Abstract In this paper, a discontinuous projection-based output feedback adaptive robust learning control (OARLC) scheme is constructed for a class of nonlinear systems in a semi-strict feedback form by incorporating ...
Abstract In this paper, a discontinuous projection-based output feedback adaptive robust learning control (OARLC) scheme is constructed for a class of nonlinear systems in a semi-strict feedback form by incorporating an observer and a dynamic normalization signal. Since only output signal is available for measurement, an observer is firstly designed to provide exponentially convergent estimates of the unmeasurable states. Using certain known basis functions to capture the characteristics of unknown general periodic disturbances, the discontinuous projection type adaptation law can then be used to tune the amplitudes of those basis functions on-line to recover the unknown general periodic disturbances asymptotically. The estimation errors due to the unknown initial states, uncompensated disturbances, and the uncertain nonlinearities are also effectively dealt with via certain robust feedback at each step of the proposed OARLC backstepping design. The resulting controller achieves a guaranteed transient and a prescribed final tracking accuracy for output tracking performance. In addition, when the general periodic disturbances fall within the approximation ranges of the periodic basis functions, asymptotic output tracking performance is achieved as well.
Rubber mixing process is a typical non-linear fed-batch process without well developed mechanism. Soft-sensing modeling of the mixture's Mooney viscosity is crucial and challenging since this index is an important...
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Fed-batch processes are inherently more difficult to characterize than continuous processes due to the variations under different operation stages, drifting and small-sample condition. The classical kernel-based regre...
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To monitor industrialprocesses through a probabilistic manner, the probabilistic principal component analysis (PPCA) method has recently been introduced. However, PPCA has its inherent limitation that it cannot deter...
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In this paper, a robust control approach is proposed for a class of nonlinear systems that contain both nonlinear dynamics uncertainty and an unknown time-varying control direction, which is the multiplier of the cont...
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ISBN:
(纸本)9787894631046
In this paper, a robust control approach is proposed for a class of nonlinear systems that contain both nonlinear dynamics uncertainty and an unknown time-varying control direction, which is the multiplier of the control term. In particular, the unknown control direction is allowed to switch its sign for an unlimited number of times. A new Nussbaum gain is designed and integrated with robust controller to tackle the sign-switching unknown control direction. It is proven that the proposed control approach can yield asymptotic convergence and guarantee the boundedness of the closed-loop signals.
Aiming at a kind of uncertainties of models in complex industry processes, a novel method for selecting robust parameters is stated in the paperBased on the analysis, parameters selecting for robust control is reduced...
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Aiming at a kind of uncertainties of models in complex industry processes, a novel method for selecting robust parameters is stated in the paperBased on the analysis, parameters selecting for robust control is reduced to be an object optimization problem, and the particle swarm optimization(PSO) is used for solving the problem, and the corresponding robust parameters are obtainedSimulation results show that the robust parameters designed by this method have good robustness and satisfactory performance.
Congestion in wireless sensor networks (WSNs) not only causes severe information loss but also leads to excessive energy consumption. To address this problem, a novel scheme for congestion avoidance, detection and all...
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Congestion in wireless sensor networks (WSNs) not only causes severe information loss but also leads to excessive energy consumption. To address this problem, a novel scheme for congestion avoidance, detection and alleviation (CADA) in WSNs is proposed in this paper. By exploiting data characteristics, a small number of representative nodes are chosen from those in the event area as data sources, so that the source traffic can be suppressed proactively to avoid potential congestion. Once congestion occurs inevitably due to traffic mergence, it will be detected in a timely way by the hotspot node based on a combination of buffer occupancy and channel utilization. Congestion is then alleviated reactively by either dynamic traffic multiplexing or source rate regulation in accordance with the specific hotspot scenarios. Extensive simulation results under typical congestion scenarios are presented to illuminate the distinguished performance of the proposed scheme.
In order to build high accuracy integral dynamic models of cold rolling mill system, by analyzing the vibration process of cold rolling, the dynamic model of 4-h mill, including the rolling process model, the mill rol...
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In order to build high accuracy integral dynamic models of cold rolling mill system, by analyzing the vibration process of cold rolling, the dynamic model of 4-h mill, including the rolling process model, the mill roll stand structure model and the hydraulic servo system model is built. These three models are coupled and linearized, then the multiple input and multiple output (MIMO) linear transfer function model of single stand 4-h cold mill system is obtained. The model with the proposed data proves its validity, meanwhile the effects of different working conditions on the stability of cold rolling mill system have been discussed. Simulation resulsts show that the model accords with former models and has its own advancement. It contributes to the further study and supression of coupling vibraiton.
Fed-batch processes are inherently more difficult to characterize than continuous processes due to the variations under different operation stages, drifting and small-sample condition. The classical kernel-based regre...
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Fed-batch processes are inherently more difficult to characterize than continuous processes due to the variations under different operation stages, drifting and small-sample condition. The classical kernel-based regression (KR) methods, e.g., least squares support vector regression (LSSVR), aim to achieve a universal generalization performance, which may fail in some local regions when applied to batch process modeling. Local LSSVR model which only uses the neighbors of the query instance helps improve the accuracy, but it generally leads to a heavy computation load. Inspired by the idea of universal and local learning simultaneously, an adaptive local weighted kernel-based regression (ALWKR) method is proposed. That is. adaptive weights are assigned to corresponding samples based on the similarity measurement, followed by a recursive updating to obtain local models. This ALW-KR framework is applied to the prediction of biomass concentration in the penicillin fed-batch process. The experimental results show that the proposed ALWKR model could predict the biomass concentration more accurate and robust to batch-to-batch variation than traditional KR methods.
The problem of on-line parameter identification was discussed for linear multivariable discrete time stochastic systems with communication access constraints. Based on the concept of parameter estimability defined wit...
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The problem of on-line parameter identification was discussed for linear multivariable discrete time stochastic systems with communication access constraints. Based on the concept of parameter estimability defined with mutual information, a condition for identifiability was proved under the assumption that the time-varying parameter can be modeled as a Gauss-Markov process, and the sensors access status is described by binary-value function. Analytical analysis and simulation results show that, there is a proper communication strategy which preserving the identifiability of the system under access constraints.
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