In this paper an adaptive way of mainsteam temperature control is proposed for a thermal power plant at the ramping stage. A physical model of the super-heater system is built up based on the experimental knowledge on...
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In this paper an adaptive way of mainsteam temperature control is proposed for a thermal power plant at the ramping stage. A physical model of the super-heater system is built up based on the experimental knowledge on actual thermal power plants. The model yields a continuous time nonlinear system with several unknown varying parameters. A quick identification method is Introduced to estimate online the model parameters. The identified model is used for designing a control signal to raise the mainsteam temperature at the outlet of the super- heater along a reference curve. In this way, an adaptive control of thermal power plant can be realized in the framework of MRACS. The effectiveness of the method has been confirmed through simulation studies.
An exhaust gas recirculation (EGR) control system for automotive application is briefly presented. Robustness is one of the main issues in this particular system due to nonlinearities, time delays, and the effects of ...
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An exhaust gas recirculation (EGR) control system for automotive application is briefly presented. Robustness is one of the main issues in this particular system due to nonlinearities, time delays, and the effects of complex exhaust gas dynamics. It was found that a good approximation of the system dynamics consists of a first order transfer function with a time delay where both transfer function coefficients and the time delay depend on the reference signal (desired EGR(%)). Moreover, it is sufficient to identify only four models corresponding to four different values of desired EGR (%) and assume interpolation for transfer function coefficients to characterize the system dynamics. Since the value of the reference signal is available in real time the controller design can be reduced to four controllers corresponding to four identified models and interpolation for coefficients of the controller transfer function in cases when the value of desired EGR (%) is between the assumed values. Simulation results for such designs are presented.
Approaches to uncertainty modeling for robust control of large flexible space structures (LFSS) such as additive or multiplicative perturbations in H/sub /spl infin// do not work very well because of the special prope...
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Approaches to uncertainty modeling for robust control of large flexible space structures (LFSS) such as additive or multiplicative perturbations in H/sub /spl infin// do not work very well because of the special properties of LFSS dynamics. In this paper we propose the use of a left coprime factorization (LCF) of LFSS dynamics in modal coordinates for robust control design. The plant uncertainty is then described as stable perturbations of the coprime factors accounting for modal parameter uncertainty and unmodeled dynamics. Two multivariable H/sub /spl infin// designs based on LCFs of 46th-order colocated and noncolocated models of an LFSS experimental testbed are presented together with simulation and experimental results to illustrate the technique.
In a board level design with boundary scans, each chip on a board can be tested by loading test vectors and collecting responses through a boundary scan chain. Since the boundary scan may serialize the test process, t...
In a board level design with boundary scans, each chip on a board can be tested by loading test vectors and collecting responses through a boundary scan chain. Since the boundary scan may serialize the test process, the overall test time can be reduced if multiple boundary scan chains are used. In that case the test time depends on how the boundary scan chips are connected into multiple chains. In this paper, we present a technique for configuring multiple boundary scan chains to minimize the test time for boundary scan chips on a board.
Artificial neural networks, also called neural networks, have been used successfully in many fields including engineering, science and business. This paper presents the implementation of several neural network simulat...
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Artificial neural networks, also called neural networks, have been used successfully in many fields including engineering, science and business. This paper presents the implementation of several neural network simulators and their applications in character recognition and other engineering areas.< >
Passivity based controllers are used in structural control due to their inherent robustness properties. These controllers require sensor/actuator collocation. In this paper, we consider the design of a "squaring ...
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Passivity based controllers are used in structural control due to their inherent robustness properties. These controllers require sensor/actuator collocation. In this paper, we consider the design of a "squaring down" matrix which renders a system passive by using a linear combination of all collocated and non-collocated sensor/actuator pairs. The design uses experimental transfer functions and does not require the knowledge of the system model. The problem of finding the squaring down matrix is cast as a solution to a set of linear matrix inequalities (LMIs) subject to some additional performance considerations. The design procedure of the squaring down matrix assumes that velocity information is available from the sensors which is not generally the case. We show that the squaring down matrix can be implemented without the use of such velocity information. We provide experimental results gathered from the single link flexible beam setup in the C/sub La/MS laboratory at RPI to show that implementation of passive loops without velocity measurements provides very good results.
Smart materials such as piezoceramics and shape memory alloys (SMAs) exhibit significant hysteresis and in order to estimate the effect on open and closed loop control a suitable model is needed. One promising candida...
