer is a kind of quantization methods and has been studied in control engineering field. Optimal quantizing width designed of dynamic has been designed based on invariant sets. However, quantizing width of dynamic quantizer designed based on invariant sets has maintainability than one of designed based on reachable sets and big maintainability and poor control performance. We need to design quantizing width of dynamic quantizer based on reachable sets. In this study, we propose design method of quantizing width of dynamic quantizer based on reachable sets. The effectiveness is shown by numerical example.

著者

Hiroshi OKAJIMA Nobutomo MATSUNAGA

出版者

The Society of Instrument and Control Engineers

雑誌

Transactions of the Society of Instrument and Control Engineers (ISSN:04534654)

巻号頁・発行日

vol.47, no.4, pp.217-219, 2011 (Released:2011-12-19)

参考文献数

8

被引用文献数

2

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In the field of signal processing, AD/DA converter takes an important role for data compressing and circuits design. This paper proposes new design method of AD/DA system with pre-filter and post-filters for achieving small quantization noise effect. Both filters are designed to minimize noise and distortion toward original signal. The effectiveness is illustrated by numerical example.

著者

Hiroshi OKAJIMA Kenji SAWADA Nobutomo MATSUNAGA

出版者

The Society of Instrument and Control Engineers

雑誌

Transactions of the Society of Instrument and Control Engineers (ISSN:04534654)

巻号頁・発行日

vol.47, no.2, pp.126-133, 2011 (Released:2011-12-19)

参考文献数

15

被引用文献数

4 2

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This paper proposes a design method of the dynamic quantizer for the networked control systems. In the networked control systems, the data size of the signals is limited because of the transmission rate of the communication channel. It is well known that feedback type dynamic quantizers such as Delta/Sigma modulator are effective for quantization of data series. The dynamic quantizer includes a set of the dynamic filter and the static quantizer. Many methods have been proposed to design the dynamic filter. However, the static quantizer part has not been designed although the quantization level number of the static quantizer has an effect on the data size. The simultaneous design of dynamic filter and the quantization level will be important issue to satisfy the given communication rate. In this paper, the integrated design method of the filter and the static quantizer is proposed based on the communication rate constraints. The proposed method is derived based on the invariant set analysis with LMIs. The effectiveness is shown by numerical examples.

著者

Hiroshi OKAJIMA Nobutomo MATSUNAGA Kenji SAWADA

出版者

The Society of Instrument and Control Engineers

雑誌

Transactions of the Society of Instrument and Control Engineers (ISSN:04534654)

巻号頁・発行日

vol.46, no.6, pp.327-335, 2010 (Released:2011-11-03)

参考文献数

21

被引用文献数

6 3

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This paper proposes the design method of the dynamic quantizer for the networked control systems. It is well known that feedback type dynamic quantizer such as Delta/Sigma modulator is effective for quantization of data series and many methods for designing the dynamics have been proposed. When it is required to control with network communication, the data size of signal should be minimized appropriately by quantizers. Since the quantizing width of the quantizer concern with the data size, determination of quantizing width is important problem in networked control systems. However, the quantizing width has not been designed analytically in the past researches. In this paper, we propose the design method of the quantizing width based on the LMIs. The quantizing width would be determined explicitly with the communication rate constraints. By the proposed method, the quantizing width guarantee that the signals are quantized appropriately within the given data size. The effectiveness is illustrated by numerical examples.

著者

Hiroshi OKAJIMA Tatsuya UMEMOTO Nobutomo MATSUNAGA Shigeyasu KAWAJI

出版者

The Society of Instrument and Control Engineers

雑誌

Transactions of the Society of Instrument and Control Engineers (ISSN:04534654)

巻号頁・発行日

vol.46, no.3, pp.149-156, 2010 (Released:2011-11-03)

参考文献数

16

被引用文献数

5 4

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It is well known that plants with time delay are hard to be controlled by using traditional method. For this, controller with delay, such as Internal Model Control (IMC), Smith-method, have been proposed for input-delay systems. However, it would be difficult to realize the delay of controller because of memory limit of micro control unit(MCU). Also, the sampling time might be large in case of the application to the plant with large time delay, because of the limitation of the memory in MCU. Hence, the trade-off exists between sampling time and maximum quantizing error, and the assignment of the quantizer affects the quantization error. In this paper, dynamic quantizers are designed for achieving small quantizing error for input-delay control systems in MCU system. Also, the attainable performance caused by assignment of the quantizer is discussed. The effectiveness of the proposed method is shown by numerical example.