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Smart materials such as piezoceramics and shape memory alloys (SMAs) exhibit significant hysteresis and in order to estimate the effect on open and closed loop control a suitable model is needed. One promising candidate is the Preisach independent domain hysteresis model that is characterized by the congruent minor loop and wiping out properties. Comparable minor loop and decaying oscillation test data for a multi-sheet piezoceramic actuator (made of lead zirconate titanate) attached to a flexible beam are presented and are seen to be very consistent with the two Preisach model properties. The commanded parameter is the sheet transverse electric field while the measured parameter is an approximately colocated strain induced in the beam. Equivalent data for a Nitinol SMA wire muscle, attached to the same beam, are also presented. The input and output parameters are the SMA current and a beam strain respectfully. The minor loop and wiping out evidence is less strong than that of the piezoceramic case, but encouraging. In all experiments the quasi-steady state responses were generated in order to avoid exciting beam flexible modes which would complicate the analysis.
The Digital Wave Processor, DWP [1-10], is an example of a dependable distributed system which has been built and will be flown on the ESA/NASA Cluster satellites. Pre-flight testing of the DWP instruments is nearly c...
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In various adaptive estimation applications, the unknown channel is characterized by an impulse response which consists of extended regions of negligible response or 'inactivity'. We consider the LMS estimatio...
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In various adaptive estimation applications, the unknown channel is characterized by an impulse response which consists of extended regions of negligible response or 'inactivity'. We consider the LMS estimation of a channel that may be well approximated by an FIR (filter) model with only a few nonzero tap coefficients within a given delay horizon or tap length n. When the number of nonzero tap coefficients m is small compared to the delay horizon n, the performance of the LMS estimator is greatly enhanced when this specific structure is exploited. We propose a consistent algorithm that performs identification of nonzero taps only.
作者:
FUJIWARA, ETANAKA, TMemberFaculty of Engineering
Tokyo Institute of Technology Tokyo Japan 152 Eui Fujiwara:received his B.S. and M.S. degrees in Electronics Engineering in 1968 and 1970
respectively and his Dr. of Eng. degree in 1981 all from Tokyo Institute of Technology. In 1970 he joined the NTT Musashino Electrical Communication Laboratories and engaged in developing PIPS-1 and PIPS-11 computer systems. In 1988 he joined the Department of Computer Science Tokyo Institute of Technology as an Associate Professor. In 1990 he became a full Professor. He was a Visiting Professor at the Center for Advanced Computer Studies the University of Southwestern Louisiana from June 1985 to July 1986. His current research interests include coding theory for computers fault-tolerant memories VLSI defect-toleranceand WSI systems. He is a co-author ofError Control Coding for Computer Systems(Prentice-Hall1989) EssentiaLF of Error-Correcting Coding Techniques (Academic Press 1990) and other books. Dr. Fujiwara received the Young Engineer Award from the I.E.I.C.E. in 1978 and the Teshima Memorial Research Award in 1991. He is a senior member of the IEEE and a member of the Information Processing Society Japan. Associate Member
Because of its capability of high-speed search, the associative memory (CAM) is expected to be used in a variety of information processing systems. In this paper, novel fault-tolerant techniques which are effective fo...
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Because of its capability of high-speed search, the associative memory (CAM) is expected to be used in a variety of information processing systems. In this paper, novel fault-tolerant techniques which are effective for on-line use are proposed for TLB which is an example of the application of CAM. First, fault and error models of the TLB consisting of the CAM part and the SRAM part are clarified. Then, the fault-tolerant techniques for these faults and errors, such as distance separable technique, cod-ing technique, simplified 1-out-of-n check and graceful degradation, are proposed. The distance separable technique which encodes the data stored in the CAM part is the one which masks the faulty CAM part and prevents errors from propagating to the subsequent circuits. The coding technique checks the one-to-one correspondence between the data in the CAM and those in SRAM by using the SEC-DED code with byte error detection capability, i.e., SEC-DED-SbED code, and at the same time it detects and corrects errors in the data stored in SRAM. The simplified 1-out-of-n check processes association errors. The graceful degradation gives a flag in the faulty memory section and prevents it from being used. The methods proposed in this paper are evaluated from area augmentation and error detection capability perspectives. The results show that the fault-tolerant TLB with 32 virtual address bits, 32 physical address bits and 128 entries gives single fault detection probability of nearly 99 percent with 28 percent area increase.
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