著者

Hiroshi OKAJIMA Nobutomo MATSUNAGA Shigeyasu KAWAJI

出版者

The Society of Instrument and Control Engineers

雑誌

Transactions of the Society of Instrument and Control Engineers (ISSN:04534654)

巻号頁・発行日

vol.44, no.5, pp.458-460, 2008-05-31 (Released:2013-02-25)

参考文献数

4

被引用文献数

2 3

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This paper is concerned with dynamic quantizer for controlling plants with discrete-valued input.l∞ norm of error between outputs with continuous-input and with quantized-input was guaranteed by the quantizer proposed by Azuma et al. In this paper, the degree of freedom of quantizer, which also guarantees the l∞ norm, is considered for treating the other objectives such as robustness, reduced-order controller etc. Then a design method of reduced-order quantizer is proposed by using the design parameter. The effectiveness of reduced-order quantizer is shown by numerical examples.

著者

Hiroshi OKAJIMA Toru ASAI Shigeyasu KAWAJI

出版者

The Society of Instrument and Control Engineers

雑誌

Transactions of the Society of Instrument and Control Engineers (ISSN:04534654)

巻号頁・発行日

vol.45, no.6, pp.313-319, 2009 (Released:2011-11-03)

参考文献数

18

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In this paper, tracking performance limitations for plants with input delay are considered. It is important to know the performance limitations for plants to design controllers and to design plants. Our objective is to find the fundamental limitation of the transient response in tracking control problem. When plant have input delay, no one would deny that tracking performance becomes worse than the plants without input delay. However performance limitations for such plants have not been derived analytically. We derive the performance limitations based on internal model control framework. The difference between plants with delay and without delay is compared by numerical examples.

著者

Hiroshi OKAJIMA Toru ASAI Shigeyasu KAWAJI

出版者

The Society of Instrument and Control Engineers

雑誌

Transactions of the Society of Instrument and Control Engineers (ISSN:04534654)

巻号頁・発行日

vol.44, no.10, pp.793-801, 2008-10-31 (Released:2013-02-25)

参考文献数

19

被引用文献数

1 1

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This paper is concerned with optimal reference tracking control problem for discrete time 1-DOF/2-DOF systems. It is well known that l2 norm of an error, which is defined by difference between an output and a reference, does not turn zero for all possible controllers when plant is given as a non-minimum phase system. Purpose of this research is to derive closed-form expression of the optimal value of l2 norm of the error and its controller. The references for tracking are e.g. step, sine, impulse train, triangle wave and linear combination of these signals. Therefore, we can handle various signals as a reference. Moreover, our results can also characterize impact of the relative degree of plant. Those effectiveness are shown by numerical examples.

著者

Hisao MIYANO

出版者

The Society of Instrument and Control Engineers

雑誌

Transactions of the Society of Instrument and Control Engineers (ISSN:04534654)

巻号頁・発行日

vol.23, no.4, pp.394-399, 1987-04-30 (Released:2009-03-27)

参考文献数

13

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This paper describes a new parameter estimation method for weighted euclidean distance model, in which individual configurations obtained from multidimensional scaling are directly fitted to some common space. The new method is based on an alternating least squares estimation method, and is easily extended for more general weighted euclidean model. Validity of the method is illustrated by using and analyzing a set of artificial data and color perception data.

著者

Susumu TACHI

出版者

The Society of Instrument and Control Engineers

雑誌

Transactions of the Society of Instrument and Control Engineers (ISSN:04534654)

巻号頁・発行日

vol.9, no.6, pp.729-738, 1973-12-30 (Released:2009-03-27)

参考文献数

10

被引用文献数

1 3

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A method is proposed for separating a desired periodic signal, i.e., for detecting its direction and estimating its Fourier components, from other periodic signals scattered in a field contaminated with Gaussian random noise.The auto-bispectrum of a signal composed of a periodic signal plus Gaussian random noise preserves the information about both relative amplitudes and relative phases of the components of the periodic signal, while it cancels out the over-all phase shift caused by the time delay of the signal.The cross-bispectrum of the two waveforms observed at two different points, on the other hand, preserves information about the inter-regional phase shift of each component.These characteristics are clarified and used as the basis, of the method. The direction of the desired signal is measured by means of the auto- and cross-bispectra of the observed waveforms. The Fourier components of the desired signal are estimated by using the auto-bispectrum, and the desired signal can be reconstructed by means of Fourier synthesis.An example of reconstruction is shown, and the estimation errors of the program used are discussed. The estimated value varies because of finite averaging, and the distribution of the deviation from the true value can be regarded as almost normal. The relative error diminishes almost linearly as the signal/noise ratio increases when the signal/noise ratio is larger than 1.0.